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/*
* 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* Unpublished-- rights reserved under the copyright laws of the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.
*/
/*
* aaindex.c
* This program draws shows how to draw anti-aliased lines in color
* index mode. It draws two diagonal lines to form an X; when 'r'
* is typed in the window, the lines are rotated in opposite
* directions.
*/
#include <GL/glut.h>
#include "stdlib.h"
#define RAMPSIZE 16
#define RAMP1START 32
#define RAMP2START 48
static float rotAngle = 0.;
/* Initialize antialiasing for color index mode,
* including loading a green color ramp starting
* at RAMP1START, and a blue color ramp starting
* at RAMP2START. The ramps must be a multiple of 16.
*/
void init(void)
{
int i;
for (i = 0; i < RAMPSIZE; i++) {
GLfloat shade;
shade = (GLfloat) i/(GLfloat) RAMPSIZE;
glutSetColor(RAMP1START+(GLint)i, 0., shade, 0.);
glutSetColor(RAMP2START+(GLint)i, 0., 0., shade);
}
glEnable (GL_LINE_SMOOTH);
glHint (GL_LINE_SMOOTH_HINT, GL_DONT_CARE);
glLineWidth (1.5);
glClearIndex ((GLfloat) RAMP1START);
}
/* Draw 2 diagonal lines to form an X
*/
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT);
glIndexi(RAMP1START);
glPushMatrix();
glRotatef(-rotAngle, 0.0, 0.0, 0.1);
glBegin (GL_LINES);
glVertex2f (-0.5, 0.5);
glVertex2f (0.5, -0.5);
glEnd ();
glPopMatrix();
glIndexi(RAMP2START);
glPushMatrix();
glRotatef(rotAngle, 0.0, 0.0, 0.1);
glBegin (GL_LINES);
glVertex2f (0.5, 0.5);
glVertex2f (-0.5, -0.5);
glEnd ();
glPopMatrix();
glFlush();
}
void reshape(int w, int h)
{
glViewport(0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (w <= h)
gluOrtho2D (-1.0, 1.0,
-1.0*(GLfloat)h/(GLfloat)w, 1.0*(GLfloat)h/(GLfloat)w);
else
gluOrtho2D (-1.0*(GLfloat)w/(GLfloat)h,
1.0*(GLfloat)w/(GLfloat)h, -1.0, 1.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
/* ARGSUSED1 */
void keyboard(unsigned char key, int x, int y)
{
switch (key) {
case 'r':
case 'R':
rotAngle += 20.;
if (rotAngle >= 360.) rotAngle = 0.;
glutPostRedisplay();
break;
case 27: /* Escape Key */
exit(0);
break;
default:
break;
}
}
/* Main Loop
* Open window with initial window size, title bar,
* color index display mode, and handle input events.
*/
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode (GLUT_SINGLE | GLUT_INDEX);
glutInitWindowSize (200, 200);
glutCreateWindow (argv[0]);
init();
glutReshapeFunc (reshape);
glutKeyboardFunc (keyboard);
glutDisplayFunc (display);
glutMainLoop();
return 0;
}
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