(svn r26259) -Codechange: add and maintain some general flags about sprites to prevent unneeded execution of expensive code (MJP)

src/blitter/32bpp_sse2.cpp

@@ -57,7 +57,10 @@ Sprite *Blitter_32bppSSE_Base::Encode(const SpriteLoader::Sprite *sprite, Alloca
 	dst_sprite->y_offs = sprite->y_offs;
 	memcpy(dst_sprite->data, &sd, sizeof(SpriteData));
 
-	/* Copy colours. */
+	/* Copy colours and determine flags. */
+	bool has_remap = false;
+	bool has_anim = false;
+	bool has_translucency = false;
 	for (ZoomLevel z = zoom_min; z <= zoom_max; z++) {
 		const SpriteLoader::Sprite *src_sprite = &sprite[z];
 		const SpriteLoader::CommonPixel *src = (const SpriteLoader::CommonPixel *) src_sprite->data;
@@ -68,8 +71,13 @@ Sprite *Blitter_32bppSSE_Base::Encode(const SpriteLoader::Sprite *sprite, Alloca
 			for (uint x = src_sprite->width; x != 0; x--) {
 				if (src->a != 0) {
 					dst_rgba->a = src->a;
+					if (src->a != 0 && src->a != 255) has_translucency = true;
 					dst_mv->m = src->m;
 					if (src->m != 0) {
+						/* Do some accounting for flags. */
+						has_remap = true;
+						if (src->m >= PALETTE_ANIM_START) has_anim = true;
+
 						/* Get brightest value (or default brightness if it's a black pixel). */
 						const uint8 rgb_max = max(src->r, max(src->g, src->b));
 						dst_mv->v = (rgb_max == 0) ? Blitter_32bppBase::DEFAULT_BRIGHTNESS : rgb_max;
@@ -119,6 +127,13 @@ Sprite *Blitter_32bppSSE_Base::Encode(const SpriteLoader::Sprite *sprite, Alloca
 		}
 	}
 
+	/* Store sprite flags. */
+	sd.flags = SF_NONE;
+	if (has_translucency) sd.flags |= SF_TRANSLUCENT;
+	if (!has_remap) sd.flags |= SF_NO_REMAP;
+	if (!has_anim) sd.flags |= SF_NO_ANIM;
+	memcpy(dst_sprite->data, &sd, sizeof(SpriteData));
+
 	return dst_sprite;
 }
 

src/blitter/32bpp_sse2.hpp

@@ -49,6 +49,18 @@ public:
 		BT_NONE, ///< No specialisation for either case.
 	};
 
+	/** Helper for using specialised functions designed to prevent whenever it's possible things like:
+	 *  - IO (reading video buffer),
+	 *  - calculations (alpha blending),
+	 *  - heavy branching (remap lookups and animation buffer handling).
+	 */
+	enum SpriteFlags {
+		SF_NONE        = 0,
+		SF_TRANSLUCENT = 1 << 1, ///< The sprite has at least 1 translucent pixel.
+		SF_NO_REMAP    = 1 << 2, ///< The sprite has no remappable colour pixel.
+		SF_NO_ANIM     = 1 << 3, ///< The sprite has no palette animated pixel.
+	};
+
 	/** Data stored about a (single) sprite. */
 	struct SpriteInfo {
 		uint32 sprite_offset;    ///< The offset to the sprite data.
@@ -57,6 +69,7 @@ public:
 		uint16 sprite_width;     ///< The width of the sprite.
 	};
 	struct SpriteData {
+		SpriteFlags flags;
 		SpriteInfo infos[ZOOM_LVL_COUNT];
 		byte data[]; ///< Data, all zoomlevels.
 	};
@@ -64,6 +77,8 @@ public:
 	Sprite *Encode(const SpriteLoader::Sprite *sprite, AllocatorProc *allocator);
 };
 
+DECLARE_ENUM_AS_BIT_SET(Blitter_32bppSSE_Base::SpriteFlags);
+
 /** The SSE2 32 bpp blitter (without palette animation). */
 class Blitter_32bppSSE2 : public Blitter_32bppSimple, public Blitter_32bppSSE_Base {
 public: