167 lines
5.3 KiB
C
167 lines
5.3 KiB
C
/*
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* (c) Copyright 1993, Silicon Graphics, Inc.
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* ALL RIGHTS RESERVED
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* Permission to use, copy, modify, and distribute this software for
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* any 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 notice
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* and this permission notice appear in supporting documentation, and that
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* the name of Silicon Graphics, Inc. not be used in advertising
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* or publicity pertaining to distribution of the software without specific,
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* written prior permission.
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*
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* THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
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* AND 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
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* KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
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* LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
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* THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
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* ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
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* ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
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* POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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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
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* clauses in the FAR or the DOD or NASA FAR Supplement.
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* Unpublished-- rights reserved under the copyright laws of the
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* United States. Contractor/manufacturer is Silicon Graphics,
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* Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
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*
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* OpenGL(TM) is a trademark of Silicon Graphics, Inc.
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*/
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/*
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* fog.c
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* This program draws 5 red teapots, each at a different
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* z distance from the eye, in different types of fog.
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* Pressing the left mouse button chooses between 3 types of
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* fog: exponential, exponential squared, and linear.
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* In this program, there is a fixed density value, as well
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* as fixed start and end values for the linear fog.
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*/
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#include <windows.h>
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#include <stdio.h>
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#include <GL/gl.h>
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#include <GL/glu.h>
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#include <math.h>
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#include "glaux.h"
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GLint fogMode;
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void cycleFog (AUX_EVENTREC *event)
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{
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if (fogMode == GL_EXP) {
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fogMode = GL_EXP2;
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printf ("Fog mode is GL_EXP2\n");
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}
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else if (fogMode == GL_EXP2) {
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fogMode = GL_LINEAR;
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printf ("Fog mode is GL_LINEAR\n");
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glFogf (GL_FOG_START, 1.0);
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glFogf (GL_FOG_END, 5.0);
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}
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else if (fogMode == GL_LINEAR) {
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fogMode = GL_EXP;
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printf ("Fog mode is GL_EXP\n");
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}
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glFogi (GL_FOG_MODE, fogMode);
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}
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/* Initialize z-buffer, projection matrix, light source,
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* and lighting model. Do not specify a material property here.
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*/
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void myinit(void)
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{
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GLfloat position[] = { 0.0, 3.0, 3.0, 0.0 };
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GLfloat local_view[] = { 0.0 };
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glEnable(GL_DEPTH_TEST);
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glDepthFunc(GL_LESS);
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glLightfv(GL_LIGHT0, GL_POSITION, position);
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glLightModelfv(GL_LIGHT_MODEL_LOCAL_VIEWER, local_view);
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glFrontFace (GL_CW);
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glEnable(GL_LIGHTING);
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glEnable(GL_LIGHT0);
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glEnable(GL_AUTO_NORMAL);
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glEnable(GL_NORMALIZE);
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glEnable(GL_FOG);
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{
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GLfloat density;
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GLfloat fogColor[4] = {0.5, 0.5, 0.5, 1.0};
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fogMode = GL_EXP;
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glFogi (GL_FOG_MODE, fogMode);
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glFogfv (GL_FOG_COLOR, fogColor);
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glFogf (GL_FOG_DENSITY, 0.35);
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glHint (GL_FOG_HINT, GL_DONT_CARE);
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glClearColor(0.5, 0.5, 0.5, 1.0);
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}
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}
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void renderRedTeapot (GLfloat x, GLfloat y, GLfloat z)
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{
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float mat[3];
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mat[3] = 1.0f;
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glPushMatrix();
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glTranslatef (x, y, z);
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mat[0] = 0.1745; mat[1] = 0.01175; mat[2] = 0.01175;
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glMaterialfv (GL_FRONT, GL_AMBIENT, mat);
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mat[0] = 0.61424; mat[1] = 0.04136; mat[2] = 0.04136;
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glMaterialfv (GL_FRONT, GL_DIFFUSE, mat);
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mat[0] = 0.727811; mat[1] = 0.626959; mat[2] = 0.626959;
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glMaterialfv (GL_FRONT, GL_SPECULAR, mat);
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glMaterialf (GL_FRONT, GL_SHININESS, 0.6*128.0);
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auxSolidTeapot(1.0);
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glPopMatrix();
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}
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/* display() draws 5 teapots at different z positions.
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*/
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void display(void)
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{
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glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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renderRedTeapot (-4.0, -0.5, -1.0);
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renderRedTeapot (-2.0, -0.5, -2.0);
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renderRedTeapot (0.0, -0.5, -3.0);
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renderRedTeapot (2.0, -0.5, -4.0);
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renderRedTeapot (4.0, -0.5, -5.0);
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glFlush();
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}
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void myReshape(GLsizei w, GLsizei h)
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{
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glViewport(0, 0, w, h);
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glMatrixMode(GL_PROJECTION);
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glLoadIdentity();
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if (w <= (h*3))
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glOrtho (-6.0, 6.0, -2.0*((GLfloat) h*3)/(GLfloat) w,
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2.0*((GLfloat) h*3)/(GLfloat) w, 0.0, 10.0);
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else
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glOrtho (-6.0*(GLfloat) w/((GLfloat) h*3),
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6.0*(GLfloat) w/((GLfloat) h*3), -2.0, 2.0, 0.0, 10.0);
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glMatrixMode(GL_MODELVIEW);
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glLoadIdentity ();
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}
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/* Main Loop
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* Open window with initial window size, title bar,
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* RGBA display mode, depth buffer, and handle input events.
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*/
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int main(int argc, char** argv)
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{
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auxInitDisplayMode (AUX_SINGLE | AUX_RGB | AUX_DEPTH16);
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auxInitPosition (0, 0, 450, 150);
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auxInitWindow (argv[0]);
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auxMouseFunc (AUX_LEFTBUTTON, AUX_MOUSEDOWN, cycleFog);
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myinit();
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auxReshapeFunc (myReshape);
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auxMainLoop(display);
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}
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