main.cpp

#include <glad/glad.h>
#include <GLFW/glfw3.h>

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>

#include "Shader.h"
#include "Camera.h"
#include "Model.h"
#include "Spring.h"
#include "MouseControl.hpp"

#include <iostream>

using namespace std;

void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void cursor_pos_callback(GLFWwindow* window, double xpos, double ypos);
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
void processInput(GLFWwindow* window);
void mouse_button_callback(GLFWwindow* window, int button, int action, int mods);

// 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 clastX = SCR_WIDTH / 2.0f;
float clastY = SCR_HEIGHT / 2.0f;
bool cameraFirstMouse = true;
bool cameraCanRotate = false;

// mouseControl
Spring* springs = nullptr;
MouseControl* mouse_control = nullptr;

// 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);

    // 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);
    glfwSetMouseButtonCallback(window, mouse_button_callback);
    glfwSetCursorPosCallback(window, cursor_pos_callback);
    glfwSetScrollCallback(window, scroll_callback);

    // tell GLFW to capture/hide 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 ourShader("vertexShaderSource.vert", "fragmentShaderSource.frag");

    // load models
    // -----------
    Model ourModel("liver_model/liver.obj");

    // add springs and mouseControl
    springs = new Spring(&ourModel.meshes[0]);
    mouse_control = new MouseControl(&ourModel.meshes[0]);

    // draw in wireframe
    //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

    // render loop
    // -----------
    while (!glfwWindowShouldClose(window))
    {
        // per-frame time logic
        // --------------------
        float currentFrame = glfwGetTime();
        deltaTime = currentFrame - lastFrame;
        lastFrame = currentFrame;

        springs->update(deltaTime);

        // input
        // -----
        processInput(window);

        // render
        // ------
        glClearColor(0.2f, 0.1f, 0.1f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        // don't forget to enable shader before setting uniforms
        ourShader.use();

        // view/projection transformations
        glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
        glm::mat4 view = camera.GetViewMatrix();
        ourShader.setMat4("projection", projection);
        ourShader.setMat4("view", view);

        // render the loaded model
        glm::mat4 model = glm::mat4(1.0f);
        model = glm::translate(model, glm::vec3(0.0f, 0.0f, 0.0f));
        model = glm::scale(model, glm::vec3(0.12f, 0.12f, 0.12f));
        ourShader.setMat4("model", model);

        mouse_control->update(projection * view * model);

        ourModel.Draw(ourShader);


        // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
        // -------------------------------------------------------------------------------
        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    delete springs;
    delete mouse_control;

    // glfw: terminate, clearing all previously allocated GLFW resources.
    // ------------------------------------------------------------------
    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);
}

// 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 cursor_pos_callback(GLFWwindow* window, double xpos, double ypos)
{
    if (cameraCanRotate) {
        if (cameraFirstMouse)
        {
            clastX = xpos;
            clastY = ypos;
            cameraFirstMouse = false;
        }

        float xoffset = xpos - clastX;
        float yoffset = clastY - ypos; // reversed since y-coordinates go from bottom to top

        clastX = xpos;
        clastY = ypos;

        camera.ProcessMouseMovement(xoffset, yoffset);
    }
    if (mouse_control) mouse_control->onDrag(xpos, ypos);
}

// glfw: whenever the mouse scroll wheel scrolls, this callback is called
// ----------------------------------------------------------------------
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
{
    camera.ProcessMouseScroll(yoffset);
}

void mouse_button_callback(GLFWwindow* window, int button, int action, int mods)
{
    if (action == GLFW_PRESS) {
        if (button == GLFW_MOUSE_BUTTON_RIGHT) cameraCanRotate = true;
        else if (button == GLFW_MOUSE_BUTTON_LEFT) {
            double xpos, ypos;
            glfwGetCursorPos(window, &xpos, &ypos);
            mouse_control->getVertex(xpos, ypos);
        }
    } else if (action == GLFW_RELEASE) {
        if (button == GLFW_MOUSE_BUTTON_RIGHT) {
            cameraCanRotate = false; 
            cameraFirstMouse = true;
        } else if (button == GLFW_MOUSE_BUTTON_LEFT) {
            mouse_control->releaseVertex();
            springs->restoreVelocities();
        }
    }
    return;
}