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* Unpublished-- rights reserved under the copyright laws of the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
* Use of multiple names and picking are demonstrated.
41
* A 3x3 grid of squares is drawn. When the left mouse
42
* button is pressed, all squares under the cursor position
43
* have their color changed.
49
int board[3][3]; /* amount of color for each square */
51
/* Clear color value for every square on the board */
52
static void init(void)
55
for (i = 0; i < 3; i++)
56
for (j = 0; j < 3; j ++)
58
glClearColor (0.0, 0.0, 0.0, 0.0);
61
/* The nine squares are drawn. In selection mode, each
62
* square is given two names: one for the row and the
63
* other for the column on the grid. The color of each
64
* square is determined by its position on the grid, and
65
* the value in the board[][] array.
67
static void drawSquares(GLenum mode)
70
for (i = 0; i < 3; i++) {
71
if (mode == GL_SELECT)
73
for (j = 0; j < 3; j ++) {
74
if (mode == GL_SELECT)
76
glColor3f ((GLfloat) i/3.0, (GLfloat) j/3.0,
77
(GLfloat) board[i][j]/3.0);
78
glRecti (i, j, i+1, j+1);
79
if (mode == GL_SELECT)
85
/* processHits prints out the contents of the
88
static void processHits (GLint hits, GLuint buffer[])
91
GLuint j, ii = 0, jj = 0, names, *ptr;
93
printf ("hits = %d\n", hits);
94
ptr = (GLuint *) buffer;
95
for (i = 0; i < hits; i++) { /* for each hit */
97
printf (" number of names for this hit = %d\n", names); ptr++;
98
printf(" z1 is %g;", (float) *ptr/0x7fffffff); ptr++;
99
printf(" z2 is %g\n", (float) *ptr/0x7fffffff); ptr++;
100
printf (" names are ");
101
for (j = 0; j < names; j++) { /* for each name */
102
printf ("%d ", *ptr);
103
if (j == 0) /* set row and column */
110
board[ii][jj] = (board[ii][jj] + 1) % 3;
114
/* pickSquares() sets up selection mode, name stack,
115
* and projection matrix for picking. Then the
120
static void pickSquares(int button, int state, int x, int y)
122
GLuint selectBuf[BUFSIZE];
126
if (button != GLUT_LEFT_BUTTON || state != GLUT_DOWN)
129
glGetIntegerv (GL_VIEWPORT, viewport);
131
glSelectBuffer (BUFSIZE, selectBuf);
132
(void) glRenderMode (GL_SELECT);
137
glMatrixMode (GL_PROJECTION);
140
/* create 5x5 pixel picking region near cursor location */
141
gluPickMatrix ((GLdouble) x, (GLdouble) (viewport[3] - y),
143
gluOrtho2D (0.0, 3.0, 0.0, 3.0);
144
drawSquares (GL_SELECT);
146
glMatrixMode (GL_PROJECTION);
150
hits = glRenderMode (GL_RENDER);
151
processHits (hits, selectBuf);
155
static void display(void)
157
glClear(GL_COLOR_BUFFER_BIT);
158
drawSquares (GL_RENDER);
162
static void reshape(int w, int h)
164
glViewport(0, 0, w, h);
165
glMatrixMode(GL_PROJECTION);
167
gluOrtho2D (0.0, 3.0, 0.0, 3.0);
168
glMatrixMode(GL_MODELVIEW);
173
static void keyboard(unsigned char key, int x, int y)
183
int main(int argc, char** argv)
185
glutInit(&argc, argv);
186
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
187
glutInitWindowSize (100, 100);
188
glutInitWindowPosition (100, 100);
189
glutCreateWindow (argv[0]);
191
glutReshapeFunc (reshape);
192
glutDisplayFunc(display);
193
glutMouseFunc (pickSquares);
194
glutKeyboardFunc (keyboard);