func windowDrawLoop(cb Callbacks, w *C.ANativeWindow, queue *C.AInputQueue) {
C.createEGLWindow(w)
// TODO: is the library or the app responsible for clearing the buffers?
gl.ClearColor(0, 0, 0, 1)
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
C.eglSwapBuffers(C.display, C.surface)
if errv := gl.GetError(); errv != gl.NO_ERROR {
log.Printf("GL initialization error: %s", errv)
}
geom.Width = geom.Pt(float32(C.windowWidth) / geom.PixelsPerPt)
geom.Height = geom.Pt(float32(C.windowHeight) / geom.PixelsPerPt)
for {
processEvents(cb, queue)
select {
case <-windowDestroyed:
return
default:
if cb.Draw != nil {
cb.Draw()
}
C.eglSwapBuffers(C.display, C.surface)
}
}
}
func checkGLError() {
if glErr := gl.GetError(); glErr != gl.NO_ERROR {
log.Fatalf("gl. error: %v", glErr)
}
}