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Add source code for the cascaded shadow mapping guest article.

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Joey de Vries
2021-09-08 19:06:07 +02:00
parent 54dd372518
commit 0ce49088e5
8 changed files with 877 additions and 0 deletions
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11
src/8.guest/2021/2.csm/10.debug_quad.vs Normal file
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#version 460 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec2 aTexCoords;
out vec2 TexCoords;
void main()
{
TexCoords = aTexCoords;
gl_Position = vec4(aPos, 1.0);
}

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src/8.guest/2021/2.csm/10.debug_quad_depth.fs Normal file
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#version 460 core
out vec4 FragColor;
in vec2 TexCoords;
uniform sampler2DArray depthMap;
uniform float near_plane;
uniform float far_plane;
uniform int layer;
// required when using a perspective projection matrix
float LinearizeDepth(float depth)
{
float z = depth * 2.0 - 1.0; // Back to NDC
return (2.0 * near_plane * far_plane) / (far_plane + near_plane - z * (far_plane - near_plane));
}
void main()
{
float depthValue = texture(depthMap, vec3(TexCoords, layer)).r;
// FragColor = vec4(vec3(LinearizeDepth(depthValue) / far_plane), 1.0); // perspective
FragColor = vec4(vec3(depthValue), 1.0); // orthographic
}

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src/8.guest/2021/2.csm/10.shadow_mapping.fs Normal file
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#version 460 core
out vec4 FragColor;
in VS_OUT {
vec3 FragPos;
vec3 Normal;
vec2 TexCoords;
} fs_in;
uniform sampler2D diffuseTexture;
uniform sampler2DArray shadowMap;
uniform vec3 lightDir;
uniform vec3 viewPos;
uniform float farPlane;
uniform mat4 view;
layout (std140, binding = 0) uniform LightSpaceMatrices
{
mat4 lightSpaceMatrices[16];
};
uniform float cascadePlaneDistances[16];
uniform int cascadeCount; // number of frusta - 1
float ShadowCalculation(vec3 fragPosWorldSpace)
{
// select cascade layer
vec4 fragPosViewSpace = view * vec4(fragPosWorldSpace, 1.0);
float depthValue = abs(fragPosViewSpace.z);
int layer = -1;
for (int i = 0; i < cascadeCount; ++i)
{
if (depthValue < cascadePlaneDistances[i])
{
layer = i;
break;
}
}
if (layer == -1)
{
layer = cascadeCount;
}
vec4 fragPosLightSpace = lightSpaceMatrices[layer] * vec4(fragPosWorldSpace, 1.0);
// perform perspective divide
vec3 projCoords = fragPosLightSpace.xyz / fragPosLightSpace.w;
// transform to [0,1] range
projCoords = projCoords * 0.5 + 0.5;
// get depth of current fragment from light's perspective
float currentDepth = projCoords.z;
if (currentDepth > 1.0)
{
return 0.0;
}
// calculate bias (based on depth map resolution and slope)
vec3 normal = normalize(fs_in.Normal);
float bias = max(0.05 * (1.0 - dot(normal, lightDir)), 0.005);
if (layer == cascadeCount)
{
bias *= 1 / (farPlane * 0.5f);
}
else
{
bias *= 1 / (cascadePlaneDistances[layer] * 0.5f);
}
// PCF
float shadow = 0.0;
vec2 texelSize = 1.0 / vec2(textureSize(shadowMap, 0));
for(int x = -1; x <= 1; ++x)
{
for(int y = -1; y <= 1; ++y)
{
float pcfDepth = texture(shadowMap, vec3(projCoords.xy + vec2(x, y) * texelSize, layer)).r;
shadow += (currentDepth - bias) > pcfDepth ? 1.0 : 0.0;
}
}
shadow /= 9.0;
// keep the shadow at 0.0 when outside the far_plane region of the light's frustum.
if(projCoords.z > 1.0)
{
shadow = 0.0;
}
return shadow;
}
void main()
{
vec3 color = texture(diffuseTexture, fs_in.TexCoords).rgb;
vec3 normal = normalize(fs_in.Normal);
vec3 lightColor = vec3(0.3);
// ambient
vec3 ambient = 0.3 * color;
// diffuse
float diff = max(dot(lightDir, normal), 0.0);
vec3 diffuse = diff * lightColor;
// specular
vec3 viewDir = normalize(viewPos - fs_in.FragPos);
vec3 reflectDir = reflect(-lightDir, normal);
float spec = 0.0;
vec3 halfwayDir = normalize(lightDir + viewDir);
spec = pow(max(dot(normal, halfwayDir), 0.0), 64.0);
vec3 specular = spec * lightColor;
// calculate shadow
float shadow = ShadowCalculation(fs_in.FragPos);
vec3 lighting = (ambient + (1.0 - shadow) * (diffuse + specular)) * color;
FragColor = vec4(lighting, 1.0);
}

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src/8.guest/2021/2.csm/10.shadow_mapping.vs Normal file
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#version 460 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aNormal;
layout (location = 2) in vec2 aTexCoords;
out vec2 TexCoords;
out VS_OUT {
vec3 FragPos;
vec3 Normal;
vec2 TexCoords;
} vs_out;
uniform mat4 projection;
uniform mat4 view;
uniform mat4 model;
void main()
{
vs_out.FragPos = vec3(model * vec4(aPos, 1.0));
vs_out.Normal = transpose(inverse(mat3(model))) * aNormal;
vs_out.TexCoords = aTexCoords;
gl_Position = projection * view * model * vec4(aPos, 1.0);
}

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src/8.guest/2021/2.csm/10.shadow_mapping_depth.fs Normal file
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#version 460 core
void main()
{
}

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src/8.guest/2021/2.csm/10.shadow_mapping_depth.gs Normal file
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#version 460 core
layout(triangles, invocations = 5) in;
layout(triangle_strip, max_vertices = 3) out;
layout (std140, binding = 0) uniform LightSpaceMatrices
{
mat4 lightSpaceMatrices[16];
};
void main()
{
for (int i = 0; i < 3; ++i)
{
gl_Position = lightSpaceMatrices[gl_InvocationID] * gl_in[i].gl_Position;
gl_Layer = gl_InvocationID;
EmitVertex();
}
EndPrimitive();
}

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src/8.guest/2021/2.csm/10.shadow_mapping_depth.vs Normal file
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#version 460 core
layout (location = 0) in vec3 aPos;
uniform mat4 model;
void main()
{
gl_Position = model * vec4(aPos, 1.0);
}

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src/8.guest/2021/2.csm/shadow_mapping.cpp Normal file
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#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <stb_image.h>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <learnopengl/filesystem.h>
#include <learnopengl/shader.h>
#include <learnopengl/camera.h>
#include <learnopengl/model.h>
#include <iostream>
#include <random>
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void mouse_callback(GLFWwindow* window, double xpos, double ypos);
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
void processInput(GLFWwindow *window);
unsigned int loadTexture(const char *path);
void renderScene(const Shader &shader);
void renderCube();
void renderQuad();
std::vector<glm::mat4> getLightSpaceMatrices();
// settings
const unsigned int SCR_WIDTH = 2560;
const unsigned int SCR_HEIGHT = 1440;
// camera
Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
float lastX = (float)SCR_WIDTH / 2.0;
float lastY = (float)SCR_HEIGHT / 2.0;
bool firstMouse = true;
float cameraNearPlane = 0.1f;
float cameraFarPlane = 500.0f;
// timing
float deltaTime = 0.0f;
float lastFrame = 0.0f;
std::vector<float> shadowCascadeLevels{ cameraFarPlane / 50.0f, cameraFarPlane / 25.0f, cameraFarPlane / 10.0f, cameraFarPlane / 2.0f };
int debugLayer = 0;
// meshes
unsigned int planeVAO;
// lighting info
// -------------
const glm::vec3 lightDir = glm::normalize(glm::vec3(20.0f, 50, 20.0f));
unsigned int lightFBO;
unsigned int lightDepthMaps;
constexpr unsigned int depthMapResolution = 4096;
bool showQuad = false;
std::random_device device;
std::mt19937 generator = std::mt19937(device());
int main()
{
// glfw: initialize and configure
// ------------------------------
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 6);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#ifdef __APPLE__
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
#endif
// glfw window creation
// --------------------
GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
if (window == NULL)
{
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
glfwSetCursorPosCallback(window, mouse_callback);
glfwSetScrollCallback(window, scroll_callback);
// tell GLFW to capture our mouse
glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
// glad: load all OpenGL function pointers
// ---------------------------------------
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
{
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
// configure global opengl state
// -----------------------------
glEnable(GL_DEPTH_TEST);
// build and compile shaders
// -------------------------
Shader shader("10.shadow_mapping.vs", "10.shadow_mapping.fs");
Shader simpleDepthShader("10.shadow_mapping_depth.vs", "10.shadow_mapping_depth.fs", "10.shadow_mapping_depth.gs");
Shader debugDepthQuad("10.debug_quad.vs", "10.debug_quad_depth.fs");
// set up vertex data (and buffer(s)) and configure vertex attributes
// ------------------------------------------------------------------
float planeVertices[] = {
// positions // normals // texcoords
25.0f, -2.0f, 25.0f, 0.0f, 1.0f, 0.0f, 25.0f, 0.0f,
-25.0f, -2.0f, 25.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f,
-25.0f, -2.0f, -25.0f, 0.0f, 1.0f, 0.0f, 0.0f, 25.0f,
25.0f, -2.0f, 25.0f, 0.0f, 1.0f, 0.0f, 25.0f, 0.0f,
-25.0f, -2.0f, -25.0f, 0.0f, 1.0f, 0.0f, 0.0f, 25.0f,
25.0f, -2.0f, -25.0f, 0.0f, 1.0f, 0.0f, 25.0f, 25.0f
};
// plane VAO
unsigned int planeVBO;
glGenVertexArrays(1, &planeVAO);
glGenBuffers(1, &planeVBO);
glBindVertexArray(planeVAO);
glBindBuffer(GL_ARRAY_BUFFER, planeVBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(planeVertices), planeVertices, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
glEnableVertexAttribArray(2);
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
glBindVertexArray(0);
// load textures
// -------------
unsigned int woodTexture = loadTexture(FileSystem::getPath("resources/textures/wood.png").c_str());
// configure light FBO
// -----------------------
glGenFramebuffers(1, &lightFBO);
glGenTextures(1, &lightDepthMaps);
glBindTexture(GL_TEXTURE_2D_ARRAY, lightDepthMaps);
glTexImage3D(
GL_TEXTURE_2D_ARRAY, 0, GL_DEPTH_COMPONENT32F, depthMapResolution, depthMapResolution, int(shadowCascadeLevels.size()) + 1,
0, GL_DEPTH_COMPONENT, GL_FLOAT, nullptr);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
constexpr float bordercolor[] = { 1.0f, 1.0f, 1.0f, 1.0f };
glTexParameterfv(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_BORDER_COLOR, bordercolor);
glBindFramebuffer(GL_FRAMEBUFFER, lightFBO);
glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, lightDepthMaps, 0);
glDrawBuffer(GL_NONE);
glReadBuffer(GL_NONE);
int status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if (status != GL_FRAMEBUFFER_COMPLETE)
{
std::cout << "ERROR::FRAMEBUFFER:: Framebuffer is not complete!";
throw 0;
}
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// configure UBO
// --------------------
unsigned int matricesUBO;
glGenBuffers(1, &matricesUBO);
glBindBuffer(GL_UNIFORM_BUFFER, matricesUBO);
glBufferData(GL_UNIFORM_BUFFER, sizeof(glm::mat4x4) * 16, nullptr, GL_STATIC_DRAW);
glBindBufferBase(GL_UNIFORM_BUFFER, 0, matricesUBO);
glBindBuffer(GL_UNIFORM_BUFFER, 0);
// shader configuration
// --------------------
shader.use();
shader.setInt("diffuseTexture", 0);
shader.setInt("shadowMap", 1);
debugDepthQuad.use();
debugDepthQuad.setInt("depthMap", 0);
// render loop
// -----------
while (!glfwWindowShouldClose(window))
{
// per-frame time logic
// --------------------
float currentFrame = glfwGetTime();
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
// input
// -----
processInput(window);
// change light position over time
//lightPos.x = sin(glfwGetTime()) * 3.0f;
//lightPos.z = cos(glfwGetTime()) * 2.0f;
//lightPos.y = 5.0 + cos(glfwGetTime()) * 1.0f;
// render
// ------
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// 0. UBO setup
const auto lightMatrices = getLightSpaceMatrices();
glBindBuffer(GL_UNIFORM_BUFFER, matricesUBO);
for (size_t i = 0; i < lightMatrices.size(); ++i)
{
glBufferSubData(GL_UNIFORM_BUFFER, i * sizeof(glm::mat4x4), sizeof(glm::mat4x4), &lightMatrices[i]);
}
glBindBuffer(GL_UNIFORM_BUFFER, 0);
// 1. render depth of scene to texture (from light's perspective)
// --------------------------------------------------------------
//lightProjection = glm::perspective(glm::radians(45.0f), (GLfloat)SHADOW_WIDTH / (GLfloat)SHADOW_HEIGHT, near_plane, far_plane); // note that if you use a perspective projection matrix you'll have to change the light position as the current light position isn't enough to reflect the whole scene
// render scene from light's point of view
simpleDepthShader.use();
glBindFramebuffer(GL_FRAMEBUFFER, lightFBO);
glFramebufferTexture(GL_FRAMEBUFFER, GL_TEXTURE_2D_ARRAY, lightDepthMaps, 0);
glViewport(0, 0, depthMapResolution, depthMapResolution);
glClear(GL_DEPTH_BUFFER_BIT);
glCullFace(GL_FRONT); // peter panning
renderScene(simpleDepthShader);
glCullFace(GL_BACK);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// reset viewport
glViewport(0, 0, SCR_WIDTH, SCR_HEIGHT);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// 2. render scene as normal using the generated depth/shadow map
// --------------------------------------------------------------
glViewport(0, 0, SCR_WIDTH, SCR_HEIGHT);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
shader.use();
const glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, cameraNearPlane, cameraFarPlane);
const glm::mat4 view = camera.GetViewMatrix();
shader.setMat4("projection", projection);
shader.setMat4("view", view);
// set light uniforms
shader.setVec3("viewPos", camera.Position);
shader.setVec3("lightDir", lightDir);
shader.setFloat("farPlane", cameraFarPlane);
shader.setInt("cascadeCount", shadowCascadeLevels.size());
for (size_t i = 0; i < shadowCascadeLevels.size(); ++i)
{
shader.setFloat("cascadePlaneDistances[" + std::to_string(i) + "]", shadowCascadeLevels[i]);
}
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, woodTexture);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D_ARRAY, lightDepthMaps);
renderScene(shader);
// render Depth map to quad for visual debugging
// ---------------------------------------------
debugDepthQuad.use();
debugDepthQuad.setInt("layer", debugLayer);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D_ARRAY, lightDepthMaps);
if (showQuad)
{
renderQuad();
}
std::cout << glm::length(camera.Position) << "\n";
// glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
// -------------------------------------------------------------------------------
glfwSwapBuffers(window);
glfwPollEvents();
}
// optional: de-allocate all resources once they've outlived their purpose:
// ------------------------------------------------------------------------
glDeleteVertexArrays(1, &planeVAO);
glDeleteBuffers(1, &planeVBO);
glfwTerminate();
return 0;
}
// renders the 3D scene
// --------------------
void renderScene(const Shader &shader)
{
// floor
glm::mat4 model = glm::mat4(1.0f);
shader.setMat4("model", model);
glBindVertexArray(planeVAO);
glDrawArrays(GL_TRIANGLES, 0, 6);
static std::vector<glm::mat4> modelMatrices;
if (modelMatrices.size() == 0)
{
for (int i = 0; i < 10; ++i)
{
static std::uniform_real_distribution<float> offsetDistribution = std::uniform_real_distribution<float>(-10, 10);
static std::uniform_real_distribution<float> scaleDistribution = std::uniform_real_distribution<float>(1.0, 2.0);
static std::uniform_real_distribution<float> rotationDistribution = std::uniform_real_distribution<float>(0, 180);
auto model = glm::mat4(1.0f);
model = glm::translate(model, glm::vec3(offsetDistribution(generator), offsetDistribution(generator) + 10.0f, offsetDistribution(generator)));
model = glm::rotate(model, glm::radians(rotationDistribution(generator)), glm::normalize(glm::vec3(1.0, 0.0, 1.0)));
model = glm::scale(model, glm::vec3(scaleDistribution(generator)));
modelMatrices.push_back(model);
}
}
for (const auto& model : modelMatrices)
{
shader.setMat4("model", model);
renderCube();
}
// cubes
//model = glm::mat4(1.0f);
//model = glm::translate(model, glm::vec3(-5.0f, -3.0f, 0.0));
//model = glm::scale(model, glm::vec3(2));
//shader.setMat4("model", model);
//renderCube();
//model = glm::mat4(1.0f);
//model = glm::translate(model, glm::vec3(2.0f, 3.0f, 1.0));
//model = glm::scale(model, glm::vec3(2));
//shader.setMat4("model", model);
//renderCube();
//model = glm::mat4(1.0f);
//model = glm::translate(model, glm::vec3(-1.0f, 3.0f, 2.0));
//model = glm::rotate(model, glm::radians(60.0f), glm::normalize(glm::vec3(1.0, 0.0, 1.0)));
//model = glm::scale(model, glm::vec3(2));
//shader.setMat4("model", model);
//renderCube();
}
// renderCube() renders a 1x1 3D cube in NDC.
// -------------------------------------------------
unsigned int cubeVAO = 0;
unsigned int cubeVBO = 0;
void renderCube()
{
// initialize (if necessary)
if (cubeVAO == 0)
{
float vertices[] = {
// back face
-1.0f, -1.0f, -1.0f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, // bottom-left
1.0f, 1.0f, -1.0f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f, // top-right
1.0f, -1.0f, -1.0f, 0.0f, 0.0f, -1.0f, 1.0f, 0.0f, // bottom-right
1.0f, 1.0f, -1.0f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f, // top-right
-1.0f, -1.0f, -1.0f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, // bottom-left
-1.0f, 1.0f, -1.0f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f, // top-left
// front face
-1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom-left
1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, // bottom-right
1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, // top-right
1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, // top-right
-1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, // top-left
-1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom-left
// left face
-1.0f, 1.0f, 1.0f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-right
-1.0f, 1.0f, -1.0f, -1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top-left
-1.0f, -1.0f, -1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-left
-1.0f, -1.0f, -1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-left
-1.0f, -1.0f, 1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 0.0f, // bottom-right
-1.0f, 1.0f, 1.0f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-right
// right face
1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-left
1.0f, -1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-right
1.0f, 1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top-right
1.0f, -1.0f, -1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-right
1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-left
1.0f, -1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, // bottom-left
// bottom face
-1.0f, -1.0f, -1.0f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f, // top-right
1.0f, -1.0f, -1.0f, 0.0f, -1.0f, 0.0f, 1.0f, 1.0f, // top-left
1.0f, -1.0f, 1.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, // bottom-left
1.0f, -1.0f, 1.0f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, // bottom-left
-1.0f, -1.0f, 1.0f, 0.0f, -1.0f, 0.0f, 0.0f, 0.0f, // bottom-right
-1.0f, -1.0f, -1.0f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f, // top-right
// top face
-1.0f, 1.0f, -1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, // top-left
1.0f, 1.0f , 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // bottom-right
1.0f, 1.0f, -1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, // top-right
1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // bottom-right
-1.0f, 1.0f, -1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, // top-left
-1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f // bottom-left
};
glGenVertexArrays(1, &cubeVAO);
glGenBuffers(1, &cubeVBO);
// fill buffer
glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
// link vertex attributes
glBindVertexArray(cubeVAO);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
glEnableVertexAttribArray(2);
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
// render Cube
glBindVertexArray(cubeVAO);
glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);
}
// renderQuad() renders a 1x1 XY quad in NDC
// -----------------------------------------
unsigned int quadVAO = 0;
unsigned int quadVBO;
void renderQuad()
{
if (quadVAO == 0)
{
float quadVertices[] = {
// positions // texture Coords
-1.0f, 1.0f, 0.0f, 0.0f, 1.0f,
-1.0f, -1.0f, 0.0f, 0.0f, 0.0f,
1.0f, 1.0f, 0.0f, 1.0f, 1.0f,
1.0f, -1.0f, 0.0f, 1.0f, 0.0f,
};
// setup plane VAO
glGenVertexArrays(1, &quadVAO);
glGenBuffers(1, &quadVBO);
glBindVertexArray(quadVAO);
glBindBuffer(GL_ARRAY_BUFFER, quadVBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(quadVertices), &quadVertices, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
}
glBindVertexArray(quadVAO);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glBindVertexArray(0);
}
// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
// ---------------------------------------------------------------------------------------------------------
void processInput(GLFWwindow *window)
{
if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
glfwSetWindowShouldClose(window, true);
camera.MovementSpeed = glfwGetKey(window, GLFW_KEY_LEFT_SHIFT) == GLFW_PRESS ? 2.5 * 10 : 2.5;
if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
camera.ProcessKeyboard(FORWARD, deltaTime);
if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
camera.ProcessKeyboard(BACKWARD, deltaTime);
if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
camera.ProcessKeyboard(LEFT, deltaTime);
if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
camera.ProcessKeyboard(RIGHT, deltaTime);
static int fPress = GLFW_RELEASE;
if (glfwGetKey(window, GLFW_KEY_F) == GLFW_RELEASE && fPress == GLFW_PRESS)
{
showQuad = !showQuad;
}
fPress = glfwGetKey(window, GLFW_KEY_F);
static int plusPress = GLFW_RELEASE;
if (glfwGetKey(window, GLFW_KEY_KP_ADD) == GLFW_RELEASE && plusPress == GLFW_PRESS)
{
debugLayer++;
if (debugLayer > shadowCascadeLevels.size())
{
debugLayer = 0;
}
}
plusPress = glfwGetKey(window, GLFW_KEY_KP_ADD);
}
// glfw: whenever the window size changed (by OS or user resize) this callback function executes
// ---------------------------------------------------------------------------------------------
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
// make sure the viewport matches the new window dimensions; note that width and
// height will be significantly larger than specified on retina displays.
glViewport(0, 0, width, height);
}
// glfw: whenever the mouse moves, this callback is called
// -------------------------------------------------------
void mouse_callback(GLFWwindow* window, double xpos, double ypos)
{
if (firstMouse)
{
lastX = xpos;
lastY = ypos;
firstMouse = false;
}
float xoffset = xpos - lastX;
float yoffset = lastY - ypos; // reversed since y-coordinates go from bottom to top
lastX = xpos;
lastY = ypos;
camera.ProcessMouseMovement(xoffset, yoffset);
}
// glfw: whenever the mouse scroll wheel scrolls, this callback is called
// ----------------------------------------------------------------------
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
{
camera.ProcessMouseScroll(yoffset);
}
// utility function for loading a 2D texture from file
// ---------------------------------------------------
unsigned int loadTexture(char const * path)
{
unsigned int textureID;
glGenTextures(1, &textureID);
int width, height, nrComponents;
unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0);
if (data)
{
GLenum format;
if (nrComponents == 1)
format = GL_RED;
else if (nrComponents == 3)
format = GL_RGB;
else if (nrComponents == 4)
format = GL_RGBA;
glBindTexture(GL_TEXTURE_2D, textureID);
glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, format == GL_RGBA ? GL_CLAMP_TO_EDGE : GL_REPEAT); // for this tutorial: use GL_CLAMP_TO_EDGE to prevent semi-transparent borders. Due to interpolation it takes texels from next repeat
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, format == GL_RGBA ? GL_CLAMP_TO_EDGE : GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
stbi_image_free(data);
}
else
{
std::cout << "Texture failed to load at path: " << path << std::endl;
stbi_image_free(data);
}
return textureID;
}
std::vector<glm::vec4> getFrustumCornersWorldSpace(const glm::mat4& proj, const glm::mat4& view)
{
const auto inv = glm::inverse(proj * view);
std::vector<glm::vec4> frustumCorners;
for (unsigned int x = 0; x < 2; ++x)
{
for (unsigned int y = 0; y < 2; ++y)
{
for (unsigned int z = 0; z < 2; ++z)
{
const glm::vec4 pt = inv * glm::vec4(2.0f * x - 1.0f, 2.0f * y - 1.0f, 2.0f * z - 1.0f, 1.0f);
frustumCorners.push_back(pt / pt.w);
}
}
}
return frustumCorners;
}
glm::mat4 getLightSpaceMatrix(const float nearPlane, const float farPlane)
{
const auto proj = glm::perspective(
glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, nearPlane,
farPlane);
const auto corners = getFrustumCornersWorldSpace(proj, camera.GetViewMatrix());
glm::vec3 center = glm::vec3(0, 0, 0);
for (const auto& v : corners)
{
center += glm::vec3(v);
}
center /= corners.size();
const auto lightView = glm::lookAt(center + lightDir, center, glm::vec3(0.0f, 1.0f, 0.0f));
float minX = std::numeric_limits<float>::max();
float maxX = std::numeric_limits<float>::min();
float minY = std::numeric_limits<float>::max();
float maxY = std::numeric_limits<float>::min();
float minZ = std::numeric_limits<float>::max();
float maxZ = std::numeric_limits<float>::min();
for (const auto& v : corners)
{
const auto trf = lightView * v;
minX = std::min(minX, trf.x);
maxX = std::max(maxX, trf.x);
minY = std::min(minY, trf.y);
maxY = std::max(maxY, trf.y);
minZ = std::min(minZ, trf.z);
maxZ = std::max(maxZ, trf.z);
}
// Tune this parameter according to the scene
constexpr float zMult = 10.0f;
if (minZ < 0)
{
minZ *= zMult;
}
else
{
minZ /= zMult;
}
if (maxZ < 0)
{
maxZ /= zMult;
}
else
{
maxZ *= zMult;
}
const glm::mat4 lpMatrix = glm::ortho(-1.0f, 1.0f, -1.0f, 1.0f, minZ, maxZ);
const float scaleX = 2.0f / (maxX - minX);
const float scaleY = 2.0f / (maxY - minY);
const float offsetX = -0.5f * (minX + maxX) * scaleX;
const float offsetY = -0.5f * (minY + maxY) * scaleY;
glm::mat4 cropMatrix(1.0f);
cropMatrix[0][0] = scaleX;
cropMatrix[1][1] = scaleY;
cropMatrix[3][0] = offsetX;
cropMatrix[3][1] = offsetY;
return cropMatrix * lpMatrix * lightView;
}
std::vector<glm::mat4> getLightSpaceMatrices()
{
std::vector<glm::mat4> ret;
for (size_t i = 0; i < shadowCascadeLevels.size() + 1; ++i)
{
if (i == 0)
{
ret.push_back(getLightSpaceMatrix(cameraNearPlane, shadowCascadeLevels[i]));
}
else if (i < shadowCascadeLevels.size())
{
ret.push_back(getLightSpaceMatrix(shadowCascadeLevels[i - 1], shadowCascadeLevels[i]));
}
else
{
ret.push_back(getLightSpaceMatrix(shadowCascadeLevels[i - 1], cameraFarPlane));
}
}
return ret;
}