(svn r20627) -Codechange: unify the animation code of station, airport, house and industry tiles

1 files changed, 125 insertions, 0 deletions

diff --git a/src/newgrf_animation_base.h b/src/newgrf_animation_base.h
new file mode 100644
index 000000000..ee60f48f8
--- /dev/null
+++ b/src/newgrf_animation_base.h
@@ -0,0 +1,125 @@
+/* $Id$ */
+
+/*
+ * 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/>.
+ */
+
+/** @file newgrf_animation_base.h Function implementations related to NewGRF animation. */
+
+/* No inclusion guards as this file must only be included from .cpp files. */
+
+/**
+ * Helper class for a unified approach to NewGRF animation.
+ * @tparam Tbase       Instantiation of this class.
+ * @tparam Tspec       NewGRF specification related to the animated tile.
+ * @tparam Tobj        Object related to the animated tile.
+ * @tparam GetCallback The callback function pointer.
+ */
+template <typename Tbase, typename Tspec, typename Tobj, uint16 (*GetCallback)(CallbackID callback, uint32 param1, uint32 param2, const Tspec *statspec, const Tobj *st, TileIndex tile)>
+struct AnimationBase {
+	/**
+	 * Animate a single tile.
+	 * @param cb          The callback to actually call.
+	 * @param spec        Specification related to the tile.
+	 * @param obj         Object related to the tile.
+	 * @param tile        Tile to animate changes for.
+	 * @param random_animation Whether to pass random bits to the "next frame" callback.
+	 */
+	static void AnimateTile(const Tspec *spec, const Tobj *obj, TileIndex tile, bool random_animation)
+	{
+		assert(spec != NULL);
+
+		/* Acquire the animation speed from the NewGRF. */
+		uint8 animation_speed = spec->animation.speed;
+		if (HasBit(spec->callback_mask, Tbase::cbm_animation_speed)) {
+			uint16 callback = GetCallback(Tbase::cb_animation_speed, 0, 0, spec, obj, tile);
+			if (callback != CALLBACK_FAILED) 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 (_tick_counter % (1 << animation_speed) != 0) return;
+
+		uint8 frame      = GetAnimationFrame(tile);
+		uint8 num_frames = spec->animation.frames;
+
+		bool frame_set_by_callback = false;
+
+		if (HasBit(spec->callback_mask, Tbase::cbm_animation_next_frame)) {
+			uint16 callback = GetCallback(Tbase::cb_animation_next_frame, random_animation ? Random() : 0, 0, spec, obj, tile);
+
+			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) 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);
+			}
+		}
+
+		SetAnimationFrame(tile, frame);
+		MarkTileDirtyByTile(tile);
+	}
+
+	/**
+	 * Check a callback to determine what the next animation step is and
+	 * execute that step. This includes stopping and starting animations
+	 * as well as updating animation frames and playing sounds.
+	 * @param cb          The callback to actually call.
+	 * @param spec        Specification related to the tile.
+	 * @param obj         Object related to the tile.
+	 * @param tile        Tile to consider animation changes for.
+	 * @param random_bits Random bits for this update. To be passed as parameter to the NewGRF.
+	 * @param trigger     What triggered this update? To be passed as parameter to the NewGRF.
+	 */
+	static void ChangeAnimationFrame(CallbackID cb, const Tspec *spec, const Tobj *obj, TileIndex tile, uint32 random_bits, uint32 trigger)
+	{
+		uint16 callback = GetCallback(cb, random_bits, trigger, spec, obj, tile);
+		if (callback == CALLBACK_FAILED) return;
+
+		switch (callback & 0xFF) {
+			case 0xFD: /* Do nothing. */         break;
+			case 0xFE: AddAnimatedTile(tile);    break;
+			case 0xFF: DeleteAnimatedTile(tile); break;
+			default:
+				SetAnimationFrame(tile, callback);
+				AddAnimatedTile(tile);
+				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) PlayTileSound(spec->grf_prop.grffile, GB(callback, 8, 7), tile);
+	}
+};