#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_m.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 processInput(GLFWwindow *window);
// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;
// 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);
// 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 shaderRed("8.advanced_glsl.vs", "8.red.fs");
Shader shaderGreen("8.advanced_glsl.vs", "8.green.fs");
Shader shaderBlue("8.advanced_glsl.vs", "8.blue.fs");
Shader shaderYellow("8.advanced_glsl.vs", "8.yellow.fs");
// set up vertex data (and buffer(s)) and configure vertex attributes
// ------------------------------------------------------------------
float cubeVertices[] = {
// positions
-0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, 0.5f, -0.5f,
0.5f, 0.5f, -0.5f,
-0.5f, 0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, 0.5f,
0.5f, -0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, -0.5f, -0.5f,
0.5f, -0.5f, -0.5f,
0.5f, -0.5f, 0.5f,
0.5f, -0.5f, 0.5f,
-0.5f, -0.5f, 0.5f,
-0.5f, -0.5f, -0.5f,
-0.5f, 0.5f, -0.5f,
0.5f, 0.5f, -0.5f,
0.5f, 0.5f, 0.5f,
0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, 0.5f,
-0.5f, 0.5f, -0.5f,
};
// cube VAO
unsigned int cubeVAO, cubeVBO;
glGenVertexArrays(1, &cubeVAO);
glGenBuffers(1, &cubeVBO);
glBindVertexArray(cubeVAO);
glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(cubeVertices), &cubeVertices, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
// configure a uniform buffer object
// ---------------------------------
// first. We get the relevant block indices
unsigned int uniformBlockIndexRed = glGetUniformBlockIndex(shaderRed.ID, "Matrices");
unsigned int uniformBlockIndexGreen = glGetUniformBlockIndex(shaderGreen.ID, "Matrices");
unsigned int uniformBlockIndexBlue = glGetUniformBlockIndex(shaderBlue.ID, "Matrices");
unsigned int uniformBlockIndexYellow = glGetUniformBlockIndex(shaderYellow.ID, "Matrices");
// then we link each shader's uniform block to this uniform binding point
glUniformBlockBinding(shaderRed.ID, uniformBlockIndexRed, 0);
glUniformBlockBinding(shaderGreen.ID, uniformBlockIndexGreen, 0);
glUniformBlockBinding(shaderBlue.ID, uniformBlockIndexBlue, 0);
glUniformBlockBinding(shaderYellow.ID, uniformBlockIndexYellow, 0);
// Now actually create the buffer
unsigned int uboMatrices;
glGenBuffers(1, &uboMatrices);
glBindBuffer(GL_UNIFORM_BUFFER, uboMatrices);
glBufferData(GL_UNIFORM_BUFFER, 2 * sizeof(glm::mat4), NULL, GL_STATIC_DRAW);
glBindBuffer(GL_UNIFORM_BUFFER, 0);
// define the range of the buffer that links to a uniform binding point
glBindBufferRange(GL_UNIFORM_BUFFER, 0, uboMatrices, 0, 2 * sizeof(glm::mat4));
// store the projection matrix (we only do this once now) (note: we're not using zoom anymore by changing the FoV)
glm::mat4 projection = glm::perspective(45.0f, (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
glBindBuffer(GL_UNIFORM_BUFFER, uboMatrices);
glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(glm::mat4), glm::value_ptr(projection));
glBindBuffer(GL_UNIFORM_BUFFER, 0);
// 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);
// set the view and projection matrix in the uniform block - we only have to do this once per loop iteration.
glm::mat4 view = camera.GetViewMatrix();
glBindBuffer(GL_UNIFORM_BUFFER, uboMatrices);
glBufferSubData(GL_UNIFORM_BUFFER, sizeof(glm::mat4), sizeof(glm::mat4), glm::value_ptr(view));
glBindBuffer(GL_UNIFORM_BUFFER, 0);
// draw 4 cubes
// RED
glBindVertexArray(cubeVAO);
shaderRed.use();
glm::mat4 model = glm::mat4(1.0f);
model = glm::translate(model, glm::vec3(-0.75f, 0.75f, 0.0f)); // move top-left
shaderRed.setMat4("model", model);
glDrawArrays(GL_TRIANGLES, 0, 36);
// GREEN
shaderGreen.use();
model = glm::mat4(1.0f);
model = glm::translate(model, glm::vec3(0.75f, 0.75f, 0.0f)); // move top-right
shaderGreen.setMat4("model", model);
glDrawArrays(GL_TRIANGLES, 0, 36);
// YELLOW
shaderYellow.use();
model = glm::mat4(1.0f);
model = glm::translate(model, glm::vec3(-0.75f, -0.75f, 0.0f)); // move bottom-left
shaderYellow.setMat4("model", model);
glDrawArrays(GL_TRIANGLES, 0, 36);
// BLUE
shaderBlue.use();
model = glm::mat4(1.0f);
model = glm::translate(model, glm::vec3(0.75f, -0.75f, 0.0f)); // move bottom-right
shaderBlue.setMat4("model", model);
glDrawArrays(GL_TRIANGLES, 0, 36);
// 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, &cubeVAO);
glDeleteBuffers(1, &cubeVBO);
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);
}
// 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);
}
HI