mapview_common.c

Go to the documentation of this file.

/***********************************************************************
 Freeciv - Copyright (C) 1996 - A Kjeldberg, L Gregersen, P Unold
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
***********************************************************************/
 
#ifdef HAVE_CONFIG_H
#include <fc_config.h>
#endif
 
/* utility */
#include "fcintl.h"
#include "log.h"
#include "rand.h"
#include "support.h"
#include "timing.h"
 
/* common */
#include "featured_text.h"
#include "game.h"
#include "map.h"
#include "traderoutes.h"
#include "unitlist.h"
 
/* client/include */
#include "graphics_g.h"
#include "gui_main_g.h"
#include "mapctrl_g.h"
#include "mapview_g.h"
 
/* client */
#include "client_main.h"
#include "climap.h"
#include "control.h"
#include "editor.h"
#include "goto.h"
#include "citydlg_common.h"
#include "overview_common.h"
#include "svgflag.h"
#include "tilespec.h"
#include "zoom.h"
 
#include "mapview_common.h"
 
 
struct tile_hash *mapdeco_highlight_table;
struct tile_hash *mapdeco_crosshair_table;
 
struct gotoline_counter {
  int line_count[DIR8_MAGIC_MAX];
};
 
static inline struct gotoline_counter *gotoline_counter_new(void);
static void gotoline_counter_destroy(struct gotoline_counter *pglc);
 
#define SPECHASH_TAG gotoline
#define SPECHASH_IKEY_TYPE struct tile *
#define SPECHASH_IDATA_TYPE struct gotoline_counter *
#define SPECHASH_IDATA_FREE gotoline_counter_destroy
#include "spechash.h"
#define gotoline_hash_iterate(hash, ptile, pglc)                            \
  TYPED_HASH_ITERATE(struct tile *, struct gotoline_counter *,              \
                     hash, ptile, pglc)
#define gotoline_hash_iterate_end HASH_ITERATE_END
 
struct gotoline_hash *mapdeco_gotoline_table;
 
struct view mapview;
bool can_slide = TRUE;
 
static bool frame_by_frame_animation = FALSE;
 
const struct tile *center_tile = nullptr;
 
struct tile *infratile = nullptr;
 
static void base_canvas_to_map_pos(float zoom, int *map_x, int *map_y,
                                   float canvas_x, float canvas_y);
 
static void show_full_citybar(struct canvas *pcanvas,
                              const int canvas_x0, const int canvas_y0,
                              struct city *pcity, int *width, int *height)
  fc__attribute((nonnull(5, 6)));
static void show_city_desc(struct canvas *pcanvas,
                           int canvas_x, int canvas_y,
                           struct city *pcity, int *width, int *height)
  fc__attribute((nonnull(5, 6)));
 
enum update_type {
  /* Masks */
  UPDATE_NONE = 0,
  UPDATE_CITY_DESCRIPTIONS  = 1,
  UPDATE_MAP_CANVAS_VISIBLE = 2,
  UPDATE_TILE_LABELS        = 4
};
 
/* A tile update has a tile associated with it as well as an area type.
 * See unqueue_mapview_updates() for a thorough explanation. */
enum tile_update_type {
  TILE_UPDATE_TILE_SINGLE,
  TILE_UPDATE_TILE_FULL,
  TILE_UPDATE_UNIT,
  TILE_UPDATE_CITY_DESC,
  TILE_UPDATE_CITYMAP,
  TILE_UPDATE_TILE_LABEL,
  TILE_UPDATE_COUNT
};
 
static void queue_mapview_update(enum update_type update);
static void queue_mapview_tile_update(struct tile *ptile,
                                      enum tile_update_type type);
 
/* Helper struct for drawing trade routes. */
struct trade_route_line {
  float x, y, width, height;
};
 
/* A trade route line might need to be drawn in two parts. */
static const int MAX_TRADE_ROUTE_DRAW_LINES = 2;
 
static struct timer *anim_timer = nullptr;
 
enum animation_type { ANIM_MOVEMENT, ANIM_BATTLE, ANIM_EXPL, ANIM_NUKE };
 
struct animation
{
  enum animation_type type;
  int id;
  bool finished;
  int old_x;
  int old_y;
  int width;
  int height;
  union {
    struct {
      struct unit *mover;
      struct tile *src;
      struct tile *dest;
      float canvas_dx;
      float canvas_dy;
    } movement;
    struct {
      struct unit *virt_loser;
      struct tile *loser_tile;
      int loser_hp_start;
      int loser_hp_end;
      struct unit *virt_winner;
      struct tile *winner_tile;
      int winner_hp_start;
      int winner_hp_end;
      int steps;
    } battle;
    struct {
      struct tile *tile;
      const struct sprite_vector *sprites;
      int sprite_count;
    } expl;
    struct {
      bool shown;
      struct tile *nuke_tile;
    } nuke;
  };
};
 
#define SPECLIST_TAG animation
#define SPECLIST_TYPE struct animation
#include "speclist.h"
 
struct animation_list *animations = nullptr;
 
/************************************************************************/
void animations_init(void)
{
  animations = animation_list_new();
}
 
/************************************************************************/
void animations_free(void)
{
  if (animations != nullptr) {
    int i;
    size_t last = animation_list_size(animations);
 
    for (i = 0; i < last; i++) {
      struct animation *anim = animation_list_get(animations, i);
 
      switch (anim->type) {
      case ANIM_MOVEMENT:
        unit_virtual_destroy(anim->movement.mover);
        break;
      case ANIM_BATTLE:
        unit_virtual_destroy(anim->battle.virt_winner);
        unit_virtual_destroy(anim->battle.virt_loser);
        break;
      case ANIM_EXPL:
      case ANIM_NUKE:
        /* Nothing to free */
        break;
      }
 
      free(anim);
    }
 
    animation_list_destroy(animations);
    animations = nullptr;
  }
}
 
/************************************************************************/
static void anim_timer_renew(void)
{
  anim_timer = timer_renew(anim_timer, TIMER_USER, TIMER_ACTIVE,
                           anim_timer != nullptr ? nullptr : "anim");
  timer_start(anim_timer);
}
 
/************************************************************************/
static void animation_add(struct animation *anim)
{
  if (animation_list_size(animations) == 0) {
    anim_timer_renew();
  }
 
  anim->finished = FALSE;
  anim->old_x = -1; /* Initial frame */
  animation_list_append(animations, anim);
}
 
/************************************************************************/
static bool movement_animation(struct animation *anim, double time_gone)
{
  float start_x, start_y;
  int new_x, new_y;
  double timing_sec = (double)gui_options.smooth_move_unit_msec / 1000.0;
  double mytime = MIN(time_gone, timing_sec);
  struct unit *punit = anim->movement.mover;
 
  if (punit != nullptr) {
    tile_to_canvas_pos(&start_x, &start_y, map_zoom, anim->movement.src);
    if (tileset_is_isometric(tileset) && tileset_hex_height(tileset) == 0) {
      start_y -= tileset_tile_height(tileset) / 2 * map_zoom;
      start_y -= (tileset_unit_height(tileset) - tileset_full_tile_height(tileset)) * map_zoom;
    }
    new_x = start_x + anim->movement.canvas_dx * (mytime / timing_sec);
    new_y = start_y + anim->movement.canvas_dy * (mytime / timing_sec);
 
    if (anim->old_x >= 0) {
      update_map_canvas(anim->old_x, anim->old_y,
                        anim->width, anim->height);
    }
    put_unit(punit, mapview.store, map_zoom, new_x, new_y);
    dirty_rect(new_x, new_y, anim->width, anim->height);
    anim->old_x = new_x;
    anim->old_y = new_y;
 
    if (time_gone >= timing_sec) {
      /* Animation over */
      unit_virtual_destroy(anim->movement.mover);
 
      return TRUE;
    }
  } else {
    return TRUE;
  }
 
  return FALSE;
}
 
/************************************************************************/
static bool battle_animation(struct animation *anim, double time_gone)
{
  double time_per_step;
  int step;
  float canvas_x, canvas_y;
  double timing_sec = (double)gui_options.smooth_combat_step_msec
    * anim->battle.steps / 1000.0;
 
  if (time_gone >= timing_sec) {
    /* Animation over */
 
    unit_virtual_destroy(anim->battle.virt_winner);
    unit_virtual_destroy(anim->battle.virt_loser);
 
    return TRUE;
  }
 
  time_per_step = timing_sec / anim->battle.steps;
  step = time_gone / time_per_step;
 
  if (tile_to_canvas_pos(&canvas_x, &canvas_y, map_zoom, anim->battle.loser_tile)) {
    anim->battle.virt_loser->hp
      = anim->battle.loser_hp_start - ((anim->battle.loser_hp_start
                                        - anim->battle.loser_hp_end)
                                       * step / anim->battle.steps);
 
    if (tileset_is_isometric(tileset) && tileset_hex_height(tileset) == 0) {
      canvas_y -= tileset_tile_height(tileset) / 2 * map_zoom;
      canvas_y -= (tileset_unit_height(tileset) - tileset_full_tile_height(tileset)) * map_zoom;
    }
 
    put_unit(anim->battle.virt_loser, mapview.store, map_zoom,
             canvas_x, canvas_y);
    dirty_rect(canvas_x, canvas_y,
               tileset_tile_width(tileset),
               tileset_tile_height(tileset));
  }
 
  if (tile_to_canvas_pos(&canvas_x, &canvas_y, map_zoom, anim->battle.winner_tile)) {
    anim->battle.virt_winner->hp
      = anim->battle.winner_hp_start - ((anim->battle.winner_hp_start
                                         - anim->battle.winner_hp_end)
                                        * step / anim->battle.steps);
 
    if (tileset_is_isometric(tileset) && tileset_hex_height(tileset) == 0) {
      canvas_y -= tileset_tile_height(tileset) / 2 * map_zoom;
      canvas_y -= (tileset_unit_height(tileset) - tileset_full_tile_height(tileset)) * map_zoom;
    }
    put_unit(anim->battle.virt_winner, mapview.store, map_zoom,
             canvas_x, canvas_y);
    dirty_rect(canvas_x, canvas_y,
               tileset_tile_width(tileset),
               tileset_tile_height(tileset));
  }
 
  return FALSE;
}
 
/************************************************************************/
static bool explosion_animation(struct animation *anim, double time_gone)
{
  float canvas_x, canvas_y;
  double timing_sec;
 
  if (anim->expl.sprite_count <= 0) {
    return TRUE;
  }
 
  timing_sec = (double)gui_options.smooth_combat_step_msec
    * anim->expl.sprite_count / 1000.0;
 
  if (tile_to_canvas_pos(&canvas_x, &canvas_y, map_zoom, anim->expl.tile)) {
    double time_per_frame = timing_sec / anim->expl.sprite_count;
    int frame = time_gone / time_per_frame;
    struct sprite *spr;
    int w, h;
 
    frame = MIN(frame, anim->expl.sprite_count - 1);
 
    if (anim->old_x >= 0) {
      update_map_canvas(anim->old_x, anim->old_y,
                        anim->width, anim->height);
    }
 
    spr = *sprite_vector_get(anim->expl.sprites, frame);
    get_sprite_dimensions(spr, &w, &h);
 
    canvas_put_sprite_full(mapview.store,
                           canvas_x + tileset_tile_width(tileset) / 2 * map_zoom
                           - w / 2,
                           canvas_y + tileset_tile_height(tileset) / 2 * map_zoom
                           - h / 2,
                           spr);
    dirty_rect(canvas_x, canvas_y, tileset_tile_width(tileset) * map_zoom,
               tileset_tile_height(tileset) * map_zoom);
 
    anim->old_x = canvas_x;
    anim->old_y = canvas_y;
  }
 
  if (time_gone >= timing_sec) {
    /* Animation over */
    return TRUE;
  }
 
  return FALSE;
}
 
/************************************************************************/
static bool nuke_animation(struct animation *anim, double time_gone)
{
  if (!anim->nuke.shown) {
    float canvas_x, canvas_y;
    struct sprite *nuke_spr = get_nuke_explode_sprite(tileset);
    int w, h;
 
    (void) tile_to_canvas_pos(&canvas_x, &canvas_y, map_zoom, anim->nuke.nuke_tile);
    get_sprite_dimensions(nuke_spr, &w, &h);
 
    canvas_put_sprite_full(mapview.store,
                           canvas_x + tileset_tile_width(tileset) / 2 * map_zoom
                           - w / 2,
                           canvas_y + tileset_tile_height(tileset) / 2 * map_zoom
                           - h / 2,
                           nuke_spr);
    dirty_rect(canvas_x, canvas_y, tileset_tile_width(tileset) * map_zoom,
               tileset_tile_height(tileset) * map_zoom);
 
    anim->old_x = canvas_x;
    anim->old_y = canvas_y;
 
    anim->nuke.shown = TRUE;
 
    return FALSE;
  }
 
  if (time_gone > 1.0) {
    update_map_canvas_visible();
 
    return TRUE;
  }
 
  return FALSE;
}
 
/************************************************************************/
void update_animation(void)
{
  if (animations != nullptr && animation_list_size(animations) > 0) {
    struct animation *anim = animation_list_get(animations, 0);
 
    if (anim->finished) {
      /* Animation over */
 
      anim->id = -1;
      if (anim->old_x >= 0) {
        update_map_canvas(anim->old_x, anim->old_y, anim->width, anim->height);
      }
      animation_list_remove(animations, anim);
      free(anim);
 
      if (animation_list_size(animations) > 0) {
        /* Start next */
        anim_timer_renew();
      }
    } else {
      double time_gone = timer_read_seconds(anim_timer);
      bool finished = FALSE;
 
      switch (anim->type) {
      case ANIM_MOVEMENT:
        finished = movement_animation(anim, time_gone);
        break;
      case ANIM_BATTLE:
        finished = battle_animation(anim, time_gone);
        break;
      case ANIM_EXPL:
        finished = explosion_animation(anim, time_gone);
        break;
      case ANIM_NUKE:
        finished = nuke_animation(anim, time_gone);
      }
 
      if (finished) {
        anim->finished = TRUE;
      }
    }
  }
}
 
/************************************************************************/
static inline struct gotoline_counter *gotoline_counter_new(void)
{
  struct gotoline_counter *pglc = fc_calloc(1, sizeof(*pglc));
  return pglc;
}
 
/************************************************************************/
static void gotoline_counter_destroy(struct gotoline_counter *pglc)
{
  fc_assert_ret(pglc != nullptr);
 
  free(pglc);
}
 
/************************************************************************/
void refresh_tile_mapcanvas(struct tile *ptile,
                            bool full_refresh, bool write_to_screen)
{
  if (full_refresh) {
    queue_mapview_tile_update(ptile, TILE_UPDATE_TILE_FULL);
  } else {
    queue_mapview_tile_update(ptile, TILE_UPDATE_TILE_SINGLE);
  }
  if (write_to_screen) {
    unqueue_mapview_updates(TRUE);
  }
}
 
/************************************************************************/
void refresh_unit_mapcanvas(struct unit *punit, struct tile *ptile,
                            bool full_refresh, bool write_to_screen)
{
  if (full_refresh && gui_options.draw_native) {
    queue_mapview_update(UPDATE_MAP_CANVAS_VISIBLE);
  } else if (full_refresh && unit_drawn_with_city_outline(punit, TRUE)) {
    queue_mapview_tile_update(ptile, TILE_UPDATE_CITYMAP);
  } else {
    queue_mapview_tile_update(ptile, TILE_UPDATE_UNIT);
  }
  if (write_to_screen) {
    unqueue_mapview_updates(TRUE);
  }
}
 
/************************************************************************/
void refresh_city_mapcanvas(struct city *pcity, struct tile *ptile,
                            bool full_refresh, bool write_to_screen)
{
  if (full_refresh && (gui_options.draw_map_grid || gui_options.draw_borders)) {
    queue_mapview_tile_update(ptile, TILE_UPDATE_CITYMAP);
  } else {
    queue_mapview_tile_update(ptile, TILE_UPDATE_UNIT);
  }
  if (write_to_screen) {
    unqueue_mapview_updates(TRUE);
  }
}
 
/************************************************************************/
void map_to_gui_vector(const struct tileset *t, float zoom,
                       float *gui_dx, float *gui_dy, int map_dx, int map_dy)
{
  if (tileset_is_isometric(t)) {
    /*
     * Convert the map coordinates to isometric GUI
     * coordinates. We'll make tile map(0,0) be the origin, and
     * transform like this:
     *
     *                     3
     * 123                2 6
     * 456 -> becomes -> 1 5 9
     * 789                4 8
     *                     7
     */
    *gui_dx = (map_dx - map_dy) * tileset_tile_width(t) / 2 * zoom;
    *gui_dy = (map_dx + map_dy) * tileset_tile_height(t) / 2 * zoom;
  } else {
    *gui_dx = map_dx * tileset_tile_height(t) * zoom;
    *gui_dy = map_dy * tileset_tile_width(t) * zoom;
  }
}
 
/************************************************************************/
static void map_to_gui_pos(const struct tileset *t, float zoom,
                           float *gui_x, float *gui_y, int map_x, int map_y)
{
  /* Since the GUI origin is the same as the map origin we can just do a
   * vector conversion. */
  map_to_gui_vector(t, zoom, gui_x, gui_y, map_x, map_y);
}
 
/************************************************************************/
static void gui_to_map_pos(const struct tileset *t, float zoom,
                           int *map_x, int *map_y, float gui_x, float gui_y)
{
  const float W = tileset_tile_width(t) * zoom, H = tileset_tile_height(t) * zoom;
  const float HH = tileset_hex_height(t) * zoom, HW = tileset_hex_width(t) * zoom;
 
  if (HH > 0 || HW > 0) {
    /* To handle hexagonal cases we have to revert to a less elegant method
     * of calculation. */
    float x, y;
    int dx, dy;
    int xmult, ymult, mod, compar;
 
    fc_assert(tileset_is_isometric(t));
 
    x = DIVIDE((int)gui_x, (int)W);
    y = DIVIDE((int)gui_y, (int)H);
    dx = gui_x - x * W;
    dy = gui_y - y * H;
    fc_assert(dx >= 0 && dx < W);
    fc_assert(dy >= 0 && dy < H);
 
    /* Now fold so we consider only one-quarter tile. */
    xmult = (dx >= W / 2) ? -1 : 1;
    ymult = (dy >= H / 2) ? -1 : 1;
    dx = (dx >= W / 2) ? (W - 1 - dx) : dx;
    dy = (dy >= H / 2) ? (H - 1 - dy) : dy;
 
    /* Next compare to see if we're across onto the next tile. */
    if (HW > 0) {
      compar = (dx - HW / 2) * (H / 2) - (H / 2 - 1 - dy) * (W / 2 - HW);
    } else {
      compar = (dy - HH / 2) * (W / 2) - (W / 2 - 1 - dx) * (H / 2 - HH);
    }
    mod = (compar < 0) ? -1 : 0;
 
    *map_x = (x + y) + mod * (xmult + ymult) / 2;
    *map_y = (y - x) + mod * (ymult - xmult) / 2;
  } else if (tileset_is_isometric(t)) {
    /* The basic operation here is a simple pi/4 rotation; however, we
     * have to first scale because the tiles have different width and
     * height. Mathematically, this looks like
     *   | 1/W  1/H | |x|    |x`|
     *   |          | | | -> |  |
     *   |-1/W  1/H | |y|    |y`|
     *
     * Where W is the tile width and H the height.
     *
     * In simple terms, this is
     *   map_x = [   x / W + y / H ]
     *   map_y = [ - x / W + y / H ]
     * where [q] stands for integer part of q.
     *
     * Here the division is proper mathematical floating point division.
     *
     * We have to subtract off a half-tile in the X direction before doing
     * the transformation. This is because, although the origin of the tile
     * is the top-left corner of the bounding box, after the transformation
     * the top corner of the diamond-shaped tile moves into this position.
     *
     * The calculation is complicated somewhat because of two things: we
     * only use integer math, and C integer division rounds toward zero
     * instead of rounding down.
     *
     * For another example of this math, see canvas_to_city_pos().
     */
    gui_x -= W / 2;
    *map_x = DIVIDE((int)(gui_x * H + gui_y * W), (int)(W * H));
    *map_y = DIVIDE((int)(gui_y * W - gui_x * H), (int)(W * H));
  } else {                      /* tileset_is_isometric(t) */
    /* We use DIVIDE so that we will get the correct result even
     * for negative coordinates. */
    *map_x = DIVIDE((int)gui_x, (int)W);
    *map_y = DIVIDE((int)gui_y, (int)H);
  }
}
 
/************************************************************************/
bool tile_to_canvas_pos(float *canvas_x, float *canvas_y, float zoom,
                        const struct tile *ptile)
{
  int center_map_x, center_map_y, dx, dy, tile_x, tile_y;
 
  /*
   * First we wrap the coordinates to hopefully be within the mapview
   * window. We do this by finding the position closest to the center
   * of the window.
   */
  /* TODO: Cache the value of this position */
  base_canvas_to_map_pos(zoom, &center_map_x, &center_map_y,
                         mapview.width / 2,
                         mapview.height / 2);
  index_to_map_pos(&tile_x, &tile_y, tile_index(ptile));
  base_map_distance_vector(&dx, &dy, center_map_x, center_map_y, tile_x,
                           tile_y);
 
  map_to_gui_pos(tileset, map_zoom,
                 canvas_x, canvas_y, center_map_x + dx, center_map_y + dy);
  *canvas_x -= mapview.gui_x0;
  *canvas_y -= mapview.gui_y0;
 
  /*
   * Finally we clip.
   *
   * This check is tailored to work for both iso-view and classic view.
   * Note that (canvas_x, canvas_y) need not be aligned to a tile boundary, and
   * that the position is at the top-left of the NORMAL (not UNIT) tile.
   * This checks to see if _any part_ of the tile is present on the backing
   * store. Even if it's not visible on the canvas, if it's present on the
   * backing store we need to draw it in case the canvas is resized.
   */
  return (*canvas_x > -tileset_tile_width(tileset) * map_zoom
          && *canvas_x < mapview.store_width
          && *canvas_y > -tileset_tile_height(tileset) * map_zoom
          && *canvas_y < (mapview.store_height
                          + (tileset_full_tile_height(tileset)
                             - tileset_tile_height(tileset)) * map_zoom));
}
 
/************************************************************************/
static void base_canvas_to_map_pos(float zoom, int *map_x, int *map_y,
                                   float canvas_x, float canvas_y)
{
  gui_to_map_pos(tileset, zoom, map_x, map_y,
                 canvas_x + mapview.gui_x0 / map_zoom * zoom,
                 canvas_y + mapview.gui_y0 / map_zoom * zoom);
}
 
/************************************************************************/
struct tile *canvas_pos_to_tile(float canvas_x, float canvas_y,
                                float zoom)
{
  int map_x, map_y;
 
  base_canvas_to_map_pos(zoom, &map_x, &map_y, canvas_x, canvas_y);
  if (normalize_map_pos(&(wld.map), &map_x, &map_y)) {
    return map_pos_to_tile(&(wld.map), map_x, map_y);
  } else {
    return nullptr;
  }
}
 
/************************************************************************/
struct tile *canvas_pos_to_nearest_tile(float canvas_x, float canvas_y,
                                        float zoom)
{
  int map_x, map_y;
 
  base_canvas_to_map_pos(zoom, &map_x, &map_y, canvas_x, canvas_y);
 
  return nearest_real_tile(&(wld.map), map_x, map_y);
}
 
/************************************************************************/
static void normalize_gui_pos(const struct tileset *t, float zoom,
                              float *gui_x, float *gui_y)
{
  int map_x, map_y, nat_x, nat_y, diff_x, diff_y;
  float gui_x0, gui_y0;
 
  /* Convert the (gui_x, gui_y) into a (map_x, map_y) plus a GUI offset
   * from this tile. */
  gui_to_map_pos(t, zoom, &map_x, &map_y, *gui_x, *gui_y);
  map_to_gui_pos(t, zoom, &gui_x0, &gui_y0, map_x, map_y);
  diff_x = *gui_x - gui_x0;
  diff_y = *gui_y - gui_y0;
 
  /* Perform wrapping without any realness check. It's important that
   * we wrap even if the map position is unreal, which normalize_map_pos()
   * doesn't necessarily do. */
  MAP_TO_NATIVE_POS(&nat_x, &nat_y, map_x, map_y);
  if (current_wrap_has_flag(WRAP_X)) {
    nat_x = FC_WRAP(nat_x, MAP_NATIVE_WIDTH);
  }
  if (current_wrap_has_flag(WRAP_Y)) {
    nat_y = FC_WRAP(nat_y, MAP_NATIVE_HEIGHT);
  }
  NATIVE_TO_MAP_POS(&map_x, &map_y, nat_x, nat_y);
 
  /* Now convert the wrapped map position back to a GUI position and add the
   * offset back on. */
  map_to_gui_pos(t, zoom, gui_x, gui_y, map_x, map_y);
  *gui_x += diff_x;
  *gui_y += diff_y;
}
 
/************************************************************************/
static void gui_distance_vector(const struct tileset *t, float zoom,
                                float *gui_dx, float *gui_dy,
                                float gui_x0, float gui_y0,
                                float gui_x1, float gui_y1)
{
  int map_x0, map_y0, map_x1, map_y1;
  float gui_x0_base, gui_y0_base, gui_x1_base, gui_y1_base;
  int gui_x0_diff, gui_y0_diff, gui_x1_diff, gui_y1_diff;
  int map_dx, map_dy;
 
  /* Make sure positions are canonical. Yes, this is the only way. */
  normalize_gui_pos(t, zoom, &gui_x0, &gui_y0);
  normalize_gui_pos(t, zoom, &gui_x1, &gui_y1);
 
  /* Now we have to find the offset of each GUI position from its tile
   * origin. This is complicated: it means converting to a map position and
   * then back to the GUI position to find the tile origin, then subtracting
   * to get the offset. */
  gui_to_map_pos(t, zoom, &map_x0, &map_y0, gui_x0, gui_y0);
  gui_to_map_pos(t, zoom, &map_x1, &map_y1, gui_x1, gui_y1);
 
  map_to_gui_pos(t, zoom, &gui_x0_base, &gui_y0_base, map_x0, map_y0);
  map_to_gui_pos(t, zoom, &gui_x1_base, &gui_y1_base, map_x1, map_y1);
 
  gui_x0_diff = gui_x0 - gui_x0_base;
  gui_y0_diff = gui_y0 - gui_y0_base;
  gui_x1_diff = gui_x1 - gui_x1_base;
  gui_y1_diff = gui_y1 - gui_y1_base;
 
  /* Next we find the map distance vector and convert this into a GUI
   * vector. */
  base_map_distance_vector(&map_dx, &map_dy, map_x0, map_y0, map_x1, map_y1);
  map_to_gui_pos(t, zoom, gui_dx, gui_dy, map_dx, map_dy);
 
  /* Finally we add on the difference in offsets to retain pixel
   * resolution. */
  *gui_dx += gui_x1_diff - gui_x0_diff;
  *gui_dy += gui_y1_diff - gui_y0_diff;
}
 
/************************************************************************/
static void base_set_mapview_origin(float gui_x0, float gui_y0, float zoom)
{
  float old_gui_x0, old_gui_y0;
  float dx, dy;
  const int width = mapview.width, height = mapview.height;
  int common_x0, common_x1, common_y0, common_y1;
  int update_x0, update_x1, update_y0, update_y1;
 
  /* Then update everything. This does some tricky math to avoid having
   * to do unnecessary redraws in update_map_canvas(). This makes for ugly
   * code but speeds up the mapview by a large factor. */
 
  /* We need to calculate the vector of movement of the mapview. So
   * we find the GUI distance vector and then use this to calculate
   * the original mapview origin relative to the current position. Thus
   * if we move one tile to the left, even if this causes GUI positions
   * to wrap the distance vector is only one tile. */
  normalize_gui_pos(tileset, zoom, &gui_x0, &gui_y0);
  gui_distance_vector(tileset, zoom, &dx, &dy,
                      mapview.gui_x0, mapview.gui_y0,
                      gui_x0, gui_y0);
  old_gui_x0 = gui_x0 - dx;
  old_gui_y0 = gui_y0 - dy;
 
  mapview.gui_x0 = gui_x0;
  mapview.gui_y0 = gui_y0;
 
  /* Find the overlapping area of the new and old mapview. This is
   * done in GUI coordinates. Note that if the GUI coordinates wrap
   * no overlap will be found. */
  common_x0 = MAX(old_gui_x0, gui_x0);
  common_x1 = MIN(old_gui_x0, gui_x0) + width;
  common_y0 = MAX(old_gui_y0, gui_y0);
  common_y1 = MIN(old_gui_y0, gui_y0) + height;
 
  if (mapview.can_do_cached_drawing && !zoom_is_enabled()
      && common_x1 > common_x0 && common_y1 > common_y0) {
    /* Do a partial redraw only. This means the area of overlap (a
     * rectangle) is copied. Then the remaining areas (two rectangles)
     * are updated through update_map_canvas(). */
    struct canvas *target = mapview.tmp_store;
 
    if (old_gui_x0 < gui_x0) {
      update_x0 = MAX(old_gui_x0 + width, gui_x0);
      update_x1 = gui_x0 + width;
    } else {
      update_x0 = gui_x0;
      update_x1 = MIN(old_gui_x0, gui_x0 + width);
    }
    if (old_gui_y0 < gui_y0) {
      update_y0 = MAX(old_gui_y0 + height, gui_y0);
      update_y1 = gui_y0 + height;
    } else {
      update_y0 = gui_y0;
      update_y1 = MIN(old_gui_y0, gui_y0 + height);
    }
 
    dirty_all();
    canvas_copy(target, mapview.store,
                common_x0 - old_gui_x0,
                common_y0 - old_gui_y0,
                common_x0 - gui_x0, common_y0 - gui_y0,
                common_x1 - common_x0, common_y1 - common_y0);
    mapview.tmp_store = mapview.store;
    mapview.store = target;
 
    if (update_y1 > update_y0) {
      update_map_canvas(0, update_y0 - gui_y0,
                        width, update_y1 - update_y0);
    }
    if (update_x1 > update_x0) {
      update_map_canvas(update_x0 - gui_x0, common_y0 - gui_y0,
                        update_x1 - update_x0, common_y1 - common_y0);
    }
  } else {
    dirty_all();
    update_map_canvas(0, 0, mapview.store_width, mapview.store_height);
  }
 
  center_tile_overviewcanvas();
 
  switch (hover_state) {
  case HOVER_GOTO:
  case HOVER_PATROL:
  case HOVER_CONNECT:
    create_line_at_mouse_pos();
    break;
  case HOVER_GOTO_SEL_TGT:
  case HOVER_NONE:
  case HOVER_TELEPORT:
  case HOVER_PARADROP:
  case HOVER_ACT_SEL_TGT:
    break;
  }
 
  if (rectangle_active) {
    update_rect_at_mouse_pos();
  }
}
 
/************************************************************************/
static bool calc_mapview_origin(float *gui_x0, float *gui_y0, float zoom)
{
  float xmin, ymin, xmax, ymax;
  int xsize, ysize;
 
  /* Normalize (wrap) the mapview origin. */
  normalize_gui_pos(tileset, zoom, gui_x0, gui_y0);
 
  /* First wrap/clip the position. Wrapping is done in native positions
   * while clipping is done in scroll (native) positions. */
  get_mapview_scroll_window(&xmin, &ymin, &xmax, &ymax, &xsize, &ysize);
 
  if (!current_wrap_has_flag(WRAP_X)) {
    *gui_x0 = CLIP(xmin, *gui_x0, xmax - xsize);
  }
 
  if (!current_wrap_has_flag(WRAP_Y)) {
    *gui_y0 = CLIP(ymin, *gui_y0, ymax - ysize);
  }
 
  if (mapview.gui_x0 == *gui_x0 && mapview.gui_y0 == *gui_y0) {
    return FALSE;
  }
 
  return TRUE;
}
 
/************************************************************************/
void set_mapview_origin(float gui_x0, float gui_y0, float zoom)
{
  if (!calc_mapview_origin(&gui_x0, &gui_y0, zoom)) {
    return;
  }
 
  if (can_slide && gui_options.smooth_center_slide_msec > 0) {
    if (frame_by_frame_animation) {
      /* TODO: Implement animation */
      base_set_mapview_origin(gui_x0, gui_y0, zoom);
    } else {
      int start_x = mapview.gui_x0, start_y = mapview.gui_y0;
      float diff_x, diff_y;
      double timing_sec = (double)gui_options.smooth_center_slide_msec / 1000.0;
      double currtime;
      int frames = 0;
 
      /* We track the average FPS, which is used to predict how long the
       * next draw will take. We start with a 100 FPS estimate - this
       * value will quickly become irrelevant as the correct value is
       * calculated, but it's needed to give an estimate of the FPS for
       * the first draw.
       *
       * Note that the initial value shouldn't be larger than the sliding
       * time, or we'll jump straight to the last frame. The FPS should
       * therefore be a "high" estimate. */
      static double total_frames = 0.01;
      static double total_time = 0.0001;
 
      gui_distance_vector(tileset, zoom,
                          &diff_x, &diff_y, start_x, start_y, gui_x0, gui_y0);
      anim_timer_renew();
 
      unqueue_mapview_updates(TRUE);
 
      do {
        double mytime;
 
        /* Get the current time, and add on the average 1/FPS, which is the
         * expected time this frame will take. This is done so that the
         * frame's position is calculated from the expected time when the
         * frame will complete, rather than the time when the frame drawing
         * is started. */
        currtime = timer_read_seconds(anim_timer);
        currtime += total_time / total_frames;
 
        mytime = MIN(currtime, timing_sec);
        base_set_mapview_origin(start_x + diff_x * (mytime / timing_sec),
                                start_y + diff_y * (mytime / timing_sec),
                                zoom);
        flush_dirty();
        gui_flush();
        frames++;
      } while (currtime < timing_sec);
 
      currtime = timer_read_seconds(anim_timer);
      total_frames += frames;
      total_time += currtime;
      log_debug("Got %d frames in %f seconds: %f FPS (avg %f).",
                frames, currtime, (double)frames / currtime,
                total_frames / total_time);
 
      /* A very small decay factor to make things more accurate when something
       * changes (mapview size, tileset change, etc.). This gives a
       * half-life of 68 slides. */
      total_frames *= 0.99;
      total_time *= 0.99;
    }
  } else {
    base_set_mapview_origin(gui_x0, gui_y0, zoom);
  }
 
  update_map_canvas_scrollbars();
}
 
/************************************************************************/
void get_mapview_scroll_window(float *xmin, float *ymin,
                               float *xmax, float *ymax,
                               int *xsize, int *ysize)
{
  int diff;
 
  *xsize = mapview.width;
  *ysize = mapview.height;
 
  if (MAP_IS_ISOMETRIC == tileset_is_isometric(tileset)) {
    /* If the map and view line up, it's easy. */
    NATIVE_TO_MAP_POS(xmin, ymin, 0, 0);
    map_to_gui_pos(tileset, map_zoom, xmin, ymin, *xmin, *ymin);
 
    NATIVE_TO_MAP_POS(xmax, ymax, MAP_NATIVE_WIDTH - 1, MAP_NATIVE_HEIGHT - 1);
    map_to_gui_pos(tileset, map_zoom, xmax, ymax, *xmax, *ymax);
    *xmax += tileset_tile_width(tileset) * map_zoom;
    *ymax += tileset_tile_height(tileset) * map_zoom;
 
    /* To be able to center on positions near the edges, we have to be
     * allowed to scroll all the way to those edges. To allow wrapping the
     * clipping boundary needs to extend past the edge - a half-tile in
     * iso-view or a full tile in non-iso view. The above math already has
     * taken care of some of this so all that's left is to fix the corner
     * cases. */
    if (current_wrap_has_flag(WRAP_X)) {
      *xmax += *xsize;
 
      /* We need to be able to scroll a little further to the left. */
      *xmin -= tileset_tile_width(tileset) * map_zoom;
    }
    if (current_wrap_has_flag(WRAP_Y)) {
      *ymax += *ysize;
 
      /* We need to be able to scroll a little further up. */
      *ymin -= tileset_tile_height(tileset) * map_zoom;
    }
  } else {
    /* Otherwise it's hard. Very hard. Impossible, in fact. This is just
     * an approximation - a huge bounding box. */
    float gui_x1, gui_y1, gui_x2, gui_y2, gui_x3, gui_y3, gui_x4, gui_y4;
    int map_x, map_y;
 
    NATIVE_TO_MAP_POS(&map_x, &map_y, 0, 0);
    map_to_gui_pos(tileset, map_zoom, &gui_x1, &gui_y1, map_x, map_y);
 
    NATIVE_TO_MAP_POS(&map_x, &map_y, MAP_NATIVE_WIDTH - 1, 0);
    map_to_gui_pos(tileset, map_zoom, &gui_x2, &gui_y2, map_x, map_y);
 
    NATIVE_TO_MAP_POS(&map_x, &map_y, 0, MAP_NATIVE_HEIGHT - 1);
    map_to_gui_pos(tileset, map_zoom, &gui_x3, &gui_y3, map_x, map_y);
 
    NATIVE_TO_MAP_POS(&map_x, &map_y, MAP_NATIVE_WIDTH - 1, MAP_NATIVE_HEIGHT - 1);
    map_to_gui_pos(tileset, map_zoom, &gui_x4, &gui_y4, map_x, map_y);
 
    *xmin = MIN(gui_x1, MIN(gui_x2, gui_x3)) - mapview.width / 2;
    *ymin = MIN(gui_y1, MIN(gui_y2, gui_y3)) - mapview.height / 2;
 
    *xmax = MAX(gui_x4, MAX(gui_x2, gui_x3)) + mapview.width / 2;
    *ymax = MAX(gui_y4, MAX(gui_y2, gui_y3)) + mapview.height / 2;
  }
 
  /* Make sure the scroll window is big enough to hold the mapview. If
   * not scrolling will be very ugly and the GUI may become confused. */
  diff = *xsize - (*xmax - *xmin);
  if (diff > 0) {
    *xmin -= diff / 2;
    *xmax += (diff + 1) / 2;
  }
 
  diff = *ysize - (*ymax - *ymin);
  if (diff > 0) {
    *ymin -= diff / 2;
    *ymax += (diff + 1) / 2;
  }
 
  log_debug("x: %f<-%d->%f; y: %f<-%f->%d",
            *xmin, *xsize, *xmax, *ymin, *ymax, *ysize);
}
 
/************************************************************************/
void get_mapview_scroll_step(int *xstep, int *ystep)
{
  *xstep = tileset_tile_width(tileset) * map_zoom;
  *ystep = tileset_tile_height(tileset) * map_zoom;
 
  if (tileset_is_isometric(tileset)) {
    *xstep /= 2;
    *ystep /= 2;
  }
}
 
/************************************************************************/
void get_mapview_scroll_pos(int *scroll_x, int *scroll_y)
{
  *scroll_x = mapview.gui_x0;
  *scroll_y = mapview.gui_y0;
}
 
/************************************************************************/
void set_mapview_scroll_pos(int scroll_x, int scroll_y, float zoom)
{
  int gui_x0 = scroll_x, gui_y0 = scroll_y;
 
  can_slide = FALSE;
  set_mapview_origin(gui_x0, gui_y0, zoom);
  can_slide = TRUE;
}
 
/************************************************************************/
struct tile *get_center_tile_mapcanvas(void)
{
  return canvas_pos_to_nearest_tile(mapview.width / 2,
                                    mapview.height / 2,
                                    map_zoom);
}
 
/************************************************************************/
void center_tile_mapcanvas(const struct tile *ptile)
{
  float gui_x, gui_y;
  int tile_x, tile_y;
  static bool first = TRUE;
 
  if (first && can_slide) {
    return;
  }
  first = FALSE;
 
  index_to_map_pos(&tile_x, &tile_y, tile_index(ptile));
  map_to_gui_pos(tileset, map_zoom, &gui_x, &gui_y, tile_x, tile_y);
 
  /* Put the center pixel of the tile at the exact center of the mapview. */
  gui_x -= (mapview.width - tileset_tile_width(tileset) * map_zoom) / 2;
  gui_y -= (mapview.height - tileset_tile_height(tileset) * map_zoom) / 2;
 
  set_mapview_origin(gui_x, gui_y, map_zoom);
 
  center_tile = ptile;
}
 
/************************************************************************/
bool tile_visible_mapcanvas(struct tile *ptile)
{
  float dummy_x, dummy_y; /* Well, it needs two pointers... */
 
  return tile_to_canvas_pos(&dummy_x, &dummy_y, map_zoom, ptile);
}
 
/************************************************************************/
bool tile_visible_and_not_on_border_mapcanvas(struct tile *ptile)
{
  float canvas_x, canvas_y;
  float xmin, ymin, xmax, ymax;
  int xsize, ysize, scroll_x, scroll_y;
  const int border_x = (tileset_is_isometric(tileset) ? tileset_tile_width(tileset) / 2 * map_zoom
                        : 2 * tileset_tile_width(tileset) * map_zoom);
  const int border_y = (tileset_is_isometric(tileset) ? tileset_tile_height(tileset) / 2 * map_zoom
                        : 2 * tileset_tile_height(tileset) * map_zoom);
  bool same = (tileset_is_isometric(tileset) == MAP_IS_ISOMETRIC);
 
  get_mapview_scroll_window(&xmin, &ymin, &xmax, &ymax, &xsize, &ysize);
  get_mapview_scroll_pos(&scroll_x, &scroll_y);
 
  if (!tile_to_canvas_pos(&canvas_x, &canvas_y, map_zoom, ptile)) {
    /* The tile isn't visible at all. */
    return FALSE;
  }
 
  /* For each direction: if the tile is too close to the mapview border
   * in that direction, and scrolling can get us any closer to the
   * border, then it's a border tile. We can only really check the
   * scrolling when the mapview window lines up with the map. */
  if (canvas_x < border_x
      && (!same || scroll_x > xmin || current_wrap_has_flag(WRAP_X))) {
    return FALSE;
  }
  if (canvas_y < border_y
      && (!same || scroll_y > ymin || current_wrap_has_flag(WRAP_Y))) {
    return FALSE;
  }
  if (canvas_x + tileset_tile_width(tileset) * map_zoom > mapview.width - border_x
      && (!same || scroll_x + xsize < xmax || current_wrap_has_flag(WRAP_X))) {
    return FALSE;
  }
  if (canvas_y + tileset_tile_height(tileset) * map_zoom > mapview.height - border_y
      && (!same || scroll_y + ysize < ymax || current_wrap_has_flag(WRAP_Y))) {
    return FALSE;
  }
 
  return TRUE;
}
 
/************************************************************************/
void put_drawn_sprites(struct canvas *pcanvas, float zoom,
                       int canvas_x, int canvas_y,
                       int count, struct drawn_sprite *pdrawn,
                       bool fog)
{
  int i;
 
  for (i = 0; i < count; i++) {
    if (!pdrawn[i].sprite) {
      /* This can happen, although it should probably be avoided. */
      continue;
    }
 
    if (pdrawn[i].w > 0) {
      /* TODO: Fog support */
      canvas_put_flag_sprite(pcanvas,
                             canvas_x / zoom + pdrawn[i].offset_x,
                             canvas_y / zoom + pdrawn[i].offset_y,
                             pdrawn[i].w / zoom,
                             pdrawn[i].h / zoom,
                             pdrawn[i].sprite);
    } else if (fog && pdrawn[i].foggable) {
      canvas_put_sprite_fogged(pcanvas,
                               canvas_x / zoom + pdrawn[i].offset_x,
                               canvas_y / zoom + pdrawn[i].offset_y,
                               pdrawn[i].sprite,
                               TRUE,
                               canvas_x, canvas_y);
    } else {
      /* We avoid calling canvas_put_sprite_fogged(), even though it
       * should be a valid thing to do, because gui-gtk-2.0 doesn't have
       * a full implementation. */
      canvas_put_sprite_full(pcanvas,
                             canvas_x / zoom + pdrawn[i].offset_x,
                             canvas_y / zoom + pdrawn[i].offset_y,
                             pdrawn[i].sprite);
    }
  }
}
 
/************************************************************************/
void put_one_element(struct canvas *pcanvas, float zoom,
                     enum mapview_layer layer,
                     const struct tile *ptile,
                     const struct tile_edge *pedge,
                     const struct tile_corner *pcorner,
                     const struct unit *punit, const struct city *pcity,
                     int canvas_x, int canvas_y,
                     const struct city *citymode,
                     const struct unit_type *putype)
{
  struct drawn_sprite tile_sprs[80];
  int count = fill_sprite_array(tileset, tile_sprs, layer,
                                ptile, pedge, pcorner,
                                punit, pcity, citymode, putype);
  bool fog = (ptile && gui_options.draw_fog_of_war
              && TILE_KNOWN_UNSEEN == client_tile_get_known(ptile));
 
  /*** Draw terrain and specials ***/
  put_drawn_sprites(pcanvas, zoom, canvas_x, canvas_y, count, tile_sprs, fog);
}
 
/************************************************************************/
void put_unit(const struct unit *punit, struct canvas *pcanvas, float zoom,
              int canvas_x, int canvas_y)
{
  canvas_y
    += (tileset_unit_height(tileset) - tileset_tile_height(tileset)) * zoom;
 
  mapview_layer_iterate(layer) {
    put_one_element(pcanvas, zoom, layer, nullptr, nullptr, nullptr,
                    punit, nullptr, canvas_x, canvas_y, nullptr, nullptr);
  } mapview_layer_iterate_end;
}
 
/************************************************************************/
void put_unittype(const struct unit_type *putype, struct canvas *pcanvas,
                  float zoom, int canvas_x, int canvas_y)
{
  canvas_y
    += (tileset_unit_height(tileset) - tileset_tile_height(tileset)) * zoom;
 
  mapview_layer_iterate(layer) {
    put_one_element(pcanvas, zoom, layer, nullptr, nullptr, nullptr,
                    nullptr, nullptr, canvas_x, canvas_y, nullptr, putype);
  } mapview_layer_iterate_end;
}
 
/************************************************************************/
void put_city(struct city *pcity, struct canvas *pcanvas, float zoom,
              int canvas_x, int canvas_y)
{
  canvas_y
    += (tileset_full_tile_height(tileset) - tileset_tile_height(tileset)) * zoom;
 
  mapview_layer_iterate(layer) {
    put_one_element(pcanvas, zoom, layer,
                    nullptr, nullptr, nullptr, nullptr, pcity,
                    canvas_x, canvas_y, nullptr, nullptr);
  } mapview_layer_iterate_end;
}
 
/************************************************************************/
void put_terrain(struct tile *ptile, struct canvas *pcanvas, float zoom,
                 int canvas_x, int canvas_y)
{
  /* Use full tile height, even for terrains. */
  canvas_y
    += (tileset_full_tile_height(tileset) - tileset_tile_height(tileset)) * zoom;
 
  mapview_layer_iterate(layer) {
    put_one_element(pcanvas, zoom, layer, ptile, nullptr, nullptr, nullptr,
                    nullptr, canvas_x, canvas_y, nullptr, nullptr);
  } mapview_layer_iterate_end;
}
 
/************************************************************************/
void put_unit_city_overlays(struct unit *punit,
                            struct canvas *pcanvas,
                            int canvas_x, int canvas_y, int *upkeep_cost,
                            int happy_cost)
{
  struct sprite *sprite;
 
  sprite = get_unit_unhappy_sprite(tileset, punit, happy_cost);
  if (sprite) {
    canvas_put_sprite_full(pcanvas, canvas_x, canvas_y, sprite);
  }
 
  output_type_iterate(o) {
    sprite = get_unit_upkeep_sprite(tileset, o, punit, upkeep_cost);
    if (sprite) {
      canvas_put_sprite_full(pcanvas, canvas_x, canvas_y, sprite);
    }
  } output_type_iterate_end;
}
 
/*
 * pcity->client.color_index is an index into the city_colors array.
 * When toggle_city_color is called the city's coloration is toggled. When
 * a city is newly colored its color is taken from color_index and
 * color_index is moved forward one position. Each color in the array
 * tells what color the citymap will be drawn on the mapview.
 *
 * This array can be added to without breaking anything elsewhere.
 */
static int color_index = 0;
#define NUM_CITY_COLORS tileset_num_city_colors(tileset)
 
 
/************************************************************************/
void toggle_city_color(struct city *pcity)
{
  if (pcity->client.colored) {
    pcity->client.colored = FALSE;
  } else {
    pcity->client.colored = TRUE;
    pcity->client.color_index = color_index;
    color_index = (color_index + 1) % NUM_CITY_COLORS;
  }
 
  refresh_city_mapcanvas(pcity, pcity->tile, TRUE, FALSE);
}
 
/************************************************************************/
void toggle_unit_color(struct unit *punit)
{
  if (punit->client.colored) {
    punit->client.colored = FALSE;
  } else {
    punit->client.colored = TRUE;
    punit->client.color_index = color_index;
    color_index = (color_index + 1) % NUM_CITY_COLORS;
  }
 
  refresh_unit_mapcanvas(punit, unit_tile(punit), TRUE, FALSE);
}
 
/************************************************************************/
void put_nuke_mushroom_pixmaps(struct tile *ptile)
{
  float canvas_x, canvas_y;
  struct sprite *mysprite = get_nuke_explode_sprite(tileset);
  int width, height;
 
  get_sprite_dimensions(mysprite, &width, &height);
 
  if (frame_by_frame_animation) {
    struct animation *anim = fc_malloc(sizeof(struct animation));
 
    anim->type = ANIM_NUKE;
    anim->id = -1;
    anim->nuke.shown = FALSE;
    anim->nuke.nuke_tile = ptile;
 
    (void) tile_to_canvas_pos(&canvas_x, &canvas_y, map_zoom, ptile);
    get_sprite_dimensions(mysprite, &width, &height);
 
    anim->width = width * map_zoom;
    anim->height = height * map_zoom;
    animation_add(anim);
  } else {
    /* We can't count on the return value of tile_to_canvas_pos() since the
     * sprite may span multiple tiles. */
    (void) tile_to_canvas_pos(&canvas_x, &canvas_y, map_zoom, ptile);
 
    canvas_x += (tileset_tile_width(tileset) - width) / 2 * map_zoom;
    canvas_y += (tileset_tile_height(tileset) - height) / 2 * map_zoom;
 
    /* Make sure everything is flushed and synced before proceeding. First
     * we update everything to the store, but don't write this to screen.
     * Then add the nuke graphic to the store. Finally flush everything to
     * the screen and wait 1 second. */
    unqueue_mapview_updates(FALSE);
 
    canvas_put_sprite_full(mapview.store, canvas_x, canvas_y, mysprite);
    dirty_rect(canvas_x, canvas_y, width, height);
 
    flush_dirty();
    gui_flush();
 
    fc_usleep(1000000);
 
    update_map_canvas_visible();
  }
}
 
/************************************************************************/
static void put_one_tile(struct canvas *pcanvas, enum mapview_layer layer,
                         struct tile *ptile, int canvas_x, int canvas_y,
                         const struct city *citymode)
{
  if (client_tile_get_known(ptile) != TILE_UNKNOWN
      || (editor_is_active() && editor_tile_is_selected(ptile))) {
    struct unit *punit = get_drawable_unit(tileset, ptile, citymode);
    struct animation *anim = nullptr;
 
    if (animation_list_size(animations) > 0) {
      anim = animation_list_get(animations, 0);
    }
 
    if (anim != nullptr && punit != nullptr
        && punit->id == anim->id) {
      punit = nullptr;
    }
 
    put_one_element(pcanvas, map_zoom, layer, ptile, nullptr, nullptr, punit,
                    tile_city(ptile), canvas_x, canvas_y, citymode, nullptr);
  }
}
 
/************************************************************************/
static int trade_route_to_canvas_lines(const struct tile *ptile1,
                                       const struct tile *ptile2,
                                       struct trade_route_line *lines)
{
  int dx, dy;
 
  if (!ptile1 || !ptile2 || !lines) {
    return 0;
  }
 
  base_map_distance_vector(&dx, &dy, TILE_XY(ptile1), TILE_XY(ptile2));
  map_to_gui_pos(tileset, map_zoom, &lines[0].width, &lines[0].height, dx, dy);
 
  /* FIXME: Remove these casts. */
  tile_to_canvas_pos(&lines[0].x, &lines[0].y, map_zoom, (struct tile *)ptile1);
  tile_to_canvas_pos(&lines[1].x, &lines[1].y, map_zoom, (struct tile *)ptile2);
 
  if (lines[1].x - lines[0].x == lines[0].width
      && lines[1].y - lines[0].y == lines[0].height) {
    return 1;
  }
 
  lines[1].width = -lines[0].width;
  lines[1].height = -lines[0].height;
  return 2;
}
 
/************************************************************************/
static void draw_trade_route_line(const struct tile *ptile1,
                                  const struct tile *ptile2,
                                  enum color_std color)
{
  struct trade_route_line lines[MAX_TRADE_ROUTE_DRAW_LINES];
  int line_count, i;
  struct color *pcolor;
 
  if (!ptile1 || !ptile2) {
    return;
  }
 
  pcolor = get_color(tileset, color);
  if (!pcolor) {
    return;
  }
 
  /* Order the source and destination tiles consistently
   * so that if a line is drawn twice it does not produce
   * ugly effects due to dashes not lining up. */
  if (tile_index(ptile2) > tile_index(ptile1)) {
    const struct tile *tmp;
    tmp = ptile1;
    ptile1 = ptile2;
    ptile2 = tmp;
  }
 
  line_count = trade_route_to_canvas_lines(ptile1, ptile2, lines);
  for (i = 0; i < line_count; i++) {
    /* XXX: canvas_put_line doesn't currently take map_zoom into account
     * itself, but it probably should? */
    canvas_put_line(mapview.store, pcolor, LINE_BORDER,
                    lines[i].x + tileset_tile_width(tileset) / 2 * map_zoom,
                    lines[i].y + tileset_tile_height(tileset) / 2 * map_zoom,
                    lines[i].width, lines[i].height);
  }
}
 
/************************************************************************/
static void draw_trade_routes_for_city(const struct city *pcity_src)
{
  if (!pcity_src) {
    return;
  }
 
  trade_partners_iterate(pcity_src, pcity_dest) {
    if (pcity_dest != nullptr) {
      draw_trade_route_line(city_tile(pcity_src), city_tile(pcity_dest),
                            COLOR_MAPVIEW_TRADE_ROUTE_LINE);
    }
  } trade_partners_iterate_end;
}
 
/************************************************************************/
static void draw_trade_routes(void)
{
  if (!gui_options.draw_city_trade_routes) {
    return;
  }
 
  if (client_is_global_observer()) {
    cities_iterate(pcity) {
      draw_trade_routes_for_city(pcity);
    } cities_iterate_end;
  } else {
    struct player *pplayer = client_player();
 
    if (!pplayer) {
      return;
    }
 
    city_list_iterate(pplayer->cities, pcity) {
      draw_trade_routes_for_city(pcity);
    } city_list_iterate_end;
  }
}
 
/************************************************************************/
void update_map_canvas(int canvas_x, int canvas_y, int width, int height)
{
  int gui_x0, gui_y0;
  bool full;
  struct canvas *tmp;
 
  if (canvas_x < 0) {
    width += canvas_x;
    canvas_x = 0;
  } else if (canvas_x > mapview.store_width) {
    width -= (canvas_x - mapview.store_width);
    canvas_x = mapview.store_width;
  }
 
  if (canvas_y < 0) {
    height += canvas_y;
    canvas_y = 0;
  } else if (canvas_y > mapview.store_height) {
    height -= (canvas_y - mapview.store_height);
    canvas_y = mapview.store_height;
  }
 
  if (width <= 0 || height <= 0) {
    /* Area outside mapview */
    return;
  }
 
  gui_x0 = mapview.gui_x0 + canvas_x;
  gui_y0 = mapview.gui_y0 + canvas_y;
  full = (canvas_x == 0 && canvas_y == 0
          && width == mapview.store_width
          && height == mapview.store_height);
 
  log_debug("update_map_canvas(pos=(%d,%d), size=(%d,%d))",
            canvas_x, canvas_y, width, height);
 
  /* If a full redraw is done, we just draw everything onto the canvas.
   * However if a partial redraw is done we draw everything onto the
   * tmp_canvas then copy *just* the area of update onto the canvas. */
  if (!full) {
    /* Swap store and tmp_store. */
    tmp = mapview.store;
    mapview.store = mapview.tmp_store;
    mapview.tmp_store = tmp;
  }
 
  /* Clear the area. This is necessary since some parts of the rectangle
   * may not actually have any tiles drawn on them. This will happen when
   * the mapview is large enough so that the tile is visible in multiple
   * locations. In this case it will only be drawn in one place.
   *
   * Of course it's necessary to draw to the whole area to cover up any old
   * drawing that was done there. */
  canvas_put_rectangle(mapview.store,
                       get_color(tileset, COLOR_MAPVIEW_UNKNOWN),
                       canvas_x, canvas_y, width / map_zoom, height / map_zoom);
 
  mapview_layer_iterate(layer) {
    if (layer == LAYER_TILELABEL) {
      show_tile_labels(canvas_x, canvas_y, width, height);
    }
    if (layer == LAYER_CITYBAR) {
      show_city_descriptions(canvas_x, canvas_y, width, height);
      continue;
    }
    gui_rect_iterate_coord(gui_x0, gui_y0, width,
                           height + (tileset_is_isometric(tileset)
                                     ? (tileset_tile_height(tileset) / 2 * map_zoom) : 0),
                           ptile, pedge, pcorner, gui_x, gui_y, map_zoom) {
      const int cx = gui_x - mapview.gui_x0, cy = gui_y - mapview.gui_y0;
 
      if (ptile) {
        put_one_tile(mapview.store, layer, ptile, cx, cy, nullptr);
      } else if (pedge) {
        put_one_element(mapview.store, map_zoom, layer, nullptr, pedge,
                        nullptr, nullptr, nullptr, cx, cy, nullptr, nullptr);
      } else if (pcorner) {
        put_one_element(mapview.store, map_zoom, layer, nullptr, nullptr,
                        pcorner, nullptr, nullptr, cx, cy, nullptr, nullptr);
      } else {
        /* This can happen, for instance for unreal tiles. */
      }
    } gui_rect_iterate_coord_end;
  } mapview_layer_iterate_end;
 
  draw_trade_routes();
  link_marks_draw_all();
 
  /* Draw the goto lines on top of the whole thing. This is done last as
   * we want it completely on top.
   *
   * Note that a pixel right on the border of a tile may actually contain a
   * goto line from an adjacent tile. Thus we draw any extra goto lines
   * from adjacent tiles (if they're close enough). */
  gui_rect_iterate(gui_x0 - GOTO_WIDTH, gui_y0 - GOTO_WIDTH,
                   width + 2 * GOTO_WIDTH, height + 2 * GOTO_WIDTH,
                   ptile, pedge, pcorner, map_zoom) {
    if (!ptile) {
      continue;
    }
    adjc_dir_base_iterate(&(wld.map), ptile, dir) {
      if (mapdeco_is_gotoline_set(ptile, dir)) {
        draw_segment(ptile, dir);
      }
    } adjc_dir_base_iterate_end;
  } gui_rect_iterate_end;
 
  if (!full) {
    /* Swap store and tmp_store back. */
    tmp = mapview.store;
    mapview.store = mapview.tmp_store;
    mapview.tmp_store = tmp;
 
    /* And copy store to tmp_store. */
    canvas_copy(mapview.store, mapview.tmp_store,
                canvas_x, canvas_y, canvas_x, canvas_y, width, height);
  }
 
  dirty_rect(canvas_x, canvas_y, width, height);
}
 
/************************************************************************/
void update_map_canvas_visible(void)
{
  queue_mapview_update(UPDATE_MAP_CANVAS_VISIBLE);
}
 
/* The maximum city description width and height. This gives the dimensions
 * of a rectangle centered directly beneath the tile a city is on, that
 * contains the city description.
 *
 * These values are increased when drawing is done. This may mean that
 * the change (from increasing the value) won't take place until the
 * next redraw. */
static int max_desc_width = 0, max_desc_height = 0;
 
/* Same for tile labels */
static int max_label_width = 0, max_label_height = 0 ;
 
/************************************************************************/
void update_city_description(struct city *pcity)
{
  queue_mapview_tile_update(pcity->tile, TILE_UPDATE_CITY_DESC);
}
 
/************************************************************************/
void update_tile_label(struct tile *ptile)
{
  queue_mapview_tile_update(ptile, TILE_UPDATE_TILE_LABEL);
}
 
/************************************************************************/
static void show_full_citybar(struct canvas *pcanvas,
                              const int canvas_x0, const int canvas_y0,
                              struct city *pcity, int *width, int *height)
{
  const struct citybar_sprites *citybar = get_citybar_sprites(tileset);
  static char name[512], growth[32], prod[512], size[32], trade_routes[32];
  enum color_std growth_color;
  enum color_std production_color;
  /* trade_routes_color initialized just to get rid of gcc warning
   * on optimization level 3 when it misdiagnoses that it would be used
   * uninitialized otherwise. Funny thing here is that warning would
   * go away also by *not* setting it to values other than
   * COLOR_MAPVIEW_CITYTEXT in get_city_mapview_trade_routes() */
  enum color_std trade_routes_color = COLOR_MAPVIEW_CITYTEXT;
  struct color *owner_color;
  struct area_rect
    name_rect = {0, 0, 0, 0}, growth_rect = {0, 0, 0, 0},
    prod_rect = {0, 0, 0, 0}, size_rect = {0, 0, 0, 0},
    flag_rect = {0, 0, 0, 0}, occupy_rect = {0, 0, 0, 0},
    food_rect = {0, 0, 0, 0}, shield_rect = {0, 0, 0, 0},
    trade_routes_rect = {0,}, trade_rect = {0,};
  int width1 = 0, width2 = 0, height1 = 0, height2 = 0;
  struct sprite *bg = citybar->background;
  struct sprite *flag = get_city_flag_sprite(tileset, pcity);
  struct sprite *occupy = nullptr;
  int bg_w, bg_h, x, y;
  const int canvas_x = canvas_x0 + tileset_tile_width(tileset) / 2 * map_zoom;
  const int canvas_y = canvas_y0 + tileset_citybar_offset_y(tileset) * map_zoom;
  const int border = 6;
  const enum client_font FONT_CITY_SIZE = FONT_CITY_NAME; /* TODO: new font */
 
  /* We can see the city's production or growth values if
   * we are observing or playing as the owner of the city. */
  const bool can_see_inside
    = (client_is_global_observer() || city_owner(pcity) == client_player());
  const bool should_draw_productions
    = can_see_inside && gui_options.draw_city_productions;
  const bool should_draw_growth = can_see_inside && gui_options.draw_city_growth;
  const bool should_draw_trade_routes = can_see_inside
    && gui_options.draw_city_trade_routes;
  const bool should_draw_lower_bar
    = should_draw_productions || should_draw_growth
    || should_draw_trade_routes;
 
 
  *width = 0;
  *height = 0;
 
  if (!gui_options.draw_city_names && !should_draw_lower_bar) {
    return;
  }
 
 
  /* First: calculate rect dimensions (but not positioning). */
 
  get_sprite_dimensions(bg, &bg_w, &bg_h);
  bg_w *= map_zoom;
  bg_h *= map_zoom;
  get_city_mapview_name_and_growth(pcity, name, sizeof(name),
                                   growth, sizeof(growth),
                                   &growth_color, &production_color);
 
  if (gui_options.draw_city_names) {
    fc_snprintf(size, sizeof(size), "%d", city_size_get(pcity));
 
    get_text_size(&size_rect.w, &size_rect.h, FONT_CITY_SIZE, size);
    get_text_size(&name_rect.w, &name_rect.h, FONT_CITY_NAME, name);
 
    if (can_player_see_units_in_city(client.conn.playing, pcity)) {
      int count = unit_list_size(pcity->tile->units);
 
      count = CLIP(0, count, citybar->occupancy.size - 1);
      occupy = citybar->occupancy.p[count];
    } else {
      if (pcity->client.occupied) {
        occupy = citybar->occupied;
      } else {
        occupy = citybar->occupancy.p[0];
      }
    }
 
    get_flag_dimensions(flag, &flag_rect, tileset_svg_flag_height(tileset));
    flag_rect.w *= map_zoom; flag_rect.h *= map_zoom;
    get_sprite_dimensions(occupy, &occupy_rect.w, &occupy_rect.h);
    occupy_rect.w *= map_zoom; occupy_rect.h *= map_zoom;
 
    width1 = (flag_rect.w + occupy_rect.w + name_rect.w
              + 2 * border + size_rect.w);
    height1 = MAX(flag_rect.h,
                  MAX(occupy_rect.h,
                      MAX(name_rect.h + border,
                          size_rect.h + border)));
  }
 
  if (should_draw_lower_bar) {
    width2 = 0;
    height2 = 0;
 
    if (should_draw_productions) {
      get_city_mapview_production(pcity, prod, sizeof(prod));
      get_text_size(&prod_rect.w, &prod_rect.h, FONT_CITY_PROD, prod);
 
      get_sprite_dimensions(citybar->shields, &shield_rect.w, &shield_rect.h);
      shield_rect.w *= map_zoom; shield_rect.h *= map_zoom;
      width2 += shield_rect.w + prod_rect.w + border;
      height2 = MAX(height2, shield_rect.h);
      height2 = MAX(height2, prod_rect.h + border);
    }
 
    if (should_draw_growth) {
      get_text_size(&growth_rect.w, &growth_rect.h, FONT_CITY_PROD, growth);
      get_sprite_dimensions(citybar->food, &food_rect.w, &food_rect.h);
      food_rect.w *= map_zoom; food_rect.h *= map_zoom;
      width2 += food_rect.w + growth_rect.w + border;
      height2 = MAX(height2, food_rect.h);
      height2 = MAX(height2, growth_rect.h + border);
    }
 
    if (should_draw_trade_routes) {
      get_city_mapview_trade_routes(pcity, trade_routes,
                                    sizeof(trade_routes),
                                    &trade_routes_color);
      get_text_size(&trade_routes_rect.w, &trade_routes_rect.h,
                    FONT_CITY_PROD, trade_routes);
      get_sprite_dimensions(citybar->trade, &trade_rect.w, &trade_rect.h);
      trade_rect.w *= map_zoom; trade_rect.h *= map_zoom;
      width2 += trade_rect.w + trade_routes_rect.w + border;
      height2 = MAX(height2, trade_rect.h);
      height2 = MAX(height2, trade_routes_rect.h + border);
    }
  }
 
  *width = MAX(width1, width2);
  *height = height1 + height2;
 
  /* Next fill in X and Y locations. */
 
  if (gui_options.draw_city_names) {
    flag_rect.x = canvas_x - *width / 2;
    flag_rect.y = canvas_y + (height1 - flag_rect.h) / 2;
 
    occupy_rect.x = flag_rect.x + flag_rect.w;
    occupy_rect.y = canvas_y + (height1 - occupy_rect.h) / 2;
 
    name_rect.x = canvas_x + (flag_rect.w + occupy_rect.w
                              - name_rect.w - size_rect.w - border) / 2;
    name_rect.y = canvas_y + (height1 - name_rect.h) / 2;
 
    size_rect.x = canvas_x + (*width + 1) / 2 - size_rect.w - border / 2;
    size_rect.y = canvas_y + (height1 - size_rect.h) / 2;
  }
 
  if (should_draw_lower_bar) {
    if (should_draw_productions) {
      shield_rect.x = canvas_x - *width / 2;
      shield_rect.y = canvas_y + height1 + (height2 - shield_rect.h) / 2;
 
      prod_rect.x = shield_rect.x + shield_rect.w + border / 2;
      prod_rect.y = canvas_y + height1 + (height2 - prod_rect.h) / 2;
    }
 
    if (should_draw_trade_routes) {
      trade_routes_rect.x = canvas_x + (*width + 1) / 2
        - trade_routes_rect.w - border / 2;
      trade_routes_rect.y = canvas_y + height1
        + (height2 - trade_routes_rect.h) / 2;
 
      trade_rect.x = trade_routes_rect.x - border / 2 - trade_rect.w;
      trade_rect.y = canvas_y + height1 + (height2 - trade_rect.h) / 2;
    }
 
    if (should_draw_growth) {
      growth_rect.x = canvas_x + (*width + 1) / 2
        - growth_rect.w - border / 2;
      if (trade_routes_rect.w > 0) {
        growth_rect.x = growth_rect.x
          - trade_routes_rect.w - border / 2 - trade_rect.w - border / 2;
      }
      growth_rect.y = canvas_y + height1 + (height2 - growth_rect.h) / 2;
 
      food_rect.x = growth_rect.x - border / 2 - food_rect.w;
      food_rect.y = canvas_y + height1 + (height2 - food_rect.h) / 2;
    }
  }
 
 
  /* Now draw. */
 
  /* Draw the city bar's background. */
  for (x = 0; x < *width; x += bg_w) {
    for (y = 0; y < *height; y += bg_h) {
      canvas_put_sprite(pcanvas, (canvas_x - *width / 2 + x) / map_zoom,
                        (canvas_y + y) / map_zoom,
                        bg, 0, 0,
                        (*width - x) / map_zoom, (*height - y) / map_zoom);
    }
  }
 
  owner_color = get_player_color(tileset, city_owner(pcity));
 
  if (gui_options.draw_city_names) {
    canvas_put_flag_sprite(pcanvas,
                           flag_rect.x / map_zoom, flag_rect.y / map_zoom,
                           flag_rect.w / map_zoom, flag_rect.h / map_zoom,
                           flag);
    /* XXX: canvas_put_line() doesn't currently take map_zoom into account.
     * Should it?
     * In the meantime, don't compensate with '/ map_zoom' here, unlike
     * for canvas_put_sprite/text/rectangle */
    canvas_put_line(pcanvas, owner_color, LINE_NORMAL,
                    (flag_rect.x + flag_rect.w) /* / map_zoom */ - 1,
                    canvas_y /* / map_zoom */,
                    0, height1 /* / map_zoom */);
    canvas_put_sprite_full(pcanvas,
                           occupy_rect.x / map_zoom, occupy_rect.y / map_zoom,
                           occupy);
    canvas_put_text(pcanvas, name_rect.x / map_zoom, name_rect.y / map_zoom,
                    FONT_CITY_NAME,
                    get_color(tileset, COLOR_MAPVIEW_CITYTEXT), name);
    canvas_put_rectangle(pcanvas, owner_color,
                         (size_rect.x - border / 2) / map_zoom,
                         canvas_y / map_zoom,
                         (size_rect.w + border) / map_zoom,
                         height1 / map_zoom);
    {
      /* Try to pick a color for city size text that contrasts with
       * player color */
      struct color *textcolors[2] = {
        get_color(tileset, COLOR_MAPVIEW_CITYTEXT),
        get_color(tileset, COLOR_MAPVIEW_CITYTEXT_DARK)
      };
 
      canvas_put_text(pcanvas, size_rect.x / map_zoom, size_rect.y / map_zoom,
                      FONT_CITY_NAME,
                      color_best_contrast(owner_color, textcolors,
                                          ARRAY_SIZE(textcolors)), size);
    }
  }
 
  if (should_draw_lower_bar) {
 
    if (should_draw_productions) {
      canvas_put_sprite_full(pcanvas,
                             shield_rect.x / map_zoom, shield_rect.y / map_zoom,
                             citybar->shields);
      canvas_put_text(pcanvas, prod_rect.x / map_zoom, prod_rect.y / map_zoom,
                      FONT_CITY_PROD,
                      get_color(tileset, production_color), prod);
    }
 
    if (should_draw_trade_routes) {
      canvas_put_sprite_full(pcanvas,
                             trade_rect.x / map_zoom, trade_rect.y / map_zoom,
                             citybar->trade);
      canvas_put_text(pcanvas,
                      trade_routes_rect.x / map_zoom, trade_routes_rect.y / map_zoom,
                      FONT_CITY_PROD,
                      get_color(tileset, trade_routes_color), trade_routes);
    }
 
    if (should_draw_growth) {
      canvas_put_sprite_full(pcanvas,
                             food_rect.x / map_zoom, food_rect.y / map_zoom,
                             citybar->food);
      canvas_put_text(pcanvas, growth_rect.x / map_zoom, growth_rect.y / map_zoom,
                      FONT_CITY_PROD,
                      get_color(tileset, growth_color), growth);
    }
  }
 
  /* Draw the city bar's outline. */
  /* XXX not scaling by map_zoom, see above */
  canvas_put_line(pcanvas, owner_color, LINE_NORMAL,
                  (canvas_x - *width / 2) /* / map_zoom */,
                  canvas_y /* / map_zoom */,
                  *width /* / map_zoom */, 0);
  canvas_put_line(pcanvas, owner_color, LINE_NORMAL,
                  (canvas_x - *width / 2) /* / map_zoom */,
                  canvas_y /* / map_zoom */,
                  0, *height /* / map_zoom */);
  canvas_put_line(pcanvas, owner_color, LINE_NORMAL,
                  (canvas_x - *width / 2) /* / map_zoom */,
                  (canvas_y + *height) /* / map_zoom */ - 1,
                  *width /* / map_zoom */, 0);
  canvas_put_line(pcanvas, owner_color, LINE_NORMAL,
                  (canvas_x - *width / 2 + *width) /* / map_zoom */,
                  canvas_y /* / map_zoom */,
                  0, *height /* / map_zoom */);
 
  /* Draw the dividing line if we drew both the
   * upper and lower parts. */
  if (gui_options.draw_city_names && should_draw_lower_bar) {
    canvas_put_line(pcanvas, owner_color, LINE_NORMAL,
                    (canvas_x - *width / 2) /* / map_zoom */,
                    (canvas_y + height1) /* / map_zoom */ - 1,
                    *width /* / map_zoom */, 0);
  }
}
 
/************************************************************************/
static void show_small_citybar(struct canvas *pcanvas,
                               int canvas_x, int canvas_y,
                               struct city *pcity, int *width, int *height)
{
  static char name[512], growth[32], prod[512], trade_routes[32];
  enum color_std growth_color;
  enum color_std production_color;
 /* trade_routes_color initialized just to get rid off gcc warning
   * on optimization level 3 when it misdiagnoses that it would be used
   * uninitialized otherwise. Funny thing here is that warning would
   * go away also by *not* setting it to values other than
   * COLOR_MAPVIEW_CITYTEXT in get_city_mapview_trade_routes() */
  enum color_std trade_routes_color = COLOR_MAPVIEW_CITYTEXT;
  struct {
    int x, y, w, h;
  } name_rect = {0, 0, 0, 0}, growth_rect = {0, 0, 0, 0},
    prod_rect = {0, 0, 0, 0}, trade_routes_rect = {0,};
  int total_width, total_height;
  int spacer_width = 0;
  const bool can_see_inside = (client_is_global_observer()
                               || city_owner(pcity) == client_player());
 
  *width = *height = 0;
 
  canvas_x += tileset_tile_width(tileset) / 2 * map_zoom;
  canvas_y += tileset_citybar_offset_y(tileset) * map_zoom;
 
  get_city_mapview_name_and_growth(pcity, name, sizeof(name),
                                   growth, sizeof(growth), &growth_color,
                                   &production_color);
 
  if (gui_options.draw_city_names) {
    int drawposx;
 
    /* HACK: Put a character's worth of space between the two
     * strings if needed. */
    get_text_size(&spacer_width, nullptr, FONT_CITY_NAME, "M");
 
    total_width = 0;
    total_height = 0;
 
    get_text_size(&name_rect.w, &name_rect.h, FONT_CITY_NAME, name);
    total_width += name_rect.w;
    total_height = MAX(total_height, name_rect.h);
 
    if (gui_options.draw_city_growth && can_see_inside) {
      get_text_size(&growth_rect.w, &growth_rect.h, FONT_CITY_PROD, growth);
      total_width += spacer_width + growth_rect.w;
      total_height = MAX(total_height, growth_rect.h);
    }
 
    if (gui_options.draw_city_trade_routes && can_see_inside) {
      get_city_mapview_trade_routes(pcity, trade_routes,
                                    sizeof(trade_routes),
                                    &trade_routes_color);
      get_text_size(&trade_routes_rect.w, &trade_routes_rect.h,
                    FONT_CITY_PROD, trade_routes);
      total_width += spacer_width + trade_routes_rect.w;
      total_height = MAX(total_height, trade_routes_rect.h);
    }
 
    drawposx = canvas_x;
    drawposx -= total_width / 2;
    canvas_put_text(pcanvas, drawposx / map_zoom, canvas_y / map_zoom,
                    FONT_CITY_NAME,
                    get_color(tileset, COLOR_MAPVIEW_CITYTEXT), name);
    drawposx += name_rect.w;
 
    if (gui_options.draw_city_growth && can_see_inside) {
      drawposx += spacer_width;
      canvas_put_text(pcanvas, drawposx / map_zoom,
                      (canvas_y + total_height - growth_rect.h) / map_zoom,
                      FONT_CITY_PROD,
                      get_color(tileset, growth_color), growth);
      drawposx += growth_rect.w;
    }
 
    if (gui_options.draw_city_trade_routes && can_see_inside) {
      drawposx += spacer_width;
      canvas_put_text(pcanvas, drawposx / map_zoom,
                      (canvas_y + total_height - trade_routes_rect.h) / map_zoom,
                      FONT_CITY_PROD,
                      get_color(tileset, trade_routes_color), trade_routes);
    }
 
    canvas_y += total_height + 3;
 
    *width = MAX(*width, total_width);
    *height += total_height + 3;
  }
 
  if (gui_options.draw_city_productions && can_see_inside) {
    get_city_mapview_production(pcity, prod, sizeof(prod));
    get_text_size(&prod_rect.w, &prod_rect.h, FONT_CITY_PROD, prod);
 
    total_width = prod_rect.w;
    total_height = prod_rect.h;
 
    canvas_put_text(pcanvas, (canvas_x - total_width / 2) / map_zoom,
                    canvas_y / map_zoom,
                    FONT_CITY_PROD,
                    get_color(tileset, production_color), prod);
 
    *width = MAX(*width, total_width);
    *height += total_height;
  }
}
 
/************************************************************************/
static void show_city_desc(struct canvas *pcanvas,
                           int canvas_x, int canvas_y,
                           struct city *pcity, int *width, int *height)
{
  if (gui_options.draw_full_citybar) {
    show_full_citybar(pcanvas, canvas_x, canvas_y, pcity, width, height);
  } else {
    show_small_citybar(pcanvas, canvas_x, canvas_y, pcity, width, height);
  }
}
 
/************************************************************************/
static void show_tile_label(struct canvas *pcanvas,
                            int canvas_x, int canvas_y,
                            struct tile *ptile, int *width, int *height)
{
  const enum client_font FONT_TILE_LABEL = FONT_CITY_NAME; /* TODO: new font */
#define COLOR_MAPVIEW_TILELABEL COLOR_MAPVIEW_CITYTEXT
 
  canvas_x += tileset_tile_width(tileset) / 2 * map_zoom;
  canvas_y += tileset_tilelabel_offset_y(tileset) * map_zoom;
 
  get_text_size(width, height, FONT_TILE_LABEL, ptile->label);
 
  canvas_put_text(pcanvas, (canvas_x - * width / 2) / map_zoom, canvas_y / map_zoom,
                  FONT_TILE_LABEL,
                  get_color(tileset, COLOR_MAPVIEW_TILELABEL), ptile->label);
#undef COLOR_MAPVIEW_TILELABEL
}
 
/************************************************************************/
void show_city_descriptions(int canvas_base_x, int canvas_base_y,
                            int width_base, int height_base)
{
  const int dx = max_desc_width - tileset_tile_width(tileset) * map_zoom;
  const int dy = max_desc_height;
  const int offset_y = tileset_citybar_offset_y(tileset) * map_zoom;
  int new_max_width = max_desc_width, new_max_height = max_desc_height;
 
  if (gui_options.draw_full_citybar && !(gui_options.draw_city_names
                                         || gui_options.draw_city_productions
                                         || gui_options.draw_city_growth)) {
    return;
  }
 
  if (!gui_options.draw_full_citybar && !(gui_options.draw_city_names
                                          || gui_options.draw_city_productions)) {
    return;
  }
 
  /* A city description is shown below the city. It has a specified
   * maximum width and height (although these are only estimates). Thus
   * we need to update some tiles above the mapview and some to the left
   * and right.
   *
   *                    /--W1--\   (W1 = tileset_tile_width(tileset))
   *                    -------- \
   *                    | CITY | H1 (H1 = tileset_tile_height(tileset))
   *                    |      | /
   *               ------------------ \
   *               |  DESCRIPTION   | H2  (H2 = MAX_CITY_DESC_HEIGHT)
   *               |                | /
   *               ------------------
   *               \-------W2-------/    (W2 = MAX_CITY_DESC_WIDTH)
   *
   * We must draw H2 extra pixels above and (W2 - W1) / 2 extra pixels
   * to each side of the mapview.
   */
  gui_rect_iterate_coord(mapview.gui_x0 + canvas_base_x - dx / 2,
                         mapview.gui_y0 + canvas_base_y - dy,
                         width_base + dx, height_base + dy - offset_y,
                         ptile, pedge, pcorner, gui_x, gui_y, map_zoom) {
    const int canvas_x = gui_x - mapview.gui_x0;
    const int canvas_y = gui_y - mapview.gui_y0;
 
    if (ptile && tile_city(ptile)) {
      int width = 0, height = 0;
      struct city *pcity = tile_city(ptile);
 
      show_city_desc(mapview.store, canvas_x, canvas_y,
                     pcity, &width, &height);
      log_debug("Drawing %s.", city_name_get(pcity));
 
      if (width > max_desc_width || height > max_desc_height) {
        /* The update was incomplete! We queue a new update. Note that
         * this is recursively queueing an update within a dequeuing of an
         * update. This is allowed specifically because of the code in
         * unqueue_mapview_updates. See that function for more. */
        log_debug("Re-queuing %s.", city_name_get(pcity));
        update_city_description(pcity);
      }
      new_max_width = MAX(width, new_max_width);
      new_max_height = MAX(height, new_max_height);
    }
  } gui_rect_iterate_coord_end;
 
  /* We don't update the new max values until the end, so that the
   * check above to see what cities need redrawing will be complete. */
  max_desc_width = MAX(max_desc_width, new_max_width);
  max_desc_height = MAX(max_desc_height, new_max_height);
}
 
/************************************************************************/
void show_tile_labels(int canvas_base_x, int canvas_base_y,
                      int width_base, int height_base)
{
  const int dx = max_label_width - tileset_tile_width(tileset) * map_zoom;
  const int dy = max_label_height;
  int new_max_width = max_label_width, new_max_height = max_label_height;
 
  gui_rect_iterate_coord(mapview.gui_x0 + canvas_base_x - dx / 2,
                         mapview.gui_y0 + canvas_base_y - dy,
                         width_base + dx, height_base + dy,
                         ptile, pedge, pcorner, gui_x, gui_y, map_zoom) {
    const int canvas_x = gui_x - mapview.gui_x0;
    const int canvas_y = gui_y - mapview.gui_y0;
 
    if (ptile && ptile->label != nullptr) {
      int width = 0, height = 0;
 
      show_tile_label(mapview.store, canvas_x, canvas_y,
                      ptile, &width, &height);
      log_debug("Drawing label %s.", ptile->label);
 
      if (width > max_label_width || height > max_label_height) {
        /* The update was incomplete! We queue a new update. Note that
         * this is recursively queueing an update within a dequeuing of an
         * update. This is allowed specifically because of the code in
         * unqueue_mapview_updates(). See that function for more. */
        log_debug("Re-queuing tile label %s drawing.", ptile->label);
        update_tile_label(ptile);
      }
      new_max_width = MAX(width, new_max_width);
      new_max_height = MAX(height, new_max_height);
    }
  } gui_rect_iterate_coord_end;
 
  /* We don't update the new max values until the end, so that the
   * check above to see what cities need redrawing will be complete. */
  max_label_width = MAX(max_label_width, new_max_width);
  max_label_height = MAX(max_label_height, new_max_height);
}
 
/************************************************************************/
void draw_segment(struct tile *src_tile, enum direction8 dir)
{
  float canvas_x, canvas_y, canvas_dx, canvas_dy;
 
  /* Determine the source position of the segment. */
  (void) tile_to_canvas_pos(&canvas_x, &canvas_y, map_zoom, src_tile);
  canvas_x += tileset_tile_width(tileset) / 2 * map_zoom;
  canvas_y += tileset_tile_height(tileset) / 2 * map_zoom;
 
  /* Determine the vector of the segment. */
  map_to_gui_vector(tileset, map_zoom, &canvas_dx, &canvas_dy,
                    DIR_DX[dir], DIR_DY[dir]);
 
  /* Draw the segment. */
  /* XXX: canvas_put_line doesn't currently take map_zoom into account
   * itself, but it probably should? If so this will need adjusting */
  canvas_put_line(mapview.store,
                  get_color(tileset, COLOR_MAPVIEW_GOTO), LINE_GOTO,
                  canvas_x, canvas_y, canvas_dx, canvas_dy);
 
  /* The actual area drawn will extend beyond the base rectangle, since
   * the goto lines have width. */
  dirty_rect(MIN(canvas_x, canvas_x + canvas_dx) - GOTO_WIDTH,
             MIN(canvas_y, canvas_y + canvas_dy) - GOTO_WIDTH,
             ABS(canvas_dx) + 2 * GOTO_WIDTH,
             ABS(canvas_dy) + 2 * GOTO_WIDTH);
 
  /* It is possible that the mapview wraps between the source and dest
   * tiles. In this case they will not be next to each other; they'll be
   * on the opposite sides of the screen. If this happens then the dest
   * tile will not be updated. This is consistent with the mapview design
   * which fails when the size of the mapview approaches that of the map. */
}
 
/************************************************************************/
void decrease_unit_hp_smooth(struct unit *punit0, int hp0,
                             struct unit *punit1, int hp1)
{
  struct unit *losing_unit = (hp0 == 0 ? punit0 : punit1);
  float canvas_x, canvas_y;
  int i;
 
  set_units_in_combat(punit0, punit1);
 
  /* Make sure we don't start out with fewer HP than we're supposed to
   * end up with (which would cause the following loop to break). */
  punit0->hp = MAX(punit0->hp, hp0);
  punit1->hp = MAX(punit1->hp, hp1);
 
  unqueue_mapview_updates(TRUE);
 
  if (frame_by_frame_animation) {
    struct animation *anim = fc_malloc(sizeof(struct animation));
    struct unit *winning_unit;
    int winner_end_hp;
    int loser_end_hp;
    int aw = tileset_tile_width(tileset) * map_zoom;
    int ah = tileset_tile_height(tileset) * map_zoom;
 
    if (losing_unit == punit1) {
      winning_unit = punit0;
      winner_end_hp = hp0;
      loser_end_hp = hp1;
    } else {
      winning_unit = punit1;
      winner_end_hp = hp1;
      loser_end_hp = hp0;
    }
 
    anim->type = ANIM_BATTLE;
    anim->id = -1;
    anim->battle.virt_loser
      = unit_virtual_create(unit_owner(losing_unit),
                            nullptr, unit_type_get(losing_unit),
                            losing_unit->veteran);
    anim->battle.loser_tile = unit_tile(losing_unit);
    anim->battle.virt_loser->facing = losing_unit->facing;
    anim->battle.loser_hp_start = losing_unit->hp;
    anim->battle.loser_hp_end = loser_end_hp;
    anim->battle.virt_winner
      = unit_virtual_create(unit_owner(winning_unit),
                            nullptr, unit_type_get(winning_unit),
                            winning_unit->veteran);
    anim->battle.winner_tile = unit_tile(winning_unit);
    anim->battle.virt_winner->facing = winning_unit->facing;
    anim->battle.winner_hp_start = MAX(winning_unit->hp, winner_end_hp);
    anim->battle.winner_hp_end = winner_end_hp;
    anim->battle.steps = MAX(losing_unit->hp,
                             anim->battle.winner_hp_start - winner_end_hp);
    anim->width = aw;
    anim->height = ah;
    animation_add(anim);
 
    if (loser_end_hp <= 0) {
      anim = fc_malloc(sizeof(struct animation));
      anim->type = ANIM_EXPL;
      anim->id = winning_unit->id;
      anim->expl.tile = losing_unit->tile;
      anim->expl.sprites = get_unit_explode_animation(tileset);
      anim->expl.sprite_count = sprite_vector_size(anim->expl.sprites);
      anim->width = aw;
      anim->height = ah;
      animation_add(anim);
    }
  } else {
    const struct sprite_vector *anim = get_unit_explode_animation(tileset);
    const int num_tiles_explode_unit = sprite_vector_size(anim);
 
    while (punit0->hp > hp0 || punit1->hp > hp1) {
      const int diff0 = punit0->hp - hp0, diff1 = punit1->hp - hp1;
 
      anim_timer_renew();
 
      if (fc_rand(diff0 + diff1) < diff0) {
        punit0->hp--;
        refresh_unit_mapcanvas(punit0, unit_tile(punit0), FALSE, FALSE);
      } else {
        punit1->hp--;
        refresh_unit_mapcanvas(punit1, unit_tile(punit1), FALSE, FALSE);
      }
 
      unqueue_mapview_updates(TRUE);
      gui_flush();
 
      timer_usleep_since_start(anim_timer,
                               gui_options.smooth_combat_step_msec * 1000ul);
    }
 
    if (num_tiles_explode_unit > 0
        && tile_to_canvas_pos(&canvas_x, &canvas_y, map_zoom,
                              unit_tile(losing_unit))) {
      refresh_unit_mapcanvas(losing_unit, unit_tile(losing_unit), FALSE, FALSE);
      unqueue_mapview_updates(FALSE);
      canvas_copy(mapview.tmp_store, mapview.store,
                  canvas_x, canvas_y, canvas_x, canvas_y,
                  tileset_tile_width(tileset) * map_zoom,
                  tileset_tile_height(tileset) * map_zoom);
 
      for (i = 0; i < num_tiles_explode_unit; i++) {
        int w, h;
        struct sprite *sprite = *sprite_vector_get(anim, i);
 
        get_sprite_dimensions(sprite, &w, &h);
        anim_timer_renew();
 
        /* We first draw the explosion onto the unit and draw draw the
         * complete thing onto the map canvas window. This avoids
         * flickering. */
        canvas_copy(mapview.store, mapview.tmp_store,
                    canvas_x, canvas_y, canvas_x, canvas_y,
                    tileset_tile_width(tileset) * map_zoom,
                    tileset_tile_height(tileset) * map_zoom);
        canvas_put_sprite_full(mapview.store,
                               canvas_x + tileset_tile_width(tileset) / 2 * map_zoom
                               - w / 2,
                               canvas_y + tileset_tile_height(tileset) / 2 * map_zoom
                               - h / 2,
                               sprite);
        dirty_rect(canvas_x, canvas_y, tileset_tile_width(tileset) * map_zoom,
                   tileset_tile_height(tileset) * map_zoom);
 
        flush_dirty();
        gui_flush();
 
        timer_usleep_since_start(anim_timer,
                                 gui_options.smooth_combat_step_msec * 2 * 1000ul);
      }
    }
  }
 
  set_units_in_combat(nullptr, nullptr);
  refresh_unit_mapcanvas(punit0, unit_tile(punit0), TRUE, FALSE);
  refresh_unit_mapcanvas(punit1, unit_tile(punit1), TRUE, FALSE);
}
 
/************************************************************************/
void move_unit_map_canvas(struct unit *punit,
                          struct tile *src_tile, int dx, int dy)
{
  struct tile *dest_tile;
  int dest_x, dest_y, src_x, src_y;
  int prev_x = -1;
  int prev_y = -1;
  int tuw;
  int tuh;
 
  /* Only works for adjacent-square moves */
  if (dx < -1 || dx > 1 || dy < -1 || dy > 1 || (dx == 0 && dy == 0)) {
    return;
  }
 
  index_to_map_pos(&src_x, &src_y, tile_index(src_tile));
  dest_x = src_x + dx;
  dest_y = src_y + dy;
  dest_tile = map_pos_to_tile(&(wld.map), dest_x, dest_y);
  if (!dest_tile) {
    return;
  }
 
  if (tile_visible_mapcanvas(src_tile)
      || tile_visible_mapcanvas(dest_tile)) {
    float start_x, start_y;
    float canvas_dx, canvas_dy;
    double timing_sec = (double)gui_options.smooth_move_unit_msec / 1000.0;
    double mytime;
 
    fc_assert(gui_options.smooth_move_unit_msec > 0);
 
    map_to_gui_vector(tileset, map_zoom, &canvas_dx, &canvas_dy, dx, dy);
 
    tile_to_canvas_pos(&start_x, &start_y, map_zoom, src_tile);
    if (tileset_is_isometric(tileset) && tileset_hex_height(tileset) == 0) {
      start_y -= tileset_tile_height(tileset) / 2 * map_zoom;
      start_y -= (tileset_unit_height(tileset) - tileset_full_tile_height(tileset)) * map_zoom;
    }
 
    /* Bring the backing store up to date, but don't flush. */
    unqueue_mapview_updates(FALSE);
 
    tuw = tileset_unit_width(tileset) * map_zoom;
    tuh = tileset_unit_height(tileset) * map_zoom;
 
    if (frame_by_frame_animation) {
      struct animation *anim = fc_malloc(sizeof(struct animation));
 
      anim->type = ANIM_MOVEMENT;
      anim->id = punit->id;
      anim->movement.mover
        = unit_virtual_create(unit_owner(punit), nullptr,
                              unit_type_get(punit), punit->veteran);
      anim->movement.mover->hp = punit->hp;
      anim->movement.mover->facing = punit->facing;
      anim->movement.src = src_tile;
      anim->movement.dest = dest_tile;
      anim->movement.canvas_dx = canvas_dx;
      anim->movement.canvas_dy = canvas_dy;
      anim->width = tuw;
      anim->height = tuh;
      animation_add(anim);
    } else {
 
      /* Start the timer (AFTER the unqueue above). */
      anim_timer_renew();
 
      do {
        int new_x, new_y;
        double asecs = timer_read_seconds(anim_timer);
 
        mytime = MIN(asecs, timing_sec);
 
        new_x = start_x + canvas_dx * (mytime / timing_sec);
        new_y = start_y + canvas_dy * (mytime / timing_sec);
 
        if (new_x != prev_x || new_y != prev_y) {
          /* Backup the canvas store to the temp store. */
          canvas_copy(mapview.tmp_store, mapview.store,
                      new_x, new_y, new_x, new_y,
                      tuw, tuh);
 
          /* Draw */
          put_unit(punit, mapview.store, map_zoom, new_x, new_y);
          dirty_rect(new_x, new_y, tuw, tuh);
 
          /* Flush. */
          flush_dirty();
          gui_flush();
 
          /* Restore the backup. It won't take effect until the next flush. */
          canvas_copy(mapview.store, mapview.tmp_store,
                      new_x, new_y, new_x, new_y,
                      tuw, tuh);
          dirty_rect(new_x, new_y, tuw, tuh);
 
          prev_x = new_x;
          prev_y = new_y;
        } else {
          fc_usleep(500);
        }
      } while (mytime < timing_sec);
    }
  }
}
 
/************************************************************************/
struct city *find_city_or_settler_near_tile(const struct tile *ptile,
                                            struct unit **punit)
{
  struct city *closest_city;
  struct city *pcity;
  struct unit *closest_settler = nullptr, *best_settler = nullptr;
  int max_rad = rs_max_city_radius_sq();
 
  if (punit) {
    *punit = nullptr;
  }
 
  /* Check if there is visible city working that tile */
  pcity = tile_worked(ptile);
  if (pcity && pcity->tile) {
    if (client.conn.playing == nullptr
        || city_owner(pcity) == client.conn.playing) {
      /* Rule a */
      return pcity;
    } else {
      /* Rule b */
      return nullptr;
    }
  }
 
  /* Rule e */
  closest_city = nullptr;
 
  /* Check within maximum (squared) city radius */
  city_tile_iterate(&(wld.map), max_rad, ptile, tile1) {
    pcity = tile_city(tile1);
    if (pcity
        && (client.conn.playing == nullptr
            || city_owner(pcity) == client.conn.playing)
        && client_city_can_work_tile(pcity, tile1)) {
      /*
       * Note, we must explicitly check if the tile is workable (with
       * city_can_work_tile() above), since it is possible that another
       * city (perhaps an UNSEEN city) may be working it!
       */
 
      if (mapdeco_is_highlight_set(city_tile(pcity))) {
        /* Rule c */
        return pcity;
      }
      if (!closest_city) {
        closest_city = pcity;
      }
    }
  } city_tile_iterate_end;
 
  /* Rule d */
  if (closest_city || !punit) {
    return closest_city;
  }
 
  if (!game.scenario.prevent_new_cities) {
    /* Check within maximum (squared) city radius */
    city_tile_iterate(&(wld.map), max_rad, ptile, tile1) {
      unit_list_iterate(tile1->units, psettler) {
        if ((client.conn.playing == nullptr
             || unit_owner(psettler) == client.conn.playing)
            && unit_can_do_action(psettler, ACTION_FOUND_CITY)
            && city_can_be_built_here(&(wld.map), unit_tile(psettler),
                                      psettler, FALSE)) {
          if (closest_settler == nullptr) {
            closest_settler = psettler;
          }
          if (best_settler == nullptr && psettler->client.colored) {
            best_settler = psettler;
          }
        }
      } unit_list_iterate_end;
    } city_tile_iterate_end;
 
    if (best_settler != nullptr) {
      /* Rule e */
      *punit = best_settler;
    } else if (closest_settler != nullptr) {
      /* Rule f */
      *punit = closest_settler;
    }
  }
 
  /* Rule g */
  return nullptr;
}
 
/************************************************************************/
struct city *find_city_near_tile(const struct tile *ptile)
{
  return find_city_or_settler_near_tile(ptile, nullptr);
}
 
/************************************************************************/
static void append_city_buycost_string(const struct city *pcity,
                                       char *buffer, int buffer_len)
{
  if (!pcity || !buffer || buffer_len < 1) {
    return;
  }
 
  if (!gui_options.draw_city_buycost || !city_can_buy(pcity)) {
    return;
  }
 
  cat_snprintf(buffer, buffer_len, "/%d", pcity->client.buy_cost);
}
 
/************************************************************************/
void get_city_mapview_production(struct city *pcity,
                                 char *buffer, size_t buffer_len)
{
  int turns;
 
  universal_name_translation(&pcity->production, buffer, buffer_len);
 
  if (city_production_is_genus(pcity, IG_CONVERT)) {
    return;
  }
  turns = city_production_turns_to_build(pcity, TRUE);
 
  if (999 < turns) {
    cat_snprintf(buffer, buffer_len, " -");
  } else {
    cat_snprintf(buffer, buffer_len, " %d", turns);
  }
 
  append_city_buycost_string(pcity, buffer, buffer_len);
}
 
/************************************************************************/
void get_city_mapview_trade_routes(struct city *pcity,
                                   char *trade_routes_buffer,
                                   size_t trade_routes_buffer_len,
                                   enum color_std *pcolor)
{
  int num_trade_routes;
  int max_routes;
 
  if (!trade_routes_buffer || trade_routes_buffer_len <= 0) {
    return;
  }
 
  if (!pcity) {
    trade_routes_buffer[0] = '\0';
    if (pcolor) {
      *pcolor = COLOR_MAPVIEW_CITYTEXT;
    }
    return;
  }
 
  num_trade_routes = trade_route_list_size(pcity->routes);
  max_routes = max_trade_routes(pcity);
 
  fc_snprintf(trade_routes_buffer, trade_routes_buffer_len,
              "%d/%d", num_trade_routes, max_routes);
 
  if (pcolor) {
    if (num_trade_routes == max_routes) {
      *pcolor = COLOR_MAPVIEW_TRADE_ROUTES_ALL_BUILT;
    } else if (num_trade_routes == 0) {
      *pcolor = COLOR_MAPVIEW_TRADE_ROUTES_NO_BUILT;
    } else {
      *pcolor = COLOR_MAPVIEW_TRADE_ROUTES_SOME_BUILT;
    }
  }
}
 
/***************************************************************************/
static enum update_type needed_updates = UPDATE_NONE;
static bool callback_queued = FALSE;
 
/* These values hold the tiles that need city, unit, or tile updates.
 * These different types of updates just tell what area need to be updated,
 * not necessarily what's sitting on the tile. A city update covers the
 * whole citymap area. A unit update covers just the "full" unit tile
 * area. A tile update covers the base tile plus half a tile in each
 * direction. */
struct tile_list *tile_updates[TILE_UPDATE_COUNT];
 
/************************************************************************/
static void queue_callback(void *data)
{
  callback_queued = FALSE;
  unqueue_mapview_updates(TRUE);
}
 
/************************************************************************/
static void queue_add_callback(void)
{
  if (!callback_queued) {
    callback_queued = TRUE;
    add_idle_callback(queue_callback, nullptr);
  }
}
 
/************************************************************************/
void queue_mapview_update(enum update_type update)
{
  if (can_client_change_view()) {
    needed_updates |= update;
    queue_add_callback();
  }
}
 
/************************************************************************/
void queue_mapview_tile_update(struct tile *ptile,
                               enum tile_update_type type)
{
  if (can_client_change_view()) {
    if (!tile_updates[type]) {
      tile_updates[type] = tile_list_new();
    }
    tile_list_append(tile_updates[type], ptile);
    queue_add_callback();
  }
}
 
/************************************************************************/
void unqueue_mapview_updates(bool write_to_screen)
{
  /* Calculate the area covered by each update type. The area array gives
   * the offset from the tile origin as well as the width and height of the
   * area to be updated. This is initialized each time when entering the
   * function from the existing tileset variables.
   *
   * A TILE update covers the base tile (W x H) plus a half-tile in each
   * direction (for edge/corner graphics), making its area 2W x 2H.
   *
   * A UNIT update covers a UW x UH area. This is centered horizontally
   * over the tile but extends up above the tile (e.g., units in iso-view).
   *
   * A CITYMAP update covers the whole citymap of a tile. This includes
   * the citymap area itself plus an extra half-tile in each direction (for
   * edge/corner graphics).
   */
  const float W = tileset_tile_width(tileset) * map_zoom;
  const float H = tileset_tile_height(tileset) * map_zoom;
  const float UW = tileset_unit_width(tileset) * map_zoom;
  const float UH = tileset_unit_height(tileset) * map_zoom;
  const float city_width = get_citydlg_canvas_width() * map_zoom + W;
  const float city_height = get_citydlg_canvas_height() * map_zoom + H;
  const struct {
    float dx, dy, w, h;
  } area[TILE_UPDATE_COUNT] = {
    {0, 0, W, H},
    {-W / 2, -H / 2, 2 * W, 2 * H},
    {(W - UW) / 2, H - UH, UW, UH},
    {-(max_desc_width - W) / 2, H, max_desc_width, max_desc_height},
    {-(city_width - W) / 2, -(city_height - H) / 2, city_width, city_height},
    {-(max_label_width - W) / 2, H, max_label_width, max_label_height}
  };
  struct tile_list *my_tile_updates[TILE_UPDATE_COUNT];
 
  int i;
 
  if (!can_client_change_view()) {
    /* Double sanity check: make sure we don't unqueue an invalid update
     * after we've already detached. */
    return;
  }
 
  log_debug("unqueue_mapview_update: needed_updates=%d",
            needed_updates);
 
  /* This code "pops" the lists of tile updates off of the static array and
   * stores them locally. This allows further updates to be queued within
   * the function itself (namely, within update_map_canvas() ). */
  for (i = 0; i < TILE_UPDATE_COUNT; i++) {
    my_tile_updates[i] = tile_updates[i];
    tile_updates[i] = nullptr;
  }
 
  if (!map_is_empty()) {
    if ((needed_updates & UPDATE_MAP_CANVAS_VISIBLE)
        || (needed_updates & UPDATE_CITY_DESCRIPTIONS)
        || (needed_updates & UPDATE_TILE_LABELS)) {
      dirty_all();
      update_map_canvas(0, 0, mapview.store_width,
                        mapview.store_height);
      /* Have to update the overview too, since some tiles may have changed. */
      refresh_overview_canvas();
    } else {
      int min_x = mapview.width, min_y = mapview.height;
      int max_x = 0, max_y = 0;
 
      for (i = 0; i < TILE_UPDATE_COUNT; i++) {
        if (my_tile_updates[i]) {
          tile_list_iterate(my_tile_updates[i], ptile) {
            float xl, yt;
            int xr, yb;
 
            (void) tile_to_canvas_pos(&xl, &yt, map_zoom, ptile);
 
            xl += area[i].dx;
            yt += area[i].dy;
            xr = xl + area[i].w;
            yb = yt + area[i].h;
 
            if (xr > 0 && xl < mapview.width
                && yb > 0 && yt < mapview.height) {
              min_x = MIN(min_x, xl);
              min_y = MIN(min_y, yt);
              max_x = MAX(max_x, xr);
              max_y = MAX(max_y, yb);
            }
 
            /* FIXME: These overview updates should be batched as well.
             * Right now they account for as much as 90% of the runtime of
             * the unqueue. */
            overview_update_tile(ptile);
          } tile_list_iterate_end;
        }
      }
 
      if (min_x < max_x && min_y < max_y) {
        update_map_canvas(min_x, min_y, max_x - min_x, max_y - min_y);
      }
    }
  }
 
  for (i = 0; i < TILE_UPDATE_COUNT; i++) {
    if (my_tile_updates[i]) {
      tile_list_destroy(my_tile_updates[i]);
    }
  }
  needed_updates = UPDATE_NONE;
 
  if (write_to_screen) {
    flush_dirty();
    flush_dirty_overview();
  }
}
 
/************************************************************************/
void get_city_mapview_name_and_growth(struct city *pcity,
                                      char *name_buffer,
                                      size_t name_buffer_len,
                                      char *growth_buffer,
                                      size_t growth_buffer_len,
                                      enum color_std *growth_color,
                                      enum color_std *production_color)
{
  fc_strlcpy(name_buffer, city_name_getx(pcity), name_buffer_len);
 
  *production_color = COLOR_MAPVIEW_CITYTEXT;
  if (client.conn.playing == nullptr
      || city_owner(pcity) == client.conn.playing) {
    int turns = city_turns_to_grow(pcity);
 
    if (turns == 0) {
      fc_snprintf(growth_buffer, growth_buffer_len, "X");
    } else if (turns == FC_INFINITY) {
      fc_snprintf(growth_buffer, growth_buffer_len, "-");
    } else {
      /* Negative turns means we're shrinking, but that's handled
         down below. */
      fc_snprintf(growth_buffer, growth_buffer_len, "%d", abs(turns));
    }
 
    if (turns <= 0) {
      /* A blocked or shrinking city has its growth status shown in red. */
      *growth_color = COLOR_MAPVIEW_CITYGROWTH_BLOCKED;
    } else {
      *growth_color = COLOR_MAPVIEW_CITYTEXT;
    }
 
    if (pcity->surplus[O_SHIELD] < 0) {
      *production_color = COLOR_MAPVIEW_CITYPROD_NEGATIVE;
    }
  } else {
    growth_buffer[0] = '\0';
    *growth_color = COLOR_MAPVIEW_CITYTEXT;
  }
}
 
/************************************************************************/
static bool can_do_cached_drawing(void)
{
  const int W = tileset_tile_width(tileset) * map_zoom;
  const int H = tileset_tile_height(tileset) * map_zoom;
  int w = mapview.store_width, h = mapview.store_height;
 
  /* If the mapview window is too large, cached drawing is not possible.
   *
   * BACKGROUND: cached drawing occurs when the mapview is scrolled just
   * a short distance. The majority of the mapview window can simply be
   * copied while the newly visible areas must be drawn from scratch. This
   * speeds up drawing significantly, especially when using the scrollbars
   * or mapview sliding.
   *
   * When the mapview is larger than the map, however, some tiles may become
   * visible twice. In this case one instance of the tile will be drawn
   * while all others are drawn black. When this happens the cached drawing
   * system breaks since it assumes the mapview canvas is an "ideal" window
   * over the map. So black tiles may be scrolled from the edges of the
   * mapview into the center, while drawn tiles may be scrolled from the
   * center of the mapview out to the edges. The result is very bad.
   *
   * There are a few different ways this could be solved. One way is simply
   * to turn off cached drawing, which is what we do now. If the mapview
   * window gets to be too large, the caching is disabled. Another would
   * be to prevent the window from getting too large in the first place -
   * but because the window boundaries aren't at an even tile this would
   * mean the entire map could never be shown. Yet another way would be
   * to draw tiles more than once if they are visible in multiple locations
   * on the mapview.
   *
   * The logic below is complicated and determined in part by
   * trial-and-error. */
  if (!current_wrap_has_flag(WRAP_X) && !current_wrap_has_flag(WRAP_Y)) {
    /* An unwrapping map: no limitation. On an unwrapping map no tile can
     * be visible twice so there's no problem. */
    return TRUE;
  }
  if (XOR(current_topo_has_flag(TF_ISO) || current_topo_has_flag(TF_HEX),
          tileset_is_isometric(tileset))) {
    /* Non-matching. In this case the mapview does not line up with the
     * map's axis of wrapping. This will give very bad results for the
     * player!
     * We can never show more than half of the map.
     *
     * We divide by 4 below because we have to divide by 2 twice. The
     * first division by 2 is because the square must be half the size
     * of the (width+height). The second division by two is because for
     * an iso-map, MAP_NATURAL_XXX has a scale of 2, whereas for iso-view
     * NORMAL_TILE_XXX has a scale of 2. */
    return (w <= (MAP_NATURAL_WIDTH + MAP_NATURAL_HEIGHT) * W / 4
            && h <= (MAP_NATURAL_WIDTH + MAP_NATURAL_HEIGHT) * H / 4);
  } else {
    /* Matching. */
    const int isofactor = (tileset_is_isometric(tileset) ? 2 : 1);
    const int isodiff = (tileset_is_isometric(tileset) ? 6 : 2);
 
    /* Now we can use the full width and height, with the exception of a small
     * area on each side. */
    if (current_wrap_has_flag(WRAP_X)
        && w > (MAP_NATURAL_WIDTH - isodiff) * W / isofactor) {
      return FALSE;
    }
    if (current_wrap_has_flag(WRAP_Y)
        && h > (MAP_NATURAL_HEIGHT - isodiff) * H / isofactor) {
      return FALSE;
    }
 
    return TRUE;
  }
}
 
/************************************************************************/
void mapdeco_init(void)
{
  /* HACK: this must be called on a map_info packet. */
  mapview.can_do_cached_drawing = can_do_cached_drawing();
 
  mapdeco_free();
  mapdeco_highlight_table = tile_hash_new();
  mapdeco_crosshair_table = tile_hash_new();
  mapdeco_gotoline_table = gotoline_hash_new();
}
 
/************************************************************************/
void mapdeco_free(void)
{
  if (mapdeco_highlight_table) {
    tile_hash_destroy(mapdeco_highlight_table);
    mapdeco_highlight_table = nullptr;
  }
  if (mapdeco_crosshair_table) {
    tile_hash_destroy(mapdeco_crosshair_table);
    mapdeco_crosshair_table = nullptr;
  }
  if (mapdeco_gotoline_table) {
    gotoline_hash_destroy(mapdeco_gotoline_table);
    mapdeco_gotoline_table = nullptr;
  }
}
 
/************************************************************************/
void mapdeco_set_highlight(const struct tile *ptile, bool highlight)
{
  bool changed = FALSE;
 
  if (!ptile || !mapdeco_highlight_table) {
    return;
  }
 
  if (highlight) {
    changed = tile_hash_insert(mapdeco_highlight_table, ptile, nullptr);
  } else {
    changed = tile_hash_remove(mapdeco_highlight_table, ptile);
  }
 
  if (changed) {
    /* FIXME: Remove the cast. */
    refresh_tile_mapcanvas((struct tile *) ptile, TRUE, FALSE);
  }
}
 
/************************************************************************/
bool mapdeco_is_highlight_set(const struct tile *ptile)
{
  if (!ptile || !mapdeco_highlight_table) {
    return FALSE;
  }
 
  return tile_hash_lookup(mapdeco_highlight_table, ptile, nullptr);
}
 
/************************************************************************/
void mapdeco_clear_highlights(void)
{
  if (!mapdeco_highlight_table) {
    return;
  }
 
  tile_hash_iterate(mapdeco_highlight_table, ptile) {
    refresh_tile_mapcanvas(ptile, TRUE, FALSE);
  } tile_hash_iterate_end;
 
  tile_hash_clear(mapdeco_highlight_table);
}
 
/************************************************************************/
void mapdeco_set_crosshair(const struct tile *ptile, bool crosshair)
{
  bool changed;
 
  if (!mapdeco_crosshair_table || !ptile) {
    return;
  }
 
  if (crosshair) {
    changed = tile_hash_insert(mapdeco_crosshair_table, ptile, nullptr);
  } else {
    changed = tile_hash_remove(mapdeco_crosshair_table, ptile);
  }
 
  if (changed) {
    /* FIXME: Remove the cast. */
    refresh_tile_mapcanvas((struct tile *) ptile, FALSE, FALSE);
  }
}
 
/************************************************************************/
bool mapdeco_is_crosshair_set(const struct tile *ptile)
{
  if (!mapdeco_crosshair_table || !ptile) {
    return FALSE;
  }
 
  return tile_hash_lookup(mapdeco_crosshair_table, ptile, nullptr);
}
 
/************************************************************************/
void mapdeco_clear_crosshairs(void)
{
  if (!mapdeco_crosshair_table) {
    return;
  }
 
  tile_hash_iterate(mapdeco_crosshair_table, ptile) {
    refresh_tile_mapcanvas(ptile, FALSE, FALSE);
  } tile_hash_iterate_end;
 
  tile_hash_clear(mapdeco_crosshair_table);
}
 
/************************************************************************/
void mapdeco_add_gotoline(const struct tile *ptile, enum direction8 dir)
{
  struct gotoline_counter *pglc;
  const struct tile *ptile_dest;
  bool changed;
 
  if (!mapdeco_gotoline_table || !ptile
      || !(dir <= direction8_max())) {
    return;
  }
  ptile_dest = mapstep(&(wld.map), ptile, dir);
  if (!ptile_dest) {
    return;
  }
 
  if (!gotoline_hash_lookup(mapdeco_gotoline_table, ptile, &pglc)) {
    pglc = gotoline_counter_new();
    gotoline_hash_insert(mapdeco_gotoline_table, ptile, pglc);
  }
  changed = (pglc->line_count[dir] < 1);
  pglc->line_count[dir]++;
 
  if (changed) {
    /* FIXME: Remove cast. */
    refresh_tile_mapcanvas((struct tile *) ptile, FALSE, FALSE);
    refresh_tile_mapcanvas((struct tile *) ptile_dest, FALSE, FALSE);
  }
}
 
/************************************************************************/
void mapdeco_remove_gotoline(const struct tile *ptile,
                             enum direction8 dir)
{
  struct gotoline_counter *pglc;
  bool changed = FALSE;
 
  if (!mapdeco_gotoline_table || !ptile
      || !(dir <= direction8_max())) {
    return;
  }
 
  if (!gotoline_hash_lookup(mapdeco_gotoline_table, ptile, &pglc)) {
    return;
  }
 
  pglc->line_count[dir]--;
  if (pglc->line_count[dir] <= 0) {
    pglc->line_count[dir] = 0;
    changed = TRUE;
  }
 
  if (changed) {
    /* FIXME: Remove the casts. */
    refresh_tile_mapcanvas((struct tile *) ptile, FALSE, FALSE);
    ptile = mapstep(&(wld.map), ptile, dir);
    if (ptile != nullptr) {
      refresh_tile_mapcanvas((struct tile *) ptile, FALSE, FALSE);
    }
  }
}
 
/************************************************************************/
void mapdeco_set_gotoroute(const struct unit *punit)
{
  const struct unit_order *porder;
  const struct tile *ptile;
  int i, ind;
 
  if (!punit || !unit_tile(punit) || !unit_has_orders(punit)
      || punit->orders.length < 1) {
    return;
  }
 
  ptile = unit_tile(punit);
 
  for (i = 0; ptile != nullptr && i < punit->orders.length; i++) {
    if (punit->orders.index + i >= punit->orders.length
        && !punit->orders.repeat) {
      break;
    }
 
    ind = (punit->orders.index + i) % punit->orders.length;
    porder = &punit->orders.list[ind];
    if (porder->order != ORDER_MOVE) {
      /* FIXME: Should display some indication of non-move orders here. */
      continue;
    }
 
    mapdeco_add_gotoline(ptile, porder->dir);
    ptile = mapstep(&(wld.map), ptile, porder->dir);
  }
}
 
/************************************************************************/
bool mapdeco_is_gotoline_set(const struct tile *ptile,
                             enum direction8 dir)
{
  struct gotoline_counter *pglc;
 
  if (!ptile || !(dir <= direction8_max())
      || !mapdeco_gotoline_table) {
    return FALSE;
  }
 
  if (!gotoline_hash_lookup(mapdeco_gotoline_table, ptile, &pglc)) {
    return FALSE;
  }
 
  return pglc->line_count[dir] > 0;
}
 
/************************************************************************/
void mapdeco_clear_gotoroutes(void)
{
  if (!mapdeco_gotoline_table) {
    return;
  }
 
  gotoline_hash_iterate(mapdeco_gotoline_table, ptile, pglc) {
    refresh_tile_mapcanvas(ptile, FALSE, FALSE);
    adjc_dir_iterate(&(wld.map), ptile, ptile_dest, dir) {
      if (pglc->line_count[dir] > 0) {
        refresh_tile_mapcanvas(ptile_dest, FALSE, FALSE);
      }
    } adjc_dir_iterate_end;
  } gotoline_hash_iterate_end;
  gotoline_hash_clear(mapdeco_gotoline_table);
}
 
/************************************************************************/
bool map_canvas_resized(int width, int height)
{
  int old_tile_width = mapview.tile_width;
  int old_tile_height = mapview.tile_height;
  int old_width = mapview.width, old_height = mapview.height;
  int tile_width = (width + tileset_tile_width(tileset) * map_zoom - 1) /
    (tileset_tile_width(tileset) * map_zoom);
  int tile_height = (height + tileset_tile_height(tileset) * map_zoom - 1) /
    (tileset_tile_height(tileset) * map_zoom);
  int full_width = tile_width * tileset_tile_width(tileset) * map_zoom;
  int full_height = tile_height * tileset_tile_height(tileset) * map_zoom;
  bool tile_size_changed, size_changed, redrawn = FALSE;
 
  /* Resized */
 
  /* Since a resize is only triggered when the tile_*** changes, the canvas
   * width and height must include the entire backing store - otherwise
   * small resizings may lead to undrawn tiles. */
  mapview.tile_width = tile_width;
  mapview.tile_height = tile_height;
  mapview.width = width;
  mapview.height = height;
  mapview.store_width = full_width;
  mapview.store_height = full_height;
 
  /* Check for what's changed. */
  tile_size_changed = (tile_width != old_tile_width
                       || tile_height != old_tile_height);
  size_changed = (width != old_width || height != old_height);
 
  /* If the tile size has changed, resize the canvas. */
  if (tile_size_changed) {
    if (mapview.store) {
      canvas_free(mapview.store);
      canvas_free(mapview.tmp_store);
    }
    mapview.store = canvas_create(full_width, full_height);
    canvas_set_zoom(mapview.store, map_zoom);
    canvas_mapview_init(mapview.store);
    canvas_put_rectangle(mapview.store,
                         get_color(tileset, COLOR_MAPVIEW_UNKNOWN),
                         0, 0, full_width / mouse_zoom, full_height / mouse_zoom);
 
    mapview.tmp_store = canvas_create(full_width, full_height);
    canvas_set_zoom(mapview.tmp_store, map_zoom);
    canvas_mapview_init(mapview.tmp_store);
  }
 
  if (!map_is_empty() && can_client_change_view()) {
    if (tile_size_changed) {
      if (center_tile != nullptr) {
        int x_left, y_top;
        float gui_x, gui_y;
 
        index_to_map_pos(&x_left, &y_top, tile_index(center_tile));
        map_to_gui_pos(tileset, map_zoom, &gui_x, &gui_y, x_left, y_top);
 
        /* Put the center pixel of the tile at the exact center of the mapview. */
        gui_x -= (mapview.width - tileset_tile_width(tileset) * map_zoom) / 2;
        gui_y -= (mapview.height - tileset_tile_height(tileset) * map_zoom) / 2;
 
        calc_mapview_origin(&gui_x, &gui_y, map_zoom);
        mapview.gui_x0 = gui_x;
        mapview.gui_y0 = gui_y;
      }
      update_map_canvas_visible();
      center_tile_overviewcanvas();
 
      /* Do not draw to the screen here as that could cause problems
       * when we are only initially setting up the view and some widgets
       * are not yet ready. */
      unqueue_mapview_updates(FALSE);
      redrawn = TRUE;
    }
 
    /* If the width/height has changed, update the scrollbars even if
     * the backing store is not resized. */
    if (size_changed) {
      update_map_canvas_scrollbars_size();
      update_map_canvas_scrollbars();
    }
  }
 
  mapview.can_do_cached_drawing = can_do_cached_drawing();
 
  return redrawn;
}
 
/************************************************************************/
void init_mapcanvas_and_overview(void)
{
  /* Create a dummy map to make sure mapview.store is never nullptr. */
  map_canvas_resized(1, 1);
}
 
/************************************************************************/
void free_mapcanvas_and_overview(void)
{
  canvas_free(mapview.store);
  canvas_free(mapview.tmp_store);
}
 
/************************************************************************/
void get_spaceship_dimensions(int *width, int *height)
{
  struct sprite *sprite
    = get_spaceship_sprite(tileset, SPACESHIP_HABITATION);
 
  get_sprite_dimensions(sprite, width, height);
  *width *= 7;
  *height *= 7;
}
 
/************************************************************************/
void put_spaceship(struct canvas *pcanvas, int canvas_x, int canvas_y,
                   const struct player *pplayer)
{
  int i, x, y;
  const struct player_spaceship *ship = &pplayer->spaceship;
  int w, h;
  struct sprite *spr;
  struct tileset *t = tileset;
 
  spr = get_spaceship_sprite(t, SPACESHIP_HABITATION);
  get_sprite_dimensions(spr, &w, &h);
 
  canvas_put_rectangle(pcanvas,
                       get_color(tileset, COLOR_SPACESHIP_BACKGROUND),
                       0, 0, w * 7, h * 7);
 
  for (i = 0; i < NUM_SS_MODULES; i++) {
    const int j = i / 3;
    const int k = i % 3;
 
    if ((k == 0 && j >= ship->habitation)
        || (k == 1 && j >= ship->life_support)
        || (k == 2 && j >= ship->solar_panels)) {
      continue;
    }
    x = modules_info[i].x * w / 4 - w / 2;
    y = modules_info[i].y * h / 4 - h / 2;
 
    spr = (k == 0 ? get_spaceship_sprite(t, SPACESHIP_HABITATION)
           : k == 1 ? get_spaceship_sprite(t, SPACESHIP_LIFE_SUPPORT)
           : get_spaceship_sprite(t, SPACESHIP_SOLAR_PANEL));
    canvas_put_sprite_full(pcanvas, x, y, spr);
  }
 
  for (i = 0; i < NUM_SS_COMPONENTS; i++) {
    const int j = i / 2;
    const int k = i % 2;
 
    if ((k == 0 && j >= ship->fuel)
        || (k == 1 && j >= ship->propulsion)) {
      continue;
    }
    x = components_info[i].x * w / 4 - w / 2;
    y = components_info[i].y * h / 4 - h / 2;
 
    spr = ((k == 0) ? get_spaceship_sprite(t, SPACESHIP_FUEL)
           : get_spaceship_sprite(t, SPACESHIP_PROPULSION));
 
    canvas_put_sprite_full(pcanvas, x, y, spr);
 
    if (k && ship->state == SSHIP_LAUNCHED) {
      spr = get_spaceship_sprite(t, SPACESHIP_EXHAUST);
      canvas_put_sprite_full(pcanvas, x + w, y, spr);
    }
  }
 
  for (i = 0; i < NUM_SS_STRUCTURALS; i++) {
    if (!BV_ISSET(ship->structure, i)) {
      continue;
    }
    x = structurals_info[i].x * w / 4 - w / 2;
    y = structurals_info[i].y * h / 4 - h / 2;
 
    spr = get_spaceship_sprite(t, SPACESHIP_STRUCTURAL);
    canvas_put_sprite_full(pcanvas, x, y, spr);
  }
}
 
/****************************************************************************
  Map link mark module: it makes link marks when a link is sent by chating,
  or restore a mark with clicking a link on the chatline.
****************************************************************************/
struct link_mark {
  enum text_link_type type;     /* The target type. */
  int id;                       /* The city or unit id, or tile index. */
  int turn_counter;             /* The turn counter before it disappears. */
};
 
#define SPECLIST_TAG link_mark
#define SPECLIST_TYPE struct link_mark
#include "speclist.h"
#define link_marks_iterate(pmark) \
  TYPED_LIST_ITERATE(struct link_mark, link_marks, pmark)
#define link_marks_iterate_end LIST_ITERATE_END
 
static struct link_mark_list *link_marks = nullptr;
 
/************************************************************************/
static struct link_mark *link_mark_find(enum text_link_type type, int id)
{
  link_marks_iterate(pmark) {
    if (pmark->type == type && pmark->id == id) {
      return pmark;
    }
  } link_marks_iterate_end;
 
  return nullptr;
}
 
/************************************************************************/
static struct link_mark *link_mark_new(enum text_link_type type,
                                       int id, int turns)
{
  struct link_mark *pmark = fc_malloc(sizeof(struct link_mark));
 
  pmark->type = type;
  pmark->id = id;
  pmark->turn_counter = turns;
 
  return pmark;
}
 
/************************************************************************/
static void link_mark_destroy(struct link_mark *pmark)
{
  free(pmark);
}
 
/************************************************************************/
static struct tile *link_mark_tile(const struct link_mark *pmark)
{
  switch (pmark->type) {
  case TLT_CITY:
    {
      struct city *pcity = game_city_by_number(pmark->id);
 
      return pcity ? pcity->tile : nullptr;
    }
  case TLT_TILE:
    return index_to_tile(&(wld.map), pmark->id);
  case TLT_UNIT:
    {
      struct unit *punit = game_unit_by_number(pmark->id);
 
      return punit ? unit_tile(punit) : nullptr;
    }
  }
 
  return nullptr;
}
 
/************************************************************************/
static struct color *link_mark_color(const struct link_mark *pmark)
{
  switch (pmark->type) {
  case TLT_CITY:
    return get_color(tileset, COLOR_MAPVIEW_CITY_LINK);
  case TLT_TILE:
    return get_color(tileset, COLOR_MAPVIEW_TILE_LINK);
  case TLT_UNIT:
    return get_color(tileset, COLOR_MAPVIEW_UNIT_LINK);
  }
 
  return nullptr;
}
 
/************************************************************************/
static void link_mark_draw(const struct link_mark *pmark)
{
  int width = tileset_tile_width(tileset) * map_zoom;
  int height = tileset_tile_height(tileset) * map_zoom;
  int xd = width / 20, yd = height / 20;
  int xlen = width / 3, ylen = height / 3;
  float canvas_x, canvas_y;
  int x_left, x_right, y_top, y_bottom;
  struct tile *ptile = link_mark_tile(pmark);
  struct color *pcolor = link_mark_color(pmark);
 
  if (!ptile || !tile_to_canvas_pos(&canvas_x, &canvas_y, map_zoom, ptile)) {
    return;
  }
 
  x_left = canvas_x + xd;
  x_right = canvas_x + width - xd;
  y_top = canvas_y + yd;
  y_bottom = canvas_y + height - yd;
 
  /* XXX: canvas_put_line() doesn't currently take map_zoom into account
   * itself, but it probably should? If so these will need adjusting */
  canvas_put_line(mapview.store, pcolor, LINE_TILE_FRAME, x_left, y_top,
                  xlen, 0);
  canvas_put_line(mapview.store, pcolor, LINE_TILE_FRAME, x_left, y_top,
                  0, ylen);
 
  canvas_put_line(mapview.store, pcolor, LINE_TILE_FRAME, x_right, y_top,
                  -xlen, 0);
  canvas_put_line(mapview.store, pcolor, LINE_TILE_FRAME, x_right, y_top,
                  0, ylen);
 
  canvas_put_line(mapview.store, pcolor, LINE_TILE_FRAME, x_left, y_bottom,
                  xlen, 0);
  canvas_put_line(mapview.store, pcolor, LINE_TILE_FRAME, x_left, y_bottom,
                  0, -ylen);
 
  canvas_put_line(mapview.store, pcolor, LINE_TILE_FRAME, x_right, y_bottom,
                  -xlen, 0);
  canvas_put_line(mapview.store, pcolor, LINE_TILE_FRAME, x_right, y_bottom,
                  0, -ylen);
}
 
/************************************************************************/
void link_marks_init(void)
{
  if (link_marks) {
    link_marks_free();
  }
 
  link_marks = link_mark_list_new_full(link_mark_destroy);
}
 
/************************************************************************/
void link_marks_free(void)
{
  if (!link_marks) {
    return;
  }
 
  link_mark_list_destroy(link_marks);
  link_marks = nullptr;
}
 
/************************************************************************/
void link_marks_draw_all(void)
{
  link_marks_iterate(pmark) {
    link_mark_draw(pmark);
  } link_marks_iterate_end;
}
 
/************************************************************************/
void link_marks_clear_all(void)
{
  link_mark_list_clear(link_marks);
  update_map_canvas_visible();
}
 
/************************************************************************/
void link_marks_decrease_turn_counters(void)
{
  link_marks_iterate(pmark) {
    if (--pmark->turn_counter <= 0) {
      link_mark_list_remove(link_marks, pmark);
    }
  } link_marks_iterate_end;
 
  /* update_map_canvas_visible(); not needed here. */
}
 
/************************************************************************/
void link_mark_add_new(enum text_link_type type, int id)
{
  struct link_mark *pmark = link_mark_find(type, id);
  struct tile *ptile;
 
  if (pmark) {
    /* Already displayed, but maybe increase the turn counter. */
    pmark->turn_counter = MAX(pmark->turn_counter, 2);
    return;
  }
 
  pmark = link_mark_new(type, id, 2);
  link_mark_list_append(link_marks, pmark);
  ptile = link_mark_tile(pmark);
  if (ptile && tile_visible_mapcanvas(ptile)) {
    refresh_tile_mapcanvas(ptile, FALSE, FALSE);
  }
}
 
/************************************************************************/
void link_mark_restore(enum text_link_type type, int id)
{
  struct link_mark *pmark;
  struct tile *ptile;
 
  if (link_mark_find(type, id)) {
    return;
  }
 
  pmark = link_mark_new(type, id, 1);
  link_mark_list_append(link_marks, pmark);
  ptile = link_mark_tile(pmark);
  if (ptile && tile_visible_mapcanvas(ptile)) {
    refresh_tile_mapcanvas(ptile, FALSE, FALSE);
  }
}
 
/************************************************************************/
enum topo_comp_lvl tileset_map_topo_compatible(int topology_id,
                                               struct tileset *tset,
                                               int *tset_topo)
{
  int tileset_topology;
 
  if (tileset_hex_width(tset) > 0) {
    fc_assert(tileset_is_isometric(tset));
    tileset_topology = TF_HEX | TF_ISO;
  } else if (tileset_hex_height(tset) > 0) {
    fc_assert(tileset_is_isometric(tset));
    tileset_topology = TF_HEX;
  } else if (tileset_is_isometric(tset)) {
    tileset_topology = TF_ISO;
  } else {
    tileset_topology = 0;
  }
 
  if (tset_topo != nullptr) {
    *tset_topo = tileset_topology;
  }
 
  if (tileset_topology & TF_HEX) {
    if ((topology_id & (TF_HEX | TF_ISO)) == tileset_topology) {
      return TOPO_COMPATIBLE;
    }
 
    /* Hex topology must match for both hexness and iso/non-iso */
    return TOPO_INCOMP_HARD;
  }
 
  if (topology_id & TF_HEX) {
    return TOPO_INCOMP_HARD;
  }
 
  if ((topology_id & TF_ISO) != (tileset_topology & TF_ISO)) {
    /* Non-hex iso/non-iso incompatibility is a soft one */
    return TOPO_INCOMP_SOFT;
  }
 
  return TOPO_COMPATIBLE;
}
 
/************************************************************************/
const char *describe_topology(int topo)
{
  if (topo & TF_ISO) {
    if (topo & TF_HEX) {
      return _("ISO|Hex");
    }
    return _("ISO");
  }
  if (topo & TF_HEX) {
    return _("Hex");
  }
 
  return _("Overhead");
}
 
/************************************************************************/
void set_frame_by_frame_animation(void)
{
  frame_by_frame_animation = TRUE;
}
 
/************************************************************************/
struct tile *client_infratile(void)
{
  return infratile;
}
 
/************************************************************************/
void client_infratile_set(struct tile *ptile)
{
  struct tile *old_tile = infratile;
 
  infratile = ptile;
 
  if (old_tile != nullptr) {
    refresh_tile_mapcanvas(old_tile, FALSE, TRUE);
  }
  if (ptile != nullptr) {
    refresh_tile_mapcanvas(ptile, FALSE, TRUE);
  }
}