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 windowDraw(w *C.ANativeWindow, queue *C.AInputQueue, donec chan struct{}) (done bool) {
// Android can send a windowRedrawNeeded event any time, including
// in the middle of a paint cycle. The redraw event may have changed
// the size of the screen, so any partial painting is now invalidated.
// We must also not return to Android (via sending on windowRedrawDone)
// until a complete paint with the new configuration is complete.
//
// When a windowRedrawNeeded request comes in, we increment redrawGen
// (Gen is short for generation number), and do not make a paint cycle
// visible on <-endPaint unless paintGen agrees. If possible,
// windowRedrawDone is signalled, allowing onNativeWindowRedrawNeeded
// to return.
var redrawGen, paintGen uint32
for {
processEvents(queue)
select {
case <-donec:
return true
case cfg := <-windowConfigChange:
// TODO save orientation
pixelsPerPt = cfg.pixelsPerPt
case w := <-windowRedrawNeeded:
sendLifecycle(lifecycle.StageFocused)
widthPx := int(C.ANativeWindow_getWidth(w))
heightPx := int(C.ANativeWindow_getHeight(w))
eventsIn <- config.Event{
WidthPx: widthPx,
HeightPx: heightPx,
WidthPt: geom.Pt(float32(widthPx) / pixelsPerPt),
HeightPt: geom.Pt(float32(heightPx) / pixelsPerPt),
PixelsPerPt: pixelsPerPt,
}
if paintGen == 0 {
paintGen++
C.createEGLWindow(w)
eventsIn <- paint.Event{}
}
redrawGen++
case <-windowDestroyed:
sendLifecycle(lifecycle.StageAlive)
return false
case <-gl.WorkAvailable:
gl.DoWork()
case <-endPaint:
if paintGen == redrawGen {
// eglSwapBuffers blocks until vsync.
C.eglSwapBuffers(C.display, C.surface)
select {
case windowRedrawDone <- struct{}{}:
default:
}
}
paintGen = redrawGen
eventsIn <- paint.Event{}
}
}
}
func windowDraw(w *C.ANativeWindow, queue *C.AInputQueue, donec chan struct{}) (done bool) {
C.createEGLWindow(w)
// TODO: is this needed if we also have the "case <-windowRedrawNeeded:" below??
sendLifecycle(lifecycle.StageFocused)
eventsIn <- config.Event{
Width: geom.Pt(float32(C.windowWidth) / pixelsPerPt),
Height: geom.Pt(float32(C.windowHeight) / pixelsPerPt),
PixelsPerPt: pixelsPerPt,
}
if firstWindowDraw {
firstWindowDraw = false
// TODO: be more principled about when to send a paint event.
eventsIn <- paint.Event{}
}
for {
processEvents(queue)
select {
case <-donec:
return true
case <-windowRedrawNeeded:
// Re-query the width and height.
C.querySurfaceWidthAndHeight()
sendLifecycle(lifecycle.StageFocused)
eventsIn <- config.Event{
Width: geom.Pt(float32(C.windowWidth) / pixelsPerPt),
Height: geom.Pt(float32(C.windowHeight) / pixelsPerPt),
PixelsPerPt: pixelsPerPt,
}
case <-windowDestroyed:
sendLifecycle(lifecycle.StageAlive)
return false
case <-gl.WorkAvailable:
gl.DoWork()
case <-endDraw:
// eglSwapBuffers blocks until vsync.
C.eglSwapBuffers(C.display, C.surface)
eventsIn <- paint.Event{}
}
}
}
func windowDraw(w *C.ANativeWindow, queue *C.AInputQueue, donec chan struct{}) (done bool) {
C.createEGLWindow(w)
// TODO: is this needed if we also have the "case <-windowRedrawNeeded:" below??
sendLifecycle(event.LifecycleStageFocused)
eventsIn <- event.Config{
Width: geom.Pt(float32(C.windowWidth) / pixelsPerPt),
Height: geom.Pt(float32(C.windowHeight) / pixelsPerPt),
PixelsPerPt: pixelsPerPt,
}
if firstWindowDraw {
firstWindowDraw = false
// TODO: be more principled about when to send a draw event.
eventsIn <- event.Draw{}
}
for {
processEvents(queue)
select {
case <-donec:
return true
case <-windowRedrawNeeded:
// Re-query the width and height.
C.querySurfaceWidthAndHeight()
sendLifecycle(event.LifecycleStageFocused)
eventsIn <- event.Config{
Width: geom.Pt(float32(C.windowWidth) / pixelsPerPt),
Height: geom.Pt(float32(C.windowHeight) / pixelsPerPt),
PixelsPerPt: pixelsPerPt,
}
// This gl.Viewport call has to be in a separate goroutine because any gl
// call can block until gl.DoWork is called, but this goroutine is the one
// responsible for calling gl.DoWork.
// TODO: again, should x/mobile/app be responsible for calling GL code, or
// should package gl instead call event.RegisterFilter?
{
c := make(chan struct{})
go func() {
gl.Viewport(0, 0, int(C.windowWidth), int(C.windowHeight))
close(c)
}()
loop1:
for {
select {
case <-gl.WorkAvailable:
gl.DoWork()
case <-c:
break loop1
}
}
}
case <-windowDestroyed:
sendLifecycle(event.LifecycleStageAlive)
return false
case <-gl.WorkAvailable:
gl.DoWork()
case <-endDraw:
// eglSwapBuffers blocks until vsync.
C.eglSwapBuffers(C.display, C.surface)
eventsIn <- event.Draw{}
}
}
}