From cc59845233bedf480c405e6903756112fe03ff7f Mon Sep 17 00:00:00 2001
From: sumi <sumi@local>
Date: Tue, 23 Dec 2025 15:29:58 -0600
Subject: [PATCH] automated snapshot

---
 main.go   | 30 +++++++++++++++++-------------
 sketch.go |  1 +
 utils.go  |  5 +++++
 3 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/main.go b/main.go
index 6714e7c..cddb9fd 100644
--- a/main.go
+++ b/main.go
@@ -60,15 +60,17 @@ func main() {
 
 	sierpinskiLayer := &SierpinskiArrow { dirty: true }
 
-	imageLayer := NewImageLayer("/home/d/Dropbox/photos/Events/2025/Aurora/Photo Nov 11 2025, 9 52 03 PM.jpg")
+	aurora := NewImageLayer("/home/d/Dropbox/photos/Events/2025/Aurora/Photo Nov 11 2025, 9 52 03 PM.jpg")
+	cave := NewImageLayer("/home/d/Dropbox/photos/Events/2025/ Chelsea and James visit Lindell/Photo Nov 29 2025, 5 26 40 PM (29).jpg")
 
-	//sketch.AddColorLayer("background-black", rl.Black)
-	sketch.AddColorLayer("background-magenta", rl.Magenta)
-	sketch.AddLayer("field", &FieldLayer{field: field, dirty: true})
+	sketch.AddColorLayer("background-black", rl.Black)
+	//sketch.AddColorLayer("background-magenta", rl.Magenta)
+	sketch.AddLayer("field", &FieldLayer{field: field, loColor: rl.NewColor(0, 0, 0, 0), hiColor: rl.Magenta, dirty: true})
 	contourLayer := NewContourLayer(&sketch, rng, field)
 	sketch.AddLayer("contours", contourLayer)
-	sketch.AddLayer("sierpinski", sierpinskiLayer)
-	sketch.AddLayer("aurora", imageLayer)
+	sketch.AddLayer("sierpinski-arrowhead", sierpinskiLayer)
+	sketch.AddLayer("aurora", aurora)
+	sketch.AddLayer("cave", cave)
 
 	ports := MakePorts()
 	ports["sierpinskiArrowAngle"] =
@@ -218,25 +220,27 @@ func main() {
 
 type FieldLayer struct {
 	field Field
+	loColor rl.Color
+	hiColor rl.Color
 	dirty bool
 }
 
-func (s *FieldLayer) Update(ctx *RenderCtx) {
+func (fl *FieldLayer) Update(ctx *RenderCtx) {
 	;
 }
 
-func (s *FieldLayer) Draw(ctx *RenderCtx) {
+func (fl *FieldLayer) Draw(ctx *RenderCtx) {
 	for x := range ctx.SourceWidth {
 		for y := range ctx.SourceHeight {
-			v := s.field.Get(float32(x), float32(y))
-			clr := GrayCurve(v, 1.0)
+			v := fl.field.Get(float32(x), float32(y))
+			clr := LerpCurve(v, 1.0, fl.loColor, fl.hiColor)
 			rl.DrawPixel(x, y, clr)
 		}
 	}
-	s.dirty = false
+	fl.dirty = false
 }
 
-func (s *FieldLayer) IsDirty() bool {
-	return s.dirty
+func (fl *FieldLayer) IsDirty() bool {
+	return fl.dirty
 }
 
diff --git a/sketch.go b/sketch.go
index d58dfaa..d2a1174 100644
--- a/sketch.go
+++ b/sketch.go
@@ -283,6 +283,7 @@ func (cl *ColorLayer) Update(ctx *RenderCtx) {
 
 func (cl *ColorLayer) Draw(ctx *RenderCtx) {
 	rl.DrawRectangle(0, 0, ctx.SourceWidth, ctx.SourceHeight, cl.color)
+	cl.dirty = false
 }
 
 func (cl *ColorLayer) IsDirty() bool {
diff --git a/utils.go b/utils.go
index ef2c340..f7814de 100644
--- a/utils.go
+++ b/utils.go
@@ -21,6 +21,11 @@ func GrayCurve(v, k float32) rl.Color {
 	return rl.Color{R: c, G: c, B: c, A: 255}
 }
 
+func LerpCurve(v, k float32, lo rl.Color, hi rl.Color) rl.Color {
+	v = float32(math.Pow(float64(clamp01(v)), float64(k))) // k < 1 boosts highlights, k > 1 boosts shadows
+	return rl.ColorLerp(lo, hi, v)
+}
+
 func Brightness(c rl.Color) float32 {
 	r := float32(c.R) / 255
 	g := float32(c.G) / 255