From daa850622a174c13ddd41054fd72cc4ab1ed00fe Mon Sep 17 00:00:00 2001
From: Lightling <contactlightling@gmail.com>
Date: Sat, 19 Mar 2022 18:07:52 -0400
Subject: [PATCH] shader comments

---
 Helpers.hlsli          | 6 ++++++
 SimplePixelShader.hlsl | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/Helpers.hlsli b/Helpers.hlsli
index 99e296a..80f6e47 100644
--- a/Helpers.hlsli
+++ b/Helpers.hlsli
@@ -1,21 +1,25 @@
 #ifndef __SHADER_HELPERS__
 #define __SHADER_HELPERS__
 
+// gets view vector, needed once per shader
 float3 getView(float3 cameraPosition, float3 pixelWorldPosition)
 {
 	return normalize(cameraPosition - pixelWorldPosition);
 }
 
+// gets reflection vector, needed per light
 float3 getReflection(float3 direction, float3 normal)
 {
 	return reflect(direction, normal);
 }
 
+// gets specular exponent: (1-roughness) * max
 float getSpecularExponent(float roughness, float max)
 {
 	return (1.0f - roughness) * max;
 }
 
+// gets specular value: clamp(dot(r,v))^e
 float getSpecular(float3 view, float3 reflection, float exponent)
 {
 	float specular = 0;
@@ -26,11 +30,13 @@ float getSpecular(float3 view, float3 reflection, float exponent)
 	return specular;
 }
 
+// gets diffuse value: clamp(dot(n,d))
 float getDiffuse(float3 normal, float3 direction)
 {
 	return saturate(dot(normal, direction));
 }
 
+// gets attenuation: clamp(1 - (distance^2 / range^2))^2
 float getAttenuation(float3 pointPosition, float3 worldPosition, float3 range)
 {
 	float dist = distance(pointPosition, worldPosition);
diff --git a/SimplePixelShader.hlsl b/SimplePixelShader.hlsl
index 2443ab5..8667f0e 100644
--- a/SimplePixelShader.hlsl
+++ b/SimplePixelShader.hlsl
@@ -14,6 +14,7 @@ cbuffer ExternalData : register(b0)
 	Light lights[LIGHT_COUNT];
 }
 
+// Gets the specular value for any light
 float calculateSpecular(float3 normal, float3 direction, float3 worldPosition, float3 cameraPosition, float roughness)
 {
 	return getSpecular(
@@ -23,6 +24,7 @@ float calculateSpecular(float3 normal, float3 direction, float3 worldPosition, f
 	);
 }
 
+// Gets the RGB value of a pixel with a directional light
 float3 calculateDirectionalLight(Light light, float3 normal, float3 worldPosition, float3 cameraPosition, float roughness, float3 surfaceColor)
 {
 	float3 lightDirection = normalize(light.Direction);
@@ -32,6 +34,7 @@ float3 calculateDirectionalLight(Light light, float3 normal, float3 worldPositio
 	return (diffuse * surfaceColor + specular) * light.Intensity * light.Color;
 }
 
+// Gets the RGB value of a pixel with a point light
 float3 calculatePointLight(Light light, float3 normal, float3 worldPosition, float3 cameraPosition, float roughness, float3 surfaceColor)
 {
 	float3 lightDirection = normalize(worldPosition - light.Position);
@@ -42,11 +45,15 @@ float3 calculatePointLight(Light light, float3 normal, float3 worldPosition, flo
 	return (diffuse * surfaceColor + specular) * attenuation * light.Intensity * light.Color;
 }
 
+// shader entry point
 float4 main(VertexToPixel input) : SV_TARGET
 {
 	input.normal = normalize(input.normal);
 
+	// start with ambient light and material tint
 	float3 light = ambient * tint;
+
+	// loop through lights
 	for (int i = 0; i < LIGHT_COUNT; i++)
 	{
 		switch (lights[i].Type)