/*
 * (c) Copyright 1993, Silicon Graphics, Inc.
 * ALL RIGHTS RESERVED 
 * Permission to use, copy, modify, and distribute this software for 
 * any purpose and without fee is hereby granted, provided that the above
 * copyright notice appear in all copies and that both the copyright notice
 * and this permission notice appear in supporting documentation, and that 
 * the name of Silicon Graphics, Inc. not be used in advertising
 * or publicity pertaining to distribution of the software without specific,
 * written prior permission. 
 *
 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "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, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
 * 
 * US Government Users Restricted Rights 
 * Use, duplication, or disclosure by the Government is subject to
 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
 * clause at DFARS 252.227-7013 and/or in similar or successor
 * clauses in the FAR or the DOD or NASA FAR Supplement.
 * Unpublished-- rights reserved under the copyright laws of the
 * United States.  Contractor/manufacturer is Silicon Graphics,
 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
 *
 * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
 */
/*
 * accpersp.c
 */
#include <GL/gl.h>
#include <GL/glu.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glaux.h>
#include "jitter.h"

#define PI_ 3.14159265358979323846

/*
 * accFrustum()
 * *  The first 6 arguments are identical to the glFrustum() call.
 * *  
 * *  pixdx and pixdy are anti-alias jitter in pixels. 
 * *  Set both equal to 0.0 for no anti-alias jitter.
 * *  eyedx and eyedy are depth-of field jitter in pixels. 
 * *  Set both equal to 0.0 for no depth of field effects.
 * *
 * *  focus is distance from eye to plane in focus. 
 * *  focus must be greater than, but not equal to 0.0.
 * *
 * *  Note that accFrustum() calls glTranslatef().  You will 
 * *  probably want to insure that your ModelView matrix has been 
 * *  initialized to identity before calling accFrustum().
 */
void accFrustum(GLdouble left, GLdouble right, GLdouble bottom, GLdouble top,
		GLdouble near, GLdouble far, GLdouble pixdx, GLdouble pixdy,
		GLdouble eyedx, GLdouble eyedy, GLdouble focus)
{
  GLdouble xwsize, ywsize;
  GLdouble dx, dy;
  GLint viewport[4];

  glGetIntegerv(GL_VIEWPORT, viewport);

  xwsize = right - left;
  ywsize = top - bottom;

  dx = -(pixdx * xwsize / (GLdouble) viewport[2] + eyedx * near / focus);
  dy = -(pixdy * ywsize / (GLdouble) viewport[3] + eyedy * near / focus);

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glFrustum(left + dx, right + dx, bottom + dy, top + dy, near, far);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  glTranslatef(-eyedx, -eyedy, 0.0);
}

/*
 * accPerspective()
 * * 
 * *  The first 4 arguments are identical to the gluPerspective() call.
 * *  pixdx and pixdy are anti-alias jitter in pixels. 
 * *  Set both equal to 0.0 for no anti-alias jitter.
 * *  eyedx and eyedy are depth-of field jitter in pixels. 
 * *  Set both equal to 0.0 for no depth of field effects.
 * *
 * *  focus is distance from eye to plane in focus. 
 * *  focus must be greater than, but not equal to 0.0.
 * *
 * *  Note that accPerspective() calls accFrustum().
 */
void accPerspective(GLdouble fovy, GLdouble aspect,
		  GLdouble near, GLdouble far, GLdouble pixdx, GLdouble pixdy,
		    GLdouble eyedx, GLdouble eyedy, GLdouble focus)
{
  GLdouble fov2, left, right, bottom, top;

  fov2 = ((fovy * PI_) / 180.0) / 2.0;

  top = near / (cos(fov2) / sin(fov2));
  bottom = -top;

  right = top * aspect;
  left = -right;

  accFrustum(left, right, bottom, top, near, far,
	     pixdx, pixdy, eyedx, eyedy, focus);
}

/*
 * Initialize lighting and other values.
 */
void myinit(void)
{
  GLfloat mat_ambient[] =
  {1.0, 1.0, 1.0, 1.0};
  GLfloat mat_specular[] =
  {1.0, 1.0, 1.0, 1.0};
  GLfloat light_position[] =
  {0.0, 0.0, 10.0, 1.0};
  GLfloat lm_ambient[] =
  {0.2, 0.2, 0.2, 1.0};

  glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
  glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
  glMaterialf(GL_FRONT, GL_SHININESS, 50.0);
  glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lm_ambient);

  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
  glShadeModel(GL_FLAT);

  glClearColor(0.0, 0.0, 0.0, 0.0);
  glClearAccum(0.0, 0.0, 0.0, 0.0);
}

void displayObjects(void)
{
  GLfloat torus_diffuse[] =
  {0.7, 0.7, 0.0, 1.0};
  GLfloat cube_diffuse[] =
  {0.0, 0.7, 0.7, 1.0};
  GLfloat sphere_diffuse[] =
  {0.7, 0.0, 0.7, 1.0};
  GLfloat octa_diffuse[] =
  {0.7, 0.4, 0.4, 1.0};

  glPushMatrix();
  glTranslatef(0.0, 0.0, -5.0);
  glRotatef(30.0, 1.0, 0.0, 0.0);

  glPushMatrix();
  glTranslatef(-0.80, 0.35, 0.0);
  glRotatef(100.0, 1.0, 0.0, 0.0);
  glMaterialfv(GL_FRONT, GL_DIFFUSE, torus_diffuse);
  auxSolidTorus(0.275, 0.85);
  glPopMatrix();

  glPushMatrix();
  glTranslatef(-0.75, -0.50, 0.0);
  glRotatef(45.0, 0.0, 0.0, 1.0);
  glRotatef(45.0, 1.0, 0.0, 0.0);
  glMaterialfv(GL_FRONT, GL_DIFFUSE, cube_diffuse);
  auxSolidCube(1.5);
  glPopMatrix();

  glPushMatrix();
  glTranslatef(0.75, 0.60, 0.0);
  glRotatef(30.0, 1.0, 0.0, 0.0);
  glMaterialfv(GL_FRONT, GL_DIFFUSE, sphere_diffuse);
  auxSolidSphere(1.0);
  glPopMatrix();

  glPushMatrix();
  glTranslatef(0.70, -0.90, 0.25);
  glMaterialfv(GL_FRONT, GL_DIFFUSE, octa_diffuse);
  auxSolidOctahedron(1.0);
  glPopMatrix();

  glPopMatrix();
}

#define ACSIZE	8

void display(void)
{
  GLint viewport[4];
  int jitter;

  glGetIntegerv(GL_VIEWPORT, viewport);

  glClear(GL_ACCUM_BUFFER_BIT);
  for (jitter = 0; jitter < ACSIZE; jitter++) {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    accPerspective(50.0,
		   (GLdouble) viewport[2] / (GLdouble) viewport[3],
		   1.0, 15.0, j8[jitter].x, j8[jitter].y,
		   0.0, 0.0, 1.0);
    displayObjects();
    glAccum(GL_ACCUM, 1.0 / ACSIZE);
  }
  glAccum(GL_RETURN, 1.0);
  glFlush();
}

void myReshape(int w, int h)
{
  glViewport(0, 0, w, h);
}

/*
 * Main Loop
 * *  Open window with initial window size, title bar, 
 * *  RGBA display mode, and handle input events.
 */
int main(int argc, char **argv)
{
  auxInitDisplayMode(AUX_SINGLE | AUX_RGB
		     | AUX_ACCUM | AUX_DEPTH);
  auxInitPosition(0, 0, 250, 250);
  if (!auxInitWindow(argv[0]))
    auxQuit();
  myinit();
  auxReshapeFunc(myReshape);
  auxMainLoop(display);
  return 0;
}