From 48dad727b1a5c9af7513aba61526f2349b4c8438 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Fri, 7 May 2004 11:28:55 +0000
Subject: [PATCH] From Bob Kuehne, added getting of the max number of texture
 units in the Texture::Extension object

---
 include/osg/Texture | 8 ++++++++
 src/osg/Texture.cpp | 4 +++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/include/osg/Texture b/include/osg/Texture
index f11de0af8..b8278760a 100644
--- a/include/osg/Texture
+++ b/include/osg/Texture
@@ -113,6 +113,10 @@
 #define TEXTURE_COMPARE_FAIL_VALUE_ARB    0x80BF
 #endif
 
+#if !defined( GL_MAX_TEXTURE_UNITS )
+#define GL_MAX_TEXTURE_UNITS              0x84E2
+#endif
+
 namespace osg {
 
 /** Texture base class which encapsulates OpenGl texture functionality which common betweent the various types of OpenGL textures.*/
@@ -360,6 +364,9 @@ class SG_EXPORT Texture : public osg::StateAttribute
                 void setMaxTextureSize(GLint maxsize) { _maxTextureSize=maxsize; }
                 GLint maxTextureSize() const { return _maxTextureSize; }
 
+                void setNumTextureUnits(GLint nunits ) { _numTextureUnits=nunits; }
+                GLint numTextureUnits() const { return _numTextureUnits; }
+
                 bool isCompressedTexImage2DSupported() const { return _glCompressedTexImage2D!=0; }
 
                 void setCompressedTexImage2DProc(void* ptr) { _glCompressedTexImage2D = ptr; }
@@ -391,6 +398,7 @@ class SG_EXPORT Texture : public osg::StateAttribute
                 bool    _isClientStorageSupported;
                 
                 GLint   _maxTextureSize;
+                GLint   _numTextureUnits;
 
                 void*   _glCompressedTexImage2D;
                 void*   _glCompressedTexSubImage2D;
diff --git a/src/osg/Texture.cpp b/src/osg/Texture.cpp
index dbdfa4155..38cc20fbe 100644
--- a/src/osg/Texture.cpp
+++ b/src/osg/Texture.cpp
@@ -1102,6 +1102,7 @@ void Texture::Extensions::lowestCommonDenominator(const Extensions& rhs)
     if (!rhs._isGenerateMipMapSupported) _isGenerateMipMapSupported = false;
 
     if (rhs._maxTextureSize<_maxTextureSize) _maxTextureSize = rhs._maxTextureSize;
+    if (rhs._numTextureUnits<_numTextureUnits) _numTextureUnits = rhs._numTextureUnits;
 
     if (!rhs._glCompressedTexImage2D) _glCompressedTexImage2D = 0;
     if (!rhs._glCompressedTexSubImage2D) _glCompressedTexSubImage2D = 0;
@@ -1147,8 +1148,9 @@ void Texture::Extensions::setupGLExtensions()
 
             _maxTextureSize = osg_max_size;
         }
+    }
 
-    }      
+    glGetIntegerv(GL_MAX_TEXTURE_UNITS,&_numTextureUnits);
 
     _glCompressedTexImage2D = getGLExtensionFuncPtr("glCompressedTexImage2D","glCompressedTexImage2DARB");
     _glCompressedTexSubImage2D = getGLExtensionFuncPtr("glCompressedTexSubImage2D","glCompressedTexSubImage2DARB");