automated snapshot

sketch.go

@@ -7,31 +7,37 @@ import (
 
 type Sketch struct {
 	layerTools map[string]LayerTools
+	layerToolsOrdered []LayerTools
 }
 
 func NewSketch() Sketch {
 	return Sketch{
 		layerTools: make(map[string]LayerTools),
+		layerToolsOrdered: []LayerTools {},
 	}
 }
 
 func (s *Sketch) CreateLayer(name string, layer Layer, sourceWidth int32, sourceHeight int32) {
 	texture := rl.LoadRenderTexture(sourceWidth, sourceHeight)
-	s.layerTools[name] = LayerTools{
+	layerTools := LayerTools {
 		name:    name,
 		texture: &texture,
 		layer:   layer,
 	}
+	s.layerToolsOrdered = append(s.layerToolsOrdered, layerTools)
+	s.layerTools[name] = layerTools
 }
 
 func (s *Sketch) Draw(ctx *RenderCtx) {
 	// render onto all layer textures
-	for _, instance := range s.layerTools {
-		layer := instance.layer
-		rl.BeginTextureMode(*instance.texture)
-		rl.ClearBackground(rl.Blank)
-		layer.Draw(ctx)
-		rl.EndTextureMode()
+	for _, instance := range s.layerToolsOrdered {
+		instance.layer.Update(ctx)
+		if instance.layer.IsDirty() {
+			layer := instance.layer
+			rl.BeginTextureMode(*instance.texture)
+			layer.Draw(ctx)
+			rl.EndTextureMode()
+		}
 	}
 
 	// composite all layers to screen
@@ -45,7 +51,7 @@ func (s *Sketch) Draw(ctx *RenderCtx) {
 
 	viewport := s.CalcViewport(ctx)
 
-	for _, instance := range s.layerTools {
+	for _, instance := range s.layerToolsOrdered {
 		rl.DrawTexturePro(instance.texture.Texture, viewport, screen, rl.Vector2{}, 0, rl.White)
 	}
 
@@ -101,20 +107,17 @@ type LayerTools struct {
 /** Layer **/
 
 type Layer interface {
+	Update(ctx *RenderCtx)
 	Draw(ctx *RenderCtx)
+	IsDirty() bool
 }
 
-type TestPattern struct{}
+type TestPattern struct{
+	dirty bool
+}
 
-func DrawGrid(spacing int32, halfExtent int32) {
-	col := rl.Color{R: 220, G: 220, B: 220, A: 255}
-
-	for x := -halfExtent; x <= halfExtent; x += spacing {
-		rl.DrawLine(x, -halfExtent, x, halfExtent, col)
-	}
-	for y := -halfExtent; y <= halfExtent; y += spacing {
-		rl.DrawLine(-halfExtent, y, halfExtent, y, col)
-	}
+func (tp *TestPattern) Update(ctx *RenderCtx) {
+	;
 }
 
 func (tp *TestPattern) Draw(ctx *RenderCtx) {
@@ -137,6 +140,12 @@ func (tp *TestPattern) Draw(ctx *RenderCtx) {
 	rl.DrawLine(0, -10000, 0, 10000, rl.Green)
 	rl.DrawRectangleLines(-50, -50, 100, 100, rl.Magenta)
 	rl.PopMatrix()
+
+	tp.dirty = false
+}
+
+func (tp *TestPattern) IsDirty() bool {
+	return tp.dirty
 }
 
 /** Ports **/