From 0ea573aa004f06dfdf152c9295142ba148f1894c Mon Sep 17 00:00:00 2001
From: Hjalte Sorgenfrei Mac Dalland <hjaltesorgenfrei@gmail.com>
Date: Thu, 29 Sep 2022 15:37:05 +0200
Subject: [PATCH] Create a single point light

---
 src/RenderData.h        |  3 +++
 src/Renderer.cpp        |  2 +-
 src/shaders/shader.frag | 19 ++++++++++++++++++-
 src/shaders/shader.vert | 23 +++++++++++++----------
 4 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/src/RenderData.h b/src/RenderData.h
index 6bc86a2..624dae0 100644
--- a/src/RenderData.h
+++ b/src/RenderData.h
@@ -9,6 +9,9 @@ struct UniformBufferObject {
     glm::mat4 view;
     glm::mat4 proj;
     glm::mat4 projView;
+	glm::vec4 ambientLightColor{1.f, 1.f, 1.f, .04f};  // w is intensity
+	glm::vec4 lightPosition{2.f, 1.f, 0.0f, 0.0f}; // w is ignored
+	glm::vec4 lightColor{1.f};  // w is light intensity
 };
 
 class RenderData {
diff --git a/src/Renderer.cpp b/src/Renderer.cpp
index 444678c..9f28fd4 100644
--- a/src/Renderer.cpp
+++ b/src/Renderer.cpp
@@ -791,7 +791,7 @@ void Renderer::createDescriptorSetLayout() {
 		.binding = 0,
 		.descriptorType = vk::DescriptorType::eUniformBuffer,
 		.descriptorCount = 1,
-		.stageFlags = vk::ShaderStageFlagBits::eVertex,
+		.stageFlags = vk::ShaderStageFlagBits::eAllGraphics,
 		.pImmutableSamplers = nullptr
 	};
 
diff --git a/src/shaders/shader.frag b/src/shaders/shader.frag
index 3915b59..0b81ae6 100644
--- a/src/shaders/shader.frag
+++ b/src/shaders/shader.frag
@@ -1,14 +1,31 @@
 #version 450
 #extension GL_EXT_nonuniform_qualifier : enable
 
+layout(set = 0, binding = 0) uniform UniformBufferObject {
+	mat4 view;
+	mat4 proj;
+	mat4 projView;
+	vec4 ambientLightColor; // w is intensity
+	vec4 lightPosition; // w is ignored
+	vec4 lightColor; // w is intensity
+} ubo;
+
 layout(set = 1, binding = 0) uniform sampler2D texSampler[];
 
 layout(location = 0) in vec3 fragColor;
 layout(location = 1) in vec2 fragTexCoord;
 layout(location = 2) in flat uint materialIndex;
+layout(location = 3) in vec3 fragPosWorld;
+layout(location = 4) in vec3 fragNormalWorld;
 
 layout(location = 0) out vec4 outColor;
 
 void main() {
-	outColor = texture(texSampler[int(materialIndex)], fragTexCoord.xy) * vec4(fragColor, 1.0); // Shitty shadows
+	vec3 directionToLight = ubo.lightPosition.xyz - fragPosWorld;
+	float attenuation = 1.0 / dot(directionToLight, directionToLight); // distance squared
+
+	vec3 lightColor = ubo.lightColor.xyz * ubo.lightColor.w * attenuation;
+	vec3 ambientLight = ubo.ambientLightColor.xyz * ubo.ambientLightColor.w;
+	vec3 diffuseLight = lightColor * max(dot(normalize(fragNormalWorld), normalize(directionToLight)), 0);
+	outColor = texture(texSampler[int(materialIndex)], fragTexCoord.xy) * vec4((diffuseLight + ambientLight) * fragColor, 1.0);
 }
\ No newline at end of file
diff --git a/src/shaders/shader.vert b/src/shaders/shader.vert
index d0ecb3e..dc3106a 100644
--- a/src/shaders/shader.vert
+++ b/src/shaders/shader.vert
@@ -4,6 +4,9 @@ layout(set = 0, binding = 0) uniform UniformBufferObject {
 	mat4 view;
 	mat4 proj;
 	mat4 projView;
+	vec4 ambientLightColor; // w is intensity
+	vec4 lightPosition; // w is ignored
+	vec4 lightColor; // w is intensity
 } ubo;
 
 layout (push_constant) uniform constants {
@@ -20,20 +23,20 @@ layout(location = 4) in uint inMaterialIndex;
 layout(location = 0) out vec3 fragColor;
 layout(location = 1) out vec2 fragTexCoord;
 layout(location = 2) out uint materialIndex;
-
-const vec3 DIRECTION_TO_LIGHT = normalize(vec3(1.0, 3.0, -1.0));
-const float AMBIENT = 0.02;
+layout(location = 3) out vec3 fragPosWorld;
+layout(location = 4) out vec3 fragNormalWorld;
 
 void main() {
+	vec4 positionWorld = pushConstants.modelMatrix * vec4(inPosition, 1.0);
+
+	gl_Position = ubo.projView * positionWorld;
+	fragColor = inColor;
+	fragTexCoord = inTexCoord;
+	materialIndex = inMaterialIndex;
+	fragPosWorld = positionWorld.xyz;
 	// Diffuse shading does not work correctly if model is scaled non Uniformly
 	// https://paroj.github.io/gltut/Illumination/Tut09%20Normal%20Transformation.html
 	// TODO: Fix this if it becomes necessary
 	// Can be done by computing the value on the CPU and sending it as a Push Constant
-	vec3 normalWorldSpace = normalize((pushConstants.modelMatrix * vec4(inNormal, 0.0)).xyz);  
-	float lightIntensity = AMBIENT + max(dot(normalWorldSpace, DIRECTION_TO_LIGHT), 0);
-
-	gl_Position = ubo.projView * pushConstants.modelMatrix * vec4(inPosition, 1);
-	fragColor = inColor * lightIntensity;
-	fragTexCoord = inTexCoord;
-	materialIndex = inMaterialIndex;
+	fragNormalWorld = normalize((pushConstants.modelMatrix * vec4(inNormal, 0.0)).xyz);
 }