accanti.c

红宝书

/*
 * Copyright (c) 1993-1997, 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 * Unpublished-- rights reserved under the copyright laws of the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(R) is a registered trademark of Silicon Graphics, Inc.
 */

/*  accanti.c
 *  Use the accumulation buffer to do full-scene antialiasing
 *  on a scene with orthographic parallel projection.
 */
#include <GL/glut.h>
#include <stdlib.h>
#include "jitter.h"

/*  Initialize lighting and other values.
 */
void init(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);
   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 ();
   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);
   glutSolidTorus (0.275, 0.85, 16, 16);
   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);
   glutSolidCube (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);
   glutSolidSphere (1.0, 16, 16);
   glPopMatrix ();

   glPushMatrix ();
   glTranslatef (0.70, -0.90, 0.25); 
   glMaterialfv(GL_FRONT, GL_DIFFUSE, octa_diffuse);
   glutSolidOctahedron ();
   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);
      glPushMatrix ();
/*	Note that 4.5 is the distance in world space between
 *	left and right and bottom and top.
 *	This formula converts fractional pixel movement to 
 *	world coordinates.
 */
      glTranslatef (j8[jitter].x*4.5/viewport[2],
                    j8[jitter].y*4.5/viewport[3], 0.0);
      displayObjects ();
      glPopMatrix ();
      glAccum(GL_ACCUM, 1.0/ACSIZE);
   }
   glAccum (GL_RETURN, 1.0);
   glFlush();
}

void reshape(int w, int h)
{
   glViewport(0, 0, (GLsizei) w, (GLsizei) h);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   if (w <= h) 
      glOrtho (-2.25, 2.25, -2.25*h/w, 2.25*h/w, -10.0, 10.0);
   else 
      glOrtho (-2.25*w/h, 2.25*w/h, -2.25, 2.25, -10.0, 10.0);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
}

void keyboard(unsigned char key, int x, int y)
{
   switch (key) {
      case 27:
         exit(0);
         break;
   }
}

/*  Main Loop
 *  Be certain to request an accumulation buffer.
 */
int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB
			| GLUT_ACCUM | GLUT_DEPTH);
   glutInitWindowSize (250, 250);
   glutInitWindowPosition (100, 100);
   glutCreateWindow (argv[0]);
   init();
   glutReshapeFunc(reshape);
   glutDisplayFunc(display);
   glutKeyboardFunc(keyboard);
   glutMainLoop();
   return 0; 
}