created an new EGL extension called ANDROID_swap_rectangle
ANDROID_swap_rectangle allows to specify the rectangle affected by eglSwapBuffers(), anything outside of this rectangle is unchanged. in particular EGL_BUFFER_DESTROYED only applies to that rectangle. This extension as well as EGL_BUFFER_PRESERVED allow major optimizations on surfaceflinger, which can redraw only the dirty area during compositing.
However, ANDROID_swap_rectangle allows further optimizations in EGL by reducing the amount of copy-back needed. ANDROID_swap_rectangle is particularily important for software implementations.
diff --git a/opengl/libs/egl_entries.in b/opengl/libs/egl_entries.in
index 3b4551b..1fe2b57 100644
--- a/opengl/libs/egl_entries.in
+++ b/opengl/libs/egl_entries.in
@@ -50,3 +50,7 @@
EGL_ENTRY(EGLBoolean, eglUnlockSurfaceKHR, EGLDisplay, EGLSurface)
EGL_ENTRY(EGLImageKHR, eglCreateImageKHR, EGLDisplay, EGLContext, EGLenum, EGLClientBuffer, const EGLint *)
EGL_ENTRY(EGLBoolean, eglDestroyImageKHR, EGLDisplay, EGLImageKHR)
+
+/* ANDROID extensions */
+
+EGL_ENTRY(EGLBoolean, eglSetSwapRectangleANDROID, EGLDisplay, EGLSurface, EGLint, EGLint, EGLint, EGLint)