Functions added to the GPU module for best computation of GL pack/unpack alignment

GPU/Alignment.h

+/*
+ *	(c) LSIIT, UMR CNRS/UdS
+ *	Authors: F. Larue.
+ *
+ *	See licence.txt for additional information.
+ */
+
+
+#ifndef __GPU__ALIGNMENT_H__
+#define __GPU__ALIGNMENT_H__
+
+
+
+
+#include "GPUdefs.h"
+#include <assert.h>
+
+
+namespace GPU
+{
+    inline unsigned int ChannelCount( GLenum format )
+    {
+        switch( format )
+        {
+            case GL_LUMINANCE:  return 1;
+            case GL_RGB      :  return 3;
+            case GL_RGBA     :  return 4;
+            default          :  assert(false);
+        }
+        return 0;
+    }
+
+    inline unsigned int TypeSize( GLenum type )
+    {
+        switch( type )
+        {
+            case GL_UNSIGNED_BYTE :  return sizeof(GLubyte );
+            case GL_BYTE          :  return sizeof(GLbyte  );
+            case GL_UNSIGNED_SHORT:  return sizeof(GLushort);
+            case GL_SHORT         :  return sizeof(GLshort );
+            case GL_UNSIGNED_INT  :  return sizeof(GLuint  );
+            case GL_INT           :  return sizeof(GLint   );
+            case GL_FLOAT         :  return sizeof(GLfloat );
+            case GL_DOUBLE        :  return sizeof(GLdouble);
+            default               :  assert(false);
+        }
+        return 0;
+    }
+
+    inline unsigned int PixelSize( GLenum format, GLenum type )
+    {
+        return ChannelCount(format) * TypeSize(type);
+    }
+
+    inline void SetAlignment( GLenum alignParam, unsigned int stride )
+    {
+        static const int alignment[8] = { 8, 1, 2, 1, 4, 1, 2, 1 };
+        glPixelStorei( alignParam, alignment[stride & 7] );
+    }
+
+    inline void SetPackAlignment( unsigned int stride )
+    {
+        SetAlignment( GL_PACK_ALIGNMENT, stride );
+    }
+
+    inline void SetPackAlignment( unsigned int width,
+                                  GLenum format,
+                                  GLenum type )
+    {
+        SetPackAlignment( width * PixelSize(format, type) );
+    }
+
+    inline void SetUnpackAlignment( unsigned int stride )
+    {
+        SetAlignment( GL_UNPACK_ALIGNMENT, stride );
+    }
+
+    inline void SetUnpackAlignment( unsigned int width,
+                                    GLenum format,
+                                    GLenum type )
+    {
+        SetUnpackAlignment( width * PixelSize(format, type) );
+    }
+}
+
+
+
+
+#endif //__GPU__ALIGNMENT_H__

GPU/GPU.h

@@ -12,6 +12,7 @@
 
 
 
+#include "Alignment.h"
 #include "Shader.h"
 #include "VBO.h"
 #include "FrameBuffer.h"