From 253642ccff9b08da5e62449ff62b23e986dcb77d Mon Sep 17 00:00:00 2001
From: Dave Parks <davep@lindenlab.com>
Date: Thu, 23 Jun 2011 23:06:36 -0500
Subject: [PATCH] SH-1903 Don't use indexed texture rendering when GL version
is < 3.1 (fixes bad performance on cards with old drivers)
---
indra/llrender/llglslshader.cpp | 10 ++++++++++
indra/llrender/llshadermgr.cpp | 7 ++++++-
indra/newview/llvovolume.cpp | 5 +++++
3 files changed, 21 insertions(+), 1 deletion(-)
diff --git a/indra/llrender/llglslshader.cpp b/indra/llrender/llglslshader.cpp
index 8e99f62de68..ad2c662dfca 100644
--- a/indra/llrender/llglslshader.cpp
+++ b/indra/llrender/llglslshader.cpp
@@ -109,6 +109,11 @@ BOOL LLGLSLShader::createShader(vector<string> * attributes,
// Create program
mProgramObject = glCreateProgramObjectARB();
+ if (gGLManager.mGLVersion < 3.1f)
+ { //force indexed texture channels to 1 if GL version is old (performance improvement for drivers with poor branching shader model support)
+ mFeatures.mIndexedTextureChannels = llmin(mFeatures.mIndexedTextureChannels, 1);
+ }
+
//compile new source
vector< pair<string,GLenum> >::iterator fileIter = mShaderFiles.begin();
for ( ; fileIter != mShaderFiles.end(); fileIter++ )
@@ -131,6 +136,11 @@ BOOL LLGLSLShader::createShader(vector<string> * attributes,
return FALSE;
}
+ if (gGLManager.mGLVersion < 3.1f)
+ { //attachShaderFeatures may have set the number of indexed texture channels, so set to 1 again
+ mFeatures.mIndexedTextureChannels = llmin(mFeatures.mIndexedTextureChannels, 1);
+ }
+
// Map attributes and uniforms
if (success)
{
diff --git a/indra/llrender/llshadermgr.cpp b/indra/llrender/llshadermgr.cpp
index bdc103b9170..3910cd779c7 100644
--- a/indra/llrender/llshadermgr.cpp
+++ b/indra/llrender/llshadermgr.cpp
@@ -524,7 +524,12 @@ GLhandleARB LLShaderMgr::loadShaderFile(const std::string& filename, S32 & shade
text[count++] = strdup("{\n");
- if (gGLManager.mGLVersion >= 3.f)
+ if (texture_index_channels == 1)
+ { //don't use flow control, that's silly
+ text[count++] = strdup("return texture2D(tex0, texcoord);\n");
+ text[count++] = strdup("}\n");
+ }
+ else if (gGLManager.mGLVersion >= 3.f)
{
text[count++] = strdup("\tswitch (int(vary_texture_index+0.25))\n");
text[count++] = strdup("\t{\n");
diff --git a/indra/newview/llvovolume.cpp b/indra/newview/llvovolume.cpp
index c5e2c56e4b2..e6da8eb89d8 100644
--- a/indra/newview/llvovolume.cpp
+++ b/indra/newview/llvovolume.cpp
@@ -4495,6 +4495,11 @@ void LLVolumeGeometryManager::genDrawInfo(LLSpatialGroup* group, U32 mask, std::
S32 texture_index_channels = gGLManager.mNumTextureImageUnits-1; //always reserve one for shiny for now just for simplicity
+ if (gGLManager.mGLVersion < 3.1f)
+ {
+ texture_index_channels = 1;
+ }
+
if (LLPipeline::sRenderDeferred && distance_sort)
{
texture_index_channels = gDeferredAlphaProgram.mFeatures.mIndexedTextureChannels;
--
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