src/newgrf_animation_base.h

   1 /* $Id$ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD 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, version 2.
   6  * OpenTTD 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.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file newgrf_animation_base.h Function implementations related to NewGRF animation. */
  11
  12 /* No inclusion guards as this file must only be included from .cpp files. */
  13
  14 #include "animated_tile_func.h"
  15 #include "core/random_func.hpp"
  16 #include "date_func.h"
  17 #include "viewport_func.h"
  18 #include "newgrf_animation_type.h"
  19 #include "newgrf_callbacks.h"
  20 #include "map/common.h"
  21
  22 /**
  23  * Helper class for a unified approach to NewGRF animation.
  24  */
  25 struct AnimationBase {
  26         /**
  27          * Animate a single tile.
  28          * @param cb          The callback to actually call.
  29          * @param spec        Specification related to the tile.
  30          * @param obj         Object related to the tile.
  31          * @param tile        Tile to animate changes for.
  32          * @param random_animation Whether to pass random bits to the "next frame" callback.
  33          * @tparam Tbase      Instantiation of this class.
  34          * @tparam Tspec      NewGRF specification related to the animated tile.
  35          * @tparam Tobj       Object related to the animated tile.
  36          */
  37         template <typename Tbase, typename Tspec, typename Tobj>
  38         static void AnimateTile (const Tspec *spec, Tobj *obj, TileIndex tile, bool random_animation)
  39         {
  40                 assert(spec != NULL);
  41
  42                 /* Acquire the animation speed from the NewGRF. */
  43                 uint8 animation_speed = spec->animation.speed;
  44                 if (HasBit(spec->callback_mask, Tbase::cbm_animation_speed)) {
  45                         uint16 callback = Tbase::get_callback (Tbase::cb_animation_speed, 0, 0, spec, obj, tile);
  46                         if (callback != CALLBACK_FAILED) {
  47                                 if (callback >= 0x100 && spec->grf_prop.grffile->grf_version >= 8) ErrorUnknownCallbackResult(spec->grf_prop.grffile->grfid, Tbase::cb_animation_speed, callback);
  48                                 animation_speed = Clamp(callback & 0xFF, 0, 16);
  49                         }
  50                 }
  51
  52                 /* An animation speed of 2 means the animation frame changes 4 ticks, and
  53                  * increasing this value by one doubles the wait. 0 is the minimum value
  54                  * allowed for animation_speed, which corresponds to 30ms, and 16 is the
  55                  * maximum, corresponding to around 33 minutes. */
  56                 if (_tick_counter % (1 << animation_speed) != 0) return;
  57
  58                 uint8 frame      = GetAnimationFrame(tile);
  59                 uint8 num_frames = spec->animation.frames;
  60
  61                 bool frame_set_by_callback = false;
  62
  63                 if (HasBit(spec->callback_mask, Tbase::cbm_animation_next_frame)) {
  64                         uint16 callback = Tbase::get_callback (Tbase::cb_animation_next_frame, random_animation ? Random() : 0, 0, spec, obj, tile);
  65
  66                         if (callback != CALLBACK_FAILED) {
  67                                 frame_set_by_callback = true;
  68
  69                                 switch (callback & 0xFF) {
  70                                         case 0xFF:
  71                                                 DeleteAnimatedTile(tile);
  72                                                 break;
  73
  74                                         case 0xFE:
  75                                                 frame_set_by_callback = false;
  76                                                 break;
  77
  78                                         default:
  79                                                 frame = callback & 0xFF;
  80                                                 break;
  81                                 }
  82
  83                                 /* If the lower 7 bits of the upper byte of the callback
  84                                  * result are not empty, it is a sound effect. */
  85                                 if (GB(callback, 8, 7) != 0 && _settings_client.sound.ambient) PlayTileSound(spec->grf_prop.grffile, GB(callback, 8, 7), tile);
  86                         }
  87                 }
  88
  89                 if (!frame_set_by_callback) {
  90                         if (frame < num_frames) {
  91                                 frame++;
  92                         } else if (frame == num_frames && spec->animation.status == ANIM_STATUS_LOOPING) {
  93                                 /* This animation loops, so start again from the beginning */
  94                                 frame = 0;
  95                         } else {
  96                                 /* This animation doesn't loop, so stay here */
  97                                 DeleteAnimatedTile(tile);
  98                         }
  99                 }
 100
 101                 SetAnimationFrame(tile, frame);
 102                 MarkTileDirtyByTile(tile);
 103         }
 104
 105         /**
 106          * Process an animation callback result.
 107          * @param spec     Specification related to the tile.
 108          * @param tile     Tile to consider animation changes for.
 109          * @param callback The callback result.
 110          */
 111         template <typename Tspec>
 112         static void ChangeAnimationFrame (const Tspec *spec, TileIndex tile, uint16 callback)
 113         {
 114                 if (callback == CALLBACK_FAILED) return;
 115
 116                 switch (callback & 0xFF) {
 117                         case 0xFD: /* Do nothing. */         break;
 118                         case 0xFE: AddAnimatedTile(tile);    break;
 119                         case 0xFF: DeleteAnimatedTile(tile); break;
 120                         default:
 121                                 SetAnimationFrame(tile, callback);
 122                                 AddAnimatedTile(tile);
 123                                 break;
 124                 }
 125
 126                 /* If the lower 7 bits of the upper byte of the callback
 127                  * result are not empty, it is a sound effect. */
 128                 if (GB(callback, 8, 7) != 0 && _settings_client.sound.ambient) PlayTileSound(spec->grf_prop.grffile, GB(callback, 8, 7), tile);
 129         }
 130 };