GL_EXT_framebuffer_blit http://www.opengl.org/registry/specs/EXT/framebuffer_blit.txt GL_EXT_framebuffer_blit GL_DRAW_FRAMEBUFFER_BINDING_EXT 0x8CA6 GL_READ_FRAMEBUFFER_EXT 0x8CA8 GL_DRAW_FRAMEBUFFER_EXT 0x8CA9 GL_READ_FRAMEBUFFER_BINDING_EXT 0x8CAA void glBlitFramebufferEXT (GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1, GLbitfield mask, GLenum filter)