3dviewer/main.cpp

#include "lopenglprogram.h"
#include "camera.h"
#include <GL/gl.h>
#include <GL/glext.h>
#include <GLFW/glfw3.h>
#include <functional>
#include <glm/fwd.hpp>
#include <iostream>
#include <memory>
#include <utility>


class GLWidget {

public:
    struct ViewPort {
        int width;
        int height;
    };
    GLWidget(ViewPort port) : viewport_(port),
        window_(nullptr, [](GLFWwindow* w){if(w) glfwDestroyWindow(w);}) {
        lastX_ = port.width / 2;
        lastY_ = port.height / 2;
    }
    ~GLWidget() {}


    void setViewPort(int width, int height) {
        viewport_ = {width, height};
    }

    bool initGeometry() {
        // window_ = std::make_unique<GLFWwindow*>(glfwCreateWindow(800, 600, "LearnOpenGL", NULL, NULL));
        window_.reset(glfwCreateWindow(800, 600, "3dviewer", nullptr, nullptr));
        if (!window_) {
            std::cout << "Failed to create GLFW window" << std::endl;
            glfwTerminate();
            return -1;
        }
        glfwMakeContextCurrent(window_.get());
        if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) {
            std::cout << "Failed to initialize GLAD" << std::endl;
            return -1;
        }

        glViewport(0, 0, 800, 600);
        glfwSetFramebufferSizeCallback(window_.get(), &GLWidget::framebuffer_size_callback);
    }
public:
    bool initBgProgram(const std::string& vpath, const std::string fpath) {
        auto vshader = std::make_unique<LOpenGLShader>(LOpenGLShader::ShaderType::Vertex);
        auto fshader = std::make_unique<LOpenGLShader>(LOpenGLShader::ShaderType::Fragment);
        vshader->compileShaderFromFile(vpath);
        fshader->compileShaderFromFile(fpath);
        bgProg_ = std::make_unique<LOpenGLProgram>();
        bgProg_->addShader(std::move(vshader));
        bgProg_->addShader(std::move(fshader));
        bool ret = bgProg_->Link();
        if (!ret) {
            return false;
        }
        const float verts[] = {
            -1.0, -1.0, 1.0, -1.0, 1.0, 1.0,
            -1.0, -1.0, 1.0, 1.0, -1.0, 1.0,
        };
        if (bgVao_) {
            glDeleteVertexArrays(1, &bgVao_);
        }
        if (bgVbo_) {
            glDeleteBuffers(1, &bgVbo_);
        }

        glGenVertexArrays(1, &bgVao_);
        glBindVertexArray(bgVao_);

        glGenBuffers(1, &bgVbo_);
        glBindBuffer(GL_ARRAY_BUFFER, bgVbo_);
        glBufferData(GL_ARRAY_BUFFER, sizeof(verts), verts, GL_STATIC_DRAW);

        glEnableVertexAttribArray(0);
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), (void*)0);
        glBindVertexArray(0);
        
    }

    void drawBg() {
        bgProg_->Use();
        bgProg_->setUniformValue("uViewport", glm::vec2(viewport_.width, viewport_.height));
        bgProg_->setUniformValue("uMajorStep", 120.0f);
        bgProg_->setUniformValue("uMinjorStep", 24.0f);
        glBindVertexArray(bgVao_);
        glDrawArrays(GL_TRIANGLES, 0, 6);
        glBindVertexArray(0);

        glDepthMask(GL_TRUE);
        glEnable(GL_DEPTH_TEST);
    }

    void mouseCallback(GLFWwindow* window, double x, double y) {
        float xpos = static_cast<float>(x);
        float ypos = static_cast<float>(y);

        if (camera_.fir) {

        }
    }

private:
    void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
        glViewport(0, 0, viewport_.width, viewport_.height);
    }

    void process_input(GLFWwindow* window) {
        if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) {
            glfwSetWindowShouldClose(window, true);
        }
    }
private:
    std::unique_ptr<LOpenGLProgram> bgProg_;
    std::unique_ptr<GLFWwindow, std::function<void(GLFWwindow*)>> window_;
    unsigned int bgVao_;
    unsigned int bgVbo_;
    ViewPort viewport_{800, 600};
    Camera camera_;

    bool firstMouse_ = true;
    float lastX_;
    float lastY_;
};

int main() {
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#if __APPLE__
    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
#endif

    

    GLWidget glw;
    glw.initBgProgram("bg.vert", "bg.frag");

    while (!glfwWindowShouldClose(window)) {

        glw.drawBg();
    }

    glfwTerminate();
    return 0;
}