Native bindings to the MESA_framebuffer_swap_xy extension.

This extension defines a new framebuffer parameter, FRAMEBUFFER_SWAP_XY_MESA, that changes the behavior of the reads and writes to the framebuffer attachment points. When GL_FRAMEBUFFER_SWAP_XY_MESA is TRUE, render commands and pixel transfer operations access the backing store of each attachment point with an xy-swapped coordinate system. This xy-inversion is relative to the coordinate system set when GL_FRAMEBUFFER_SWAP_XY_MESA is FALSE.

Access through TexSubImage2D and similar calls will notice the effect of the swap when they are not attached to framebuffer objects because GL_FRAMEBUFFER_SWAP_XY_MESA is associated with the framebuffer object and not the attachment points.

The application should notice the display width and height are also swapped when GL_FRAMEBUFFER_SWAP_XY_MESA is GL_TRUE.

This extension is mainly for pre-rotation and recommended to use it with MESA_framebuffer_flip_x and MESA_framebuffer_flip_y to have rotated result.

Requires GLES 3.1.