automated snapshot

sketch.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"github.com/gen2brain/raylib-go/raylib"
 )
 
@@ -23,27 +24,55 @@ func (s *Sketch) CreateLayer(name string, layer Layer, sourceWidth int32, source
 	}
 }
 
+func LayerViewRect(ctx *RenderCtx) rl.Rectangle {
+
+	z := ctx.Cam.Zoom
+
+	// get the viewport width in texture space
+	viewportWidth  := float32(ctx.TargetWidth) / z
+	viewportHeight := float32(ctx.TargetHeight) / z
+
+	x := rl.Clamp(ctx.Cam.Target.X - viewportWidth/2, 0, float32(ctx.SourceWidth) - viewportWidth/2.0)
+	y := rl.Clamp(ctx.Cam.Target.Y - viewportHeight/2, 0, float32(ctx.SourceHeight) - viewportHeight/2.0)
+
+	return rl.Rectangle{
+		X: x,
+		Y: y,
+		Width:  viewportWidth,
+		Height: viewportHeight,
+	}
+}
+
 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()
 	}
 	// composite all layers to screen
 
+	//ClampCameraToLayer(ctx)
+
+	//view := LayerViewRect(ctx)
 	src := rl.Rectangle {
-		X: 0, Y: 0,
+		X: 0,
+		Y: 0,
 		Width: float32(ctx.SourceWidth),
 		Height: -float32(ctx.SourceHeight),
 	}
+
 	dst := rl.Rectangle {
-		X: 0, Y: 0,
+		X: 0,
+		Y: 0,
 		Width: float32(ctx.TargetWidth),
 		Height: float32(ctx.TargetHeight),
 	}
 
+	fmt.Printf("src = %v, dst  %v\n", src, dst)
+
 	for _, instance := range s.layerTools {
 		rl.DrawTexturePro(instance.texture.Texture, src, dst, rl.Vector2{}, 0, rl.White)
 	}
@@ -56,7 +85,6 @@ type LayerTools struct {
 	texture *rl.RenderTexture2D
 }
 
-
 /** Layer **/
 
 type Layer interface {
@@ -65,11 +93,36 @@ type Layer interface {
 
 type TestPattern struct { }
 
+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) Draw(ctx *RenderCtx) {
-	rl.DrawRectangle(0, 0, int32(ctx.SourceWidth), int32(ctx.SourceHeight), rl.Magenta)
+
+	rl.ClearBackground(rl.Black)
+	centerX := float32(ctx.SourceWidth)/2
+	centerY := float32(ctx.SourceHeight)/2
+
+	rl.DrawRectangleRec(rl.Rectangle { X: 0, Y: 0, Width: centerX, Height: centerY }, rl.Red)
+	rl.DrawRectangleRec(rl.Rectangle { X: centerX, Y: 0, Width: centerX, Height: centerY }, rl.Green)
+	rl.DrawRectangleRec(rl.Rectangle { X: 0, Y: centerY, Width: centerX, Height: centerY }, rl.Blue)
+	rl.DrawRectangleRec(rl.Rectangle { X: centerX, Y: centerY, Width: centerX, Height: centerY }, rl.White)
+
+	rl.DrawLine(0, 0, ctx.SourceWidth, ctx.SourceHeight, rl.Black)
+
 	rl.PushMatrix()
-	rl.Translatef(float32(ctx.SourceWidth)/2.0, float32(ctx.SourceHeight)/2.0, 0.0)
-	rl.DrawRectangle(-100, -100, 200, 200, rl.Green)
+	rl.Translatef(centerX, centerY, 0)
+	rl.SetLineWidth(4.0)
+	rl.DrawLine(-10000, 0, 10000, 0, rl.Red)
+	rl.DrawLine(0, -10000, 0, 10000, rl.Green)
+	rl.DrawRectangleLines(-50, -50, 100, 100, rl.Magenta)
 	rl.PopMatrix()
 }