Native bindings to the NOK_swap_region2 extension.

This extension adds a new function which provides an alternative to eglSwapBuffers. eglSwapBuffersRegion2NOK accepts two new parameters in addition to those in eglSwapBuffers. The new parameters consist of a pointer to a list of 4-integer blocks defining rectangles (x, y, width, height) and an integer specifying the number of rectangles in the list.

The new parameters allow users to declare the region of the surface that has been updated. The implementation uses this information to transfer the updated region to the front buffer. Only the pixels within the specified region are copied; any rendering outside that region will not become visible on the window surface. This in contrast with the EGL_NOK_swap_region extension which treats the modified region only as a hint.

This functional change is aimed at further reducing the processing and bandwidth requirements of optimizations of applications whose graphics are commonly subjected to region-based changes. Specifically, this extension enables partial surface updates without requiring the use of preserved swaps.

Requires EGL 1.4.