main.cpp

#include <iostream>
#include <math.h>

#include <GL/glew.h>
#include <GLFW/glfw3.h>

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

#include <string>
#include <fstream>
#include <streambuf>

#include "model.h"
#include "shader.h"
#include "util.h"
#include "common.h"
#include "glsls.h"


int main()
{
    // init GLFW
    glfwInit();
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    const unsigned int width = 500, height = 500;

    // create a window
    GLFWwindow* window = glfwCreateWindow(width, height, "OBJET", NULL, NULL);
    if (window == NULL)
    {
        std::cout << "Failed to create GLFW window" << std::endl;
        glfwTerminate();
        return -1;
    }
    glfwMakeContextCurrent(window);

    GLenum err = glewInit();
    if (err != GLEW_OK)
      exit(1);

    // hide and caputure the cursor
    glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);

    // rendering window size
    glViewport(0, 0, width, height);

    // assign callback functions
    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
    glfwSetCursorPosCallback(window, mouse_callback);

    // shader
    Shader* objectShader = new Shader(objectVertexShader, objectFragmentShader);

    // model
    Model model("./configs/ps_meta.json");

    //  make transformations
    //  projection
    glm::mat4 view = glm::mat4(1.0f);
    glm::mat4 projection = glm::mat4(1.0f);
    projection = glm::perspective(glm::radians(60.0f), 500.0f / 500.0f, 0.1f, 1000.0f);

    // run depth check (Z-buffer)
    glEnable(GL_DEPTH_TEST);

    // shadowing
    unsigned int depthMapFBO;
    glGenFramebuffers(1, &depthMapFBO);
    const unsigned int shadowWidth = 1024, shadowHeight = 1024;
    unsigned int depthMap;
    glGenTextures(1, &depthMap);
    glBindTexture(GL_TEXTURE_2D, depthMap);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT,
                 shadowWidth, shadowHeight, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
    glBindFramebuffer(GL_FRAMEBUFFER, depthMapFBO);
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depthMap, 0);
    glDrawBuffer(GL_NONE); glReadBuffer(GL_NONE);
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
    // shadow shader
    Shader* shadowShader = new Shader(shadowVertexShader, shadowFragmentShader);


    // render loop
    float time;
    float lastFrameTime = 0.0f;
    while (!glfwWindowShouldClose(window)) {

        processInput(window);

        shadowShader->use();
        model.setShadow(shadowShader);
        glViewport(0, 0, shadowWidth, shadowHeight);
        glBindFramebuffer(GL_FRAMEBUFFER, depthMapFBO);
        glClear(GL_DEPTH_BUFFER_BIT);
        model.draw(shadowShader);

        glBindFramebuffer(GL_FRAMEBUFFER, 0);
        glViewport(0, 0, width, height);
        glClearColor(0.55f, 0.77, 0.85f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        // change color
        time = glfwGetTime();
        deltaTime = time - lastFrameTime;
        lastFrameTime = time;

        // render objects with objectShader
        objectShader->use();
        objectShader->setUniform("projection", projection);
        objectShader->setUniform("cameraPosition", cameraPos);
        model.setEnvironment(objectShader);
        objectShader->setUniform("shadowMap", 0);

        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, depthMap);
           
        // overried camera settings
        view = glm::lookAt(cameraPos, cameraPos + cameraFront, cameraUp);
        objectShader->setUniform("view", view);
        // draw
        model.draw(objectShader);

        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    glfwTerminate();
    return 0;
}