mirror of
https://github.com/JoeyDeVries/LearnOpenGL.git
synced 2026-01-12 03:23:22 +08:00
203 lines
8.0 KiB
C++
203 lines
8.0 KiB
C++
#include <glad/glad.h>
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#include <GLFW/glfw3.h>
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#include <stb_image.h>
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#include <learnopengl/filesystem.h>
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#include <learnopengl/shader_s.h>
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#include <iostream>
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void framebuffer_size_callback(GLFWwindow* window, int width, int height);
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void processInput(GLFWwindow *window);
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int main()
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{
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// glfw: initialize and configure
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// ------------------------------
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glfwInit();
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glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
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glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
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glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
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//glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // uncomment this statement to fix compilation on OS X
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// glfw window creation
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// --------------------
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GLFWwindow* window = glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL);
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glfwMakeContextCurrent(window);
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if (window == NULL)
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{
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std::cout << "Failed to create GLFW window" << std::endl;
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glfwTerminate();
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return -1;
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}
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glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
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// glad: load all OpenGL function pointers
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// ---------------------------------------
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if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
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{
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std::cout << "Failed to initialize GLAD" << std::endl;
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return -1;
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}
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// build and compile our shader zprogram
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// ------------------------------------
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Shader ourShader("4.2.texture_combined.vs", "4.2.texture_combined.fs");
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// set up vertex data (and buffer(s)) and configure vertex attributes
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// ------------------------------------------------------------------
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float vertices[] = {
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// positions // colors // texture coords (note that we changed them to 'zoom in' on our texture image)
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0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 0.55f, 0.55f, // top right
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0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 0.55f, 0.45f, // bottom right
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-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.45f, 0.45f, // bottom left
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-0.5f, 0.5f, 0.0f, 1.0f, 1.0f, 0.0f, 0.45f, 0.55f // top left
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};
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unsigned int indices[] = {
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0, 1, 3, // first triangle
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1, 2, 3 // second triangle
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};
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unsigned int VBO, VAO, EBO;
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glGenVertexArrays(1, &VAO);
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glGenBuffers(1, &VBO);
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glGenBuffers(1, &EBO);
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glBindVertexArray(VAO);
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glBindBuffer(GL_ARRAY_BUFFER, VBO);
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glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
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glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
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glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
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// position attribute
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glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
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glEnableVertexAttribArray(0);
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// color attribute
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glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
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glEnableVertexAttribArray(1);
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// texture coord attribute
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glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
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glEnableVertexAttribArray(2);
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// load and create a texture
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// -------------------------
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unsigned int texture1, texture2;
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// texture 1
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// ---------
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glGenTextures(1, &texture1);
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glBindTexture(GL_TEXTURE_2D, texture1);
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// set the texture wrapping parameters
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); // note that we set the container wrapping method to GL_CLAMP_TO_EDGE
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
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// set texture filtering parameters
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); // set texture filtering to nearest neighbor to clearly see the texels/pixels
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
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// load image, create texture and generate mipmaps
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int width, height, nrComponents;
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stbi_set_flip_vertically_on_load(true); // tell stb_image.h to flip loaded texture's on the y-axis.
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unsigned char *data = stbi_load(FileSystem::getPath("resources/textures/container.jpg").c_str(), &width, &height, &nrComponents, 0);
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if (data)
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{
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glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
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glGenerateMipmap(GL_TEXTURE_2D);
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}
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else
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{
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std::cout << "Failed to load texture" << std::endl;
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}
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stbi_image_free(data);
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// texture 2
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// ---------
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glGenTextures(1, &texture2);
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glBindTexture(GL_TEXTURE_2D, texture2);
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// set the texture wrapping parameters
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
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// set texture filtering parameters
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); // set texture filtering to nearest neighbor to clearly see the texels/pixels
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
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// load image, create texture and generate mipmaps
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data = stbi_load(FileSystem::getPath("resources/textures/awesomeface.png").c_str(), &width, &height, &nrComponents, 0);
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if (data)
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{
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// note that the awesomeface.png has transparency and thus an alpha channel, so make sure to tell OpenGL the data type is of GL_RGBA
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glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, data);
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glGenerateMipmap(GL_TEXTURE_2D);
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}
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else
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{
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std::cout << "Failed to load texture" << std::endl;
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}
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stbi_image_free(data);
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// tell opengl for each sampler to which texture unit it belongs to (only has to be done once)
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// -------------------------------------------------------------------------------------------
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ourShader.use(); // don't forget to activate/use the shader before setting uniforms!
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// either set it manually like so:
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glUniform1i(glGetUniformLocation(ourShader.ID, "texture1"), 0);
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// or set it via the texture class
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ourShader.setInt("texture2", 1);
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// render loop
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// -----------
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while (!glfwWindowShouldClose(window))
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{
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// input
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// -----
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processInput(window);
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// render
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// ------
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glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
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glClear(GL_COLOR_BUFFER_BIT);
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// bind textures on corresponding texture units
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glActiveTexture(GL_TEXTURE0);
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glBindTexture(GL_TEXTURE_2D, texture1);
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glActiveTexture(GL_TEXTURE1);
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glBindTexture(GL_TEXTURE_2D, texture2);
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// render container
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ourShader.use();
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glBindVertexArray(VAO);
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glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
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// glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
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// -------------------------------------------------------------------------------
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glfwSwapBuffers(window);
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glfwPollEvents();
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}
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// optional: de-allocate all resources once they've outlived their purpose:
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// ------------------------------------------------------------------------
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glDeleteVertexArrays(1, &VAO);
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glDeleteBuffers(1, &VBO);
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glDeleteBuffers(1, &EBO);
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// glfw: terminate, clearing all previously allocated GLFW resources.
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// ------------------------------------------------------------------
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glfwTerminate();
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return 0;
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}
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// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
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// ---------------------------------------------------------------------------------------------------------
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void processInput(GLFWwindow *window)
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{
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if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
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glfwSetWindowShouldClose(window, true);
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}
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// glfw: whenever the window size changed (by OS or user resize) this callback function executes
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// ---------------------------------------------------------------------------------------------
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void framebuffer_size_callback(GLFWwindow* window, int width, int height)
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{
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// make sure the viewport matches the new window dimensions; note that width and
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// height will be significantly larger than specified on retina displays.
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glViewport(0, 0, width, height);
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} |