www.pudn.com > openglbk.rar > polyoff.c
/*
* Copyright (c) 1993-1999, 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* Unpublished-- rights reserved under the copyright laws of the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(R) is a registered trademark of Silicon Graphics, Inc.
*/
/*
* polyoff.c
* This program demonstrates polygon offset to draw a shaded
* polygon and its wireframe counterpart without ugly visual
* artifacts ("stitching").
*/
#include
#include
#include
#ifdef GL_VERSION_1_1
GLuint list;
GLint spinx = 0;
GLint spiny = 0;
GLfloat tdist = 0.0;
GLfloat polyfactor = 1.0;
GLfloat polyunits = 1.0;
/* display() draws two spheres, one with a gray, diffuse material,
* the other sphere with a magenta material with a specular highlight.
*/
void display (void)
{
GLfloat mat_ambient[] = { 0.8, 0.8, 0.8, 1.0 };
GLfloat mat_diffuse[] = { 1.0, 0.0, 0.5, 1.0 };
GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat gray[] = { 0.8, 0.8, 0.8, 1.0 };
GLfloat black[] = { 0.0, 0.0, 0.0, 1.0 };
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix ();
glTranslatef (0.0, 0.0, tdist);
glRotatef ((GLfloat) spinx, 1.0, 0.0, 0.0);
glRotatef ((GLfloat) spiny, 0.0, 1.0, 0.0);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, gray);
glMaterialfv(GL_FRONT, GL_SPECULAR, black);
glMaterialf(GL_FRONT, GL_SHININESS, 0.0);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_POLYGON_OFFSET_FILL);
glPolygonOffset(polyfactor, polyunits);
glCallList (list);
glDisable(GL_POLYGON_OFFSET_FILL);
glDisable(GL_LIGHTING);
glDisable(GL_LIGHT0);
glColor3f (1.0, 1.0, 1.0);
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
glCallList (list);
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glPopMatrix ();
glFlush ();
}
/* specify initial properties
* create display list with sphere
* initialize lighting and depth buffer
*/
void gfxinit (void)
{
GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
GLfloat global_ambient[] = { 0.2, 0.2, 0.2, 1.0 };
glClearColor (0.0, 0.0, 0.0, 1.0);
list = glGenLists(1);
glNewList (list, GL_COMPILE);
glutSolidSphere(1.0, 20, 12);
glEndList ();
glEnable(GL_DEPTH_TEST);
glLightfv (GL_LIGHT0, GL_AMBIENT, light_ambient);
glLightfv (GL_LIGHT0, GL_DIFFUSE, light_diffuse);
glLightfv (GL_LIGHT0, GL_SPECULAR, light_specular);
glLightfv (GL_LIGHT0, GL_POSITION, light_position);
glLightModelfv (GL_LIGHT_MODEL_AMBIENT, global_ambient);
}
/* call when window is resized */
void reshape(int width, int height)
{
glViewport (0, 0, width, height);
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
gluPerspective(45.0, (GLdouble)width/(GLdouble)height,
1.0, 10.0);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity ();
gluLookAt (0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
}
/* call when mouse button is pressed */
void mouse(int button, int state, int x, int y) {
switch (button) {
case GLUT_LEFT_BUTTON:
switch (state) {
case GLUT_DOWN:
spinx = (spinx + 5) % 360;
glutPostRedisplay();
break;
default:
break;
}
break;
case GLUT_MIDDLE_BUTTON:
switch (state) {
case GLUT_DOWN:
spiny = (spiny + 5) % 360;
glutPostRedisplay();
break;
default:
break;
}
break;
case GLUT_RIGHT_BUTTON:
switch (state) {
case GLUT_UP:
exit(0);
break;
default:
break;
}
break;
default:
break;
}
}
void keyboard (unsigned char key, int x, int y)
{
switch (key) {
case 't':
if (tdist < 4.0) {
tdist = (tdist + 0.5);
glutPostRedisplay();
}
break;
case 'T':
if (tdist > -5.0) {
tdist = (tdist - 0.5);
glutPostRedisplay();
}
break;
case 'F':
polyfactor = polyfactor + 0.1;
printf ("polyfactor is %f\n", polyfactor);
glutPostRedisplay();
break;
case 'f':
polyfactor = polyfactor - 0.1;
printf ("polyfactor is %f\n", polyfactor);
glutPostRedisplay();
break;
case 'U':
polyunits = polyunits + 1.0;
printf ("polyunits is %f\n", polyunits);
glutPostRedisplay();
break;
case 'u':
polyunits = polyunits - 1.0;
printf ("polyunits is %f\n", polyunits);
glutPostRedisplay();
break;
default:
break;
}
}
/* Main Loop
* Open window with initial window size, title bar,
* RGBA display mode, and handle input events.
*/
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
glutCreateWindow(argv[0]);
glutReshapeFunc(reshape);
glutDisplayFunc(display);
glutMouseFunc(mouse);
glutKeyboardFunc(keyboard);
gfxinit();
glutMainLoop();
return 0;
}
#else
int main(int argc, char** argv)
{
fprintf (stderr, "This program demonstrates a feature which is not in OpenGL Version 1.0.\n");
fprintf (stderr, "If your implementation of OpenGL Version 1.0 has the right extensions,\n");
fprintf (stderr, "you may be able to modify this program to make it run.\n");
return 0;
}
#endif