automated snapshot

sketch.go

@@ -6,14 +6,20 @@ import (
 )
 
 type Sketch struct {
+	sourceWidth int32
+	sourceHeight int32
 	layerTools map[string]LayerTools
 	layerToolsOrdered []LayerTools
+	composite rl.RenderTexture2D
 }
 
-func NewSketch() Sketch {
-	return Sketch{
+func NewSketch(sourceWidth, sourceHeight int32) Sketch {
+	return Sketch {
+		sourceWidth: sourceWidth,
+		sourceHeight: sourceHeight,
 		layerTools: make(map[string]LayerTools),
 		layerToolsOrdered: []LayerTools {},
+		composite: rl.LoadRenderTexture(sourceWidth, sourceHeight),
 	}
 }
 
@@ -49,12 +55,28 @@ func (s *Sketch) Draw(ctx *RenderCtx) {
 		Height: float32(ctx.TargetHeight),
 	}
 
-	viewport := s.CalcViewport(ctx)
-
-	for _, instance := range s.layerToolsOrdered {
-		rl.DrawTexturePro(instance.texture.Texture, viewport, screen, rl.Vector2{}, 0, rl.White)
+	// copy from full texture for compositing, with vertical flipping
+	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.SourceWidth),
+		Height: float32(ctx.SourceHeight),
 	}
 
+	viewport := s.CalcViewport(ctx)
+
+	rl.BeginTextureMode(s.composite)
+	rl.ClearBackground(rl.Black)
+	for _, instance := range s.layerToolsOrdered {
+		rl.DrawTexturePro(instance.texture.Texture, src, dst, rl.Vector2{}, 0, rl.White)
+	}
+	rl.EndTextureMode()
+
+	rl.DrawTexturePro(s.composite.Texture, viewport, screen, rl.Vector2{}, 0, rl.White)
 }
 
 func (s *Sketch) CalcViewport(ctx *RenderCtx) rl.Rectangle {
@@ -98,6 +120,24 @@ func (s *Sketch) Update(ctx *RenderCtx) {
 
 }
 
+type SketchCapture struct {
+	compositeImage *rl.Image
+	layerImages []*rl.Image
+}
+
+func (s *Sketch) Capture() *SketchCapture {
+	composite := rl.LoadImageFromTexture(s.composite.Texture)
+	layerImages := make([]*rl.Image, len(s.layerToolsOrdered))
+	for i, layerTool := range s.layerToolsOrdered {
+		layerImages[i] = rl.LoadImageFromTexture(layerTool.texture.Texture)
+	}
+	return &SketchCapture {
+		compositeImage: composite,
+		layerImages: layerImages,
+	}
+}
+
+
 type LayerTools struct {
 	name    string
 	layer   Layer