2 * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
4 * Permission to use, copy, modify, distribute, and sell this software and
5 * its documentation for any purpose is hereby granted without fee, provided
6 * that (i) the above copyright notices and this permission notice appear in
7 * all copies of the software and related documentation, and (ii) the name of
8 * Silicon Graphics may not be used in any advertising or
9 * publicity relating to the software without the specific, prior written
10 * permission of Silicon Graphics.
12 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
14 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
15 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
17 * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
18 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
19 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
20 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
21 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
25 #define GL_GLEXT_PROTOTYPES
36 static void Init(void)
38 fprintf(stderr
, "GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER
));
39 fprintf(stderr
, "GL_VERSION = %s\n", (char *) glGetString(GL_VERSION
));
40 fprintf(stderr
, "GL_VENDOR = %s\n", (char *) glGetString(GL_VENDOR
));
42 glClearColor(0.0, 0.0, 1.0, 0.0);
45 static void Reshape(int width
, int height
)
47 glViewport(0, 0, (GLint
)width
, (GLint
)height
);
49 glMatrixMode(GL_PROJECTION
);
51 glOrtho(-1.0, 1.0, -1.0, 1.0, 0, 100.0);
52 glMatrixMode(GL_MODELVIEW
);
55 static void Key(unsigned char key
, int x
, int y
)
68 expected(float z
, float size
, const float atten
[3])
71 const GLfloat q
= atten
[0] + dist
* (atten
[1] + dist
* atten
[2]);
72 const GLfloat a
= sqrt(1.0 / q
);
77 static void Draw(void)
79 static GLfloat atten
[3] = { 0.0, 0.1, .01 };
83 glClear(GL_COLOR_BUFFER_BIT
);
85 glBlendFunc(GL_SRC_ALPHA
, GL_ONE_MINUS_SRC_ALPHA
);
87 glPointParameterfvARB(GL_POINT_DISTANCE_ATTENUATION_ARB
, atten
);
91 printf("Expected point sizes:\n");
93 for (i
= 0; i
< 5; i
++) {
94 float x
= -0.8 + i
* 0.4;
95 float z
= -i
* 20 - 10;
96 glVertex3f( x
, 0.0, z
);
97 printf(" %f\n", expected(z
, size
, atten
));
109 static GLenum
Args(int argc
, char **argv
)
113 doubleBuffer
= GL_FALSE
;
115 for (i
= 1; i
< argc
; i
++) {
116 if (strcmp(argv
[i
], "-sb") == 0) {
117 doubleBuffer
= GL_FALSE
;
118 } else if (strcmp(argv
[i
], "-db") == 0) {
119 doubleBuffer
= GL_TRUE
;
121 fprintf(stderr
, "%s (Bad option).\n", argv
[i
]);
129 int main(int argc
, char **argv
)
133 glutInit(&argc
, argv
);
135 if (Args(argc
, argv
) == GL_FALSE
) {
139 glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
141 type
= GLUT_RGB
| GLUT_ALPHA
;
142 type
|= (doubleBuffer
) ? GLUT_DOUBLE
: GLUT_SINGLE
;
143 glutInitDisplayMode(type
);
145 if (glutCreateWindow(argv
[0]) == GL_FALSE
) {
151 glutReshapeFunc(Reshape
);
152 glutKeyboardFunc(Key
);
153 glutDisplayFunc(Draw
);