/*
 * 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	SOLID 1
#define	LINE 2
#define	POINT 3

GLenum rgb, doubleBuffer, directRender, windType;
GLint windW, windH;

GLenum dithering = GL_TRUE;
GLenum showVerticies = GL_TRUE;
GLenum hideBottomTriangle = GL_FALSE;
GLenum outline = GL_TRUE;
GLenum culling = GL_FALSE;
GLenum winding = GL_FALSE;
GLenum face = GL_FALSE;
GLenum state = SOLID;
GLenum aaMode = GL_FALSE;
GLenum shade = GL_TRUE;

GLint color1, color2, color3;

float zRotation = 90.0;
float zoom = 1.0;

float boxA[3] =
{-100, -100, 0};
float boxB[3] =
{100, -100, 0};
float boxC[3] =
{100, 100, 0};
float boxD[3] =
{-100, 100, 0};

float p0[3] =
{-125, -80, 0};
float p1[3] =
{-125, 80, 0};
float p2[3] =
{172, 0, 0};

static void Init(void)
{
  float r, g, b;
  float percent1, percent2;
  GLint i, j;

  glClearColor(0.0, 0.0, 0.0, 0.0);

  glLineStipple(1, 0xF0F0);

  glEnable(GL_SCISSOR_TEST);

  if (!rgb) {
    for (j = 0; j <= 12; j++) {
      if (j <= 6) {
	percent1 = j / 6.0;
	r = 1.0 - 0.8 * percent1;
	g = 0.2 + 0.8 * percent1;
	b = 0.2;
      }
      else {
	percent1 = (j - 6) / 6.0;
	r = 0.2;
	g = 1.0 - 0.8 * percent1;
	b = 0.2 + 0.8 * percent1;
      }
      tkSetOneColor(j + 18, r, g, b);
      for (i = 0; i < 16; i++) {
	percent2 = i / 15.0;
	tkSetOneColor(j * 16 + 1 + 32, r * percent2, g * percent2, b * percent2);
      }
    }
    color1 = 18;
    color2 = 24;
    color3 = 30;
  }
}

static void Reshape(int width, int height)
{

  windW = (GLint) width;
  windH = (GLint) height;
}

static GLenum Key(int key, GLenum mask)
{

  switch (key) {
    case TK_ESCAPE:
      tkQuit();
    case TK_LEFT:
      zRotation += 0.5;
      break;
    case TK_RIGHT:
      zRotation -= 0.5;
      break;
    case TK_Z:
      zoom *= 0.75;
      break;
    case TK_z:
      zoom /= 0.75;
      if (zoom > 10) {
	zoom = 10;
      }
      break;
    case TK_1:
      glPolygonMode(GL_FRONT_AND_BACK, GL_POINT);
      break;
    case TK_2:
      glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
      break;
    case TK_3:
      glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
      break;
    case TK_4:
      state = POINT;
      break;
    case TK_5:
      state = LINE;
      break;
    case TK_6:
      state = SOLID;
      break;
    case TK_7:
      culling = !culling;
      break;
    case TK_8:
      winding = !winding;
      break;
    case TK_9:
      face = !face;
      break;
    case TK_v:
      showVerticies = !showVerticies;
      break;
    case TK_s:
      shade = !shade;
      (shade) ? glShadeModel(GL_SMOOTH) : glShadeModel(GL_FLAT);
      break;
    case TK_h:
      hideBottomTriangle = !hideBottomTriangle;
      break;
    case TK_o:
      outline = !outline;
      break;
    case TK_m:
      dithering = !dithering;
      break;
    case TK_0:
      aaMode = !aaMode;
      if (aaMode) {
	glEnable(GL_POLYGON_SMOOTH);
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE);
	if (!rgb) {
	  color1 = 32;
	  color2 = 128;
	  color3 = 224;
	}
      }
      else {
	glDisable(GL_POLYGON_SMOOTH);
	glDisable(GL_BLEND);
	if (!rgb) {
	  color1 = 18;
	  color2 = 24;
	  color3 = 30;
	}
      }
      break;
    default:
      return GL_FALSE;
  }
  return GL_TRUE;
}

static void BeginPrim(void)
{

  switch (state) {
    case SOLID:
      glBegin(GL_POLYGON);
      break;
    case LINE:
      glBegin(GL_LINE_LOOP);
      break;
    case POINT:
      glBegin(GL_POINTS);
      break;
    default:
      break;
  }
}

static void EndPrim(void)
{

  glEnd();
}

static void Draw(void)
{
  float scaleX, scaleY;

  glViewport(0, 0, windW, windH);

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluOrtho2D(-175, 175, -175, 175);
  glMatrixMode(GL_MODELVIEW);

  glScissor(0, 0, windW, windH);

  (culling) ? glEnable(GL_CULL_FACE) : glDisable(GL_CULL_FACE);
  (winding) ? glFrontFace(GL_CCW) : glFrontFace(GL_CW);
  (face) ? glCullFace(GL_FRONT) : glCullFace(GL_BACK);

  (dithering) ? glEnable(GL_DITHER) : glDisable(GL_DITHER);

  glClear(GL_COLOR_BUFFER_BIT);

  TK_SETCOLOR(windType, TK_GREEN);
  glBegin(GL_LINE_LOOP);
  glVertex3fv(boxA);
  glVertex3fv(boxB);
  glVertex3fv(boxC);
  glVertex3fv(boxD);
  glEnd();

  if (!hideBottomTriangle) {
    glPushMatrix();

    glScalef(zoom, zoom, zoom);
    glRotatef(zRotation, 0, 0, 1);

    TK_SETCOLOR(windType, TK_BLUE);
    BeginPrim();
    glVertex3fv(p0);
    glVertex3fv(p1);
    glVertex3fv(p2);
    EndPrim();

    if (showVerticies) {
      (rgb) ? glColor3fv(tkRGBMap[TK_RED]) : glIndexf(color1);
      glRectf(p0[0] - 2, p0[1] - 2, p0[0] + 2, p0[1] + 2);
      (rgb) ? glColor3fv(tkRGBMap[TK_GREEN]) : glIndexf(color2);
      glRectf(p1[0] - 2, p1[1] - 2, p1[0] + 2, p1[1] + 2);
      (rgb) ? glColor3fv(tkRGBMap[TK_BLUE]) : glIndexf(color3);
      glRectf(p2[0] - 2, p2[1] - 2, p2[0] + 2, p2[1] + 2);
    }

    glPopMatrix();
  }

  scaleX = (float)(windW - 20) / 2 / 175 * (175 - 100) + 10;
  scaleY = (float)(windH - 20) / 2 / 175 * (175 - 100) + 10;

  glViewport(scaleX, scaleY, windW - 2 * scaleX, windH - 2 * scaleY);

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluOrtho2D(-100, 100, -100, 100);
  glMatrixMode(GL_MODELVIEW);

  glScissor(scaleX, scaleY, windW - 2 * scaleX, windH - 2 * scaleY);

  glPushMatrix();

  glScalef(zoom, zoom, zoom);
  glRotatef(zRotation, 0, 0, 1);

  glPointSize(10);
  glLineWidth(5);
  glEnable(GL_POINT_SMOOTH);
  glEnable(GL_LINE_STIPPLE);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

  TK_SETCOLOR(windType, TK_RED);
  BeginPrim();
  (rgb) ? glColor3fv(tkRGBMap[TK_RED]) : glIndexf(color1);
  glVertex3fv(p0);
  (rgb) ? glColor3fv(tkRGBMap[TK_GREEN]) : glIndexf(color2);
  glVertex3fv(p1);
  (rgb) ? glColor3fv(tkRGBMap[TK_BLUE]) : glIndexf(color3);
  glVertex3fv(p2);
  EndPrim();

  glPointSize(1);
  glLineWidth(1);
  glDisable(GL_POINT_SMOOTH);
  glDisable(GL_LINE_STIPPLE);
  glBlendFunc(GL_ONE, GL_ZERO);

  if (outline) {
    TK_SETCOLOR(windType, TK_WHITE);
    glBegin(GL_LINE_LOOP);
    glVertex3fv(p0);
    glVertex3fv(p1);
    glVertex3fv(p2);
    glEnd();
  }

  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)
{

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

  windW = 600;
  windH = 300;
  tkInitPosition(0, 0, windW, windH);

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

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

  Init();

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