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/include/EGL/eglext.h b/opengl/include/EGL/eglext.h
index 25cfcb8..335b0b0 100644
--- a/opengl/include/EGL/eglext.h
+++ b/opengl/include/EGL/eglext.h
@@ -131,6 +131,18 @@
/* Interfaces defined by EGL_KHR_image above */
#endif
+
+#ifndef EGL_ANDROID_swap_rectangle
+#define EGL_ANDROID_swap_rectangle 1
+#ifdef EGL_EGLEXT_PROTOTYPES
+EGLAPI EGLBoolean EGLAPIENTRY eglSetSwapRectangleANDROID (EGLDisplay dpy, EGLSurface draw, EGLint left, EGLint top, EGLint width, EGLint height);
+#endif /* EGL_EGLEXT_PROTOTYPES */
+typedef EGLBoolean (EGLAPIENTRYP PFNEGLSETSWAPRECTANGLEANDROIDPROC) (EGLDisplay dpy, EGLSurface draw, EGLint left, EGLint top, EGLint width, EGLint height);
+#endif
+
+
+
+
#ifdef __cplusplus
}
#endif