// GLEW
#define GLEW_STATIC
#include <GL/glew.h>
// GLFW
#include <GLFW/glfw3.h>
// GL includes
#include <learnopengl/shader.h>
#include <learnopengl/camera.h>
#include <learnopengl/model.h>
// GLM Mathemtics
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
// Other Libs
#include <SOIL.h>
// Properties
const GLuint SCR_WIDTH = 800, SCR_HEIGHT = 600;
// Function prototypes
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode);
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
void mouse_callback(GLFWwindow* window, double xpos, double ypos);
void Do_Movement();
GLuint loadTexture(GLchar* path);
void RenderCube();
void RenderQuad();
// Camera
Camera camera(glm::vec3(0.0f, 0.0f, 5.0f));
// Delta
GLfloat deltaTime = 0.0f;
GLfloat lastFrame = 0.0f;
// The MAIN function, from here we start our application and run our Game loop
int main()
{
// Init GLFW
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);
GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", nullptr, nullptr); // Windowed
glfwMakeContextCurrent(window);
// Set the required callback functions
glfwSetKeyCallback(window, key_callback);
glfwSetCursorPosCallback(window, mouse_callback);
glfwSetScrollCallback(window, scroll_callback);
// Options
glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
// Initialize GLEW to setup the OpenGL Function pointers
glewExperimental = GL_TRUE;
glewInit();
// Define the viewport dimensions
glViewport(0, 0, SCR_WIDTH, SCR_HEIGHT);
// Setup some OpenGL options
glEnable(GL_DEPTH_TEST);
// Setup and compile our shaders
Shader shaderGeometryPass("g_buffer.vs", "g_buffer.frag");
Shader shaderLightingPass("deferred_shading.vs", "deferred_shading.frag");
Shader shaderLightBox("deferred_light_box.vs", "deferred_light_box.frag");
// Set samplers
shaderLightingPass.Use();
glUniform1i(glGetUniformLocation(shaderLightingPass.Program, "gPosition"), 0);
glUniform1i(glGetUniformLocation(shaderLightingPass.Program, "gNormal"), 1);
glUniform1i(glGetUniformLocation(shaderLightingPass.Program, "gAlbedoSpec"), 2);
// Models
Model cyborg("../../../resources/objects/nanosuit/nanosuit.obj");
std::vector<glm::vec3> objectPositions;
objectPositions.push_back(glm::vec3(-3.0, -3.0, -3.0));
objectPositions.push_back(glm::vec3(0.0, -3.0, -3.0));
objectPositions.push_back(glm::vec3(3.0, -3.0, -3.0));
objectPositions.push_back(glm::vec3(-3.0, -3.0, 0.0));
objectPositions.push_back(glm::vec3(0.0, -3.0, 0.0));
objectPositions.push_back(glm::vec3(3.0, -3.0, 0.0));
objectPositions.push_back(glm::vec3(-3.0, -3.0, 3.0));
objectPositions.push_back(glm::vec3(0.0, -3.0, 3.0));
objectPositions.push_back(glm::vec3(3.0, -3.0, 3.0));
// - Colors
const GLuint NR_LIGHTS = 32;
std::vector<glm::vec3> lightPositions;
std::vector<glm::vec3> lightColors;
srand(13);
for (GLuint i = 0; i < NR_LIGHTS; i++)
{
// Calculate slightly random offsets
GLfloat xPos = ((rand() % 100) / 100.0) * 6.0 - 3.0;
GLfloat yPos = ((rand() % 100) / 100.0) * 6.0 - 4.0;
GLfloat zPos = ((rand() % 100) / 100.0) * 6.0 - 3.0;
lightPositions.push_back(glm::vec3(xPos, yPos, zPos));
// Also calculate random color
GLfloat rColor = ((rand() % 100) / 200.0f) + 0.5; // Between 0.5 and 1.0
GLfloat gColor = ((rand() % 100) / 200.0f) + 0.5; // Between 0.5 and 1.0
GLfloat bColor = ((rand() % 100) / 200.0f) + 0.5; // Between 0.5 and 1.0
lightColors.push_back(glm::vec3(rColor, gColor, bColor));
}
// Set up G-Buffer
// 3 textures:
// 1. Positions (RGB)
// 2. Color (RGB) + Specular (A)
// 3. Normals (RGB)
GLuint gBuffer;
glGenFramebuffers(1, &gBuffer);
glBindFramebuffer(GL_FRAMEBUFFER, gBuffer);
GLuint gPosition, gNormal, gAlbedoSpec;
// - Position color buffer
glGenTextures(1, &gPosition);
glBindTexture(GL_TEXTURE_2D, gPosition);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, SCR_WIDTH, SCR_HEIGHT, 0, GL_RGB, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, gPosition, 0);
// - Normal color buffer
glGenTextures(1, &gNormal);
glBindTexture(GL_TEXTURE_2D, gNormal);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, SCR_WIDTH, SCR_HEIGHT, 0, GL_RGB, GL_FLOAT, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, gNormal, 0);
// - Color + Specular color buffer
glGenTextures(1, &gAlbedoSpec);
glBindTexture(GL_TEXTURE_2D, gAlbedoSpec);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, SCR_WIDTH, SCR_HEIGHT, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, GL_TEXTURE_2D, gAlbedoSpec, 0);
// - Tell OpenGL which color attachments we'll use (of this framebuffer) for rendering
GLuint attachments[3] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2 };
glDrawBuffers(3, attachments);
// - Create and attach depth buffer (renderbuffer)
GLuint rboDepth;
glGenRenderbuffers(1, &rboDepth);
glBindRenderbuffer(GL_RENDERBUFFER, rboDepth);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, SCR_WIDTH, SCR_HEIGHT);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, rboDepth);
// - Finally check if framebuffer is complete
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
std::cout << "Framebuffer not complete!" << std::endl;
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
// Game loop
while (!glfwWindowShouldClose(window))
{
// Set frame time
GLfloat currentFrame = glfwGetTime();
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
// Check and call events
glfwPollEvents();
Do_Movement();
// 1. Geometry Pass: render scene's geometry/color data into gbuffer
glBindFramebuffer(GL_FRAMEBUFFER, gBuffer);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glm::mat4 projection = glm::perspective(camera.Zoom, (GLfloat)SCR_WIDTH / (GLfloat)SCR_HEIGHT, 0.1f, 100.0f);
glm::mat4 view = camera.GetViewMatrix();
glm::mat4 model;
shaderGeometryPass.Use();
glUniformMatrix4fv(glGetUniformLocation(shaderGeometryPass.Program, "projection"), 1, GL_FALSE, glm::value_ptr(projection));
glUniformMatrix4fv(glGetUniformLocation(shaderGeometryPass.Program, "view"), 1, GL_FALSE, glm::value_ptr(view));
for (GLuint i = 0; i < objectPositions.size(); i++)
{
model = glm::mat4();
model = glm::translate(model, objectPositions[i]);
model = glm::scale(model, glm::vec3(0.25f));
glUniformMatrix4fv(glGetUniformLocation(shaderGeometryPass.Program, "model"), 1, GL_FALSE, glm::value_ptr(model));
cyborg.Draw(shaderGeometryPass);
}
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// 2. Lighting Pass: calculate lighting by iterating over a screen filled quad pixel-by-pixel using the gbuffer's content.
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
shaderLightingPass.Use();
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, gPosition);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, gNormal);
glActiveTexture(GL_TEXTURE2);
glBindTexture(GL_TEXTURE_2D, gAlbedoSpec);
// Also send light relevant uniforms
for (GLuint i = 0; i < lightPositions.size(); i++)
{
glUniform3fv(glGetUniformLocation(shaderLightingPass.Program, ("lights[" + std::to_string(i) + "].Position").c_str()), 1, &lightPositions[i][0]);
glUniform3fv(glGetUniformLocation(shaderLightingPass.Program, ("lights[" + std::to_string(i) + "].Color").c_str()), 1, &lightColors[i][0]);
// Update attenuation parameters and calculate radius
const GLfloat constant = 1.0; // Note that we don't send this to the shader, we assume it is always 1.0 (in our case)
const GLfloat linear = 0.7;
const GLfloat quadratic = 1.8;
glUniform1f(glGetUniformLocation(shaderLightingPass.Program, ("lights[" + std::to_string(i) + "].Linear").c_str()), linear);
glUniform1f(glGetUniformLocation(shaderLightingPass.Program, ("lights[" + std::to_string(i) + "].Quadratic").c_str()), quadratic);
}
glUniform3fv(glGetUniformLocation(shaderLightingPass.Program, "viewPos"), 1, &camera.Position[0]);
// Finally render quad
RenderQuad();
// 2.5. Copy content of geometry's depth buffer to default framebuffer's depth buffer
glBindFramebuffer(GL_READ_FRAMEBUFFER, gBuffer);
glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0); // Write to default framebuffer
// blit to default framebuffer. Note that this may or may not work as the internal formats of both the FBO and default framebuffer have to match.
// the internal formats are implementation defined. This works on all of my systems, but if it doesn't on yours you'll likely have to write to the
// depth buffer in another shader stage (or somehow see to match the default framebuffer's internal format with the FBO's internal format).
glBlitFramebuffer(0, 0, SCR_WIDTH, SCR_HEIGHT, 0, 0, SCR_WIDTH, SCR_HEIGHT, GL_DEPTH_BUFFER_BIT, GL_NEAREST);
glBindFramebuffer(GL_FRAMEBUFFER, 0);
// 3. Render lights on top of scene, by blitting
shaderLightBox.Use();
glUniformMatrix4fv(glGetUniformLocation(shaderLightBox.Program, "projection"), 1, GL_FALSE, glm::value_ptr(projection));
glUniformMatrix4fv(glGetUniformLocation(shaderLightBox.Program, "view"), 1, GL_FALSE, glm::value_ptr(view));
for (GLuint i = 0; i < lightPositions.size(); i++)
{
model = glm::mat4();
model = glm::translate(model, lightPositions[i]);
model = glm::scale(model, glm::vec3(0.25f));
glUniformMatrix4fv(glGetUniformLocation(shaderLightBox.Program, "model"), 1, GL_FALSE, glm::value_ptr(model));
glUniform3fv(glGetUniformLocation(shaderLightBox.Program, "lightColor"), 1, &lightColors[i][0]);
RenderCube();
}
// Swap the buffers
glfwSwapBuffers(window);
}
glfwTerminate();
return 0;
}
// RenderQuad() Renders a 1x1 quad in NDC, best used for framebuffer color targets
// and post-processing effects.
GLuint quadVAO = 0;
GLuint quadVBO;
void RenderQuad()
{
if (quadVAO == 0)
{
GLfloat 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(GLfloat), (GLvoid*)0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)(3 * sizeof(GLfloat)));
}
glBindVertexArray(quadVAO);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glBindVertexArray(0);
}
// RenderCube() Renders a 1x1 3D cube in NDC.
GLuint cubeVAO = 0;
GLuint cubeVBO = 0;
void RenderCube()
{
// Initialize (if necessary)
if (cubeVAO == 0)
{
GLfloat vertices[] = {
// Back face
-0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, // Bottom-left
0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f, // top-right
0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 0.0f, // bottom-right
0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 1.0f, 1.0f, // top-right
-0.5f, -0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 0.0f, // bottom-left
-0.5f, 0.5f, -0.5f, 0.0f, 0.0f, -1.0f, 0.0f, 1.0f,// top-left
// Front face
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom-left
0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, // bottom-right
0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, // top-right
0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, // top-right
-0.5f, 0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, // top-left
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom-left
// Left face
-0.5f, 0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-right
-0.5f, 0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top-left
-0.5f, -0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-left
-0.5f, -0.5f, -0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-left
-0.5f, -0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 0.0f, 0.0f, // bottom-right
-0.5f, 0.5f, 0.5f, -1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-right
// Right face
0.5f, 0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-left
0.5f, -0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-right
0.5f, 0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top-right
0.5f, -0.5f, -0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f, // bottom-right
0.5f, 0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, // top-left
0.5f, -0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, // bottom-left
// Bottom face
-0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f, // top-right
0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 1.0f, // top-left
0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f,// bottom-left
0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 1.0f, 0.0f, // bottom-left
-0.5f, -0.5f, 0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 0.0f, // bottom-right
-0.5f, -0.5f, -0.5f, 0.0f, -1.0f, 0.0f, 0.0f, 1.0f, // top-right
// Top face
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f,// top-left
0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // bottom-right
0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, // top-right
0.5f, 0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // bottom-right
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f,// top-left
-0.5f, 0.5f, 0.5f, 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(GLfloat), (GLvoid*)0);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (GLvoid*)(3 * sizeof(GLfloat)));
glEnableVertexAttribArray(2);
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), (GLvoid*)(6 * sizeof(GLfloat)));
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
// Render Cube
glBindVertexArray(cubeVAO);
glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);
}
bool keys[1024];
bool keysPressed[1024];
// Moves/alters the camera positions based on user input
void Do_Movement()
{
// Camera controls
if (keys[GLFW_KEY_W])
camera.ProcessKeyboard(FORWARD, deltaTime);
if (keys[GLFW_KEY_S])
camera.ProcessKeyboard(BACKWARD, deltaTime);
if (keys[GLFW_KEY_A])
camera.ProcessKeyboard(LEFT, deltaTime);
if (keys[GLFW_KEY_D])
camera.ProcessKeyboard(RIGHT, deltaTime);
}
GLfloat lastX = 400, lastY = 300;
bool firstMouse = true;
// Is called whenever a key is pressed/released via GLFW
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode)
{
if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
glfwSetWindowShouldClose(window, GL_TRUE);
if (key >= 0 && key <= 1024)
{
if (action == GLFW_PRESS)
keys[key] = true;
else if (action == GLFW_RELEASE)
{
keys[key] = false;
keysPressed[key] = false;
}
}
}
void mouse_callback(GLFWwindow* window, double xpos, double ypos)
{
if (firstMouse)
{
lastX = xpos;
lastY = ypos;
firstMouse = false;
}
GLfloat xoffset = xpos - lastX;
GLfloat yoffset = lastY - ypos;
lastX = xpos;
lastY = ypos;
camera.ProcessMouseMovement(xoffset, yoffset);
}
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
{
camera.ProcessMouseScroll(yoffset);
}
HI