From 29b3605cbaab729c9181e93118aa566b7360d8c4 Mon Sep 17 00:00:00 2001
From: Lightling <contactlightling@gmail.com>
Date: Sun, 27 Mar 2022 16:07:07 -0400
Subject: [PATCH] make corrections to light calculations

---
 Game.cpp               | 18 +++++++++---------
 Helpers.hlsli          |  2 +-
 SimplePixelShader.hlsl | 11 ++++++-----
 3 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/Game.cpp b/Game.cpp
index 46aa80c..a991acf 100644
--- a/Game.cpp
+++ b/Game.cpp
@@ -123,36 +123,36 @@ void Game::LoadTextures()
 
 void Game::LoadLighting()
 {
-	ambient = XMFLOAT3(0.5f, 0.5f, 0.5f);
+	ambient = XMFLOAT3(0.1f, 0.1f, 0.25f);
 
 	Light directionalLight0 = {};
 	directionalLight0.Type = LIGHT_TYPE_DIRECTIONAL;
-	directionalLight0.Direction = XMFLOAT3(1, 0, 0);
+	directionalLight0.Direction = XMFLOAT3(1, 0.5f, 0.5f);
 	directionalLight0.Color = XMFLOAT3(1, 1, 1);
-	directionalLight0.Intensity = 0.5f;
+	directionalLight0.Intensity = 1.0f;
 
 	Light directionalLight1 = {};
 	directionalLight1.Type = LIGHT_TYPE_DIRECTIONAL;
-	directionalLight1.Direction = XMFLOAT3(0, -1, 0);
+	directionalLight1.Direction = XMFLOAT3(-0.25f, -1, 0.75f);
 	directionalLight1.Color = XMFLOAT3(1, 1, 1);
-	directionalLight1.Intensity = 0.5f;
+	directionalLight1.Intensity = 1.0f;
 
 	Light directionalLight2 = {};
 	directionalLight2.Type = LIGHT_TYPE_DIRECTIONAL;
 	directionalLight2.Direction = XMFLOAT3(-1, 1, -0.5f);
 	directionalLight2.Color = XMFLOAT3(1, 1, 1);
-	directionalLight2.Intensity = 0.5f;
+	directionalLight2.Intensity = 1.0f;
 
 	Light pointLight0 = {};
 	pointLight0.Type = LIGHT_TYPE_POINT;
-	pointLight0.Position = XMFLOAT3(-2, -2, 0);
+	pointLight0.Position = XMFLOAT3(-1.5f, 0, 0);
 	pointLight0.Color = XMFLOAT3(1, 1, 1);
-	pointLight0.Intensity = 0.5f;
+	pointLight0.Intensity = 1.0f;
 	pointLight0.Range = 10;
 
 	Light pointLight1 = {};
 	pointLight1.Type = LIGHT_TYPE_POINT;
-	pointLight1.Position = XMFLOAT3(2, 2, 0);
+	pointLight1.Position = XMFLOAT3(1.5f, 0, 0);
 	pointLight1.Color = XMFLOAT3(1, 1, 1);
 	pointLight1.Intensity = 0.5f;
 	pointLight1.Range = 10;
diff --git a/Helpers.hlsli b/Helpers.hlsli
index 80f6e47..f674ce4 100644
--- a/Helpers.hlsli
+++ b/Helpers.hlsli
@@ -10,7 +10,7 @@ float3 getView(float3 cameraPosition, float3 pixelWorldPosition)
 // gets reflection vector, needed per light
 float3 getReflection(float3 direction, float3 normal)
 {
-	return reflect(direction, normal);
+	return reflect(-direction, normal);
 }
 
 // gets specular exponent: (1-roughness) * max
diff --git a/SimplePixelShader.hlsl b/SimplePixelShader.hlsl
index 949df9d..01c58cc 100644
--- a/SimplePixelShader.hlsl
+++ b/SimplePixelShader.hlsl
@@ -40,9 +40,9 @@ float3 calculateDirectionalLight(Light light, float3 normal, float3 view, float
 // Gets the RGB value of a pixel with a point light
 float3 calculatePointLight(Light light, float3 normal, float3 view, float3 worldPosition, float roughness, float3 surfaceColor)
 {
-	float3 lightDirection = normalize(worldPosition - light.Position);
+	float3 lightDirection = normalize(light.Position - worldPosition);
 	float attenuation = getAttenuation(light.Position, worldPosition, light.Range);
-	float diffuse = getDiffuse(normal, -lightDirection);
+	float diffuse = getDiffuse(normal, lightDirection);
 	float specular = calculateSpecular(normal, lightDirection, view, roughness);
 
 	return (diffuse * surfaceColor + specular) * attenuation * light.Intensity * light.Color;
@@ -58,7 +58,8 @@ float4 main(VertexToPixel input) : SV_TARGET
 	float3 view = getView(cameraPosition, input.worldPosition);
 
 	float4 albedo = Albedo.Sample(BasicSampler, input.uv).rgba;
-	float3 light = ambient * albedo.rgb * tint;
+	float3 surface = albedo.rgb * tint;
+	float3 light = ambient * surface;
 
 	// loop through lights
 	for (int i = 0; i < LIGHT_COUNT; i++)
@@ -66,10 +67,10 @@ float4 main(VertexToPixel input) : SV_TARGET
 		switch (lights[i].Type)
 		{
 		case LIGHT_TYPE_DIRECTIONAL:
-			light += calculateDirectionalLight(lights[i], input.normal, view, roughness, tint);
+			light += calculateDirectionalLight(lights[i], input.normal, view, roughness, surface);
 			break;
 		case LIGHT_TYPE_POINT:
-			light += calculatePointLight(lights[i], input.normal, view, input.worldPosition, roughness, tint);
+			light += calculatePointLight(lights[i], input.normal, view, input.worldPosition, roughness, surface);
 			break;
 		}
 	}