From 687d74e6c20efa3b66c839365b2431c2a4caf9e4 Mon Sep 17 00:00:00 2001
From: degasus <wickmarkus@web.de>
Date: Tue, 15 Jan 2013 14:22:40 +0100
Subject: [PATCH] only change shader if needed

---
 .../Src/ProgramShaderCache.cpp                | 29 +++++++++----------
 .../Plugin_VideoOGL/Src/RasterFont.cpp        |  2 --
 Source/Plugins/Plugin_VideoOGL/Src/Render.cpp |  4 ---
 3 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/Source/Plugins/Plugin_VideoOGL/Src/ProgramShaderCache.cpp b/Source/Plugins/Plugin_VideoOGL/Src/ProgramShaderCache.cpp
index 99997b1aa6..b1930570bd 100644
--- a/Source/Plugins/Plugin_VideoOGL/Src/ProgramShaderCache.cpp
+++ b/Source/Plugins/Plugin_VideoOGL/Src/ProgramShaderCache.cpp
@@ -131,26 +131,25 @@ void ProgramShaderCache::SetProgramBindings ( ProgramShaderCache::PCacheEntry& e
 
 void ProgramShaderCache::SetBothShaders(GLuint PS, GLuint VS)
 {
+	if(!PS || !VS) {
+		ERROR_LOG(VIDEO, "tried to bind a zero shader");
+		return;
+	}
+	
 	CurrentFShader = PS;
 	CurrentVShader = VS;
 
-	if (CurrentFShader == 0 && CurrentVShader == 0)
-	{
-		CurrentProgram = 0;
-		glUseProgram(0);
-		return;
-	}
-
-	// Fragment shaders can survive without Vertex Shaders
-	// We have a valid fragment shader, let's create our program
+	// We have a valid shaders, let's create our program
 	std::pair<u32, u32> ShaderPair = std::make_pair(CurrentFShader, CurrentVShader);
 	PCache::iterator iter = pshaders.find(ShaderPair);
 	if (iter != pshaders.end())
 	{
 		PCacheEntry &entry = iter->second;
-		glUseProgram(entry.prog_id);
-		CurrentShaderProgram = ShaderPair;
-		CurrentProgram = entry.prog_id;
+		if(CurrentProgram != entry.prog_id) {
+			glUseProgram(entry.prog_id);
+			CurrentProgram = entry.prog_id;
+			CurrentShaderProgram = ShaderPair;
+		}
 		return;
 	}
 
@@ -159,9 +158,7 @@ void ProgramShaderCache::SetBothShaders(GLuint PS, GLuint VS)
 
 	// Right, the program is created now
 	// Let's attach everything
-	if (entry.vsid != 0) // attaching zero vertex shader makes it freak out
-		glAttachShader(entry.prog_id, entry.vsid);
-
+	glAttachShader(entry.prog_id, entry.vsid);
 	glAttachShader(entry.prog_id, entry.psid);
 
 	if (g_ActiveConfig.backend_info.bSupportsGLSLCache)
@@ -254,6 +251,8 @@ void ProgramShaderCache::Init(void)
 		ProgramShaderCacheInserter inserter;
 		g_program_disk_cache.OpenAndRead(cache_filename, inserter);
 	}
+	
+	CurrentProgram = 0;
 }
 
 void ProgramShaderCache::Shutdown(void)
diff --git a/Source/Plugins/Plugin_VideoOGL/Src/RasterFont.cpp b/Source/Plugins/Plugin_VideoOGL/Src/RasterFont.cpp
index 3d443f13db..7ac793527c 100644
--- a/Source/Plugins/Plugin_VideoOGL/Src/RasterFont.cpp
+++ b/Source/Plugins/Plugin_VideoOGL/Src/RasterFont.cpp
@@ -283,8 +283,6 @@ void RasterFont::printMultilineText(const char *text, double start_x, double sta
 	glActiveTexture(GL_TEXTURE0);
 	glBindTexture(GL_TEXTURE_2D, texture);
 	glDrawArrays(GL_TRIANGLES, 0, usage/4);
-	
-	glUseProgram(0);
 }
 
 }
diff --git a/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp b/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
index 069a2a90aa..1e05c0b0b8 100644
--- a/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
+++ b/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
@@ -1412,8 +1412,6 @@ void Renderer::ResetAPIState()
 {
 	// Gets us to a reasonably sane state where it's possible to do things like
 	// image copies with textured quads, etc.
-	ProgramShaderCache::SetBothShaders(0, 0);
-
 	glDisable(GL_SCISSOR_TEST);
 	glDisable(GL_DEPTH_TEST);
 	glDisable(GL_CULL_FACE);
@@ -1434,8 +1432,6 @@ void Renderer::RestoreAPIState()
 	VertexShaderManager::SetViewportChanged();
 
 	glPolygonMode(GL_FRONT_AND_BACK, g_ActiveConfig.bWireFrame ? GL_LINE : GL_FILL);
-
-	ProgramShaderCache::SetBothShaders(0, 0);
 	
 	VertexManager *vm = (OGL::VertexManager*)g_vertex_manager;
 	glBindBuffer(GL_ARRAY_BUFFER, vm->m_vertex_buffers);