From e93eee4bb96bd2d81e422dc9d453da6138fd6ba2 Mon Sep 17 00:00:00 2001
From: Martin Lehoux <martin@lehoux.net>
Date: Sun, 5 Apr 2020 22:46:01 -0700
Subject: misc - Doc

---
 color.go | 49 ++++++++++++++++++++++++++++---------------------
 1 file changed, 28 insertions(+), 21 deletions(-)

(limited to 'color.go')

diff --git a/color.go b/color.go
index bb7318a..70c65f1 100644
--- a/color.go
+++ b/color.go
@@ -2,14 +2,17 @@ package main
 
 import "math"
 
+// Color in RGB, each val being between 0 and 1
 type Color struct {
 	r, g, b float64
 }
 
+// ToPixel converts a 0-1 color to a 0-255 pixel
 func (color Color) ToPixel() Pixel {
 	return Pixel{int(color.r * 255), int(color.g * 255), int(color.b * 255)}
 }
 
+// LinearBlend mixes two colors with a float param
 func LinearBlend(color1 Color, color2 Color, param float64) Color {
 	return Color{
 		param*color1.r + (1.0-param)*color2.r,
@@ -18,6 +21,7 @@ func LinearBlend(color1 Color, color2 Color, param float64) Color {
 	}
 }
 
+// AttenuateColor multiplies two colors
 func AttenuateColor(attenuation Color, color Color) Color {
 	return Color{
 		attenuation.r * color.r,
@@ -26,37 +30,40 @@ func AttenuateColor(attenuation Color, color Color) Color {
 	}
 }
 
-func RayColor(ray Ray, hitable_list HitableList, depth int) Color {
-	if depth > MAX_DEPTH {
+// RayColor finds a hit for a ray, scatters the ray and return the ray color
+func RayColor(ray Ray, hitableList HitableList, depth int) Color {
+	if depth > MaxDepth {
 		return Color{0.0, 0.0, 0.0}
 	}
-	hit := hitable_list.Hit(ray, T_MIN, T_MAX)
+	hit := hitableList.Hit(ray, TMin, TMax)
 	if hit.time > 0.0 {
 		scattered, attenuation := hit.material.Scatter(ray, hit)
-		return AttenuateColor(attenuation, RayColor(scattered, hitable_list, depth+1))
+		return AttenuateColor(attenuation, RayColor(scattered, hitableList, depth+1))
 	}
 	param := 0.5 * (ray.direction.Unit().y + 1)
 	return LinearBlend(Color{0.5, 0.7, 1.0}, Color{1.0, 1.0, 1.0}, param)
 }
 
-func ColorMean(color_list [RAY_PER_PIXEL]Color) Color {
-	length := float64(len(color_list))
-	mean_color := Color{}
-	for _, color := range color_list {
-		mean_color.r += color.r
-		mean_color.g += color.g
-		mean_color.b += color.b
+// ColorMean computes the mean color of a color list
+func ColorMean(colorList [RaysPerPixel]Color) Color {
+	length := float64(len(colorList))
+	meanColor := Color{}
+	for _, color := range colorList {
+		meanColor.r += color.r
+		meanColor.g += color.g
+		meanColor.b += color.b
 	}
-	mean_color.r /= length
-	mean_color.g /= length
-	mean_color.b /= length
-	return mean_color
+	meanColor.r /= length
+	meanColor.g /= length
+	meanColor.b /= length
+	return meanColor
 }
 
-func ColorMeanSquare(color_list [RAY_PER_PIXEL]Color) Color {
-	mean_color := ColorMean(color_list)
-	mean_color.r = math.Sqrt(mean_color.r)
-	mean_color.g = math.Sqrt(mean_color.g)
-	mean_color.b = math.Sqrt(mean_color.b)
-	return mean_color
+// ColorMeanSquare is a more realistic color mean
+func ColorMeanSquare(colorList [RaysPerPixel]Color) Color {
+	meanColor := ColorMean(colorList)
+	meanColor.r = math.Sqrt(meanColor.r)
+	meanColor.g = math.Sqrt(meanColor.g)
+	meanColor.b = math.Sqrt(meanColor.b)
+	return meanColor
 }
-- 
cgit v1.3