Improve safe texture cache - now using sparse CRC to identify textures. Far less video glitches - metroid intro looks good.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@1298 8ced0084-cf51-0410-be5f-012b33b47a6e

Source/Core/VideoCommon/Src/TextureDecoder.cpp

@@ -57,6 +57,29 @@ int TexDecoder_GetTexelSizeInNibbles(int format)
     }
 }
 
+int TexDecoder_GetTextureSizeInBytes(int width, int height, int format)
+{
+	return (width * height * TexDecoder_GetTexelSizeInNibbles(format)) / 4;
+}
+
+u32 TexDecoder_GetSafeTextureHash(const u8 *src, int width, int height, int texformat)
+{
+	int sz = TexDecoder_GetTextureSizeInBytes(width, height, texformat);
+	u32 hash = 0x1337c0de;
+	if (sz < 2048) {
+		for (int i = 0; i < sz / 4; i += 13) {
+			hash = _rotl(hash, 17) ^ ((u32 *)src)[i];
+		}
+		return hash;
+	} else {
+		int step = sz / 13 / 4;
+		for (int i = 0; i < sz / 4; i += step) {
+			hash = _rotl(hash, 17) ^ ((u32 *)src)[i];
+		}
+	}
+	return hash;
+}
+
 int TexDecoder_GetBlockWidthInTexels(int format)
 {
     switch (format) {

Source/Core/VideoCommon/Src/TextureDecoder.h

@@ -65,6 +65,7 @@ enum TextureFormat
 };
 
 int TexDecoder_GetTexelSizeInNibbles(int format);
+int TexDecoder_GetTextureSizeInBytes(int width, int height, int format);
 int TexDecoder_GetBlockWidthInTexels(int format);
 int TexDecoder_GetPaletteSize(int fmt);
 
@@ -76,6 +77,8 @@ enum PC_TexFormat
 
 PC_TexFormat TexDecoder_Decode(u8 *dst, const u8 *src, int width, int height, int texformat, int tlutaddr, int tlutfmt);
 
+u32 TexDecoder_GetSafeTextureHash(const u8 *src, int width, int height, int texformat);
+
 void TexDecoder_SetTexFmtOverlayOptions(bool enable, bool center);
 
 #endif

Source/Plugins/Plugin_VideoOGL/Src/TextureMngr.cpp

@@ -217,10 +217,15 @@ TextureMngr::TCacheEntry* TextureMngr::Load(int texstage, u32 address, int width
         }
     }
 
+	int bs = TexDecoder_GetBlockWidthInTexels(format) - 1;
+    int expandedWidth = (width + bs) & (~bs);
+
     if (iter != textures.end()) {
         TCacheEntry &entry = iter->second;
 
-        if (entry.isRenderTarget || (((u32 *)ptr)[entry.hashoffset] == entry.hash && palhash == entry.paletteHash)) { //stupid, improve
+        if (entry.isRenderTarget || 
+			(TexDecoder_GetSafeTextureHash(ptr, expandedWidth, height, format) == entry.hash && 
+			palhash == entry.paletteHash)) {
             entry.frameCount = frameCount;
             //glEnable(entry.isNonPow2?GL_TEXTURE_RECTANGLE_ARB:GL_TEXTURE_2D);
             glBindTexture(entry.isNonPow2 ? GL_TEXTURE_RECTANGLE_ARB:GL_TEXTURE_2D, entry.texture);
@@ -251,18 +256,15 @@ TextureMngr::TCacheEntry* TextureMngr::Load(int texstage, u32 address, int width
         }
     }
     
-    int bs = TexDecoder_GetBlockWidthInTexels(format) - 1;
-    int expandedWidth = (width + bs) & (~bs);
     PC_TexFormat dfmt = TexDecoder_Decode(temp, ptr, expandedWidth, height, format, tlutaddr, tlutfmt);
 
     //Make an entry in the table
     TCacheEntry& entry = textures[address];
 
-    entry.hashoffset = 0; 
     entry.paletteHash = palhash;
     entry.oldpixel = ((u32 *)ptr)[entry.hashoffset];
 	if (g_Config.bSafeTextureCache) {
-		entry.hash = entry.oldpixel;
+		entry.hash = TexDecoder_GetSafeTextureHash(ptr, expandedWidth, height, format);
 	} else {
 		entry.hash = (u32)(((double)rand() / RAND_MAX) * 0xFFFFFFFF);
 	    ((u32 *)ptr)[entry.hashoffset] = entry.hash;