From ff64be2bc65dd6a333c45eb2551fad8b063eee37 Mon Sep 17 00:00:00 2001
From: Jonathan Hughes <10040216+jphsd@users.noreply.github.com>
Date: Mon, 19 Aug 2024 15:27:31 -0700
Subject: [PATCH] Additional surface fixes for FRGBA

---
 cmd/component.go   |  2 +-
 surface/bumpmap.go |  8 ++------
 surface/surface.go | 40 +++++++++++++++++++---------------------
 3 files changed, 22 insertions(+), 28 deletions(-)

diff --git a/cmd/component.go b/cmd/component.go
index a6b9956..a18fbbe 100644
--- a/cmd/component.go
+++ b/cmd/component.go
@@ -31,7 +31,7 @@ func main() {
 		img = texture.NewRGBA(width, height, alpha, 0, 0, 1, 1)
 		draw.Draw(res, image.Rect(width, 0, 2*width, height), img, image.Point{}, draw.Src)
 		// Bump Map
-		bm := &surface.BumpMap{nil, nil, nil, cf.Vector}
+		bm := &surface.BumpMap{surface.DefaultAmbient, nil, nil, cf.Vector}
 		img = texture.NewRGBA(width, height, bm, 0, 0, 1, 1)
 		draw.Draw(res, image.Rect(2*width, 0, 3*width, height), img, image.Point{}, draw.Src)
 		gi.SaveImage(res, fmt.Sprintf("%06d", cnt))
diff --git a/surface/bumpmap.go b/surface/bumpmap.go
index 10b905d..cf2112c 100644
--- a/surface/bumpmap.go
+++ b/surface/bumpmap.go
@@ -8,7 +8,7 @@ import (
 // BumpMap collects the ambient light, a direct light, a material, and normal map required to describe
 // an area. If the normal map is nil then the standard normal is use {0, 0, 1}
 type BumpMap struct {
-	Ambient *Ambient
+	Ambient Ambient
 	Direct  Light
 	Mat     Material
 	Normals texture.VectorField
@@ -30,11 +30,7 @@ func (bm *BumpMap) Eval2(x, y float64) color.Color {
 	_, amb, diff, _, _, _ := material.Eval2(x, y)
 
 	// Ambient
-	ambient := bm.Ambient
-	if ambient == nil {
-		ambient = &DefaultAmbient
-	}
-	col := amb.Prod(ambient.Color)
+	col := amb.Prod(bm.Ambient.Color)
 
 	// Diffuse
 	direct := bm.Direct
diff --git a/surface/surface.go b/surface/surface.go
index e65d123..58b3398 100644
--- a/surface/surface.go
+++ b/surface/surface.go
@@ -39,11 +39,9 @@ func (s *Surface) Eval2(x, y float64) col.Color {
 	lamb := amb.Prod(acol) // Ambient
 	col := em              // Emissive
 	col = col.Add(lamb)
-	/*
-		if diff == nil {
-			return col
-		}
-	*/
+	if diff.A < 0.00001  {
+		return col
+	}
 
 	// Cummulative diffuse and specular for all lights
 	normal := normals.Eval2(x, y)
@@ -64,24 +62,24 @@ func (s *Surface) Eval2(x, y float64) col.Color {
 			lcol = lcol.Scale(pow / (dist * dist))
 		}
 		cdiff = cdiff.Add(lcol.Prod(diff.Scale(lambert))) // Diffuse
-		//if spec != nil {
-		if blinn {
-			// Blinn-Phong
-			half := Unit([]float64{dir[0] + view[0], dir[1] + view[1], dir[2] + view[2]})
-			dp := Dot(half, normal)
-			if dp > 0 {
-				phong := math.Pow(dp, shine*4)
-				cspec = cspec.Add(lcol.Prod(spec.Scale(phong))) // Specular
-			}
-		} else {
-			// Phong
-			dp := Dot(Reflect(dir, normal), view)
-			if dp > 0 {
-				phong := math.Pow(dp, shine)
-				cspec = cspec.Add(lcol.Prod(spec.Scale(phong))) // Specular
+		if spec.A > 0.00001 {
+			if blinn {
+				// Blinn-Phong
+				half := Unit([]float64{dir[0] + view[0], dir[1] + view[1], dir[2] + view[2]})
+				dp := Dot(half, normal)
+				if dp > 0 {
+					phong := math.Pow(dp, shine*4)
+					cspec = cspec.Add(lcol.Prod(spec.Scale(phong))) // Specular
+				}
+			} else {
+				// Phong
+				dp := Dot(Reflect(dir, normal), view)
+				if dp > 0 {
+					phong := math.Pow(dp, shine)
+					cspec = cspec.Add(lcol.Prod(spec.Scale(phong))) // Specular
+				}
 			}
 		}
-		//}
 	}
 	col = col.Add(cdiff)
 	col = col.Add(cspec)