GLWindow.cpp

#include<iostream>
#include<vector>
#include<algorithm>
#include<glad/glad.h>
#include<GLFW/glfw3.h>
#include"Pixel.h"
#include"GLWindow.h"
GLWindow::GLWindow(int w, int h, const char* title) : width(w), height(h) {
        if (!glfwInit()) { std::cerr << "GLFW 初始化失败！" << std::endl; exit(-1); }
        glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
        glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
        glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
        window = glfwCreateWindow(width, height, title, NULL, NULL);
        if (!window) { std::cerr << "窗口创建失败！" << std::endl; glfwTerminate(); exit(-1); }
        glfwMakeContextCurrent(window);
        if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) { std::cerr << "GLAD 初始化失败！" << std::endl; exit(-1); }
        initTexture();
        initShader();
        initQuad();
    }

GLWindow::~GLWindow() {
        glDeleteVertexArrays(1, &VAO);
        glDeleteBuffers(1, &VBO);
        glDeleteTextures(1, &texture);
        glDeleteProgram(shaderProgram);
        glfwDestroyWindow(window);
        glfwTerminate();
    }

    void GLWindow::update(const std::vector<unsigned char>& framebuffer) {
        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, framebuffer.data());
        glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);
        glUseProgram(shaderProgram);
        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        glfwSwapBuffers(window);
        glfwPollEvents();
    }
    void GLWindow::update(const std::vector<Pixel>& framebuffer) {
        std::vector<unsigned char> buffer(width * height * 3);
        for (int i = 0; i < width * height; i++) {
            buffer[i * 3 + 0] = framebuffer[i].r;
            buffer[i * 3 + 1] = framebuffer[i].g;
            buffer[i * 3 + 2] = framebuffer[i].b;
        }
        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, buffer.data());
        glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);
        glUseProgram(shaderProgram);
        glBindVertexArray(VAO);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    bool GLWindow::shouldClose() {
        return glfwWindowShouldClose(window); 
    }
    void GLWindow::initTexture() {
        glGenTextures(1, &texture);
        glBindTexture(GL_TEXTURE_2D, texture);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
    }

    void GLWindow::initShader() {
        const char* vertexShaderSource = R"(
            #version 330 core
            layout (location = 0) in vec2 aPos;
            layout (location = 1) in vec2 aTexCoord;
            out vec2 TexCoord;
            void main() { gl_Position = vec4(aPos, 0.0, 1.0); TexCoord = aTexCoord; }
        )";
        const char* fragmentShaderSource = R"(
            #version 330 core
            in vec2 TexCoord;
            out vec4 FragColor;
            uniform sampler2D ourTexture;
            void main() { FragColor = texture(ourTexture, TexCoord); }
        )";
        unsigned int vertexShader = glCreateShader(GL_VERTEX_SHADER);
        glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
        glCompileShader(vertexShader);
        unsigned int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
        glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
        glCompileShader(fragmentShader);
        shaderProgram = glCreateProgram();
        glAttachShader(shaderProgram, vertexShader);
        glAttachShader(shaderProgram, fragmentShader);
        glLinkProgram(shaderProgram);
        glDeleteShader(vertexShader);
        glDeleteShader(fragmentShader);
    }

    void GLWindow::initQuad() {
        float vertices[] = {
            -1.0f, -1.0f,  0.0f, 0.0f,
             1.0f, -1.0f,  1.0f, 0.0f,
             1.0f,  1.0f,  1.0f, 1.0f,
            -1.0f, -1.0f,  0.0f, 0.0f,
             1.0f,  1.0f,  1.0f, 1.0f,
            -1.0f,  1.0f,  0.0f, 1.0f
        };
        glGenVertexArrays(1, &VAO);
        glGenBuffers(1, &VBO);
        glBindVertexArray(VAO);
        glBindBuffer(GL_ARRAY_BUFFER, VBO);
        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)0);
        glEnableVertexAttribArray(0);
        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)(2 * sizeof(float)));
        glEnableVertexAttribArray(1);
    }