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* Copyright (c) 1993-2003, Silicon Graphics, Inc.
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* Permission to use, copy, modify, and distribute this software for any
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* purpose and without fee is hereby granted, provided that the above
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* copyright notice appear in all copies and that both the copyright
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* notice and this permission notice appear in supporting documentation,
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* and that the name of Silicon Graphics, Inc. not be used in
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* advertising or publicity pertaining to distribution of the software
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* without specific, written prior permission.
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* THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS" AND
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* WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
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* INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
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* FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
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* GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
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* SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
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* OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION, LOSS OF
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* PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF THIRD
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* PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN ADVISED OF
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* THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE POSSESSION, USE
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* OR PERFORMANCE OF THIS SOFTWARE.
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* US Government Users Restricted Rights
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* Use, duplication, or disclosure by the Government is subject to
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* restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
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* (c)(1)(ii) of the Rights in Technical Data and Computer Software
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* clause at DFARS 252.227-7013 and/or in similar or successor clauses
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* in the FAR or the DOD or NASA FAR Supplement. Unpublished - rights
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* reserved under the copyright laws of the United States.
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* Contractor/manufacturer is:
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* Silicon Graphics, Inc.
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* 1500 Crittenden Lane
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* Mountain View, CA 94043
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* United State of America
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* OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
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* This program demonstrates point parameters and their effect
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* on point primitives.
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* 250 points are randomly generated within a 10 by 10 by 40
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* region, centered at the origin. In some modes (including the
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* default), points that are closer to the viewer will appear larger.
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* Pressing the 'l', 'q', and 'c' keys switch the point
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* parameters attenuation mode to linear, quadratic, or constant,
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* Pressing the 'f' and 'b' keys move the viewer forward
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* and backwards. In either linear or quadratic attenuation
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* mode, the distance from the viewer to the point will change
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* the size of the point primitive.
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* Pressing the '+' and '-' keys will change the current point
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* size. In this program, the point size is bounded, so it
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* will not get less than 2.0, nor greater than GL_POINT_SIZE_MAX.
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static GLfloat psize = 7.0;
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static GLfloat pmax[1];
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static GLfloat constant[3] = {1.0, 0.0, 0.0};
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static GLfloat linear[3] = {0.0, 0.12, 0.0};
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static GLfloat quadratic[3] = {0.0, 0.0, 0.01};
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static void init(void)
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glNewList(1, GL_COMPILE);
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for (i = 0; i < 250; i++) {
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glColor3f (1.0, ((rand()/(float) RAND_MAX) * 0.5) + 0.5,
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rand()/(float) RAND_MAX);
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/* randomly generated vertices:
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-5 < x < 5; -5 < y < 5; -5 < z < -45 */
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glVertex3f ( ((rand()/(float)RAND_MAX) * 10.0) - 5.0,
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((rand()/(float)RAND_MAX) * 10.0) - 5.0,
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((rand()/(float)RAND_MAX) * 40.0) - 45.0);
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glEnable(GL_DEPTH_TEST);
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glEnable(GL_POINT_SMOOTH);
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glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
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glGetFloatv(GL_POINT_SIZE_MAX_EXT, pmax);
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glPointParameterfvEXT (GL_DISTANCE_ATTENUATION_EXT, linear);
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glPointParameterfEXT (GL_POINT_FADE_THRESHOLD_SIZE_EXT, 2.0);
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static void display(void)
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glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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static void reshape (int w, int h)
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glViewport (0, 0, (GLsizei) w, (GLsizei) h);
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glMatrixMode (GL_PROJECTION);
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gluPerspective (35.0, 1.0, 0.25, 200.0);
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glMatrixMode (GL_MODELVIEW);
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glTranslatef (0.0, 0.0, -10.0);
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static void keyboard(unsigned char key, int x, int y)
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glMatrixMode (GL_MODELVIEW);
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glTranslatef (0.0, 0.0, -0.5);
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glPointParameterfvEXT (GL_DISTANCE_ATTENUATION_EXT, constant);
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glMatrixMode (GL_MODELVIEW);
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glTranslatef (0.0, 0.0, 0.5);
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glPointParameterfvEXT (GL_DISTANCE_ATTENUATION_EXT, linear);
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glPointParameterfvEXT (GL_DISTANCE_ATTENUATION_EXT, quadratic);
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if (psize < (pmax[0] + 1.0))
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int main(int argc, char** argv)
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glutInit(&argc, argv);
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glutInitDisplayMode (GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_MULTISAMPLE);
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glutInitWindowSize (500, 500);
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glutInitWindowPosition (100, 100);
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glutCreateWindow (argv[0]);
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glutDisplayFunc (display);
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glutReshapeFunc (reshape);
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glutKeyboardFunc (keyboard);