From Johannes Baeurele, "The osg::Image class now contains a 'supportsTextureSubloading()' method that is used inside the Texture2D::apply method. For now it only checks for the etc1 format in which case it returns 'false'. All other formats lead to a return value of 'true'.

Without the change the application does not work properly. First I get the notification that an OpenGL error occured. After some more of this error messages I see broken textures on the screen. With the changes attached to this message my application works as intended."

Note from Robert Osfield, changed the Image::supportsTextureSubloading() to be const and to be implemented in the .cpp rather than inline.

include/osg/Image

@@ -92,6 +92,10 @@
     #define GL_UNPACK_IMAGE_HEIGHT  0x806E
 #endif
 
+#ifndef GL_OES_compressed_ETC1_RGB8_texture
+    #define GL_ETC1_RGB8_OES        0x8D64   
+#endif
+
 namespace osg {
 
 // forward declare
@@ -396,6 +400,9 @@ class OSG_EXPORT Image : public BufferData
            return _data+getMipmapOffset(mipmapLevel);
         }
 
+        /** returns false for texture formats that do not support texture subloading */
+        bool supportsTextureSubloading() const;
+
         /** Return true if this image is translucent - i.e. it has alpha values that are less 1.0 (when normalized). */
         virtual bool isImageTranslucent() const;