examples/wheel: Improve message

examples/wheel/main.go

@@ -17,6 +17,7 @@
 package main
 
 import (
+	"fmt"
 	"image/color"
 	"log"
 
@@ -55,7 +56,8 @@ func update(screen *ebiten.Image) error {
 	op.GeoM.Translate(screenWidth/2, screenHeight/2)
 	screen.DrawImage(pointerImage, op)
 
-	ebitenutil.DebugPrint(screen, "Move the red point by mouse wheeling")
+	ebitenutil.DebugPrint(screen,
+		fmt.Sprintf("Move the red point by mouse wheel\n(%0.2f, %0.2f)", x, y))
 
 	return nil
 }

internal/input/input_js.go

@@ -248,6 +248,7 @@ func OnMouseMove(e js.Value) {
 }
 
 func OnWheel(e js.Value) {
+	// TODO: What if e.deltaMode is not DOM_DELTA_PIXEL?
 	theInput.wheelX = e.Get("deltaX").Float()
 	theInput.wheelY = e.Get("deltaY").Float()
 }