13 files changed, 373 insertions, 73 deletions
diff --git a/indra/llrender/llcubemap.cpp b/indra/llrender/llcubemap.cpp
index fb22d7f1f5..1b10354c22 100644
--- a/indra/llrender/llcubemap.cpp
+++ b/indra/llrender/llcubemap.cpp
@@ -259,7 +259,7 @@ void LLCubeMap::setMatrix(S32 stage)
 	
 	if (mMatrixStage < 0) return;
 	
-	if (stage > 0)
+	//if (stage > 0)
 	{
 		gGL.getTexUnit(stage)->activate();
 	}
@@ -278,17 +278,17 @@ void LLCubeMap::setMatrix(S32 stage)
 	glLoadMatrixf((F32 *)trans.mMatrix);
 	glMatrixMode(GL_MODELVIEW);
 	
-	if (stage > 0)
+	/*if (stage > 0)
 	{
 		gGL.getTexUnit(0)->activate();
-	}
+	}*/
 }
 
 void LLCubeMap::restoreMatrix()
 {
 	if (mMatrixStage < 0) return;
 
-	if (mMatrixStage > 0)
+	//if (mMatrixStage > 0)
 	{
 		gGL.getTexUnit(mMatrixStage)->activate();
 	}
@@ -296,10 +296,10 @@ void LLCubeMap::restoreMatrix()
 	glPopMatrix();
 	glMatrixMode(GL_MODELVIEW);
 	
-	if (mMatrixStage > 0)
+	/*if (mMatrixStage > 0)
 	{
 		gGL.getTexUnit(0)->activate();
-	}
+	}*/
 }
 
 void LLCubeMap::setReflection (void)
diff --git a/indra/llrender/llgl.cpp b/indra/llrender/llgl.cpp
index c224ab0e9b..8937726209 100644
--- a/indra/llrender/llgl.cpp
+++ b/indra/llrender/llgl.cpp
@@ -128,9 +128,21 @@ PFNGLGETBUFFERPARAMETERIVARBPROC	glGetBufferParameterivARB = NULL;
 PFNGLGETBUFFERPOINTERVARBPROC		glGetBufferPointervARB = NULL;
 
 // GL_ARB_map_buffer_range
-PFNGLMAPBUFFERRANGEPROC			glMapBufferRange;
-PFNGLFLUSHMAPPEDBUFFERRANGEPROC	glFlushMappedBufferRange;
-
+PFNGLMAPBUFFERRANGEPROC			glMapBufferRange = NULL;
+PFNGLFLUSHMAPPEDBUFFERRANGEPROC	glFlushMappedBufferRange = NULL;
+
+// GL_ARB_sync
+PFNGLFENCESYNCPROC				glFenceSync = NULL;
+PFNGLISSYNCPROC					glIsSync = NULL;
+PFNGLDELETESYNCPROC				glDeleteSync = NULL;
+PFNGLCLIENTWAITSYNCPROC			glClientWaitSync = NULL;
+PFNGLWAITSYNCPROC				glWaitSync = NULL;
+PFNGLGETINTEGER64VPROC			glGetInteger64v = NULL;
+PFNGLGETSYNCIVPROC				glGetSynciv = NULL;
+
+// GL_APPLE_flush_buffer_range
+PFNGLBUFFERPARAMETERIAPPLEPROC	glBufferParameteriAPPLE = NULL;
+PFNGLFLUSHMAPPEDBUFFERRANGEAPPLEPROC glFlushMappedBufferRangeAPPLE = NULL;
 
 // vertex object prototypes
 PFNGLNEWOBJECTBUFFERATIPROC			glNewObjectBufferATI = NULL;
@@ -334,9 +346,10 @@ LLGLManager::LLGLManager() :
 	mHasFramebufferObject(FALSE),
 	mMaxSamples(0),
 	mHasBlendFuncSeparate(FALSE),
-
+	mHasSync(FALSE),
 	mHasVertexBufferObject(FALSE),
 	mHasMapBufferRange(FALSE),
+	mHasFlushBufferRange(FALSE),
 	mHasPBuffer(FALSE),
 	mHasShaderObjects(FALSE),
 	mHasVertexShader(FALSE),
@@ -774,7 +787,9 @@ void LLGLManager::initExtensions()
 	mHasOcclusionQuery = ExtensionExists("GL_ARB_occlusion_query", gGLHExts.mSysExts);
 	mHasOcclusionQuery2 = ExtensionExists("GL_ARB_occlusion_query2", gGLHExts.mSysExts);
 	mHasVertexBufferObject = ExtensionExists("GL_ARB_vertex_buffer_object", gGLHExts.mSysExts);
+	mHasSync = ExtensionExists("GL_ARB_sync", gGLHExts.mSysExts);
 	mHasMapBufferRange = ExtensionExists("GL_ARB_map_buffer_range", gGLHExts.mSysExts);
+	mHasFlushBufferRange = ExtensionExists("GL_APPLE_flush_buffer_range", gGLHExts.mSysExts);
 	mHasDepthClamp = ExtensionExists("GL_ARB_depth_clamp", gGLHExts.mSysExts) || ExtensionExists("GL_NV_depth_clamp", gGLHExts.mSysExts);
 	// mask out FBO support when packed_depth_stencil isn't there 'cause we need it for LLRenderTarget -Brad
 #ifdef GL_ARB_framebuffer_object
@@ -969,6 +984,16 @@ void LLGLManager::initExtensions()
 			mHasVertexBufferObject = FALSE;
 		}
 	}
+	if (mHasSync)
+	{
+		glFenceSync = (PFNGLFENCESYNCPROC) GLH_EXT_GET_PROC_ADDRESS("glFenceSync");
+		glIsSync = (PFNGLISSYNCPROC) GLH_EXT_GET_PROC_ADDRESS("glIsSync");
+		glDeleteSync = (PFNGLDELETESYNCPROC) GLH_EXT_GET_PROC_ADDRESS("glDeleteSync");
+		glClientWaitSync = (PFNGLCLIENTWAITSYNCPROC) GLH_EXT_GET_PROC_ADDRESS("glClientWaitSync");
+		glWaitSync = (PFNGLWAITSYNCPROC) GLH_EXT_GET_PROC_ADDRESS("glWaitSync");
+		glGetInteger64v = (PFNGLGETINTEGER64VPROC) GLH_EXT_GET_PROC_ADDRESS("glGetInteger64v");
+		glGetSynciv = (PFNGLGETSYNCIVPROC) GLH_EXT_GET_PROC_ADDRESS("glGetSynciv");
+	}
 	if (mHasMapBufferRange)
 	{
 		glMapBufferRange = (PFNGLMAPBUFFERRANGEPROC) GLH_EXT_GET_PROC_ADDRESS("glMapBufferRange");
@@ -1354,6 +1379,8 @@ void LLGLState::checkStates(const std::string& msg)
 	glGetIntegerv(GL_BLEND_SRC, &src);
 	glGetIntegerv(GL_BLEND_DST, &dst);
 	
+	stop_glerror();
+
 	BOOL error = FALSE;
 
 	if (src != GL_SRC_ALPHA || dst != GL_ONE_MINUS_SRC_ALPHA)
@@ -1374,7 +1401,9 @@ void LLGLState::checkStates(const std::string& msg)
 	{
 		LLGLenum state = iter->first;
 		LLGLboolean cur_state = iter->second;
+		stop_glerror();
 		LLGLboolean gl_state = glIsEnabled(state);
+		stop_glerror();
 		if(cur_state != gl_state)
 		{
 			dumpStates();
@@ -1399,11 +1428,11 @@ void LLGLState::checkStates(const std::string& msg)
 
 void LLGLState::checkTextureChannels(const std::string& msg)
 {
+#if 0
 	if (!gDebugGL)
 	{
 		return;
 	}
-
 	stop_glerror();
 
 	GLint activeTexture;
@@ -1569,6 +1598,7 @@ void LLGLState::checkTextureChannels(const std::string& msg)
 			LL_GL_ERRS << "GL texture state corruption detected.  " << msg << LL_ENDL;
 		}
 	}
+#endif
 }
 
 void LLGLState::checkClientArrays(const std::string& msg, U32 data_mask)
@@ -1685,7 +1715,7 @@ void LLGLState::checkClientArrays(const std::string& msg, U32 data_mask)
 		}
 	}
 
-	if (glIsEnabled(GL_TEXTURE_2D))
+	/*if (glIsEnabled(GL_TEXTURE_2D))
 	{
 		if (!(data_mask & 0x0008))
 		{
@@ -1708,7 +1738,7 @@ void LLGLState::checkClientArrays(const std::string& msg, U32 data_mask)
 				gFailLog << "GL does not have GL_TEXTURE_2D enabled on channel 1." << std::endl;
 			}
 		}
-	}
+	}*/
 
 	glClientActiveTextureARB(GL_TEXTURE0_ARB);
 	gGL.getTexUnit(0)->activate();
diff --git a/indra/llrender/llgl.h b/indra/llrender/llgl.h
index d1bee00161..d736133f3f 100644
--- a/indra/llrender/llgl.h
+++ b/indra/llrender/llgl.h
@@ -88,7 +88,9 @@ public:
 		
 	// ARB Extensions
 	BOOL mHasVertexBufferObject;
+	BOOL mHasSync;
 	BOOL mHasMapBufferRange;
+	BOOL mHasFlushBufferRange;
 	BOOL mHasPBuffer;
 	BOOL mHasShaderObjects;
 	BOOL mHasVertexShader;
diff --git a/indra/llrender/llglheaders.h b/indra/llrender/llglheaders.h
index f35f329f00..851a75629e 100644
--- a/indra/llrender/llglheaders.h
+++ b/indra/llrender/llglheaders.h
@@ -68,6 +68,19 @@ extern PFNGLUNMAPBUFFERARBPROC		glUnmapBufferARB;
 extern PFNGLGETBUFFERPARAMETERIVARBPROC	glGetBufferParameterivARB;
 extern PFNGLGETBUFFERPOINTERVARBPROC	glGetBufferPointervARB;
 
+// GL_ARB_sync
+extern PFNGLFENCESYNCPROC				glFenceSync;
+extern PFNGLISSYNCPROC					glIsSync;
+extern PFNGLDELETESYNCPROC				glDeleteSync;
+extern PFNGLCLIENTWAITSYNCPROC			glClientWaitSync;
+extern PFNGLWAITSYNCPROC				glWaitSync;
+extern PFNGLGETINTEGER64VPROC			glGetInteger64v;
+extern PFNGLGETSYNCIVPROC				glGetSynciv;
+
+// GL_APPLE_flush_buffer_range
+extern PFNGLBUFFERPARAMETERIAPPLEPROC	glBufferParameteriAPPLE;
+extern PFNGLFLUSHMAPPEDBUFFERRANGEAPPLEPROC glFlushMappedBufferRangeAPPLE;
+
 // GL_ARB_map_buffer_range
 extern PFNGLMAPBUFFERRANGEPROC			glMapBufferRange;
 extern PFNGLFLUSHMAPPEDBUFFERRANGEPROC	glFlushMappedBufferRange;
@@ -310,6 +323,19 @@ extern PFNGLUNMAPBUFFERARBPROC		glUnmapBufferARB;
 extern PFNGLGETBUFFERPARAMETERIVARBPROC	glGetBufferParameterivARB;
 extern PFNGLGETBUFFERPOINTERVARBPROC	glGetBufferPointervARB;
 
+// GL_ARB_sync
+extern PFNGLFENCESYNCPROC				glFenceSync;
+extern PFNGLISSYNCPROC					glIsSync;
+extern PFNGLDELETESYNCPROC				glDeleteSync;
+extern PFNGLCLIENTWAITSYNCPROC			glClientWaitSync;
+extern PFNGLWAITSYNCPROC				glWaitSync;
+extern PFNGLGETINTEGER64VPROC			glGetInteger64v;
+extern PFNGLGETSYNCIVPROC				glGetSynciv;
+
+// GL_APPLE_flush_buffer_range
+extern PFNGLBUFFERPARAMETERIAPPLEPROC	glBufferParameteriAPPLE;
+extern PFNGLFLUSHMAPPEDBUFFERRANGEAPPLEPROC glFlushMappedBufferRangeAPPLE;
+
 // GL_ARB_map_buffer_range
 extern PFNGLMAPBUFFERRANGEPROC			glMapBufferRange;
 extern PFNGLFLUSHMAPPEDBUFFERRANGEPROC	glFlushMappedBufferRange;
@@ -519,6 +545,19 @@ extern PFNGLUNMAPBUFFERARBPROC		glUnmapBufferARB;
 extern PFNGLGETBUFFERPARAMETERIVARBPROC	glGetBufferParameterivARB;
 extern PFNGLGETBUFFERPOINTERVARBPROC	glGetBufferPointervARB;
 
+// GL_ARB_sync
+extern PFNGLFENCESYNCPROC				glFenceSync;
+extern PFNGLISSYNCPROC					glIsSync;
+extern PFNGLDELETESYNCPROC				glDeleteSync;
+extern PFNGLCLIENTWAITSYNCPROC			glClientWaitSync;
+extern PFNGLWAITSYNCPROC				glWaitSync;
+extern PFNGLGETINTEGER64VPROC			glGetInteger64v;
+extern PFNGLGETSYNCIVPROC				glGetSynciv;
+
+// GL_APPLE_flush_buffer_range
+extern PFNGLBUFFERPARAMETERIAPPLEPROC	glBufferParameteriAPPLE;
+extern PFNGLFLUSHMAPPEDBUFFERRANGEAPPLEPROC glFlushMappedBufferRangeAPPLE;
+
 // GL_ARB_map_buffer_range
 extern PFNGLMAPBUFFERRANGEPROC			glMapBufferRange;
 extern PFNGLFLUSHMAPPEDBUFFERRANGEPROC	glFlushMappedBufferRange;
diff --git a/indra/llrender/llglslshader.cpp b/indra/llrender/llglslshader.cpp
index ad2c662dfc..80c93bb0d2 100644
--- a/indra/llrender/llglslshader.cpp
+++ b/indra/llrender/llglslshader.cpp
@@ -49,6 +49,11 @@ using std::make_pair;
 using std::string;
 
 GLhandleARB LLGLSLShader::sCurBoundShader = 0;
+bool LLGLSLShader::sNoFixedFunction = false;
+
+//UI shader -- declared here so llui_libtest will link properly
+LLGLSLShader	gUIProgram;
+LLGLSLShader	gSolidColorProgram;
 
 BOOL shouldChange(const LLVector4& v1, const LLVector4& v2)
 {
@@ -376,6 +381,7 @@ BOOL LLGLSLShader::link(BOOL suppress_errors)
 
 void LLGLSLShader::bind()
 {
+	gGL.flush();
 	if (gGLManager.mHasShaderObjects)
 	{
 		glUseProgramObjectARB(mProgramObject);
@@ -390,6 +396,7 @@ void LLGLSLShader::bind()
 
 void LLGLSLShader::unbind()
 {
+	gGL.flush();
 	if (gGLManager.mHasShaderObjects)
 	{
 		stop_glerror();
diff --git a/indra/llrender/llglslshader.h b/indra/llrender/llglslshader.h
index 4922eb6d67..621e0b82ee 100644
--- a/indra/llrender/llglslshader.h
+++ b/indra/llrender/llglslshader.h
@@ -67,6 +67,7 @@ public:
 	LLGLSLShader();
 
 	static GLhandleARB sCurBoundShader;
+	static bool sNoFixedFunction;
 
 	void unload();
 	BOOL createShader(std::vector<std::string> * attributes,
@@ -141,4 +142,10 @@ public:
 	std::string mName;
 };
 
+//UI shader (declared here so llui_libtest will link properly)
+extern LLGLSLShader			gUIProgram;
+//output vec4(color.rgb,color.a*tex0[tc0].a)
+extern LLGLSLShader			gSolidColorProgram;
+
+
 #endif
diff --git a/indra/llrender/llimagegl.cpp b/indra/llrender/llimagegl.cpp
index 60a5962234..9ca3a23d52 100644
--- a/indra/llrender/llimagegl.cpp
+++ b/indra/llrender/llimagegl.cpp
@@ -1414,6 +1414,8 @@ BOOL LLImageGL::readBackRaw(S32 discard_level, LLImageRaw* imageraw, bool compre
 
 void LLImageGL::deleteDeadTextures()
 {
+	bool reset = false;
+
 	while (!sDeadTextureList.empty())
 	{
 		GLuint tex = sDeadTextureList.front();
@@ -1426,12 +1428,22 @@ void LLImageGL::deleteDeadTextures()
 			{
 				tex_unit->unbind(tex_unit->getCurrType());
 				stop_glerror();
+
+				if (i > 0)
+				{
+					reset = true;
+				}
 			}
 		}
 		
 		glDeleteTextures(1, &tex);
 		stop_glerror();
 	}
+
+	if (reset)
+	{
+		gGL.getTexUnit(0)->activate();
+	}
 }
 		
 void LLImageGL::destroyGLTexture()
diff --git a/indra/llrender/llrender.cpp b/indra/llrender/llrender.cpp
index 1d82dda30f..70df1dd1d1 100644
--- a/indra/llrender/llrender.cpp
+++ b/indra/llrender/llrender.cpp
@@ -46,6 +46,7 @@ S32	gGLViewport[4];
 
 U32 LLRender::sUICalls = 0;
 U32 LLRender::sUIVerts = 0;
+U32 LLTexUnit::sWhiteTexture = 0;
 
 static const U32 LL_NUM_TEXTURE_LAYERS = 32; 
 static const U32 LL_NUM_LIGHT_UNITS = 8;
@@ -126,7 +127,8 @@ void LLTexUnit::refreshState(void)
 	// Per apple spec, don't call glEnable/glDisable when index exceeds max texture units
 	// http://www.mailinglistarchive.com/html/mac-opengl@lists.apple.com/2008-07/msg00653.html
 	//
-	bool enableDisable = (mIndex < gGLManager.mNumTextureUnits) && mCurrTexType != LLTexUnit::TT_MULTISAMPLE_TEXTURE;
+	bool enableDisable = !LLGLSLShader::sNoFixedFunction && 
+		(mIndex < gGLManager.mNumTextureUnits) && mCurrTexType != LLTexUnit::TT_MULTISAMPLE_TEXTURE;
 		
 	if (mCurrTexType != TT_NONE)
 	{
@@ -184,7 +186,8 @@ void LLTexUnit::enable(eTextureType type)
 		mCurrTexType = type;
 
 		gGL.flush();
-		if (type != LLTexUnit::TT_MULTISAMPLE_TEXTURE &&
+		if (!LLGLSLShader::sNoFixedFunction && 
+			type != LLTexUnit::TT_MULTISAMPLE_TEXTURE &&
 			mIndex < gGLManager.mNumTextureUnits)
 		{
 			glEnable(sGLTextureType[type]);
@@ -201,7 +204,8 @@ void LLTexUnit::disable(void)
 		activate();
 		unbind(mCurrTexType);
 		gGL.flush();
-		if (mCurrTexType != LLTexUnit::TT_MULTISAMPLE_TEXTURE &&
+		if (!LLGLSLShader::sNoFixedFunction &&
+			mCurrTexType != LLTexUnit::TT_MULTISAMPLE_TEXTURE &&
 			mIndex < gGLManager.mNumTextureUnits)
 		{
 			glDisable(sGLTextureType[mCurrTexType]);
@@ -403,7 +407,14 @@ void LLTexUnit::unbind(eTextureType type)
 
 		activate();
 		mCurrTexture = 0;
-		glBindTexture(sGLTextureType[type], 0);
+		if (LLGLSLShader::sNoFixedFunction && type == LLTexUnit::TT_TEXTURE)
+		{
+			glBindTexture(sGLTextureType[type], sWhiteTexture);
+		}
+		else
+		{
+			glBindTexture(sGLTextureType[type], 0);
+		}
 		stop_glerror();
 	}
 }
@@ -474,6 +485,11 @@ void LLTexUnit::setTextureFilteringOption(LLTexUnit::eTextureFilterOptions optio
 
 void LLTexUnit::setTextureBlendType(eTextureBlendType type)
 {
+	if (LLGLSLShader::sNoFixedFunction)
+	{ //texture blend type means nothing when using shaders
+		return;
+	}
+
 	if (mIndex < 0) return;
 
 	// Do nothing if it's already correctly set.
@@ -594,6 +610,11 @@ GLint LLTexUnit::getTextureSourceType(eTextureBlendSrc src, bool isAlpha)
 
 void LLTexUnit::setTextureCombiner(eTextureBlendOp op, eTextureBlendSrc src1, eTextureBlendSrc src2, bool isAlpha)
 {
+	if (LLGLSLShader::sNoFixedFunction)
+	{ //register combiners do nothing when not using fixed function
+		return;
+	}	
+
 	if (mIndex < 0) return;
 
 	activate();
diff --git a/indra/llrender/llrender.h b/indra/llrender/llrender.h
index 41e7b35341..9eedebe2ce 100644
--- a/indra/llrender/llrender.h
+++ b/indra/llrender/llrender.h
@@ -52,6 +52,8 @@ class LLTexUnit
 {
 	friend class LLRender;
 public:
+	static U32 sWhiteTexture;
+
 	typedef enum
 	{
 		TT_TEXTURE = 0,			// Standard 2D Texture
diff --git a/indra/llrender/llrendertarget.cpp b/indra/llrender/llrendertarget.cpp
index b6463309e1..8c0d3592df 100644
--- a/indra/llrender/llrendertarget.cpp
+++ b/indra/llrender/llrendertarget.cpp
@@ -72,11 +72,11 @@ LLRenderTarget::~LLRenderTarget()
 	release();
 }
 
-void LLRenderTarget::allocate(U32 resx, U32 resy, U32 color_fmt, bool depth, bool stencil, LLTexUnit::eTextureType usage, bool use_fbo, S32 samples)
+bool LLRenderTarget::allocate(U32 resx, U32 resy, U32 color_fmt, bool depth, bool stencil, LLTexUnit::eTextureType usage, bool use_fbo, S32 samples)
 {
 	stop_glerror();
-	
 	release();
+	stop_glerror();
 
 	mResX = resx;
 	mResY = resy;
@@ -103,9 +103,11 @@ void LLRenderTarget::allocate(U32 resx, U32 resy, U32 color_fmt, bool depth, boo
 	{
 		if (depth)
 		{
-			stop_glerror();
-			allocateDepth();
-			stop_glerror();
+			if (!allocateDepth())
+			{
+				llwarns << "Failed to allocate depth buffer for render target." << llendl;
+				return false;
+			}
 		}
 
 		glGenFramebuffers(1, (GLuint *) &mFBO);
@@ -131,14 +133,14 @@ void LLRenderTarget::allocate(U32 resx, U32 resy, U32 color_fmt, bool depth, boo
 		stop_glerror();
 	}
 
-	addColorAttachment(color_fmt);
+	return addColorAttachment(color_fmt);
 }
 
-void LLRenderTarget::addColorAttachment(U32 color_fmt)
+bool LLRenderTarget::addColorAttachment(U32 color_fmt)
 {
 	if (color_fmt == 0)
 	{
-		return;
+		return true;
 	}
 
 	U32 offset = mTex.size();
@@ -158,14 +160,26 @@ void LLRenderTarget::addColorAttachment(U32 color_fmt)
 #ifdef GL_ARB_texture_multisample
 	if (mSamples > 1)
 	{
+		clear_glerror();
 		glTexImage2DMultisample(LLTexUnit::getInternalType(mUsage), mSamples, color_fmt, mResX, mResY, GL_TRUE);
+		if (glGetError() != GL_NO_ERROR)
+		{
+			llwarns << "Could not allocate multisample color buffer for render target." << llendl;
+			return false;
+		}
 	}
 	else
 #else
 	llassert_always(mSamples <= 1);
 #endif
 	{
+		clear_glerror();
 		LLImageGL::setManualImage(LLTexUnit::getInternalType(mUsage), 0, color_fmt, mResX, mResY, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+		if (glGetError() != GL_NO_ERROR)
+		{
+			llwarns << "Could not allocate color buffer for render target." << llendl;
+			return false;
+		}
 	}
 	
 	stop_glerror();
@@ -217,15 +231,18 @@ void LLRenderTarget::addColorAttachment(U32 color_fmt)
 		flush();
 	}
 
+	return true;
 }
 
-void LLRenderTarget::allocateDepth()
+bool LLRenderTarget::allocateDepth()
 {
 	if (mStencil)
 	{
 		//use render buffers where stencil buffers are in play
 		glGenRenderbuffers(1, (GLuint *) &mDepth);
 		glBindRenderbuffer(GL_RENDERBUFFER, mDepth);
+		stop_glerror();
+		clear_glerror();
 		glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, mResX, mResY);
 		glBindRenderbuffer(GL_RENDERBUFFER, 0);
 	}
@@ -237,17 +254,29 @@ void LLRenderTarget::allocateDepth()
 		{
 			U32 internal_type = LLTexUnit::getInternalType(mUsage);
 			gGL.getTexUnit(0)->setTextureFilteringOption(LLTexUnit::TFO_POINT);
+			stop_glerror();
+			clear_glerror();
 			LLImageGL::setManualImage(internal_type, 0, GL_DEPTH_COMPONENT32, mResX, mResY, GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, NULL);
 		}
 #ifdef GL_ARB_texture_multisample
 		else
 		{
+			stop_glerror();
+			clear_glerror();
 			glTexImage2DMultisample(LLTexUnit::getInternalType(mUsage), mSamples, GL_DEPTH_COMPONENT32, mResX, mResY, GL_TRUE);
 		}
 #else
 		llassert_always(mSamples <= 1);
 #endif
 	}
+
+	if (glGetError() != GL_NO_ERROR)
+	{
+		llwarns << "Unable to allocate depth buffer for render target." << llendl;
+		return false;
+	}
+
+	return true;
 }
 
 void LLRenderTarget::shareDepthBuffer(LLRenderTarget& target)
diff --git a/indra/llrender/llrendertarget.h b/indra/llrender/llrendertarget.h
index 094b58b562..dea1de12d8 100644
--- a/indra/llrender/llrendertarget.h
+++ b/indra/llrender/llrendertarget.h
@@ -66,30 +66,30 @@ public:
 	static bool sUseFBO; 
 
 	LLRenderTarget();
-	virtual ~LLRenderTarget();
+	~LLRenderTarget();
 
 	//allocate resources for rendering
 	//must be called before use
 	//multiple calls will release previously allocated resources
-	void allocate(U32 resx, U32 resy, U32 color_fmt, bool depth, bool stencil, LLTexUnit::eTextureType usage = LLTexUnit::TT_TEXTURE, bool use_fbo = false, S32 samples = 0);
+	bool allocate(U32 resx, U32 resy, U32 color_fmt, bool depth, bool stencil, LLTexUnit::eTextureType usage = LLTexUnit::TT_TEXTURE, bool use_fbo = false, S32 samples = 0);
 
 	//add color buffer attachment
 	//limit of 4 color attachments per render target
-	virtual void addColorAttachment(U32 color_fmt);
+	bool addColorAttachment(U32 color_fmt);
 
 	//allocate a depth texture
-	virtual void allocateDepth();
+	bool allocateDepth();
 
 	//share depth buffer with provided render target
-	virtual void shareDepthBuffer(LLRenderTarget& target);
+	void shareDepthBuffer(LLRenderTarget& target);
 
 	//free any allocated resources
 	//safe to call redundantly
-	virtual void release();
+	void release();
 
 	//bind target for rendering
 	//applies appropriate viewport
-	virtual void bindTarget();
+	void bindTarget();
 
 	//unbind target for rendering
 	static void unbindTarget();
diff --git a/indra/llrender/llvertexbuffer.cpp b/indra/llrender/llvertexbuffer.cpp
index 4a0b964e61..1180afa631 100644
--- a/indra/llrender/llvertexbuffer.cpp
+++ b/indra/llrender/llvertexbuffer.cpp
@@ -35,6 +35,8 @@
 #include "llmemtype.h"
 #include "llrender.h"
 #include "llvector4a.h"
+#include "llglslshader.h"
+
 
 //============================================================================
 
@@ -65,6 +67,60 @@ S32	LLVertexBuffer::sWeight4Loc = -1;
 std::vector<U32> LLVertexBuffer::sDeleteList;
 
 
+const U32 FENCE_WAIT_TIME_NANOSECONDS = 10000;  //1 ms
+
+class LLGLSyncFence : public LLGLFence
+{
+public:
+#ifdef GL_ARB_sync
+	GLsync mSync;
+#endif
+	
+	LLGLSyncFence()
+	{
+#ifdef GL_ARB_sync
+		mSync = 0;
+#endif
+	}
+
+	~LLGLSyncFence()
+	{
+#ifdef GL_ARB_sync
+		if (mSync)
+		{
+			glDeleteSync(mSync);
+		}
+#endif
+	}
+
+	void placeFence()
+	{
+#ifdef GL_ARB_sync
+		if (mSync)
+		{
+			glDeleteSync(mSync);
+		}
+		mSync = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
+#endif
+	}
+
+	void wait()
+	{
+#ifdef GL_ARB_sync
+		if (mSync)
+		{
+			while (glClientWaitSync(mSync, 0, FENCE_WAIT_TIME_NANOSECONDS) == GL_TIMEOUT_EXPIRED)
+			{ //track the number of times we've waited here
+				static S32 waits = 0;
+				waits++;
+			}
+		}
+#endif
+	}
+
+
+};
+
 S32 LLVertexBuffer::sTypeSize[LLVertexBuffer::TYPE_MAX] =
 {
 	sizeof(LLVector4), // TYPE_VERTEX,
@@ -309,6 +365,7 @@ void LLVertexBuffer::drawRange(U32 mode, U32 start, U32 end, U32 count, U32 indi
 	glDrawRangeElements(sGLMode[mode], start, end, count, GL_UNSIGNED_SHORT, 
 		idx);
 	stop_glerror();
+	placeFence();
 }
 
 void LLVertexBuffer::draw(U32 mode, U32 count, U32 indices_offset) const
@@ -340,6 +397,7 @@ void LLVertexBuffer::draw(U32 mode, U32 count, U32 indices_offset) const
 	glDrawElements(sGLMode[mode], count, GL_UNSIGNED_SHORT,
 		((U16*) getIndicesPointer()) + indices_offset);
 	stop_glerror();
+	placeFence();
 }
 
 void LLVertexBuffer::drawArrays(U32 mode, U32 first, U32 count) const
@@ -365,6 +423,7 @@ void LLVertexBuffer::drawArrays(U32 mode, U32 first, U32 count) const
 	stop_glerror();
 	glDrawArrays(sGLMode[mode], first, count);
 	stop_glerror();
+	placeFence();
 }
 
 //static
@@ -444,9 +503,11 @@ LLVertexBuffer::LLVertexBuffer(U32 typemask, S32 usage) :
 	mFilthy(FALSE),
 	mEmpty(TRUE),
 	mResized(FALSE),
-	mDynamicSize(FALSE)
+	mDynamicSize(FALSE),
+	mFence(NULL)
 {
 	LLMemType mt2(LLMemType::MTYPE_VERTEX_CONSTRUCTOR);
+	mFence = NULL;
 	if (!sEnableVBOs)
 	{
 		mUsage = 0 ; 
@@ -527,9 +588,40 @@ LLVertexBuffer::~LLVertexBuffer()
 	destroyGLIndices();
 	sCount--;
 
+	if (mFence)
+	{
+		delete mFence;
+	}
+	
+	mFence = NULL;
+
 	llassert_always(!mMappedData && !mMappedIndexData) ;
 };
 
+void LLVertexBuffer::placeFence() const
+{
+	/*if (!mFence && useVBOs())
+	{
+		if (gGLManager.mHasSync)
+		{
+			mFence = new LLGLSyncFence();
+		}
+	}
+
+	if (mFence)
+	{
+		mFence->placeFence();
+	}*/
+}
+
+void LLVertexBuffer::waitFence() const
+{
+	/*if (mFence)
+	{
+		mFence->wait();
+	}*/
+}
+
 //----------------------------------------------------------------------------
 
 void LLVertexBuffer::genBuffer()
@@ -892,17 +984,11 @@ BOOL LLVertexBuffer::useVBOs() const
 {
 	//it's generally ineffective to use VBO for things that are streaming on apple
 		
-#if LL_DARWIN
-	if (!mUsage || mUsage == GL_STREAM_DRAW_ARB)
-	{
-		return FALSE;
-	}
-#else
 	if (!mUsage)
 	{
 		return FALSE;
 	}
-#endif
+
 	return TRUE;
 }
 
@@ -967,8 +1053,7 @@ U8* LLVertexBuffer::mapVertexBuffer(S32 type, S32 index, S32 count, bool map_ran
 		
 	if (useVBOs())
 	{
-
-		if (sDisableVBOMapping || gGLManager.mHasMapBufferRange)
+		if (sDisableVBOMapping || gGLManager.mHasMapBufferRange || gGLManager.mHasFlushBufferRange)
 		{
 			if (count == -1)
 			{
@@ -1008,6 +1093,7 @@ U8* LLVertexBuffer::mapVertexBuffer(S32 type, S32 index, S32 count, bool map_ran
 			LLMemType mt_v(LLMemType::MTYPE_VERTEX_MAP_BUFFER_VERTICES);
 			setBuffer(0, type);
 			mVertexLocked = TRUE;
+			sMappedCount++;
 			stop_glerror();	
 
 			if(sDisableVBOMapping)
@@ -1018,29 +1104,50 @@ U8* LLVertexBuffer::mapVertexBuffer(S32 type, S32 index, S32 count, bool map_ran
 			else
 			{
 				U8* src = NULL;
-#ifdef GL_ARB_map_buffer_range
+				waitFence();
 				if (gGLManager.mHasMapBufferRange)
 				{
 					if (map_range)
 					{
+#ifdef GL_ARB_map_buffer_range
 						S32 offset = mOffsets[type] + sTypeSize[type]*index;
 						S32 length = (sTypeSize[type]*count+0xF) & ~0xF;
-						src = (U8*) glMapBufferRange(GL_ARRAY_BUFFER_ARB, offset, length, GL_MAP_WRITE_BIT | GL_MAP_FLUSH_EXPLICIT_BIT | GL_MAP_INVALIDATE_RANGE_BIT);
+						src = (U8*) glMapBufferRange(GL_ARRAY_BUFFER_ARB, offset, length, 
+							GL_MAP_WRITE_BIT | 
+							GL_MAP_FLUSH_EXPLICIT_BIT | 
+							GL_MAP_INVALIDATE_RANGE_BIT);
+#endif
 					}
 					else
 					{
-						src = (U8*) glMapBufferRange(GL_ARRAY_BUFFER_ARB, 0, mSize, GL_MAP_WRITE_BIT | GL_MAP_FLUSH_EXPLICIT_BIT);
+#ifdef GL_ARB_map_buffer_range
+						src = (U8*) glMapBufferRange(GL_ARRAY_BUFFER_ARB, 0, mSize, 
+							GL_MAP_WRITE_BIT | 
+							GL_MAP_FLUSH_EXPLICIT_BIT);
+#endif
+					}
+				}
+				else if (gGLManager.mHasFlushBufferRange)
+				{
+					if (map_range)
+					{
+						glBufferParameteriAPPLE(GL_ARRAY_BUFFER_ARB, GL_BUFFER_SERIALIZED_MODIFY_APPLE, GL_FALSE);
+						glBufferParameteriAPPLE(GL_ARRAY_BUFFER_ARB, GL_BUFFER_FLUSHING_UNMAP_APPLE, GL_FALSE);
+						src = (U8*) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
+					}
+					else
+					{
+						src = (U8*) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
 					}
 				}
 				else
-#else
-				llassert_always(!gGLManager.mHasMapBufferRange);
-#endif
 				{
 					map_range = false;
 					src = (U8*) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
 				}
 
+				llassert(src != NULL);
+
 				mMappedData = LL_NEXT_ALIGNED_ADDRESS<U8>(src);
 				mAlignedOffset = mMappedData - src;
 			
@@ -1082,7 +1189,6 @@ U8* LLVertexBuffer::mapVertexBuffer(S32 type, S32 index, S32 count, bool map_ran
 					llerrs << "memory allocation for vertex data failed." << llendl ;
 				}
 			}
-			sMappedCount++;
 		}
 	}
 	else
@@ -1090,7 +1196,7 @@ U8* LLVertexBuffer::mapVertexBuffer(S32 type, S32 index, S32 count, bool map_ran
 		map_range = false;
 	}
 	
-	if (map_range && !sDisableVBOMapping)
+	if (map_range && gGLManager.mHasMapBufferRange && !sDisableVBOMapping)
 	{
 		return mMappedData;
 	}
@@ -1114,7 +1220,7 @@ U8* LLVertexBuffer::mapIndexBuffer(S32 index, S32 count, bool map_range)
 
 	if (useVBOs())
 	{
-		if (sDisableVBOMapping || gGLManager.mHasMapBufferRange)
+		if (sDisableVBOMapping || gGLManager.mHasMapBufferRange || gGLManager.mHasFlushBufferRange)
 		{
 			if (count == -1)
 			{
@@ -1152,6 +1258,7 @@ U8* LLVertexBuffer::mapIndexBuffer(S32 index, S32 count, bool map_range)
 
 			setBuffer(0, TYPE_INDEX);
 			mIndexLocked = TRUE;
+			sMappedCount++;
 			stop_glerror();	
 
 			if(sDisableVBOMapping)
@@ -1162,29 +1269,51 @@ U8* LLVertexBuffer::mapIndexBuffer(S32 index, S32 count, bool map_range)
 			else
 			{
 				U8* src = NULL;
-#ifdef GL_ARB_map_buffer_range
+				waitFence();
 				if (gGLManager.mHasMapBufferRange)
 				{
 					if (map_range)
 					{
+#ifdef GL_ARB_map_buffer_range
 						S32 offset = sizeof(U16)*index;
 						S32 length = sizeof(U16)*count;
-						src = (U8*) glMapBufferRange(GL_ELEMENT_ARRAY_BUFFER_ARB, offset, length, GL_MAP_WRITE_BIT | GL_MAP_FLUSH_EXPLICIT_BIT | GL_MAP_INVALIDATE_RANGE_BIT);
+						src = (U8*) glMapBufferRange(GL_ELEMENT_ARRAY_BUFFER_ARB, offset, length, 
+							GL_MAP_WRITE_BIT | 
+							GL_MAP_FLUSH_EXPLICIT_BIT | 
+							GL_MAP_INVALIDATE_RANGE_BIT);
+#endif
+					}
+					else
+					{
+#ifdef GL_ARB_map_buffer_range
+						src = (U8*) glMapBufferRange(GL_ELEMENT_ARRAY_BUFFER_ARB, 0, sizeof(U16)*mNumIndices, 
+							GL_MAP_WRITE_BIT | 
+							GL_MAP_FLUSH_EXPLICIT_BIT);
+#endif
+					}
+				}
+				else if (gGLManager.mHasFlushBufferRange)
+				{
+					if (map_range)
+					{
+						glBufferParameteriAPPLE(GL_ELEMENT_ARRAY_BUFFER_ARB, GL_BUFFER_SERIALIZED_MODIFY_APPLE, GL_FALSE);
+						glBufferParameteriAPPLE(GL_ELEMENT_ARRAY_BUFFER_ARB, GL_BUFFER_FLUSHING_UNMAP_APPLE, GL_FALSE);
+						src = (U8*) glMapBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
 					}
 					else
 					{
-						src = (U8*) glMapBufferRange(GL_ELEMENT_ARRAY_BUFFER_ARB, 0, sizeof(U16)*mNumIndices, GL_MAP_WRITE_BIT | GL_MAP_FLUSH_EXPLICIT_BIT);
+						src = (U8*) glMapBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
 					}
 				}
 				else
-#else
-				llassert_always(!gGLManager.mHasMapBufferRange);
-#endif
 				{
 					map_range = false;
 					src = (U8*) glMapBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
 				}
 
+				llassert(src != NULL);
+
+
 				mMappedIndexData = src; //LL_NEXT_ALIGNED_ADDRESS<U8>(src);
 				mAlignedIndexOffset = mMappedIndexData - src;
 				stop_glerror();
@@ -1211,15 +1340,13 @@ U8* LLVertexBuffer::mapIndexBuffer(S32 index, S32 count, bool map_range)
 				llerrs << "memory allocation for Index data failed. " << llendl ;
 			}
 		}
-
-		sMappedCount++;
 	}
 	else
 	{
 		map_range = false;
 	}
 
-	if (map_range && !sDisableVBOMapping)
+	if (map_range && gGLManager.mHasMapBufferRange && !sDisableVBOMapping)
 	{
 		return mMappedIndexData;
 	}
@@ -1268,8 +1395,7 @@ void LLVertexBuffer::unmapBuffer(S32 type)
 		}
 		else
 		{
-#ifdef GL_ARB_map_buffer_range
-			if (gGLManager.mHasMapBufferRange)
+			if (gGLManager.mHasMapBufferRange || gGLManager.mHasFlushBufferRange)
 			{
 				if (!mMappedVertexRegions.empty())
 				{
@@ -1279,16 +1405,22 @@ void LLVertexBuffer::unmapBuffer(S32 type)
 						const MappedRegion& region = mMappedVertexRegions[i];
 						S32 offset = region.mIndex >= 0 ? mOffsets[region.mType]+sTypeSize[region.mType]*region.mIndex : 0;
 						S32 length = sTypeSize[region.mType]*region.mCount;
-						glFlushMappedBufferRange(GL_ARRAY_BUFFER_ARB, offset, length);
+						if (gGLManager.mHasMapBufferRange)
+						{
+#ifdef GL_ARB_map_buffer_range
+							glFlushMappedBufferRange(GL_ARRAY_BUFFER_ARB, offset, length);
+#endif
+						}
+						else if (gGLManager.mHasFlushBufferRange)
+						{
+							glFlushMappedBufferRangeAPPLE(GL_ARRAY_BUFFER_ARB, offset, length);
+						}
 						stop_glerror();
 					}
 
 					mMappedVertexRegions.clear();
 				}
 			}
-#else
-			llassert_always(!gGLManager.mHasMapBufferRange);
-#endif
 			stop_glerror();
 			glUnmapBufferARB(GL_ARRAY_BUFFER_ARB);
 			stop_glerror();
@@ -1326,8 +1458,7 @@ void LLVertexBuffer::unmapBuffer(S32 type)
 		}
 		else
 		{
-#ifdef GL_ARB_map_buffer_range
-			if (gGLManager.mHasMapBufferRange)
+			if (gGLManager.mHasMapBufferRange || gGLManager.mHasFlushBufferRange)
 			{
 				if (!mMappedIndexRegions.empty())
 				{
@@ -1336,16 +1467,24 @@ void LLVertexBuffer::unmapBuffer(S32 type)
 						const MappedRegion& region = mMappedIndexRegions[i];
 						S32 offset = region.mIndex >= 0 ? sizeof(U16)*region.mIndex : 0;
 						S32 length = sizeof(U16)*region.mCount;
-						glFlushMappedBufferRange(GL_ELEMENT_ARRAY_BUFFER_ARB, offset, length);
+						if (gGLManager.mHasMapBufferRange)
+						{
+#ifdef GL_ARB_map_buffer_range
+							glFlushMappedBufferRange(GL_ELEMENT_ARRAY_BUFFER_ARB, offset, length);
+#endif
+						}
+						else if (gGLManager.mHasFlushBufferRange)
+						{
+#ifdef GL_APPLE_flush_buffer_range
+							glFlushMappedBufferRangeAPPLE(GL_ELEMENT_ARRAY_BUFFER_ARB, offset, length);
+#endif
+						}
 						stop_glerror();
 					}
 
 					mMappedIndexRegions.clear();
 				}
 			}
-#else
-			llassert_always(!gGLManager.mHasMapBufferRange);
-#endif
 			stop_glerror();
 			glUnmapBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB);
 			stop_glerror();
diff --git a/indra/llrender/llvertexbuffer.h b/indra/llrender/llvertexbuffer.h
index aa5df305a6..cc5d11e1c2 100644
--- a/indra/llrender/llvertexbuffer.h
+++ b/indra/llrender/llvertexbuffer.h
@@ -70,6 +70,12 @@ protected:
 	}
 };
 
+class LLGLFence
+{
+public:
+	virtual void placeFence() = 0;
+	virtual void wait() = 0;
+};
 
 //============================================================================
 // base class 
@@ -270,6 +276,12 @@ protected:
 	std::vector<MappedRegion> mMappedVertexRegions;
 	std::vector<MappedRegion> mMappedIndexRegions;
 
+	mutable LLGLFence* mFence;
+
+	void placeFence() const;
+	void waitFence() const;
+
+
 public:
 	static S32 sCount;
 	static S32 sGLCount;