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/*
* Copyright (c) 1993-2003, 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 Unpublished - rights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.
* 1500 Crittenden Lane
* Mountain View, CA 94043
* United State of America
*
* OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
*/
/*
* multisamp.c
* This program draws shows how to use multisampling to
* draw anti-aliased geometric primitives. The same
* display list, a pinwheel of triangles and lines of
* varying widths, is rendered twice. Multisampling is
* enabled when the left side is drawn. Multisampling is
* disabled when the right side is drawn.
*
* Pressing the 'b' key toggles drawing of the checkerboard
* background. Antialiasing is sometimes easier to see
* when objects are rendered over a contrasting background.
*/
#include <GL/glew.h>
#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.h>
static int bgtoggle = 1;
/*
* Print out state values related to multisampling.
* Create display list with "pinwheel" of lines and
* triangles.
*/
static void init(void)
{
static GLint buf[1], sbuf[1];
int i, j;
glClearColor(0.0, 0.0, 0.0, 0.0);
glGetIntegerv (GL_SAMPLE_BUFFERS_ARB, buf);
printf ("number of sample buffers is %d\n", buf[0]);
glGetIntegerv (GL_SAMPLES_ARB, sbuf);
printf ("number of samples is %d\n", sbuf[0]);
glNewList (1, GL_COMPILE);
for (i = 0; i < 19; i++) {
glPushMatrix();
glRotatef(360.0*(float)i/19.0, 0.0, 0.0, 1.0);
glColor3f (1.0, 1.0, 1.0);
glLineWidth((i%3)+1.0);
glBegin (GL_LINES);
glVertex2f (0.25, 0.05);
glVertex2f (0.9, 0.2);
glEnd ();
glColor3f (0.0, 1.0, 1.0);
glBegin (GL_TRIANGLES);
glVertex2f (0.25, 0.0);
glVertex2f (0.9, 0.0);
glVertex2f (0.875, 0.10);
glEnd ();
glPopMatrix();
}
glEndList ();
glNewList (2, GL_COMPILE);
glColor3f (1.0, 0.5, 0.0);
glBegin (GL_QUADS);
for (i = 0; i < 16; i++) {
for (j = 0; j < 16; j++) {
if (((i + j) % 2) == 0) {
glVertex2f (-2.0 + (i * 0.25), -2.0 + (j * 0.25));
glVertex2f (-2.0 + (i * 0.25), -1.75 + (j * 0.25));
glVertex2f (-1.75 + (i * 0.25), -1.75 + (j * 0.25));
glVertex2f (-1.75 + (i * 0.25), -2.0 + (j * 0.25));
}
}
}
glEnd ();
glEndList ();
}
/* Draw two sets of primitives, so that you can
* compare the user of multisampling against its absence.
*
* This code enables antialiasing and draws one display list
* and disables and draws the other display list
*/
static void display(void)
{
glClear(GL_COLOR_BUFFER_BIT);
if (bgtoggle)
glCallList (2);
glEnable (GL_MULTISAMPLE_ARB);
glPushMatrix();
glTranslatef (-1.0, 0.0, 0.0);
glCallList (1);
glPopMatrix();
glDisable (GL_MULTISAMPLE_ARB);
glPushMatrix();
glTranslatef (1.0, 0.0, 0.0);
glCallList (1);
glPopMatrix();
glutSwapBuffers();
}
static void reshape(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (w <= (2 * h))
gluOrtho2D (-2.0, 2.0,
-2.0*(GLfloat)h/(GLfloat)w, 2.0*(GLfloat)h/(GLfloat)w);
else
gluOrtho2D (-2.0*(GLfloat)w/(GLfloat)h,
2.0*(GLfloat)w/(GLfloat)h, -2.0, 2.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
static void keyboard(unsigned char key, int x, int y)
{
switch (key) {
case 'b':
case 'B':
bgtoggle = !bgtoggle;
glutPostRedisplay();
break;
case 27: /* Escape Key */
exit(0);
default:
break;
}
}
/* Main Loop
* Open window with initial window size, title bar,
* RGBA display mode, and handle input events.
*/
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_MULTISAMPLE);
glutInitWindowSize (600, 300);
glutCreateWindow (argv[0]);
init();
glutReshapeFunc (reshape);
glutKeyboardFunc (keyboard);
glutDisplayFunc (display);
glutMainLoop();
return 0;
}
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