#include <GL/glut.h>
#include <GL/gl.h>
#define texWidth 256
#define texHeight 256

unsigned char texImage[texHeight][texWidth][4];

GLdouble vertex[][3] = {
  { 0.0, 0.0, 0.0 },
  { 1.0, 0.0, 0.0 },
  { 1.0, 1.0, 0.0 },
  { 0.0, 1.0, 0.0 },
  { 0.0, 0.0, 1.0 },
  { 1.0, 0.0, 1.0 },
  { 1.0, 1.0, 1.0 },
  { 0.0, 1.0, 1.0 }
};

GLfloat vertex2[][3] = {
  { 0.0f, 0.0f, 0.0f },
  { 1.0f, 0.0f, 0.0f },
  { 1.0f, 1.0f, 0.0f },
  { 0.0f, 1.0f, 0.0f },
  { 0.0f, 0.0f, 1.0f },
  { 1.0f, 0.0f, 1.0f },
  { 1.0f, 1.0f, 1.0f },
  { 0.0f, 1.0f, 1.0f }
};
int face[][4] = {
  { 0, 1, 2, 3 },
  { 1, 5, 6, 2 },
  { 5, 4, 7, 6 },
  { 4, 0, 3, 7 },
  { 4, 5, 1, 0 },
  { 3, 2, 6, 7 }
};

GLdouble normal[][3] = {
  { 0.0, 0.0,-1.0 },
  { 1.0, 0.0, 0.0 },
  { 0.0, 0.0, 1.0 },
  {-1.0, 0.0, 0.0 },
  { 0.0,-1.0, 0.0 },
  { 0.0, 1.0, 0.0 }
};

GLfloat light0pos[] = { 0.0, 3.0, 5.0, 1.0 };
GLfloat light1pos[] = { 5.0, 3.0, 0.0, 1.0 };

//GLfloat green[] = { 0.0, 1.0, 0.0, 1.0 };
//GLfloat red[] = { 0.8, 0.2, 0.2, 1.0 };

void makeCheckImage(int numCheck)
{
  int i, j, ii, jj, col;
  double ww = texWidth / (double)numCheck;
  double hh = texHeight / (double)numCheck;

  for(j = 0 ; j < texHeight ; j++)
    {
      for(i = 0 ; i < texWidth ; i++)
	{
	  ii = (int)((double)i / ww);
	  jj = (int)((double)j / hh);
	  col = ((ii + jj) & 1) * 255;

	  texImage[j][i][0] = (unsigned char)col; //red
	  texImage[j][i][1] = (unsigned char)0; //green
	  texImage[j][i][2] = (unsigned char)col; //blue
	}
    }
}

void displayTexPolygon(void)
{
  glEnable(GL_TEXTURE_2D);
  glBegin(GL_QUADS);
  glTexCoord2f(0.0f, 0.0f); glVertex3fv(vertex2[4]);
  glTexCoord2f(0.0f, 1.0f); glVertex3fv(vertex2[7]);
  glTexCoord2f(1.0f, 1.0f); glVertex3fv(vertex2[6]);
  glTexCoord2f(1.0f, 0.0f); glVertex3fv(vertex2[5]);
  glEnd();
  glDisable(GL_TEXTURE_2D);
}


void setTexture()
{
  glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texWidth, texHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, texImage);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

}


void idle(void)
{
  glutPostRedisplay();
}


void display(void)
{
  int i;
  int j;
  static int r = 0; /* 回転角 */

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  glLoadIdentity();
 
  /* 視点位置と視線方向 */
  gluLookAt(3.0, 4.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);

  /* 光源の位置設定 */
  glLightfv(GL_LIGHT0, GL_POSITION, light0pos);
  glLightfv(GL_LIGHT1, GL_POSITION, light1pos);

  /* 図形の回転 */ 
  glPushMatrix();
  {
    //glTranslatef(0.0, 0.0,-20.0);
    glRotated((double)r, 0.0, 1.0, 0.0);
    glColor3f(1.0, 1.0, 1.0);
    displayTexPolygon();
  }

  /* 図形の色 (赤)  */
  // glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red);

  /* 図形の描画 */
  glColor3d(0.0, 0.0, 0.0);
  glBegin(GL_QUADS);
  for (j = 0; j < 6; ++j) {
    glNormal3dv(normal[j]);
    for (i = 0; i < 4; ++i) {
      if(j != 2) glVertex3dv(vertex[face[j][i]]);
    }
  }

  glEnd();

  glutSwapBuffers();

  /* 一周回ったら回転角を 0 に戻す */
  if (++r >= 360) r = 0;

}

void resize(int w, int h)
{
  glViewport(0, 0, w, h);

  /* 透視変換行列の設定 */
  glMatrixMode(GL_PROJECTION);

  glLoadIdentity();
  /*   透視投影    */
  gluPerspective(30.0, (double)w / (double)h, 1.0, 100.0);

  /* モデルビュー変換行列の設定 */
  glMatrixMode(GL_MODELVIEW);
}

void mouse(int button, int state, int x, int y)
{
  switch (button) {
  case GLUT_LEFT_BUTTON:
    if (state == GLUT_DOWN) {
      /* アニメーション開始 */
      glutIdleFunc(idle);
    }
    else {
      /* アニメーション停止 */
      glutIdleFunc(0);
    }
    break;
  case GLUT_RIGHT_BUTTON:
    if (state == GLUT_DOWN) {
      /* コマ送り (1ステップだけ進める) */
      glutPostRedisplay();
    }
    break;
  default:
    break;
  }
}
  
void keyboard(unsigned char key, int x, int y)
{
  switch (key) {
  case 'q':
  case 'Q':
  case '\033':  /* '\033' は ESC の ASCII コード */
    exit(0);
  default:
    break;
  }
}

void init(void)
{
  glClearColor(1.0, 1.0, 1.0, 1.0);
  /*  デプスバッファ  */
  glEnable(GL_DEPTH_TEST);

  /* 　カリング  */
  glEnable(GL_CULL_FACE);
  glCullFace(GL_FRONT);

  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glEnable(GL_LIGHT1);
  // glLightfv(GL_LIGHT1, GL_DIFFUSE, green);
  // glLightfv(GL_LIGHT1, GL_SPECULAR, green);

  makeCheckImage(6);
  setTexture();

}

int main(int argc, char *argv[])
{
  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH);
  glutCreateWindow(argv[0]);
  glutDisplayFunc(display);
  glutReshapeFunc(resize);
  glutMouseFunc(mouse);
  glutKeyboardFunc(keyboard);
  init();
  glutMainLoop();
  return 0;
}