1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
/*
* Test GL_EXT_rescale_normal extension
* Brian Paul January 1998 This program is in the public domain.
*/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glut.h>
static GLfloat Phi = 0.0;
static void Idle( void )
{
static double t0 = -1.;
double dt, t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
if (t0 < 0.0)
t0 = t;
dt = t - t0;
t0 = t;
Phi += 3.0 * dt;
glutPostRedisplay();
}
static void Display( void )
{
GLfloat scale = 0.6 + 0.5 * sin(Phi);
glClear( GL_COLOR_BUFFER_BIT );
glPushMatrix();
glScalef(scale, scale, scale);
glutSolidSphere(2.0, 20, 20);
glPopMatrix();
glutSwapBuffers();
}
static void Reshape( int width, int height )
{
glViewport( 0, 0, width, height );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 25.0 );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
glTranslatef( 0.0, 0.0, -15.0 );
}
static void Init( void )
{
static GLfloat mat[4] = { 0.8, 0.8, 0.0, 1.0 };
static GLfloat pos[4] = { -1.0, 1.0, 1.0, 0.0 };
/* setup lighting, etc */
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, mat);
glLightfv(GL_LIGHT0, GL_POSITION, pos);
glEnable(GL_CULL_FACE);
glDisable(GL_RESCALE_NORMAL_EXT);
glDisable(GL_NORMALIZE);
}
#define UNSCALED 1
#define NORMALIZE 2
#define RESCALE 3
#define QUIT 4
static void ModeMenu(int entry)
{
if (entry==UNSCALED) {
glDisable(GL_RESCALE_NORMAL_EXT);
glDisable(GL_NORMALIZE);
}
else if (entry==NORMALIZE) {
glEnable(GL_NORMALIZE);
glDisable(GL_RESCALE_NORMAL_EXT);
}
else if (entry==RESCALE) {
glDisable(GL_NORMALIZE);
glEnable(GL_RESCALE_NORMAL_EXT);
}
else if (entry==QUIT) {
exit(0);
}
glutPostRedisplay();
}
static void
key(unsigned char k, int x, int y)
{
(void) x;
(void) y;
switch (k) {
case 27: /* Escape */
exit(0);
break;
default:
return;
}
glutPostRedisplay();
}
int main( int argc, char *argv[] )
{
glutInit( &argc, argv );
glutInitWindowPosition(0, 0);
glutInitWindowSize( 400, 400 );
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
glutCreateWindow(argv[0]);
Init();
glutIdleFunc( Idle );
glutReshapeFunc( Reshape );
glutDisplayFunc( Display );
glutKeyboardFunc(key);
glutCreateMenu(ModeMenu);
glutAddMenuEntry("Unscaled", UNSCALED);
glutAddMenuEntry("Normalize", NORMALIZE);
glutAddMenuEntry("Rescale EXT", RESCALE);
glutAddMenuEntry("Quit", QUIT);
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutMainLoop();
return 0;
}
|
