automated snapshot

sketch.go

@@ -5,21 +5,75 @@ import (
 )
 
 type Sketch struct {
-	layers []Layer
+	layerTools map[string]LayerTools
 }
 
-func (s *Sketch) Draw(ctx *RenderCtx) {
-	for _, layer := range s.layers {
-		layer.Draw(ctx)
+func NewSketch() Sketch {
+	return Sketch {
+		layerTools: make(map[string]LayerTools),
 	}
 }
 
+func (s *Sketch) CreateLayer(name string, layer Layer, sourceWidth int32, sourceHeight int32) {
+	texture := rl.LoadRenderTexture(sourceWidth, sourceHeight)
+	s.layerTools[name] = LayerTools {
+		name: name,
+		texture: &texture,
+		layer: layer,
+	}
+}
 
+func (s *Sketch) Draw(ctx *RenderCtx) {
+	// render onto all layer textures
+	for _, instance := range s.layerTools {
+		layer := instance.layer
+		rl.BeginTextureMode(*instance.texture)
+		layer.Draw(ctx)
+		rl.EndTextureMode()
+	}
+	// composite all layers to screen
+
+	src := rl.Rectangle {
+		X: 0, Y: 0,
+		Width: float32(ctx.SourceWidth),
+		Height: -float32(ctx.SourceHeight),
+	}
+	dst := rl.Rectangle {
+		X: 0, Y: 0,
+		Width: float32(ctx.TargetWidth),
+		Height: float32(ctx.TargetHeight),
+	}
+
+	for _, instance := range s.layerTools {
+		rl.DrawTexturePro(instance.texture.Texture, src, dst, rl.Vector2{}, 0, rl.White)
+	}
+	
+}
+
+type LayerTools struct {
+	name string
+	layer Layer
+	texture *rl.RenderTexture2D
+}
+
+
+/** Layer **/
 
 type Layer interface {
 	Draw(ctx *RenderCtx)
 }
 
+type TestPattern struct { }
+
+func (tp *TestPattern) Draw(ctx *RenderCtx) {
+	rl.DrawRectangle(0, 0, int32(ctx.SourceWidth), int32(ctx.SourceHeight), rl.Magenta)
+	rl.PushMatrix()
+	rl.Translatef(float32(ctx.SourceWidth)/2.0, float32(ctx.SourceHeight)/2.0, 0.0)
+	rl.DrawRectangle(-100, -100, 200, 200, rl.Green)
+	rl.PopMatrix()
+}
+
+
 /** Ports **/
 
 type Ports map[string]Signal
@@ -42,8 +96,10 @@ func (p Ports) Eval(t float64) map[string]float64 {
 /** RenderCtx **/
 
 type RenderCtx struct {
-	Width  int32
-	Height int32
+	TargetWidth  int32
+	TargetHeight int32
+	SourceWidth int32
+	SourceHeight int32
 	Time   float64
 	Ports  map[string]float64
 	Cam    rl.Camera2D