/* 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 * Unpublished-- rights reserved under the copyright laws of the * United States.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(); } static void key(unsigned char k, int x, int y) { switch (k) { case 27: /* Escape */ exit(0); break; default: return; } glutPostRedisplay(); } /* 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); glutKeyboardFunc(key); glutMainLoop(); return 0; /* ANSI C requires main to return int. */ }