hi, currently the opengl output transfers data to the GL via plain calls to glTexSubImage2D or via GL_NV_pixel_data_range. this patch adds a third method,using pixel buffer objects available in opengl 2.1. As they are part of the opengl standard i decided to depend on the correct opengl version rather than on the extension GL_ARB_pixel_buffer_object, but this could be changed easily. Because the SDL is slightly out of date i added an configure option to use the standard glext.h header,which is also the default. Last i removed the GFX_RGBONLY check from the opengl output code, which needs to be investigated, i see currently no color badness in any game.
i don't know if this code is faster at all. I (currently) think this is the equivalent standard way of the GL_NV_pixel_data_range code.
comments are welcome ;)
PS: i also added support for non power of two dimenional textures,which is completely untested, as my card doesn't support those.