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/egl.cpp b/opengl/libs/EGL/egl.cpp
index 74aed20..8c37f2e 100644
--- a/opengl/libs/EGL/egl.cpp
+++ b/opengl/libs/EGL/egl.cpp
@@ -60,6 +60,7 @@
"KHR_image_base "
"KHR_image_pixmap "
"EGL_ANDROID_image_native_buffer "
+ "EGL_ANDROID_swap_rectangle "
;
// ----------------------------------------------------------------------------
@@ -1568,3 +1569,23 @@
return EGL_FALSE;
}
+
+
+// ----------------------------------------------------------------------------
+// ANDROID extensions
+// ----------------------------------------------------------------------------
+
+EGLBoolean eglSetSwapRectangleANDROID(EGLDisplay dpy, EGLSurface draw,
+ EGLint left, EGLint top, EGLint width, EGLint height)
+{
+ if (!validate_display_surface(dpy, draw))
+ return EGL_FALSE;
+ egl_display_t const * const dp = get_display(dpy);
+ egl_surface_t const * const s = get_surface(draw);
+ if (s->cnx->hooks->egl.eglSetSwapRectangleANDROID) {
+ return s->cnx->hooks->egl.eglSetSwapRectangleANDROID(dp->dpys[s->impl],
+ s->surface, left, top, width, height);
+ }
+ return EGL_FALSE;
+}
+