Draw(image, geom) -> Draw(image, opts)

engine/camera.go

@@ -16,10 +16,12 @@ type Camera struct {
 	//Rotation float64       // radians
 	Zoom float64 // unitless
 
+	Filter ebiten.Filter // Apply to game?
+
 	game *Game
 }
 
-func (c *Camera) Draw(screen *ebiten.Image, geom ebiten.GeoM) {
+func (c *Camera) Draw(screen *ebiten.Image, opts ebiten.DrawImageOptions) {
 	// If the camera bounds are smaller than the screen dimensions, that
 	// places a lower bound on zoom.
 	// If the configured centre still puts the camera out of bounds, move it.
@@ -51,14 +53,16 @@ func (c *Camera) Draw(screen *ebiten.Image, geom ebiten.GeoM) {
 
 	// Apply camera controls to geom.
 	// 1. Move c.Centre to the origin
-	geom.Translate(-float64(centre.X), -float64(centre.Y))
+	opts.GeoM.Translate(-float64(centre.X), -float64(centre.Y))
 	// 2. Zoom and rotate
-	geom.Scale(zoom, zoom)
+	opts.GeoM.Scale(zoom, zoom)
 	//geom.Rotate(c.Rotation)
 	// 3. Move the origin to the centre of screen space.
-	geom.Translate(sw2, sh2)
+	opts.GeoM.Translate(sw2, sh2)
 
-	c.Scene.Draw(screen, geom)
+	opts.Filter = c.Filter
+
+	c.Scene.Draw(screen, opts)
 }
 
 func (c *Camera) Update() error { return c.Scene.Update() }

engine/debug.go

@@ -23,7 +23,7 @@ type PerfDisplay struct {
 	Hidden bool
 }
 
-func (p PerfDisplay) Draw(screen *ebiten.Image, _ ebiten.GeoM) {
+func (p PerfDisplay) Draw(screen *ebiten.Image, _ ebiten.DrawImageOptions) {
 	if p.Hidden {
 		return
 	}

engine/fill.go

@@ -14,9 +14,9 @@ type Fill struct {
 	ZPos
 }
 
-func (f *Fill) Draw(screen *ebiten.Image, _ ebiten.GeoM) {
+func (f *Fill) Draw(screen *ebiten.Image, opts ebiten.DrawImageOptions) {
 	if f.Hidden {
 		return
 	}
-	screen.Fill(f.Color)
+	screen.Fill(opts.ColorM.Apply(f.Color))
 }

engine/game.go

@@ -21,7 +21,7 @@ type Game struct {
 
 // Draw draws the entire thing, with no geometric transform.
 func (g *Game) Draw(screen *ebiten.Image) {
-	g.Scene.Draw(screen, ebiten.GeoM{})
+	g.Scene.Draw(screen, ebiten.DrawImageOptions{})
 }
 
 // Layout returns the configured screen width/height.

engine/interface.go

@@ -15,7 +15,7 @@ type Collider interface {
 // Each component is responsible for calling Draw on its child components
 // (so that hiding the parent can hide the children, etc).
 type Drawer interface {
-	Draw(screen *ebiten.Image, geom ebiten.GeoM)
+	Draw(screen *ebiten.Image, opts ebiten.DrawImageOptions)
 }
 
 // Identifier components have a sense of self. This makes it easier for

engine/scene.go

@@ -22,13 +22,13 @@ type Scene struct {
 }
 
 // Draw draws all components in order.
-func (s *Scene) Draw(screen *ebiten.Image, geom ebiten.GeoM) {
+func (s *Scene) Draw(screen *ebiten.Image, opts ebiten.DrawImageOptions) {
 	if s.Hidden {
 		return
 	}
 	for _, i := range s.Components {
 		if d, ok := i.(Drawer); ok {
-			d.Draw(screen, geom)
+			d.Draw(screen, opts)
 		}
 	}
 }

engine/sprite.go

@@ -24,21 +24,22 @@ type Sprite struct {
 	anim *Anim
 }
 
-func (s *Sprite) Draw(screen *ebiten.Image, geom ebiten.GeoM) {
+func (s *Sprite) Draw(screen *ebiten.Image, opts ebiten.DrawImageOptions) {
 	if s.Hidden {
 		return
 	}
-	var op ebiten.DrawImageOptions
 	dp := s.Pos.Add(s.FrameOffset)
-	op.GeoM.Translate(float64(dp.X), float64(dp.Y))
+	var geom ebiten.GeoM
-	op.GeoM.Concat(geom)
+	geom.Translate(float64(dp.X), float64(dp.Y))
+	geom.Concat(opts.GeoM)
+	opts.GeoM = geom
 
 	frame := s.anim.CurrentFrame()
 	src := s.Src.Image()
 	w, _ := src.Size()
 	sp := image.Pt((frame*s.FrameSize.X)%w, ((frame*s.FrameSize.X)/w)*s.FrameSize.Y)
 
-	screen.DrawImage(src.SubImage(image.Rectangle{sp, sp.Add(s.FrameSize)}).(*ebiten.Image), &op)
+	screen.DrawImage(src.SubImage(image.Rectangle{sp, sp.Add(s.FrameSize)}).(*ebiten.Image), &opts)
 }
 
 func (s *Sprite) Scan() []interface{} { return []interface{}{&s.Actor} }

engine/tiles.go

@@ -52,25 +52,28 @@ func (t *Tilemap) CollidesWith(r image.Rectangle) bool {
 }
 
 // Draw draws the tilemap.
-func (t *Tilemap) Draw(screen *ebiten.Image, geom ebiten.GeoM) {
+func (t *Tilemap) Draw(screen *ebiten.Image, opts ebiten.DrawImageOptions) {
 	if t.Hidden {
 		return
 	}
 	src := t.Src.Image()
 	w, _ := src.Size()
+	og := opts.GeoM
+	var geom ebiten.GeoM
 	for j, row := range t.Map {
 		for i, tile := range row {
 			if tile == nil {
 				continue
 			}
-			var op ebiten.DrawImageOptions
+			geom.Reset()
-			op.GeoM.Translate(float64(i*t.TileSize), float64(j*t.TileSize))
+			geom.Translate(float64(i*t.TileSize), float64(j*t.TileSize))
-			op.GeoM.Concat(geom)
+			geom.Concat(og)
+			opts.GeoM = geom
 
 			s := tile.TileIndex() * t.TileSize
 			sx, sy := s%w, (s/w)*t.TileSize
 			src := src.SubImage(image.Rect(sx, sy, sx+t.TileSize, sy+t.TileSize)).(*ebiten.Image)
-			screen.DrawImage(src, &op)
+			screen.DrawImage(src, &opts)
 		}
 	}
 }