From bc3a7bdce3c29cccca836259e1f50fe830a39ae7 Mon Sep 17 00:00:00 2001
From: "memberTwo.mb2" <memberTwo.mb2@gmail.com>
Date: Thu, 4 Dec 2008 22:55:17 +0000
Subject: [PATCH] Better tlut hash for fixing MPs font. Didn't notice any
 slowdown for now.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@1402 8ced0084-cf51-0410-be5f-012b33b47a6e
---
 .../Core/VideoCommon/Src/TextureDecoder.cpp   |  9 +++++++++
 Source/Core/VideoCommon/Src/TextureDecoder.h  |  2 +-
 .../Plugin_VideoOGL/Src/TextureMngr.cpp       | 20 ++++++++++++++-----
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/Source/Core/VideoCommon/Src/TextureDecoder.cpp b/Source/Core/VideoCommon/Src/TextureDecoder.cpp
index a1654a72ca..9f2b7c00bd 100644
--- a/Source/Core/VideoCommon/Src/TextureDecoder.cpp
+++ b/Source/Core/VideoCommon/Src/TextureDecoder.cpp
@@ -62,6 +62,15 @@ int TexDecoder_GetTextureSizeInBytes(int width, int height, int format)
 	return (width * height * TexDecoder_GetTexelSizeInNibbles(format)) / 2;
 }
 
+u32 TexDecoder_GetTlutHash(const u16 *src, int len)
+{
+	u32 hash = 0xbeefbabe;
+	for (int i = 0; i < len / 2; i += 2) {
+		hash = _rotl(hash, 17) ^ ((u32 *)src)[i];
+	}
+	return hash;
+}
+
 u32 TexDecoder_GetSafeTextureHash(const u8 *src, int width, int height, int texformat, u32 seed)
 {
 	int sz = TexDecoder_GetTextureSizeInBytes(width, height, texformat);
diff --git a/Source/Core/VideoCommon/Src/TextureDecoder.h b/Source/Core/VideoCommon/Src/TextureDecoder.h
index 2c0647f737..b981f3384c 100644
--- a/Source/Core/VideoCommon/Src/TextureDecoder.h
+++ b/Source/Core/VideoCommon/Src/TextureDecoder.h
@@ -77,8 +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);
 u32 TexDecoder_GetSafeTextureHash(const u8 *src, int width, int height, int texformat, u32 seed=0);
+u32 TexDecoder_GetTlutHash(const u16 *src, int len);
 
 void TexDecoder_SetTexFmtOverlayOptions(bool enable, bool center);
 
diff --git a/Source/Plugins/Plugin_VideoOGL/Src/TextureMngr.cpp b/Source/Plugins/Plugin_VideoOGL/Src/TextureMngr.cpp
index de85b75a8f..fe5c127491 100644
--- a/Source/Plugins/Plugin_VideoOGL/Src/TextureMngr.cpp
+++ b/Source/Plugins/Plugin_VideoOGL/Src/TextureMngr.cpp
@@ -203,12 +203,22 @@ TextureMngr::TCacheEntry* TextureMngr::Load(int texstage, u32 address, int width
     TexMode0 &tm0 = bpmem.tex[texstage > 3].texMode0[texstage & 3];
     u8 *ptr = g_VideoInitialize.pGetMemoryPointer(address);
 
-	// not very robust but this is a fast fix for MPs font issue.
-	// GX_TF_C4, GX_TF_C8, GX_TF_C14X2 use tlutaddr. 
-	// So the other cases could be needed later.
-	u32 hashseed = format!=GX_TF_C4 ? 0 : *(u32*)(u16*)(texMem + tlutaddr);
+	// Needed for texture format using tlut.
+	// TODO: Slower == Safer. Recalculate tlut lenght for each cases just to be sure.
+	u32 hashseed = 0;
+	switch (format) {
+	case GX_TF_C4:
+		hashseed = TexDecoder_GetTlutHash((u16*)(texMem + tlutaddr), 128);
+		break;
+	case GX_TF_C8:
+		hashseed = TexDecoder_GetTlutHash((u16*)(texMem + tlutaddr), 256);
+		break;
+	case GX_TF_C14X2:
+		hashseed = TexDecoder_GetTlutHash((u16*)(texMem + tlutaddr), 384);
+		break;
+	}
 
-    int palSize = TexDecoder_GetPaletteSize(format);
+	int palSize = TexDecoder_GetPaletteSize(format);
     u32 palhash = 0xc0debabe;
     
     if (palSize) {