change Sprite.Draw and Canvas.Draw signatures (include Matrix)

lights/main.go

@@ -27,10 +27,6 @@ func loadPicture(path string) (pixel.Picture, error) {
 	return pixel.PictureDataFromImage(img), nil
 }
 
-type drawer interface {
-	Draw(pixel.Target)
-}
-
 type colorlight struct {
 	color  pixel.RGBA
 	point  pixel.Vec
@@ -43,7 +39,7 @@ type colorlight struct {
 	imd *imdraw.IMDraw
 }
 
-func (cl *colorlight) apply(src, noise drawer, dst pixel.ComposeTarget) {
+func (cl *colorlight) apply(dst pixel.ComposeTarget, center pixel.Vec, src, noise *pixel.Sprite) {
 	// create the light arc if not created already
 	if cl.imd == nil {
 		imd := imdraw.New(nil)
@@ -66,12 +62,12 @@ func (cl *colorlight) apply(src, noise drawer, dst pixel.ComposeTarget) {
 	// draw the noise inside the light
 	dst.SetMatrix(pixel.IM)
 	dst.SetComposeMethod(pixel.ComposeIn)
-	noise.Draw(dst)
+	noise.Draw(dst, pixel.IM.Moved(center))
 
 	// draw an image inside the noisy light
 	dst.SetColorMask(cl.color)
 	dst.SetComposeMethod(pixel.ComposeIn)
-	src.Draw(dst)
+	src.Draw(dst, pixel.IM.Moved(center))
 
 	// draw the light reflected from the dust
 	dst.SetMatrix(pixel.IM.Scaled(0, cl.radius).Rotated(0, cl.angle).Moved(cl.point))
@@ -101,9 +97,7 @@ func run() {
 	}
 
 	panda := pixel.NewSprite(pandaPic, pandaPic.Bounds())
-	panda.SetMatrix(pixel.IM.Moved(win.Bounds().Center()))
 	noise := pixel.NewSprite(noisePic, noisePic.Bounds())
-	noise.SetMatrix(pixel.IM.Moved(win.Bounds().Center()))
 
 	colors := []pixel.RGBA{
 		pixel.RGB(1, 0, 0),
@@ -174,7 +168,7 @@ func run() {
 		// draw the panda visible outside the light
 		win.SetColorMask(pixel.Alpha(0.4))
 		win.SetComposeMethod(pixel.ComposePlus)
-		panda.Draw(win)
+		panda.Draw(win, pixel.IM.Moved(win.Bounds().Center()))
 
 		allLight.Clear(pixel.Alpha(0))
 		allLight.SetComposeMethod(pixel.ComposePlus)
@@ -182,13 +176,13 @@ func run() {
 		// accumulate all the lights
 		for i := range lights {
 			oneLight.Clear(pixel.Alpha(0))
-			lights[i].apply(panda, noise, oneLight)
-			oneLight.Draw(allLight)
+			lights[i].apply(oneLight, oneLight.Bounds().Center(), panda, noise)
+			oneLight.Draw(allLight, pixel.IM.Moved(allLight.Bounds().Center()))
 		}
 
 		// compose the final result
 		win.SetColorMask(pixel.Alpha(1))
-		allLight.Draw(win)
+		allLight.Draw(win, pixel.IM.Moved(win.Bounds().Center()))
 
 		win.Update()
 

platformer/main.go

@@ -215,7 +215,7 @@ func (ga *gopherAnim) draw(t pixel.Target, phys *gopherPhys) {
 	}
 	// draw the correct frame with the correct position and direction
 	ga.sprite.Set(ga.sheet, ga.frame)
-	ga.sprite.SetMatrix(pixel.IM.
+	ga.sprite.Draw(t, pixel.IM.
 		ScaledXY(0, pixel.V(
 			phys.rect.W()/ga.sprite.Frame().W(),
 			phys.rect.H()/ga.sprite.Frame().H(),
@@ -223,7 +223,6 @@ func (ga *gopherAnim) draw(t pixel.Target, phys *gopherPhys) {
 		ScaledXY(0, pixel.V(-ga.dir, 1)).
 		Moved(phys.rect.Center()),
 	)
-	ga.sprite.Draw(t)
 }
 
 type goal struct {
@@ -385,7 +384,7 @@ func run() {
 				win.Bounds().H()/canvas.Bounds().H(),
 			),
 		).Moved(win.Bounds().Center()))
-		canvas.Draw(win)
+		canvas.Draw(win, pixel.IM.Moved(canvas.Bounds().Center()))
 		win.Update()
 	}
 }

smoke/main.go

@@ -54,13 +54,14 @@ func (p *particles) DrawAll(t pixel.Target) {
 	for e := p.parts.Front(); e != nil; e = e.Next() {
 		part := e.Value.(*particle)
 
-		part.Sprite.SetMatrix(pixel.IM.
-			Scaled(0, part.Scale).
-			Rotated(0, part.Rot).
-			Moved(part.Pos),
+		part.Sprite.DrawColorMask(
+			t,
+			pixel.IM.
+				Scaled(0, part.Scale).
+				Rotated(0, part.Rot).
+				Moved(part.Pos),
+			part.Mask,
 		)
-		part.Sprite.SetColorMask(part.Mask)
-		part.Sprite.Draw(t)
 	}
 }
 

xor/main.go

@@ -66,7 +66,7 @@ func run() {
 		imd.Draw(canvas)
 
 		win.Clear(colornames.Green)
-		canvas.Draw(win)
+		canvas.Draw(win, pixel.IM.Moved(win.Bounds().Center()))
 		win.Update()
 	}
 }