newgrf_animation_base.h

Go to the documentation of this file.

/*
 * This file is part of OpenTTD.
 * 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.
 * 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.
 * 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/>.
 */
 
/* No inclusion guards as this file must only be included from .cpp files. */
 
#include "animated_tile_func.h"
#include "core/random_func.hpp"
#include "timer/timer_game_tick.h"
#include "viewport_func.h"
#include "newgrf_animation_type.h"
#include "newgrf_callbacks.h"
#include "tile_map.h"
 
template <typename Tobj>
struct TileAnimationFrameAnimationHelper {
  static uint8_t Get(Tobj *, TileIndex tile) { return GetAnimationFrame(tile); }
  static bool Set(Tobj *, TileIndex tile, uint8_t frame)
  {
    uint8_t prev_frame = GetAnimationFrame(tile);
    if (prev_frame == frame) return false;
 
    SetAnimationFrame(tile, frame);
    return true;
  }
};
 
template <typename Tbase, typename Tspec, typename Tobj, typename Textra, uint16_t (*GetCallback)(CallbackID callback, uint32_t param1, uint32_t param2, const Tspec *statspec, Tobj *st, TileIndex tile, Textra extra_data), typename Tframehelper>
struct AnimationBase {
  static void AnimateTile(const Tspec *spec, Tobj *obj, TileIndex tile, bool random_animation, Textra extra_data = 0)
  {
    assert(spec != nullptr);
 
    /* Acquire the animation speed from the NewGRF. */
    uint8_t animation_speed = spec->animation.speed;
    if (HasBit(spec->callback_mask, Tbase::cbm_animation_speed)) {
      uint16_t callback = GetCallback(Tbase::cb_animation_speed, 0, 0, spec, obj, tile, extra_data);
      if (callback != CALLBACK_FAILED) {
        if (callback >= 0x100 && spec->grf_prop.grffile->grf_version >= 8) ErrorUnknownCallbackResult(spec->grf_prop.grffile->grfid, Tbase::cb_animation_speed, callback);
        animation_speed = Clamp(callback & 0xFF, 0, 16);
      }
    }
 
    /* An animation speed of 2 means the animation frame changes 4 ticks, and
     * increasing this value by one doubles the wait. 0 is the minimum value
     * allowed for animation_speed, which corresponds to 30ms, and 16 is the
     * maximum, corresponding to around 33 minutes. */
    if (TimerGameTick::counter % (1ULL << animation_speed) != 0) return;
 
    uint8_t frame      = Tframehelper::Get(obj, tile);
    uint8_t num_frames = spec->animation.frames;
 
    bool frame_set_by_callback = false;
 
    if (HasBit(spec->callback_mask, Tbase::cbm_animation_next_frame)) {
      uint16_t callback = GetCallback(Tbase::cb_animation_next_frame, random_animation ? Random() : 0, 0, spec, obj, tile, extra_data);
 
      if (callback != CALLBACK_FAILED) {
        frame_set_by_callback = true;
 
        switch (callback & 0xFF) {
          case 0xFF:
            DeleteAnimatedTile(tile);
            break;
 
          case 0xFE:
            frame_set_by_callback = false;
            break;
 
          default:
            frame = callback & 0xFF;
            break;
        }
 
        /* If the lower 7 bits of the upper byte of the callback
         * result are not empty, it is a sound effect. */
        if (GB(callback, 8, 7) != 0 && _settings_client.sound.ambient) PlayTileSound(spec->grf_prop.grffile, GB(callback, 8, 7), tile);
      }
    }
 
    if (!frame_set_by_callback) {
      if (frame < num_frames) {
        frame++;
      } else if (frame == num_frames && spec->animation.status == ANIM_STATUS_LOOPING) {
        /* This animation loops, so start again from the beginning */
        frame = 0;
      } else {
        /* This animation doesn't loop, so stay here */
        DeleteAnimatedTile(tile);
      }
    }
 
    bool changed = Tframehelper::Set(obj, tile, frame);
    if (changed) MarkTileDirtyByTile(tile);
  }
 
  static void ChangeAnimationFrame(CallbackID cb, const Tspec *spec, Tobj *obj, TileIndex tile, uint32_t random_bits, uint32_t trigger, Textra extra_data = 0)
  {
    uint16_t callback = GetCallback(cb, random_bits, trigger, spec, obj, tile, extra_data);
    if (callback == CALLBACK_FAILED) return;
 
    switch (callback & 0xFF) {
      case 0xFD: /* Do nothing. */         break;
      case 0xFE: AddAnimatedTile(tile, false); break;
      case 0xFF: DeleteAnimatedTile(tile); break;
      default:
        bool changed = Tframehelper::Set(obj, tile, callback);
        AddAnimatedTile(tile, changed);
        break;
    }
 
    /* If the lower 7 bits of the upper byte of the callback
     * result are not empty, it is a sound effect. */
    if (GB(callback, 8, 7) != 0 && _settings_client.sound.ambient) PlayTileSound(spec->grf_prop.grffile, GB(callback, 8, 7), tile);
  }
};