examples/pcm: Improve debug messages

examples/pcm/main.go

@@ -17,7 +17,6 @@
 package main
 
 import (
-	"fmt"
 	"log"
 	"math"
 
@@ -98,7 +97,7 @@ func toBytes(l, r []int16) []byte {
 	return b
 }
 
-func addNote() error {
+func addNote() (rune, error) {
 	size := sampleRate / ebiten.FPS
 	notes := []float64{freqC, freqD, freqE, freqF, freqG, freqA * 2, freqB * 2}
 
@@ -129,27 +128,38 @@ func addNote() error {
 	b := toBytes(l, r)
 	p, err := audio.NewPlayerFromBytes(audioContext, b)
 	if err != nil {
-		return err
+		return 0, err
 	}
 	if err := p.Play(); err != nil {
-		return err
+		return 0, err
 	}
-	return nil
+	return rune(note), nil
 }
 
+var currentNote rune
+
 func update(screen *ebiten.Image) error {
-	defer func() {
-		frames++
-	}()
 	if frames%30 == 0 {
-		if err := addNote(); err != nil {
+		n, err := addNote()
+		if err != nil {
 			return err
 		}
+		currentNote = n
 	}
-	ebitenutil.DebugPrint(screen, fmt.Sprintf("FPS: %0.2f", ebiten.CurrentFPS()))
+	frames++
 	if err := audioContext.Update(); err != nil {
 		return err
 	}
+	if ebiten.IsRunningSlowly() {
+		return nil
+	}
+	msg := "Note: "
+	if currentNote == 'R' {
+		msg += "-"
+	} else {
+		msg += string(currentNote)
+	}
+	ebitenutil.DebugPrint(screen, msg)
 	return nil
 }