| /* |
| * 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 Unpublished - rights |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. |
| */ |
| |
| /* |
| * pointp.c |
| * This program demonstrates point parameters and their effect |
| * on point primitives. |
| * 250 points are randomly generated within a 10 by 10 by 40 |
| * region, centered at the origin. In some modes (including the |
| * default), points that are closer to the viewer will appear larger. |
| * |
| * Pressing the 'l', 'q', and 'c' keys switch the point |
| * parameters attenuation mode to linear, quadratic, or constant, |
| * respectively. |
| * Pressing the 'f' and 'b' keys move the viewer forward |
| * and backwards. In either linear or quadratic attenuation |
| * mode, the distance from the viewer to the point will change |
| * the size of the point primitive. |
| * Pressing the '+' and '-' keys will change the current point |
| * size. In this program, the point size is bounded, so it |
| * will not get less than 2.0, nor greater than GL_POINT_SIZE_MAX. |
| */ |
| |
| #include <GL/glew.h> |
| #include <GL/glut.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| |
| static GLfloat psize = 7.0; |
| static GLfloat pmax[1]; |
| static GLfloat constant[3] = {1.0, 0.0, 0.0}; |
| static GLfloat linear[3] = {0.0, 0.12, 0.0}; |
| static GLfloat quadratic[3] = {0.0, 0.0, 0.01}; |
| |
| static void init(void) |
| { |
| int i; |
| |
| srand (12345); |
| |
| glNewList(1, GL_COMPILE); |
| glBegin (GL_POINTS); |
| for (i = 0; i < 250; i++) { |
| glColor3f (1.0, ((rand()/(float) RAND_MAX) * 0.5) + 0.5, |
| rand()/(float) RAND_MAX); |
| /* randomly generated vertices: |
| -5 < x < 5; -5 < y < 5; -5 < z < -45 */ |
| glVertex3f ( ((rand()/(float)RAND_MAX) * 10.0) - 5.0, |
| ((rand()/(float)RAND_MAX) * 10.0) - 5.0, |
| ((rand()/(float)RAND_MAX) * 40.0) - 45.0); |
| } |
| glEnd(); |
| glEndList(); |
| |
| glEnable(GL_DEPTH_TEST); |
| glEnable(GL_POINT_SMOOTH); |
| glEnable(GL_BLEND); |
| glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); |
| glPointSize(psize); |
| glGetFloatv(GL_POINT_SIZE_MAX_EXT, pmax); |
| |
| glPointParameterfvEXT (GL_DISTANCE_ATTENUATION_EXT, linear); |
| glPointParameterfEXT (GL_POINT_FADE_THRESHOLD_SIZE_EXT, 2.0); |
| } |
| |
| static void display(void) |
| { |
| glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); |
| glCallList (1); |
| glutSwapBuffers (); |
| } |
| |
| static void reshape (int w, int h) |
| { |
| glViewport (0, 0, (GLsizei) w, (GLsizei) h); |
| glMatrixMode (GL_PROJECTION); |
| glLoadIdentity (); |
| gluPerspective (35.0, 1.0, 0.25, 200.0); |
| glMatrixMode (GL_MODELVIEW); |
| glTranslatef (0.0, 0.0, -10.0); |
| } |
| |
| static void keyboard(unsigned char key, int x, int y) |
| { |
| switch (key) { |
| case 'b': |
| glMatrixMode (GL_MODELVIEW); |
| glTranslatef (0.0, 0.0, -0.5); |
| glutPostRedisplay(); |
| break; |
| case 'c': |
| glPointParameterfvEXT (GL_DISTANCE_ATTENUATION_EXT, constant); |
| glutPostRedisplay(); |
| break; |
| case 'f': |
| glMatrixMode (GL_MODELVIEW); |
| glTranslatef (0.0, 0.0, 0.5); |
| glutPostRedisplay(); |
| break; |
| case 'l': |
| glPointParameterfvEXT (GL_DISTANCE_ATTENUATION_EXT, linear); |
| glutPostRedisplay(); |
| break; |
| case 'q': |
| glPointParameterfvEXT (GL_DISTANCE_ATTENUATION_EXT, quadratic); |
| glutPostRedisplay(); |
| break; |
| case '+': |
| if (psize < (pmax[0] + 1.0)) |
| psize = psize + 1.0; |
| glPointSize (psize); |
| glutPostRedisplay(); |
| break; |
| case '-': |
| if (psize >= 2.0) |
| psize = psize - 1.0; |
| glPointSize (psize); |
| glutPostRedisplay(); |
| break; |
| case 27: |
| exit(0); |
| break; |
| } |
| } |
| |
| int main(int argc, char** argv) |
| { |
| glutInit(&argc, argv); |
| glutInitDisplayMode (GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_MULTISAMPLE); |
| glutInitWindowSize (500, 500); |
| glutInitWindowPosition (100, 100); |
| glutCreateWindow (argv[0]); |
| glewInit(); |
| init (); |
| glutDisplayFunc (display); |
| glutReshapeFunc (reshape); |
| glutKeyboardFunc (keyboard); |
| glutMainLoop(); |
| return 0; |
| } |