From 47f518d1c7c4800bbf8b7487096b9820909fa26f Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Sun, 30 Nov 2008 15:56:47 +0000
Subject: [PATCH] From Art Tevs, "here are a small extension to the osg::Image
 class, which do computes data type from the given format, i.e. (GL_RGB32F_ARB
 -> GL_FLOAT). The method is very usefull to find out which data type a
 texture or an image have based on the internal/pixel format."

---
 include/osg/Image | 10 +++++++++
 src/osg/Image.cpp | 56 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)

diff --git a/include/osg/Image b/include/osg/Image
index 4773f9c36..2e937b0a6 100644
--- a/include/osg/Image
+++ b/include/osg/Image
@@ -255,6 +255,7 @@ class OSG_EXPORT Image : public Object
 
         static bool isPackedType(GLenum type);
         static GLenum computePixelFormat(GLenum pixelFormat);
+        static GLenum computeFormatDataType(GLenum pixelFormat);
         static unsigned int computeNumComponents(GLenum pixelFormat);
         static unsigned int computePixelSizeInBits(GLenum pixelFormat,GLenum type);
         static unsigned int computeRowWidthInBytes(int width,GLenum pixelFormat,GLenum type,int packing);
@@ -294,6 +295,15 @@ class OSG_EXPORT Image : public Object
         {
            return _data+getMipmapOffset(mipmapLevel);
         }
+
+        /*inline const unsigned char* getMipmapData(unsigned int row, unsigned int column, unsigned int mipmapLevel) const
+        {
+           if (!_data) return NULL;
+           return getMipmapData(mipmapLevel) + (column*getPixelSizeInBits())/8+row*getRowSizeInBytes();
+        }*/
+
+        /** Build all mipmap levels and change the image type to \"contain mipmaps\" **/
+        void buildMipmaps();
         
         /** Return true if this image is translucent - i.e. it has alpha values that are less 1.0 (when normalized). */
         bool isImageTranslucent() const;
diff --git a/src/osg/Image.cpp b/src/osg/Image.cpp
index a77155810..90ce0fb58 100644
--- a/src/osg/Image.cpp
+++ b/src/osg/Image.cpp
@@ -226,6 +226,62 @@ GLenum Image::computePixelFormat(GLenum format)
     }
 }
 
+GLenum Image::computeFormatDataType(GLenum pixelFormat)
+{
+    switch (pixelFormat)
+    {
+        case GL_LUMINANCE32F_ARB:
+        case GL_LUMINANCE16F_ARB: 
+        case GL_LUMINANCE_ALPHA32F_ARB:
+        case GL_LUMINANCE_ALPHA16F_ARB: 
+        case GL_RGB32F_ARB:
+        case GL_RGB16F_ARB: 
+        case GL_RGBA32F_ARB:
+        case GL_RGBA16F_ARB: return GL_FLOAT;
+
+        case GL_RGBA32UI_EXT:
+        case GL_RGB32UI_EXT:
+        case GL_LUMINANCE32UI_EXT:
+        case GL_LUMINANCE_ALPHA32UI_EXT: return GL_UNSIGNED_INT;
+
+        case GL_RGB16UI_EXT:
+        case GL_RGBA16UI_EXT:
+        case GL_LUMINANCE16UI_EXT: 
+        case GL_LUMINANCE_ALPHA16UI_EXT: return GL_UNSIGNED_SHORT;
+
+        case GL_RGBA8UI_EXT:
+        case GL_RGB8UI_EXT:
+        case GL_LUMINANCE8UI_EXT:
+        case GL_LUMINANCE_ALPHA8UI_EXT:  return GL_UNSIGNED_BYTE;
+
+        case GL_RGBA32I_EXT:  
+        case GL_RGB32I_EXT:
+        case GL_LUMINANCE32I_EXT:
+        case GL_LUMINANCE_ALPHA32I_EXT: return GL_INT;
+
+        case GL_RGBA16I_EXT:
+        case GL_RGB16I_EXT:
+        case GL_LUMINANCE16I_EXT:
+        case GL_LUMINANCE_ALPHA16I_EXT: return GL_SHORT;
+
+        case GL_RGB8I_EXT: 
+        case GL_RGBA8I_EXT: 
+        case GL_LUMINANCE8I_EXT: 
+        case GL_LUMINANCE_ALPHA8I_EXT: return GL_BYTE;
+
+        case GL_RGBA:
+        case GL_RGB:
+        case GL_LUMINANCE:
+        case GL_LUMINANCE_ALPHA: return GL_UNSIGNED_BYTE;
+
+        default: 
+        {
+            notify(WARN)<<"error computeFormatType = "<<std::hex<<pixelFormat<<std::endl;
+            return 0;
+        }
+    }
+}
+
 unsigned int Image::computeNumComponents(GLenum pixelFormat)
 {
     switch(pixelFormat)