/*
 * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the name of
 * Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Silicon Graphics.
 *
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
 * ANY KIND,
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "gltk.h"

GLenum rgb, doubleBuffer, directRender;

double plane[4] =
{
  1.0, 0.0, -1.0, 0.0
};
float rotX = 5.0, rotY = -5.0, zTranslate = -65.0;
float fogDensity = 0.02;
GLint cubeList = 1;

float scp[18][3] =
{
  {
    1.000000, 0.000000, 0.000000
  },
  {
    1.000000, 0.000000, 5.000000
  },
  {
    0.707107, 0.707107, 0.000000
  },
  {
    0.707107, 0.707107, 5.000000
  },
  {
    0.000000, 1.000000, 0.000000
  },
  {
    0.000000, 1.000000, 5.000000
  },
  {
    -0.707107, 0.707107, 0.000000
  },
  {
    -0.707107, 0.707107, 5.000000
  },
  {
    -1.000000, 0.000000, 0.000000
  },
  {
    -1.000000, 0.000000, 5.000000
  },
  {
    -0.707107, -0.707107, 0.000000
  },
  {
    -0.707107, -0.707107, 5.000000
  },
  {
    0.000000, -1.000000, 0.000000
  },
  {
    0.000000, -1.000000, 5.000000
  },
  {
    0.707107, -0.707107, 0.000000
  },
  {
    0.707107, -0.707107, 5.000000
  },
  {
    1.000000, 0.000000, 0.000000
  },
  {
    1.000000, 0.000000, 5.000000
  },
};

static void Build_lists(void)
{

  glNewList(cubeList, GL_COMPILE);
  glBegin(GL_TRIANGLE_STRIP);
  glNormal3fv(scp[0]);
  glVertex3fv(scp[0]);
  glNormal3fv(scp[0]);
  glVertex3fv(scp[1]);
  glNormal3fv(scp[2]);
  glVertex3fv(scp[2]);
  glNormal3fv(scp[2]);
  glVertex3fv(scp[3]);
  glNormal3fv(scp[4]);
  glVertex3fv(scp[4]);
  glNormal3fv(scp[4]);
  glVertex3fv(scp[5]);
  glNormal3fv(scp[6]);
  glVertex3fv(scp[6]);
  glNormal3fv(scp[6]);
  glVertex3fv(scp[7]);
  glNormal3fv(scp[8]);
  glVertex3fv(scp[8]);
  glNormal3fv(scp[8]);
  glVertex3fv(scp[9]);
  glNormal3fv(scp[10]);
  glVertex3fv(scp[10]);
  glNormal3fv(scp[10]);
  glVertex3fv(scp[11]);
  glNormal3fv(scp[12]);
  glVertex3fv(scp[12]);
  glNormal3fv(scp[12]);
  glVertex3fv(scp[13]);
  glNormal3fv(scp[14]);
  glVertex3fv(scp[14]);
  glNormal3fv(scp[14]);
  glVertex3fv(scp[15]);
  glNormal3fv(scp[16]);
  glVertex3fv(scp[16]);
  glNormal3fv(scp[16]);
  glVertex3fv(scp[17]);
  glEnd();
  glEndList();
}

static void Init(void)
{
  static float ambient[] =
  {0.1, 0.1, 0.1, 1.0};
  static float diffuse[] =
  {1.0, 1.0, 1.0, 1.0};
  static float position[] =
  {90.0, 90.0, 0.0, 0.0};
  static float front_mat_shininess[] =
  {30.0};
  static float front_mat_specular[] =
  {0.0, 0.0, 0.0, 1.0};
  static float front_mat_diffuse[] =
  {0.0, 1.0, 0.0, 1.0};
  static float back_mat_shininess[] =
  {50.0};
  static float back_mat_specular[] =
  {0.0, 0.0, 1.0, 1.0};
  static float back_mat_diffuse[] =
  {1.0, 0.0, 0.0, 1.0};
  static float lmodel_ambient[] =
  {0.0, 0.0, 0.0, 1.0};
  static float fog_color[] =
  {0.8, 0.8, 0.8, 1.0};

  glFrontFace(GL_CW);

  glEnable(GL_DEPTH_TEST);

  glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
  glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
  glLightfv(GL_LIGHT0, GL_POSITION, position);
  glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
  glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);

  glMaterialfv(GL_FRONT, GL_SHININESS, front_mat_shininess);
  glMaterialfv(GL_FRONT, GL_SPECULAR, front_mat_specular);
  glMaterialfv(GL_FRONT, GL_DIFFUSE, front_mat_diffuse);
  glMaterialfv(GL_BACK, GL_SHININESS, back_mat_shininess);
  glMaterialfv(GL_BACK, GL_SPECULAR, back_mat_specular);
  glMaterialfv(GL_BACK, GL_DIFFUSE, back_mat_diffuse);

  glEnable(GL_FOG);
  glFogi(GL_FOG_MODE, GL_EXP);
  glFogf(GL_FOG_DENSITY, fogDensity);
  if (rgb) {
    glFogfv(GL_FOG_COLOR, fog_color);
    glClearColor(0.8, 0.8, 0.8, 1.0);
  }
  else {
    glFogi(GL_FOG_INDEX, 1 << 5);
    tkSetFogRamp(5, 3);
    glClearIndex(128);
  }

  Build_lists();
}

static void Reshape(int width, int height)
{

  glViewport(0, 0, (GLint) width, (GLint) height);

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(45.0, 1.0, 1.0, 200.0);
  glMatrixMode(GL_MODELVIEW);
}

static GLenum Key(int key, GLenum mask)
{

  switch (key) {
    case TK_ESCAPE:
      tkQuit();
    case TK_UP:
      rotX -= 5;
      break;
    case TK_DOWN:
      rotX += 5;
      break;
    case TK_LEFT:
      rotY -= 5;
      break;
    case TK_RIGHT:
      rotY += 5;
      break;
    case TK_D:
      if (rgb) {
	fogDensity *= 1.10;
	glFogf(GL_FOG_DENSITY, fogDensity);
      }
      break;
    case TK_d:
      if (rgb) {
	fogDensity /= 1.10;
	glFogf(GL_FOG_DENSITY, fogDensity);
      }
      break;
    default:
      return GL_FALSE;
  }
  return GL_TRUE;
}

static void Draw(void)
{

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  glPushMatrix();

  glTranslatef(0, 0, zTranslate);
  glRotatef(rotY, 0, 1, 0);
  glRotatef(rotX, 1, 0, 0);
  glScalef(1.0, 1.0, 10.0);

  glCallList(cubeList);

  glPopMatrix();

  glFlush();

  if (doubleBuffer) {
    tkSwapBuffers();
  }
}

static GLenum Args(int argc, char **argv)
{
  GLint i;

  rgb = GL_TRUE;
  doubleBuffer = GL_FALSE;
  directRender = GL_TRUE;

  for (i = 1; i < argc; i++) {
    if (strcmp(argv[i], "-ci") == 0) {
      rgb = GL_FALSE;
    }
    else if (strcmp(argv[i], "-rgb") == 0) {
      rgb = GL_TRUE;
    }
    else if (strcmp(argv[i], "-sb") == 0) {
      doubleBuffer = GL_FALSE;
    }
    else if (strcmp(argv[i], "-db") == 0) {
      doubleBuffer = GL_TRUE;
    }
    else if (strcmp(argv[i], "-dr") == 0) {
      directRender = GL_TRUE;
    }
    else if (strcmp(argv[i], "-ir") == 0) {
      directRender = GL_FALSE;
    }
    else {
      printf("%s (Bad option).\n", argv[i]);
      return GL_FALSE;
    }
  }
  return GL_TRUE;
}

void main(int argc, char **argv)
{
  GLenum type;

  if (Args(argc, argv) == GL_FALSE) {
    tkQuit();
  }

  tkInitPosition(0, 0, 300, 300);

  type = TK_DEPTH;
  type |= (rgb) ? TK_RGB : TK_INDEX;
  type |= (doubleBuffer) ? TK_DOUBLE : TK_SINGLE;
  type |= (directRender) ? TK_DIRECT : TK_INDIRECT;
  tkInitDisplayMode(type);

  if (tkInitWindow("Fog Test") == GL_FALSE) {
    tkQuit();
  }

  Init();

  tkExposeFunc(Reshape);
  tkReshapeFunc(Reshape);
  tkKeyDownFunc(Key);
  tkDisplayFunc(Draw);
  tkExec();
}