From aa5f80b975b4bdef2a056c376d8be3c88d16f5a6 Mon Sep 17 00:00:00 2001
From: SmileTheory <SmileTheory@gmail.com>
Date: Tue, 14 Oct 2014 06:15:06 -0700
Subject: OpenGL2: Reduce redundant GL calls.

---
 src/renderergl2/tr_backend.c | 103 +++++++++++++++++++++++++------------------
 1 file changed, 60 insertions(+), 43 deletions(-)

(limited to 'src/renderergl2/tr_backend.c')

diff --git a/src/renderergl2/tr_backend.c b/src/renderergl2/tr_backend.c
index 2ba52f69..0e7bbd77 100644
--- a/src/renderergl2/tr_backend.c
+++ b/src/renderergl2/tr_backend.c
@@ -122,8 +122,6 @@ void GL_Cull( int cullType ) {
 		return;
 	}
 
-	glState.faceCulling = cullType;
-
 	if ( cullType == CT_TWO_SIDED ) 
 	{
 		qglDisable( GL_CULL_FACE );
@@ -131,7 +129,11 @@ void GL_Cull( int cullType ) {
 	else 
 	{
 		qboolean cullFront;
-		qglEnable( GL_CULL_FACE );
+
+		if ( glState.faceCulling == CT_TWO_SIDED )
+		{
+			qglEnable( GL_CULL_FACE );
+		}
 
 		cullFront = (cullType == CT_FRONT_SIDED);
 		if ( backEnd.viewParms.isMirror )
@@ -144,8 +146,13 @@ void GL_Cull( int cullType ) {
 			cullFront = !cullFront;
 		}
 
-		qglCullFace( cullFront ? GL_FRONT : GL_BACK );
+		if (glState.faceCullFront != cullFront)
+			qglCullFace( cullFront ? GL_FRONT : GL_BACK );
+
+		glState.faceCullFront = cullFront;
 	}
+
+	glState.faceCulling = cullType;
 }
 
 /*
@@ -220,10 +227,26 @@ void GL_State( unsigned long stateBits )
 	//
 	if ( diff & ( GLS_SRCBLEND_BITS | GLS_DSTBLEND_BITS ) )
 	{
-		GLenum srcFactor = GL_ONE, dstFactor = GL_ONE;
+		uint32_t oldState = glState.glStateBits & ( GLS_SRCBLEND_BITS | GLS_DSTBLEND_BITS );
+		uint32_t newState = stateBits & ( GLS_SRCBLEND_BITS | GLS_DSTBLEND_BITS );
+		uint32_t storedState = glState.storedGlState & ( GLS_SRCBLEND_BITS | GLS_DSTBLEND_BITS );
 
-		if ( stateBits & ( GLS_SRCBLEND_BITS | GLS_DSTBLEND_BITS ) )
+		if (oldState == 0)
+		{
+			qglEnable( GL_BLEND );
+		}
+		else if (newState == 0)
 		{
+			qglDisable( GL_BLEND );
+		}
+
+		if (newState != 0 && storedState != newState)
+		{
+			GLenum srcFactor = GL_ONE, dstFactor = GL_ONE;
+
+			glState.storedGlState &= ~( GLS_SRCBLEND_BITS | GLS_DSTBLEND_BITS );
+			glState.storedGlState |= newState;
+
 			switch ( stateBits & GLS_SRCBLEND_BITS )
 			{
 			case GLS_SRCBLEND_ZERO:
@@ -289,13 +312,8 @@ void GL_State( unsigned long stateBits )
 				break;
 			}
 
-			qglEnable( GL_BLEND );
 			qglBlendFunc( srcFactor, dstFactor );
 		}
-		else
-		{
-			qglDisable( GL_BLEND );
-		}
 	}
 
 	//
@@ -348,26 +366,36 @@ void GL_State( unsigned long stateBits )
 	//
 	if ( diff & GLS_ATEST_BITS )
 	{
-		switch ( stateBits & GLS_ATEST_BITS )
+		uint32_t oldState = glState.glStateBits & GLS_ATEST_BITS;
+		uint32_t newState = stateBits & GLS_ATEST_BITS;
+		uint32_t storedState = glState.storedGlState & GLS_ATEST_BITS;
+
+		if (oldState == 0)
 		{
-		case 0:
-			qglDisable( GL_ALPHA_TEST );
-			break;
-		case GLS_ATEST_GT_0:
-			qglEnable( GL_ALPHA_TEST );
-			qglAlphaFunc( GL_GREATER, 0.0f );
-			break;
-		case GLS_ATEST_LT_80:
-			qglEnable( GL_ALPHA_TEST );
-			qglAlphaFunc( GL_LESS, 0.5f );
-			break;
-		case GLS_ATEST_GE_80:
-			qglEnable( GL_ALPHA_TEST );
-			qglAlphaFunc( GL_GEQUAL, 0.5f );
-			break;
-		default:
-			assert( 0 );
-			break;
+			qglEnable(GL_ALPHA_TEST);
+		}
+		else if (newState == 0)
+		{
+			qglDisable(GL_ALPHA_TEST);
+		}
+
+		if (newState != 0 && storedState != newState)
+		{
+			glState.storedGlState &= ~GLS_ATEST_BITS;
+			glState.storedGlState |= newState;
+
+			switch ( newState )
+			{
+			case GLS_ATEST_GT_0:
+				qglAlphaFunc( GL_GREATER, 0.0f );
+				break;
+			case GLS_ATEST_LT_80:
+				qglAlphaFunc( GL_LESS, 0.5f );
+				break;
+			case GLS_ATEST_GE_80:
+				qglAlphaFunc( GL_GEQUAL, 0.5f );
+				break;
+			}
 		}
 	}
 
@@ -406,6 +434,7 @@ static void RB_Hyperspace( void ) {
 	c = ( backEnd.refdef.time & 255 ) / 255.0f;
 	qglClearColor( c, c, c, 1 );
 	qglClear( GL_COLOR_BUFFER_BIT );
+	qglClearColor(0.0f, 0.0f, 0.0f, 1.0f);
 
 	backEnd.isHyperspace = qtrue;
 }
@@ -490,25 +519,12 @@ void RB_BeginDrawingView (void) {
 	if ( r_fastsky->integer && !( backEnd.refdef.rdflags & RDF_NOWORLDMODEL ) )
 	{
 		clearBits |= GL_COLOR_BUFFER_BIT;	// FIXME: only if sky shaders have been used
-#ifdef _DEBUG
-		qglClearColor( 0.8f, 0.7f, 0.4f, 1.0f );	// FIXME: get color of sky
-#else
-		qglClearColor( 0.0f, 0.0f, 0.0f, 1.0f );	// FIXME: get color of sky
-#endif
-	}
-
-	// clear to white for shadow maps
-	if (backEnd.viewParms.flags & VPF_SHADOWMAP)
-	{
-		clearBits |= GL_COLOR_BUFFER_BIT;
-		qglClearColor( 1.0f, 1.0f, 1.0f, 1.0f );
 	}
 
 	// clear to black for cube maps
 	if (tr.renderCubeFbo && backEnd.viewParms.targetFbo == tr.renderCubeFbo)
 	{
 		clearBits |= GL_COLOR_BUFFER_BIT;
-		qglClearColor( 0.0f, 0.0f, 0.0f, 1.0f );
 	}
 
 	qglClear( clearBits );
@@ -524,6 +540,7 @@ void RB_BeginDrawingView (void) {
 	}
 
 	glState.faceCulling = -1;		// force face culling to set next time
+	glState.faceCullFront = -1;     // same as above
 
 	// we will only draw a sun if there was sky rendered in this view
 	backEnd.skyRenderedThisView = qfalse;
-- 
cgit