dynamic sizing

sketch.go

@@ -21,7 +21,7 @@ type TextureCam struct {
 
 /** RenderCtx **/
 type RenderCtx struct {
-	TargetBounds rl.Rectangle
+	TargetBounds rl.RectangleInt32
 	SourceWidth  int32
 	SourceHeight int32
 	Time         float64
@@ -200,7 +200,7 @@ func (s *Sketch) Draw(ctx *RenderCtx) {
 
 func (s *Sketch) calcOutputRectKeepingAspectRatio(ctx *RenderCtx) rl.Rectangle {
 	sourceAspect := float32(ctx.SourceWidth) / float32(ctx.SourceHeight)
-	targetAspect := ctx.TargetBounds.Width / ctx.TargetBounds.Height
+	targetAspect := float32(ctx.TargetBounds.Width) / float32(ctx.TargetBounds.Height)
 
 	outputWidth := ctx.TargetBounds.Width
 	outputHeight := ctx.TargetBounds.Height
@@ -209,22 +209,22 @@ func (s *Sketch) calcOutputRectKeepingAspectRatio(ctx *RenderCtx) rl.Rectangle {
 		// source is relatively taller than the target
 		// so we set the output height to the target height
 		// and calculate the width based on source aspect and center
-		outputWidth = outputHeight * sourceAspect
+		outputWidth = int32(float32(outputHeight) * sourceAspect)
 	} else {
 		// source is relatively wider than the target
 		// so we set the output width to the target width
 		// and calculate the height based on source aspect and center
-		outputHeight = outputWidth / sourceAspect
+		outputHeight = int32(float32(outputWidth) / sourceAspect)
 	}
 
 	// output width and height are correct -- center within TargetBounds
 	x := ctx.TargetBounds.X + ctx.TargetBounds.Width / 2.0 - outputWidth / 2.0 
 	y := ctx.TargetBounds.Y + ctx.TargetBounds.Height / 2.0 - outputHeight / 2.0 
 
-	return rl.Rectangle {
-		X: x, Y: y,
-		Width: outputWidth,
-		Height: outputHeight,
+	return rl.Rectangle{
+		X: float32(x), Y: float32(y),
+		Width: float32(outputWidth),
+		Height: float32(outputHeight),
 	}
 }
 
@@ -244,7 +244,7 @@ func (s *Sketch) Update(ctx *RenderCtx) {
 	if rl.IsMouseButtonDown(rl.MouseRightButton) {
 		// get mouse delta from last frame
 		delta := rl.GetMouseDelta()
-		sourceScale := float32(ctx.SourceWidth) / ctx.TargetBounds.Width
+		sourceScale := float32(ctx.SourceWidth) / float32(ctx.TargetBounds.Width)
 		// compute the amount to move scaled by the camera zoom
 		delta = rl.Vector2Scale(delta, -sourceScale/s.cam.Zoom)
 		delta.Y = -delta.Y