2
* Copyright (c) 1993-1997, Silicon Graphics, Inc.
4
* Permission to use, copy, modify, and distribute this software for
5
* any purpose and without fee is hereby granted, provided that the above
6
* copyright notice appear in all copies and that both the copyright notice
7
* and this permission notice appear in supporting documentation, and that
8
* the name of Silicon Graphics, Inc. not be used in advertising
9
* or publicity pertaining to distribution of the software without specific,
10
* written prior permission.
12
* THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
13
* AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
14
* INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
15
* FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
16
* GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
17
* SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
18
* KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
19
* LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
20
* THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
21
* ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
22
* ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
23
* POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
25
* US Government Users Restricted Rights
26
* Use, duplication, or disclosure by the Government is subject to
27
* restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
28
* (c)(1)(ii) of the Rights in Technical Data and Computer Software
29
* clause at DFARS 252.227-7013 and/or in similar or successor
30
* clauses in the FAR or the DOD or NASA FAR Supplement.
31
* Unpublished-- rights reserved under the copyright laws of the
32
* United States. Contractor/manufacturer is Silicon Graphics,
33
* Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
35
* OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
40
* This program demonstrates how to intermix opaque and
41
* alpha blended polygons in the same scene, by using
42
* glDepthMask. Press the 'a' key to animate moving the
43
* transparent object through the opaque object. Press
44
* the 'r' key to reset the scene.
54
static float solidZ = MAXZ;
55
static float transparentZ = MINZ;
56
static GLuint sphereList, cubeList;
58
static void init(void)
60
GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 0.15 };
61
GLfloat mat_shininess[] = { 100.0 };
62
GLfloat position[] = { 0.5, 0.5, 1.0, 0.0 };
64
glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
65
glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
66
glLightfv(GL_LIGHT0, GL_POSITION, position);
68
glEnable(GL_LIGHTING);
70
glEnable(GL_DEPTH_TEST);
72
sphereList = glGenLists(1);
73
glNewList(sphereList, GL_COMPILE);
74
glutSolidSphere (0.4, 16, 16);
77
cubeList = glGenLists(1);
78
glNewList(cubeList, GL_COMPILE);
85
GLfloat mat_solid[] = { 0.75, 0.75, 0.0, 1.0 };
86
GLfloat mat_zero[] = { 0.0, 0.0, 0.0, 1.0 };
87
GLfloat mat_transparent[] = { 0.0, 0.8, 0.8, 0.6 };
88
GLfloat mat_emission[] = { 0.0, 0.3, 0.3, 0.6 };
90
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
93
glTranslatef (-0.15, -0.15, solidZ);
94
glMaterialfv(GL_FRONT, GL_EMISSION, mat_zero);
95
glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_solid);
96
glCallList (sphereList);
100
glTranslatef (0.15, 0.15, transparentZ);
101
glRotatef (15.0, 1.0, 1.0, 0.0);
102
glRotatef (30.0, 0.0, 1.0, 0.0);
103
glMaterialfv(GL_FRONT, GL_EMISSION, mat_emission);
104
glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_transparent);
106
glDepthMask (GL_FALSE);
107
glBlendFunc (GL_SRC_ALPHA, GL_ONE);
108
glCallList (cubeList);
109
glDepthMask (GL_TRUE);
110
glDisable (GL_BLEND);
116
void reshape(int w, int h)
118
glViewport(0, 0, (GLint) w, (GLint) h);
119
glMatrixMode(GL_PROJECTION);
122
glOrtho (-1.5, 1.5, -1.5*(GLfloat)h/(GLfloat)w,
123
1.5*(GLfloat)h/(GLfloat)w, -10.0, 10.0);
125
glOrtho (-1.5*(GLfloat)w/(GLfloat)h,
126
1.5*(GLfloat)w/(GLfloat)h, -1.5, 1.5, -10.0, 10.0);
127
glMatrixMode(GL_MODELVIEW);
133
static double t0 = -1.;
134
if (solidZ <= MINZ || transparentZ >= MAXZ)
141
t = glutGet(GLUT_ELAPSED_TIME) / 1000.;
147
transparentZ += ZINC*dt;
153
void keyboard(unsigned char key, int x, int y)
160
glutIdleFunc(animate);
173
int main(int argc, char** argv)
175
glutInit(&argc, argv);
176
glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
177
glutInitWindowSize(500, 500);
178
glutCreateWindow(argv[0]);
180
glutReshapeFunc(reshape);
181
glutKeyboardFunc(keyboard);
182
glutDisplayFunc(display);