From 9ca2e3073c701c0087eb082c209a4774b3610814 Mon Sep 17 00:00:00 2001
From: Joshua Goins <josh@redstrate.com>
Date: Wed, 7 Nov 2018 05:27:00 -0500
Subject: [PATCH] Add directional light type

---
 include/light.h   |  8 +++++++-
 shaders/mesh.frag |  9 +++++++--
 src/main.cpp      |  3 ++-
 src/worldpass.cpp | 15 ++++++++-------
 4 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/include/light.h b/include/light.h
index 65c1459..bb1482c 100644
--- a/include/light.h
+++ b/include/light.h
@@ -2,8 +2,14 @@
 
 #include <glm/glm.hpp>
 
+enum class LightType {
+    Point,
+    Directional
+};
+
 class Light {
 public:
-    glm::vec3 position;
+    LightType type = LightType::Point;
+    glm::vec3 position = glm::vec3(0), direction = glm::vec3(0);
     glm::vec3 color = glm::vec3(1);
 };
diff --git a/shaders/mesh.frag b/shaders/mesh.frag
index 836e2cc..2487aba 100644
--- a/shaders/mesh.frag
+++ b/shaders/mesh.frag
@@ -7,7 +7,7 @@ layout(location = 2) in vec2 inUV;
 layout(location = 0) out vec4 outColor;
 
 struct Light {
-    vec4 position;
+    vec4 position, direction;
     vec3 color;
 };
 
@@ -21,7 +21,12 @@ void main() {
     vec3 diffuse = vec3(0);
     for(int i = 0; i < 32; i++) {
         const vec3 norm = normalize(inNormal);
-        const vec3 lightDir = normalize(lights[i].position.xyz - inFragPos);
+
+        vec3 lightDir = vec3(0);
+        if(lights[i].position.w == 0)
+            lightDir = normalize(lights[i].position.xyz - inFragPos);
+        else
+            lightDir = normalize(-lights[i].direction.xyz);
 
         const float diff = max(dot(norm, lightDir), 0.0);
         diffuse += vec3(diff) * lights[i].color;
diff --git a/src/main.cpp b/src/main.cpp
index fe38a02..dea51c2 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -238,7 +238,8 @@ int main(int argc, char* argv[]) {
     World world;
 
     auto light = new Light();
-    light->position.y = 5;
+    light->type = LightType::Directional;
+    light->direction = glm::vec3(-0.2, -0.8, 0);
 
     world.lights.push_back(light);
 
diff --git a/src/worldpass.cpp b/src/worldpass.cpp
index d879b02..3f10037 100644
--- a/src/worldpass.cpp
+++ b/src/worldpass.cpp
@@ -32,15 +32,16 @@ WorldPass::~WorldPass() {
 
 void WorldPass::render(VkCommandBuffer commandBuffer, World& world, Camera& camera, RenderTarget* target) {
     struct ShaderLight {
-        glm::vec4 position;
+        glm::vec4 position, direction;
         glm::vec3 color;
     };
 
     ShaderLight* data;
-    vkMapMemory(renderer_.getDevice(), lightMemory_, 0, sizeof(float) * (4 + 3) * 32, 0, reinterpret_cast<void**>(&data));
+    vkMapMemory(renderer_.getDevice(), lightMemory_, 0, sizeof(float) * (4 + 4 + 3) * 32, 0, reinterpret_cast<void**>(&data));
 
     for(const auto& light : world.lights) {
-        data->position = glm::vec4(light->position, 0.0);
+        data->position = glm::vec4(light->position, (int)light->type);
+        data->direction = glm::vec4(light->direction, 0.0);
         data->color = light->color;
 
         data++;
@@ -300,7 +301,7 @@ void WorldPass::createPipeline() {
 void WorldPass::createUniformBuffer() {
     VkBufferCreateInfo bufferInfo = {};
     bufferInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
-    bufferInfo.size = sizeof(float) * (4 + 3) * 32;
+    bufferInfo.size = sizeof(float) * (4 + 4 + 3) * 32;
     bufferInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT;
     bufferInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
 
@@ -329,7 +330,7 @@ void WorldPass::createDescriptorSet() {
 
     VkDescriptorBufferInfo bufferInfo = {};
     bufferInfo.buffer = lightBuffer_;
-    bufferInfo.range = sizeof(float) * (4 + 3) * 32;
+    bufferInfo.range = sizeof(float) * (4 + 4 + 3) * 32;
 
     VkWriteDescriptorSet descriptorWrite = {};
     descriptorWrite.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
@@ -341,9 +342,9 @@ void WorldPass::createDescriptorSet() {
     vkUpdateDescriptorSets(renderer_.getDevice(), 1, &descriptorWrite, 0, nullptr);
 
     float* data;
-    vkMapMemory(renderer_.getDevice(), lightMemory_, 0, sizeof(float) * (4 + 3) * 32, 0, reinterpret_cast<void**>(&data));
+    vkMapMemory(renderer_.getDevice(), lightMemory_, 0, sizeof(float) * (4 + 4 + 3) * 32, 0, reinterpret_cast<void**>(&data));
 
-    for(uint32_t i = 0; i < (4 + 3) * 32; i++)
+    for(uint32_t i = 0; i < (4 + 4 + 3) * 32; i++)
         data[i] = 0.0f;
 
     vkUnmapMemory(renderer_.getDevice(), lightMemory_);