automated snapshot

sketch.go

@@ -127,6 +127,7 @@ func (s *Sketch) Draw(ctx *RenderCtx) {
 
 	viewport := s.CalcViewport(ctx)
 
+	rl.BeginBlendMode(rl.BlendAlphaPremultiply)
 	rl.BeginTextureMode(s.composite)
 	rl.ClearBackground(rl.Black)
 	for _, instance := range s.layerToolsOrdered {
@@ -151,6 +152,7 @@ func (s *Sketch) Draw(ctx *RenderCtx) {
 		}
 	}
 	rl.EndTextureMode()
+	rl.EndBlendMode()
 
 	rl.GenTextureMipmaps(&s.composite.Texture)
 	rl.SetTextureFilter(s.composite.Texture, rl.FilterTrilinear)