
This extension lets you upload texture data from a subregion of a buffer by passing GL_UNPACK_ROW_LENGTH, GL_UNPACK_SKIP_PIXELS and GL_UNPACK_SKIP_ROWS to glPixelStore. When this extension is available the GLES texture driver will now avoid making a copy of the bitmap when a subregion is used. Note that Mesa doesn't currently advertise this extension but I've made a patch to propose it: http://lists.freedesktop.org/archives/mesa-dev/2012-March/020191.html