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Diffstat (limited to 'progs/redbook/pointp.c')
| -rw-r--r-- | progs/redbook/pointp.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/progs/redbook/pointp.c b/progs/redbook/pointp.c new file mode 100644 index 0000000000..ed62fa1771 --- /dev/null +++ b/progs/redbook/pointp.c @@ -0,0 +1,179 @@ +/* + * 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 Unpublished - rights + * reserved under the copyright laws of the United States.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. + */ + +#define GL_GLEXT_PROTOTYPES + +#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]); + init (); + glutDisplayFunc (display); + glutReshapeFunc (reshape); + glutKeyboardFunc (keyboard); + glutMainLoop(); + return 0; +} |