From 0900857333845d5eedd6f0e894dbbd9f3042fc76 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Fri, 25 Aug 2006 08:48:16 +0000
Subject: [PATCH] From Farshid Lashkari, "I was experiencing hard crashes of my
 application when using PBO's on machines that don't support PBO's. I think
 osg incorrectly checks if PBO's are supported.

I added a new method to the BufferObject::Extensions class which
returns if the "GL_ARB_pixel_buffer_object" string is supported. This
fixes the problem on my end. Machines without PBO support will
continue to work and machines with PBO support will still be able to
use it."
---
 include/osg/BufferObject     | 3 +++
 src/osg/BufferObject.cpp     | 3 ++-
 src/osg/Texture.cpp          | 4 ++--
 src/osg/TextureRectangle.cpp | 4 ++--
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/include/osg/BufferObject b/include/osg/BufferObject
index f541c3cca..c000b1667 100644
--- a/include/osg/BufferObject
+++ b/include/osg/BufferObject
@@ -106,6 +106,7 @@ class OSG_EXPORT BufferObject : public Object
         };
 
         inline bool isBufferObjectSupported(unsigned int contextID) const { return getExtensions(contextID,true)->isBufferObjectSupported(); }
+        inline bool isPBOSupported(unsigned int contextID) const { return getExtensions(contextID,true)->isPBOSupported(); }
 
         inline GLuint& buffer(unsigned int contextID) const { return _bufferObjectList[contextID]; }
         
@@ -153,6 +154,7 @@ class OSG_EXPORT BufferObject : public Object
             void setupGLExtenions(unsigned int contextID);
 
             bool isBufferObjectSupported() const { return _glGenBuffers!=0; }
+            bool isPBOSupported() const { return _isPBOSupported; }
 
             void glGenBuffers (GLsizei n, GLuint *buffers) const;
             void glBindBuffer (GLenum target, GLuint buffer) const;
@@ -192,6 +194,7 @@ class OSG_EXPORT BufferObject : public Object
             GetBufferParameterivProc _glGetBufferParameteriv;
             GetBufferPointervProc   _glGetBufferPointerv;
 
+            bool _isPBOSupported;
         };
 
         /** Function to call to get the extension of a specified context.
diff --git a/src/osg/BufferObject.cpp b/src/osg/BufferObject.cpp
index 5aa7a132b..aa4429558 100644
--- a/src/osg/BufferObject.cpp
+++ b/src/osg/BufferObject.cpp
@@ -182,7 +182,7 @@ void BufferObject::Extensions::lowestCommonDenominator(const Extensions& rhs)
     if (!rhs._glGetBufferParameteriv) _glGetBufferPointerv = rhs._glGetBufferPointerv;
 }
 
-void BufferObject::Extensions::setupGLExtenions(unsigned int)
+void BufferObject::Extensions::setupGLExtenions(unsigned int contextID)
 {
     _glGenBuffers = ((GenBuffersProc)osg::getGLExtensionFuncPtr("glGenBuffers","glGenBuffersARB"));
     _glBindBuffer = ((BindBufferProc)osg::getGLExtensionFuncPtr("glBindBuffer","glBindBufferARB"));
@@ -195,6 +195,7 @@ void BufferObject::Extensions::setupGLExtenions(unsigned int)
     _glUnmapBuffer = ((UnmapBufferProc)osg::getGLExtensionFuncPtr("glUnmapBuffer","glUnmapBufferARB"));
     _glGetBufferParameteriv = ((GetBufferParameterivProc)osg::getGLExtensionFuncPtr("glGetBufferParameteriv","glGetBufferParameterivARB"));
     _glGetBufferPointerv = ((GetBufferPointervProc)osg::getGLExtensionFuncPtr("glGetBufferPointerv","glGetBufferPointervARB"));
+    _isPBOSupported = osg::isGLExtensionSupported(contextID,"GL_ARB_pixel_buffer_object");
 }
 
 void BufferObject::Extensions::glGenBuffers(GLsizei n, GLuint *buffers) const
diff --git a/src/osg/Texture.cpp b/src/osg/Texture.cpp
index 63a36113b..72808cbcd 100644
--- a/src/osg/Texture.cpp
+++ b/src/osg/Texture.cpp
@@ -897,7 +897,7 @@ void Texture::applyTexImage2D_load(State& state, GLenum target, const Image* ima
     unsigned char* dataPlusOffset = 0;
 
     const PixelBufferObject* pbo = image->getPixelBufferObject();
-    if (pbo && pbo->isBufferObjectSupported(contextID) && !needImageRescale)
+    if (pbo && pbo->isPBOSupported(contextID) && !needImageRescale)
     {
         pbo->compileBuffer(state);
         pbo->bindBuffer(contextID);
@@ -1149,7 +1149,7 @@ void Texture::applyTexImage2D_subload(State& state, GLenum target, const Image*
     unsigned char* dataPlusOffset=0;
 
     const PixelBufferObject* pbo = image->getPixelBufferObject();
-    if (pbo && pbo->isBufferObjectSupported(contextID) && !needImageRescale)
+    if (pbo && pbo->isPBOSupported(contextID) && !needImageRescale)
     {
         pbo->compileBuffer(state);
         pbo->bindBuffer(contextID);
diff --git a/src/osg/TextureRectangle.cpp b/src/osg/TextureRectangle.cpp
index b934f5216..25a51871d 100644
--- a/src/osg/TextureRectangle.cpp
+++ b/src/osg/TextureRectangle.cpp
@@ -283,7 +283,7 @@ void TextureRectangle::applyTexImage_load(GLenum target, Image* image, State& st
     unsigned char* dataPlusOffset = 0;
 
     const PixelBufferObject* pbo = image->getPixelBufferObject();
-    if (pbo && pbo->isBufferObjectSupported(contextID))
+    if (pbo && pbo->isPBOSupported(contextID))
     {
         pbo->compileBuffer(state);
         pbo->bindBuffer(contextID);
@@ -350,7 +350,7 @@ void TextureRectangle::applyTexImage_subload(GLenum target, Image* image, State&
     unsigned char* dataPlusOffset = 0;
 
     const PixelBufferObject* pbo = image->getPixelBufferObject();
-    if (pbo && pbo->isBufferObjectSupported(contextID))
+    if (pbo && pbo->isPBOSupported(contextID))
     {
         pbo->compileBuffer(state);
         pbo->bindBuffer(contextID);