automated snapshot

sketch.go

@@ -8,23 +8,39 @@ import (
 type Sketch struct {
 	sourceWidth int32
 	sourceHeight int32
+	cam          *TextureCam
 	layerTools map[string]LayerTools
 	layerToolsOrdered []LayerTools
 	composite rl.RenderTexture2D
 }
 
+type TextureCam struct {
+	LookAt       rl.Vector2
+	Zoom         float32
+}
+
+
 func NewSketch(sourceWidth, sourceHeight int32) Sketch {
+
+	// point at source center
+	// put source center at center of screen
+	var camera = TextureCam {
+		LookAt:       rl.Vector2{X: float32(sourceWidth) / 2.0, Y: float32(sourceHeight) / 2.0},
+		Zoom:         1.0,
+	}
+
 	return Sketch {
 		sourceWidth: sourceWidth,
 		sourceHeight: sourceHeight,
 		layerTools: make(map[string]LayerTools),
 		layerToolsOrdered: []LayerTools {},
 		composite: rl.LoadRenderTexture(sourceWidth, sourceHeight),
+		cam: &camera,
 	}
 }
 
-func (s *Sketch) CreateLayer(name string, layer Layer, sourceWidth int32, sourceHeight int32) {
-	texture := rl.LoadRenderTexture(sourceWidth, sourceHeight)
+func (s *Sketch) CreateLayer(name string, layer Layer) {
+	texture := rl.LoadRenderTexture(s.sourceWidth, s.sourceHeight)
 	layerTools := LayerTools {
 		name:    name,
 		texture: &texture,
@@ -80,44 +96,49 @@ func (s *Sketch) Draw(ctx *RenderCtx) {
 }
 
 func (s *Sketch) CalcViewport(ctx *RenderCtx) rl.Rectangle {
-	viewportWidth := rl.Clamp(float32(ctx.SourceWidth) / ctx.Cam.Zoom, 0, float32(ctx.SourceWidth))
-	viewportHeight := rl.Clamp(float32(ctx.SourceHeight) / ctx.Cam.Zoom, 0, float32(ctx.SourceHeight))
+	viewportWidth := rl.Clamp(float32(ctx.SourceWidth) / s.cam.Zoom, 0, float32(ctx.SourceWidth))
+	viewportHeight := rl.Clamp(float32(ctx.SourceHeight) / s.cam.Zoom, 0, float32(ctx.SourceHeight))
 	return rl.Rectangle{
-		X:      rl.Clamp(ctx.Cam.LookAt.X - viewportWidth/2.0, 0, float32(ctx.SourceWidth)-viewportWidth),
-		Y:      rl.Clamp(ctx.Cam.LookAt.Y - viewportHeight/2.0, 0, float32(ctx.SourceHeight)-viewportHeight),
+		X:      rl.Clamp(s.cam.LookAt.X - viewportWidth/2.0, 0, float32(ctx.SourceWidth)-viewportWidth),
+		Y:      rl.Clamp(s.cam.LookAt.Y - viewportHeight/2.0, 0, float32(ctx.SourceHeight)-viewportHeight),
 		Width:  float32(viewportWidth),
 		Height: -float32(viewportHeight),
 	}
 }
 
 func (s *Sketch) Update(ctx *RenderCtx) {
+
 	if rl.IsMouseButtonDown(rl.MouseRightButton) {
 		// get mouse delta from last frame
 		delta := rl.GetMouseDelta()
 		// compute the amount to move scaled by the camera zoom
-		delta = rl.Vector2Scale(delta, -sourceScale/ctx.Cam.Zoom)
+		delta = rl.Vector2Scale(delta, -sourceScale/s.cam.Zoom)
 		delta.Y = -delta.Y
-		ctx.Cam.LookAt = rl.Vector2Add(ctx.Cam.LookAt, delta)
+		s.cam.LookAt = rl.Vector2Add(s.cam.LookAt, delta)
 	}
 
 	// clamp LookAt to be somewhere on the texture
-	ctx.Cam.LookAt.X = rl.Clamp(ctx.Cam.LookAt.X, 0, float32(ctx.SourceWidth-1))
-	ctx.Cam.LookAt.Y = rl.Clamp(ctx.Cam.LookAt.Y, 0, float32(ctx.SourceHeight-1))
+	s.cam.LookAt.X = rl.Clamp(s.cam.LookAt.X, 0, float32(ctx.SourceWidth-1))
+	s.cam.LookAt.Y = rl.Clamp(s.cam.LookAt.Y, 0, float32(ctx.SourceHeight-1))
 
 	// Zoom based on mouse wheel
 	wheel := rl.GetMouseWheelMove()
 	if wheel != 0 {
 		const zoomIncrement float32 = 0.05
 		if wheel > 0 {
-			ctx.Cam.Zoom *= 1+zoomIncrement
+			s.cam.Zoom *= 1+zoomIncrement
 		} else {
-			ctx.Cam.Zoom *= 1-zoomIncrement
+			s.cam.Zoom *= 1-zoomIncrement
 		}
 	}
 
 	// clamp zoom to > 1 so we don't ever zoom out more than necessary
-	ctx.Cam.Zoom = rl.Clamp(ctx.Cam.Zoom, 1, math.MaxInt64)
+	s.cam.Zoom = rl.Clamp(s.cam.Zoom, 1, math.MaxInt64)
+}
 
+func (s *Sketch) ResetCamera() {
+	s.cam.LookAt = rl.Vector2{X: float32(s.sourceWidth) / 2.0, Y: float32(s.sourceHeight) / 2.0}
+	s.cam.Zoom = 1.0
 }
 
 type SketchCapture struct {
@@ -218,5 +239,4 @@ type RenderCtx struct {
 	SourceHeight int32
 	Time         float64
 	Ports        map[string]float64
-	Cam          *TextureCam
 }