main.cpp

/*
 * Copyright (c) 2020 Nobuyuki Umetani
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

#include <iostream>
#include <cmath>
#ifdef EMSCRIPTEN
#  include <emscripten/emscripten.h>
#  define GLFW_INCLUDE_ES3
#else
#  include <glad/glad.h>
#endif
#if defined(_MSC_VER)
#  include <windows.h>
#endif
#include <GLFW/glfw3.h>

#include "delfem2/glfw/viewer2.h"
#include "delfem2/glfw/util.h"
#include "delfem2/opengl/tex.h"
#include "delfem2/noise.h"
#include "delfem2/opengl/new/drawer_mshtex.h"

namespace dfm2 = delfem2;

// ---------------------------
struct MyData {
  dfm2::opengl::Drawer_RectangleTex shdr;
  delfem2::glfw::CViewer2 viewer;
  GLuint m_texName = -1;
};

// ---------------------------

void draw(MyData *data) {
  ::glClearColor(0.8, 1.0, 1.0, 1.0);
  ::glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
//  ::glEnable(GL_DEPTH_TEST);
//  ::glDepthFunc(GL_LESS);
  ::glEnable(GL_POLYGON_OFFSET_FILL);
  ::glPolygonOffset(1.1f, 4.0f);

  glEnable(GL_TEXTURE_2D);
  glActiveTexture(GL_TEXTURE0); // activate the texture unit first before binding texture
  glBindTexture(GL_TEXTURE_2D, data->m_texName);
  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_REPEAT);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

  dfm2::CMat4f mP = data->viewer.GetProjectionMatrix();
  dfm2::CMat4f mMV = data->viewer.GetModelViewMatrix();
  data->shdr.Draw(mP.data(), mMV.data());

  data->viewer.SwapBuffers();
  glfwPollEvents();
}

int main() {
  MyData data;
  //
  dfm2::glfw::InitGLNew();
  data.viewer.view_height = 2.0;
  data.viewer.OpenWindow();

#ifndef EMSCRIPTEN
  if (!gladLoadGLLoader((GLADloadproc) glfwGetProcAddress)) {
    std::cout << "Failed to initialize GLAD" << std::endl;
    return -1;
  }
#endif

  data.shdr.InitGL();

  {
    const int nSize = 256;
    std::vector<double> aV;
    dfm2::ComputePerlin(aV,
                        nSize, nSize,
                        4, 4, 0.8);
    assert(aV.size() == nSize * nSize);
    std::vector<unsigned char> image(nSize * nSize * 3);
    for (unsigned int i = 0; i < aV.size(); i++) {
      int ival = int(aV[i] * 50 + 128);
      if (ival < 0) { ival = 0; }
      if (ival >= 256) { ival = 255; }
      image[i * 3 + 0] = ival;
      image[i * 3 + 1] = ival;
      image[i * 3 + 2] = ival;
    }
    // -------------
    glEnable(GL_TEXTURE_2D);
    glActiveTexture(GL_TEXTURE0);
    data.m_texName = dfm2::opengl::SetTexture_RGB(nSize, nSize, image);
    glGenerateMipmap(GL_TEXTURE_2D);
  }

#ifdef EMSCRIPTEN
  emscripten_set_main_loop_arg((em_arg_callback_func) draw, &data, 0, 1);
#else
  while (!glfwWindowShouldClose(data.viewer.window)) { draw(&data); }
#endif

  glfwDestroyWindow(data.viewer.window);
  glfwTerminate();
  exit(EXIT_SUCCESS);
}