#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/shader.h>
#include <learnopengl/camera.h>
#include <learnopengl/model.h>
#include <iostream>
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, bool gammaCorrection);
// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;
bool gammaEnabled = false;
bool gammaKeyPressed = false;
// 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;
// timing
float deltaTime = 0.0f;
float lastFrame = 0.0f;
int main()
{
// glfw: initialize and configure
// ------------------------------
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
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);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
// build and compile shaders
// -------------------------
Shader shader("2.gamma_correction.vs", "2.gamma_correction.fs");
// set up vertex data (and buffer(s)) and configure vertex attributes
// ------------------------------------------------------------------
float planeVertices[] = {
// positions // normals // texcoords
10.0f, -0.5f, 10.0f, 0.0f, 1.0f, 0.0f, 10.0f, 0.0f,
-10.0f, -0.5f, 10.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f,
-10.0f, -0.5f, -10.0f, 0.0f, 1.0f, 0.0f, 0.0f, 10.0f,
10.0f, -0.5f, 10.0f, 0.0f, 1.0f, 0.0f, 10.0f, 0.0f,
-10.0f, -0.5f, -10.0f, 0.0f, 1.0f, 0.0f, 0.0f, 10.0f,
10.0f, -0.5f, -10.0f, 0.0f, 1.0f, 0.0f, 10.0f, 10.0f
};
// plane VAO
unsigned int planeVAO, 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 floorTexture = loadTexture(FileSystem::getPath("resources/textures/wood.png").c_str(), false);
unsigned int floorTextureGammaCorrected = loadTexture(FileSystem::getPath("resources/textures/wood.png").c_str(), true);
// shader configuration
// --------------------
shader.use();
shader.setInt("floorTexture", 0);
// lighting info
// -------------
glm::vec3 lightPositions[] = {
glm::vec3(-3.0f, 0.0f, 0.0f),
glm::vec3(-1.0f, 0.0f, 0.0f),
glm::vec3 (1.0f, 0.0f, 0.0f),
glm::vec3 (3.0f, 0.0f, 0.0f)
};
glm::vec3 lightColors[] = {
glm::vec3(0.25),
glm::vec3(0.50),
glm::vec3(0.75),
glm::vec3(1.00)
};
// render loop
// -----------
while (!glfwWindowShouldClose(window))
{
// per-frame time logic
// --------------------
float currentFrame = static_cast<float>(glfwGetTime());
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
// input
// -----
processInput(window);
// render
// ------
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// draw objects
shader.use();
glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
glm::mat4 view = camera.GetViewMatrix();
shader.setMat4("projection", projection);
shader.setMat4("view", view);
// set light uniforms
glUniform3fv(glGetUniformLocation(shader.ID, "lightPositions"), 4, &lightPositions[0][0]);
glUniform3fv(glGetUniformLocation(shader.ID, "lightColors"), 4, &lightColors[0][0]);
shader.setVec3("viewPos", camera.Position);
shader.setInt("gamma", gammaEnabled);
// floor
glBindVertexArray(planeVAO);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, gammaEnabled ? floorTextureGammaCorrected : floorTexture);
glDrawArrays(GL_TRIANGLES, 0, 6);
std::cout << (gammaEnabled ? "Gamma enabled" : "Gamma disabled") << std::endl;
// 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;
}
// 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);
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);
if (glfwGetKey(window, GLFW_KEY_SPACE) == GLFW_PRESS && !gammaKeyPressed)
{
gammaEnabled = !gammaEnabled;
gammaKeyPressed = true;
}
if (glfwGetKey(window, GLFW_KEY_SPACE) == GLFW_RELEASE)
{
gammaKeyPressed = false;
}
}
// 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 xposIn, double yposIn)
{
float xpos = static_cast<float>(xposIn);
float ypos = static_cast<float>(yposIn);
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(static_cast<float>(yoffset));
}
// utility function for loading a 2D texture from file
// ---------------------------------------------------
unsigned int loadTexture(char const * path, bool gammaCorrection)
{
unsigned int textureID;
glGenTextures(1, &textureID);
int width, height, nrComponents;
unsigned char *data = stbi_load(path, &width, &height, &nrComponents, 0);
if (data)
{
GLenum internalFormat;
GLenum dataFormat;
if (nrComponents == 1)
{
internalFormat = dataFormat = GL_RED;
}
else if (nrComponents == 3)
{
internalFormat = gammaCorrection ? GL_SRGB : GL_RGB;
dataFormat = GL_RGB;
}
else if (nrComponents == 4)
{
internalFormat = gammaCorrection ? GL_SRGB_ALPHA : GL_RGBA;
dataFormat = GL_RGBA;
}
glBindTexture(GL_TEXTURE_2D, textureID);
glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, width, height, 0, dataFormat, GL_UNSIGNED_BYTE, data);
glGenerateMipmap(GL_TEXTURE_2D);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, 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;
}
HI