From 4f4f68e961321ab50bd75a0b42466934b86a13cf Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Wed, 19 Jun 2002 18:45:05 +0000
Subject: [PATCH] Added support for reading the new OSG_MAX_TEXTURE_SIZE
 environmental variable inside the osg::Image::ensureValidSizeForTexturing()
 method. The smallest of GL_MAX_TEXTURE_SIZE and OSG_MAX_TEXTURE_SIZE is used
 for the final max texture size.

This new env. var. allows users to deliberate cap the size of their textures
so they can test whether their models are limited by texture memory.  If
reducing the max texture size increases performance then you are limited
by texture memory!
---
 src/osg/Image.cpp | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/osg/Image.cpp b/src/osg/Image.cpp
index d2d80f002..026b8e86d 100644
--- a/src/osg/Image.cpp
+++ b/src/osg/Image.cpp
@@ -431,9 +431,24 @@ void Image::ensureValidSizeForTexturing()
     {
         init = false;
         glGetIntegerv(GL_MAX_TEXTURE_SIZE,&max_size);
-        notify(INFO) << "Max texture size "<<max_size<<std::endl;
+        notify(INFO) << "GL_MAX_TEXTURE_SIZE "<<max_size<<std::endl;
+        
+        char *ptr;
+        if( (ptr = getenv("OSG_MAX_TEXTURE_SIZE")) != 0)
+        {
+            GLint osg_max_size = atoi(ptr);
+            
+            notify(INFO) << "OSG_MAX_TEXTURE_SIZE "<<osg_max_size<<std::endl;
+            
+            if (osg_max_size<max_size)
+            {
+                
+                max_size = osg_max_size;
+            }
+            
+        }      
+        notify(INFO) << "Selected max texture size "<<max_size<<std::endl;
     }
-    
     //max_size = 64;
     
     if (new_s>max_size) new_s = max_size;