/*
 * 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"

#define CI_OFFSET_1 16
#define CI_OFFSET_2 32

GLenum rgb, doubleBuffer, directRender;

GLenum antiAlias, stipple;
GLubyte stippleBits[32 * 4] =
{
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
  0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
};

static void Init(void)
{
  GLint i;

  glClearColor(0.0, 0.0, 0.0, 0.0);
  glClearIndex(0.0);

  if (!rgb) {
    for (i = 0; i < 16; i++) {
      tkSetOneColor(i + CI_OFFSET_1, 0.0, 0.0, i / 15.0);
      tkSetOneColor(i + CI_OFFSET_2, 0.0, i / 15.0, 0.0);
    }
  }

  glPolygonStipple(stippleBits);

  antiAlias = GL_FALSE;
  stipple = GL_FALSE;
}

static void Reshape(int width, int height)
{

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

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  glMatrixMode(GL_MODELVIEW);
}

static GLenum Key(int key, GLenum mask)
{

  switch (key) {
    case TK_ESCAPE:
      tkQuit();
    case TK_1:
      antiAlias = !antiAlias;
      break;
    case TK_2:
      stipple = !stipple;
      break;
    default:
      return GL_FALSE;
  }
  return GL_TRUE;
}

static void Draw(void)
{
  GLint ci1, ci2;

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  if (antiAlias) {
    ci1 = CI_OFFSET_1;
    ci2 = CI_OFFSET_2;
    glBlendFunc(GL_SRC_ALPHA, GL_ONE);
    glEnable(GL_BLEND);
    glEnable(GL_POLYGON_SMOOTH);
    glDisable(GL_DEPTH_TEST);
  }
  else {
    ci1 = TK_BLUE;
    ci2 = TK_GREEN;
    glDisable(GL_BLEND);
    glDisable(GL_POLYGON_SMOOTH);
    glEnable(GL_DEPTH_TEST);
  }

  if (stipple) {
    glEnable(GL_POLYGON_STIPPLE);
  }
  else {
    glDisable(GL_POLYGON_STIPPLE);
  }

  glBegin(GL_TRIANGLES);
  (rgb) ? glColor3fv(tkRGBMap[TK_BLUE]) : glIndexi(ci1);
  glVertex3f(0.9, -0.9, -30.0);
  glVertex3f(0.9, 0.9, -30.0);
  glVertex3f(-0.9, 0.0, -30.0);
  (rgb) ? glColor3fv(tkRGBMap[TK_GREEN]) : glIndexi(ci2);
  glVertex3f(-0.9, -0.9, -40.0);
  glVertex3f(-0.9, 0.9, -40.0);
  glVertex3f(0.9, 0.0, -25.0);
  glEnd();

  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("Depth Test") == GL_FALSE) {
    tkQuit();
  }

  Init();

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