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Diffstat (limited to 'progs/redbook/fogindex.c')
-rw-r--r-- | progs/redbook/fogindex.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/progs/redbook/fogindex.c b/progs/redbook/fogindex.c new file mode 100644 index 00000000000..b409c95ac91 --- /dev/null +++ b/progs/redbook/fogindex.c @@ -0,0 +1,138 @@ + +/* Copyright (c) Mark J. Kilgard, 1994. */ + +/* + * (c) Copyright 1993, 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 + * Unpublished-- rights reserved under the copyright laws of the + * United States.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(TM) is a trademark of Silicon Graphics, Inc. + */ +/* + * fogindex.c + * This program demonstrates fog in color index mode. + * Three cones are drawn at different z values in a linear + * fog. 32 contiguous colors (from 16 to 47) are loaded + * with a color ramp. + */ +#include <stdlib.h> +#include <GL/glut.h> + +/* Initialize color map and fog. Set screen clear color + * to end of color ramp. + */ +#define NUM_COLORS 32 +#define RAMPSTART 16 + +void +myinit(void) +{ + int i; + + glEnable(GL_DEPTH_TEST); + glDepthFunc(GL_LESS); + for (i = 0; i < NUM_COLORS; i++) { + GLfloat shade; + shade = (GLfloat) (NUM_COLORS - i) / (GLfloat) NUM_COLORS; + glutSetColor(16 + i, shade, shade, shade); + } + glEnable(GL_FOG); + + glFogi(GL_FOG_MODE, GL_LINEAR); + glFogi(GL_FOG_INDEX, NUM_COLORS); + glFogf(GL_FOG_START, 0.0); + glFogf(GL_FOG_END, 4.0); + glHint(GL_FOG_HINT, GL_NICEST); + glClearIndex((GLfloat) (NUM_COLORS + RAMPSTART - 1)); +} + +/* display() renders 3 cones at different z positions. + */ +void +display(void) +{ + glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); + glPushMatrix(); + glTranslatef(-1.0, -1.0, -1.0); + glRotatef(-90.0, 1.0, 0.0, 0.0); + glIndexi(RAMPSTART); + glutSolidCone(1.0, 2.0, 10, 10); + glPopMatrix(); + + glPushMatrix(); + glTranslatef(0.0, -1.0, -2.25); + glRotatef(-90.0, 1.0, 0.0, 0.0); + glIndexi(RAMPSTART); + glutSolidCone(1.0, 2.0, 10, 10); + glPopMatrix(); + + glPushMatrix(); + glTranslatef(1.0, -1.0, -3.5); + glRotatef(-90.0, 1.0, 0.0, 0.0); + glIndexi(RAMPSTART); + glutSolidCone(1.0, 2.0, 10, 10); + glPopMatrix(); + glFlush(); +} + +void +myReshape(int w, int h) +{ + glViewport(0, 0, w, h); + glMatrixMode(GL_PROJECTION); + glLoadIdentity(); + if (w <= h) + glOrtho(-2.0, 2.0, -2.0 * (GLfloat) h / (GLfloat) w, + 2.0 * (GLfloat) h / (GLfloat) w, 0.0, 10.0); + else + glOrtho(-2.0 * (GLfloat) w / (GLfloat) h, + 2.0 * (GLfloat) w / (GLfloat) h, -2.0, 2.0, 0.0, 10.0); + glMatrixMode(GL_MODELVIEW); + glLoadIdentity(); +} + +/* Main Loop + * Open window with initial window size, title bar, + * RGBA display mode, depth buffer, and handle input events. + */ +int +main(int argc, char **argv) +{ + glutInit(&argc, argv); + glutInitDisplayMode(GLUT_SINGLE | GLUT_INDEX | GLUT_DEPTH); + glutCreateWindow(argv[0]); + myinit(); + glutReshapeFunc(myReshape); + glutDisplayFunc(display); + glutMainLoop(); + return 0; /* ANSI C requires main to return int. */ +} |