From Farshid Lashkari, "This patch adds a CoordOriginMode to the osg::PointSprite attribute.

The mode needs to be changed to LOWER_LEFT when rendering point
sprites to pbuffers or FBOs, otherwise the points will be transformed
on the CPU."

include/osg/Point

@@ -94,6 +94,7 @@ class OSG_EXPORT Point : public StateAttribute
                 void setPointParametersSupported(bool flag) { _isPointParametersSupported=flag; }
                 bool isPointParametersSupported() const { return _isPointParametersSupported; }
                 
+                void glPointParameteri(GLenum pname, GLint param) const;
                 void glPointParameterf(GLenum pname, GLfloat param) const;
                 void glPointParameterfv(GLenum pname, const GLfloat *params) const;
 
@@ -103,6 +104,7 @@ class OSG_EXPORT Point : public StateAttribute
                 
                 bool    _isPointParametersSupported;
 
+                void*   _glPointParameteri;
                 void*   _glPointParameterf;
                 void*   _glPointParameterfv;
 

include/osg/PointSprite

@@ -20,6 +20,9 @@
 #ifndef GL_ARB_point_sprite
 #define GL_POINT_SPRITE_ARB               0x8861
 #define GL_COORD_REPLACE_ARB              0x8862
+#define GL_POINT_SPRITE_COORD_ORIGIN      0x8CA0
+#define GL_LOWER_LEFT                     0x8CA1
+#define GL_UPPER_LEFT                     0x8CA2
 #endif
 
 namespace osg {
@@ -28,11 +31,12 @@ namespace osg {
 class OSG_EXPORT PointSprite : public osg::StateAttribute {
 public:
 
-        PointSprite() {}
+        PointSprite();
 
         /** Copy constructor using CopyOp to manage deep vs shallow copy.*/
-        PointSprite(const PointSprite& texenv,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY):        
-            StateAttribute(texenv,copyop) {}
+        PointSprite(const PointSprite& ps,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY):        
+            StateAttribute(ps,copyop),
+            _coordOriginMode(ps._coordOriginMode) {}
 
 
         META_StateAttribute(osg, PointSprite, POINTSPRITE);
@@ -53,9 +57,19 @@ public:
         virtual void apply(osg::State& state) const;
 
         static bool isPointSpriteSupported(unsigned int context);
+        
+        enum CoordOriginMode {
+            UPPER_LEFT = GL_UPPER_LEFT,
+            LOWER_LEFT = GL_LOWER_LEFT
+        };
+        
+        inline void setCoordOriginMode(CoordOriginMode mode) { _coordOriginMode = mode; }
+        inline CoordOriginMode getCoordOriginMode() const { return _coordOriginMode; }
 
 protected:
-        virtual ~PointSprite( void ) {}
+        virtual ~PointSprite();
+        
+        CoordOriginMode _coordOriginMode;
 };
 
 }

src/osg/Point.cpp

@@ -116,6 +116,7 @@ Point::Extensions::Extensions(const Extensions& rhs):
 void Point::Extensions::lowestCommonDenominator(const Extensions& rhs)
 {
     if (!rhs._isPointParametersSupported)  _isPointParametersSupported = false;
+    if (!rhs._glPointParameteri)           _glPointParameteri = 0;
     if (!rhs._glPointParameterf)           _glPointParameterf = 0;
     if (!rhs._glPointParameterfv)          _glPointParameterfv = 0;
 }
@@ -126,7 +127,10 @@ void Point::Extensions::setupGLExtenions(unsigned int contextID)
                                   isGLExtensionSupported(contextID,"GL_ARB_point_parameters") ||
                                   isGLExtensionSupported(contextID,"GL_EXT_point_parameters") ||
                                   isGLExtensionSupported(contextID,"GL_SGIS_point_parameters");
-                                  
+            
+    _glPointParameteri = getGLExtensionFuncPtr("glPointParameteri", "glPointParameteriARB");
+    if (!_glPointParameteri) _glPointParameteri = getGLExtensionFuncPtr("glPointParameteriEXT", "glPointParameteriSGIS");
+
     _glPointParameterf = getGLExtensionFuncPtr("glPointParameterf", "glPointParameterfARB");
     if (!_glPointParameterf) _glPointParameterf = getGLExtensionFuncPtr("glPointParameterfEXT", "glPointParameterfSGIS");
 
@@ -134,6 +138,18 @@ void Point::Extensions::setupGLExtenions(unsigned int contextID)
     if (!_glPointParameterfv) _glPointParameterfv = getGLExtensionFuncPtr("glPointParameterfvEXT", "glPointParameterfvSGIS");
 }
 
+void Point::Extensions::glPointParameteri(GLenum pname, GLint param) const
+{
+    if (_glPointParameteri)
+    {
+        typedef void (APIENTRY * GLPointParameteriProc) (GLenum pname, GLint param);
+        ((GLPointParameteriProc)_glPointParameteri)(pname, param);
+    }
+    else
+    {
+        notify(WARN)<<"Error: glPointParameteri not supported by OpenGL driver"<<std::endl;
+    }
+}
 
 void Point::Extensions::glPointParameterf(GLenum pname, GLfloat param) const
 {

src/osg/PointSprite.cpp

@@ -14,19 +14,27 @@
 #include <osg/GLExtensions>
 #include <osg/GL>
 #include <osg/PointSprite>
+#include <osg/Point>
 #include <osg/State>
 #include <osg/buffered_value>
 #include <osg/Notify>
 
 using namespace osg;
 
+PointSprite::PointSprite()
+    : _coordOriginMode(UPPER_LEFT)
+{
+}
+
+PointSprite::~PointSprite()
+{
+}
+
 int PointSprite::compare(const StateAttribute& sa) const
 {
-    if (this==&sa) return 0;\
-    const std::type_info* type_lhs = &typeid(*this);\
-    const std::type_info* type_rhs = &typeid(sa);\
-    if (type_lhs->before(*type_rhs)) return -1;\
-    if (*type_lhs != *type_rhs) return 1;\
+    COMPARE_StateAttribute_Types(PointSprite,sa)
+
+    COMPARE_StateAttribute_Parameter(_coordOriginMode)
 
     return 0; // passed all the above comparison macro's, must be equal.
 }
@@ -46,6 +54,11 @@ void PointSprite::apply(osg::State& state) const
     if(!isPointSpriteSupported(state.getContextID())) return;
 
     glTexEnvi(GL_POINT_SPRITE_ARB, GL_COORD_REPLACE_ARB, 1);
+
+    const Point::Extensions* extensions = Point::getExtensions(state.getContextID(),true);
+
+    if (extensions->isPointParametersSupported())
+        extensions->glPointParameteri(GL_POINT_SPRITE_COORD_ORIGIN,_coordOriginMode);
 }
 
 struct IntializedSupportedPair