simple stat

cmd/mxl-player/main.go

@@ -462,7 +462,7 @@ func main() {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 	grant := make(chan struct{})
-	staged := make(chan struct{})
+	staged := make(chan uint64)
 
 	go func() {
 		for {
@@ -485,7 +485,7 @@ func main() {
 			vk.CopyToMapped(staging.Mapped, f.Payload)
 			// fmt.Println("staged", f.Index)
 			select {
-			case staged <- struct{}{}:
+			case staged <- f.Index:
 			case <-ctx.Done():
 				return
 			}
@@ -500,7 +500,14 @@ func main() {
 	running := true
 	resized := false
 	fullscreen := false
+	var (
+		lastIndex  uint64
+		dropped    uint64
+		frameCount uint64
+		lastReport time.Time
+	)
 	for running {
+		frameStart := time.Now()
 		var event [128]byte
 		for sdlPollEvent(unsafe.Pointer(&event[0])) {
 			eventType := *(*uint32)(unsafe.Pointer(&event[0]))
@@ -558,12 +565,29 @@ func main() {
 			running = false
 			continue
 		}
+		var shownIndex uint64
 		select {
 		case <-staged:
 		case <-ctx.Done():
 			running = false
 			continue
 		}
+		if lastIndex != 0 && shownIndex > lastIndex {
+			if g := shownIndex - lastIndex - 1; g > 0 {
+				dropped += g
+			}
+		}
+		lastIndex = shownIndex
+		frameCount++
+		if now := time.Now(); now.Sub(lastReport) >= time.Second {
+			dt := now.Sub(lastReport).Seconds()
+			fps := float64(frameCount) / dt
+			fmt.Printf("fps=%.1f dropped=%d idx=%d frameTime=%.2fms\n",
+				fps, dropped, shownIndex, float64(now.Sub(frameStart).Microseconds())/1000.0)
+			frameCount = 0
+			dropped = 0
+			lastReport = now
+		}
 
 		// Record: copy staged V210 into device-local buffer, then clear
 		cmd := vkCommands[0]