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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
/* Copyright (c) Mark J. Kilgard, 1996. */
/* This program is freely distributable without licensing fees
and is provided without guarantee or warrantee expressed or
implied. This program is -not- in the public domain. */
#include <stdlib.h>
#include <stdio.h>
#include <GL/glut.h>
#define MAX_SPLATS 100
extern int logo_width;
extern int logo_height;
extern unsigned char logo_image[];
typedef struct _SplatInfo {
int x, y;
GLboolean alphaTest;
GLfloat xScale, yScale;
GLfloat scale[3];
GLfloat bias[3];
} SplatInfo;
int winHeight;
int numSplats = 0;
SplatInfo splatConfig;
SplatInfo splatList[MAX_SPLATS];
SplatInfo splatDefault = {
0, 0,
GL_TRUE,
1.0, 1.0,
1.0, 1.0, 1.0,
0.0, 0.0, 0.0,
};
void
reshape(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(0, w, 0, h);
glMatrixMode(GL_MODELVIEW);
winHeight = h;
}
void
renderSplat(SplatInfo *splat)
{
glRasterPos2i(splat->x, splat->y);
if(splat->yScale >= 0)
glBitmap(0, 0, 0, 0, 0, -logo_height * splat->yScale, 0);
if(splat->xScale < 0)
glBitmap(0, 0, 0, 0, logo_width * -splat->xScale, 0, 0);
glPixelZoom(splat->xScale, splat->yScale);
glPixelTransferf(GL_RED_SCALE, splat->scale[0]);
glPixelTransferf(GL_GREEN_SCALE, splat->scale[1]);
glPixelTransferf(GL_BLUE_SCALE, splat->scale[2]);
glPixelTransferf(GL_RED_BIAS, splat->bias[0]);
glPixelTransferf(GL_GREEN_BIAS, splat->bias[1]);
glPixelTransferf(GL_BLUE_BIAS, splat->bias[2]);
if (splat->alphaTest)
glEnable(GL_ALPHA_TEST);
else
glDisable(GL_ALPHA_TEST);
glDrawPixels(logo_width, logo_height, GL_RGBA,
GL_UNSIGNED_BYTE, logo_image);
}
void
display(void)
{
int i;
glClear(GL_COLOR_BUFFER_BIT);
for (i = 0; i < numSplats; i++) {
renderSplat(&splatList[i]);
}
glFlush();
}
void
mouse(int button, int state, int x, int y)
{
if (button == GLUT_LEFT_BUTTON) {
if (state == GLUT_DOWN) {
if (numSplats < MAX_SPLATS) {
splatConfig.x = x;
splatConfig.y = winHeight - y;
renderSplat(&splatConfig);
splatList[numSplats] = splatConfig;
numSplats++;
} else {
printf("out of splats!\n");
}
}
}
}
void
mainSelect(int value)
{
GLfloat rpos[4];
GLboolean valid;
switch(value) {
case 0:
numSplats = 0;
glutPostRedisplay();
break;
case 1:
splatConfig = splatDefault;
break;
case 2:
splatConfig.xScale *= 1.25;
splatConfig.yScale *= 1.25;
break;
case 3:
splatConfig.xScale *= 0.75;
splatConfig.yScale *= 0.75;
break;
case 4:
splatConfig.xScale *= -1.0;
break;
case 5:
splatConfig.yScale *= -1.0;
break;
case 6:
splatConfig.alphaTest = GL_TRUE;
break;
case 7:
splatConfig.alphaTest = GL_FALSE;
break;
case 411:
glGetFloatv(GL_CURRENT_RASTER_POSITION, rpos);
glGetBooleanv(GL_CURRENT_RASTER_POSITION_VALID, &valid);
printf("Raster position (%g,%g) is %s\n",
rpos[0], rpos[1], valid ? "valid" : "INVALID");
break;
case 666:
exit(0);
break;
}
}
void
scaleBiasSelect(int value)
{
int color = value >> 4;
int option = value & 0xf;
switch(option) {
case 1:
splatConfig.bias[color] += 0.25;
break;
case 2:
splatConfig.bias[color] -= 0.25;
break;
case 3:
splatConfig.scale[color] *= 2.0;
break;
case 4:
splatConfig.scale[color] *= 0.75;
break;
}
}
int
glutScaleBiasMenu(int mask)
{
int menu;
menu = glutCreateMenu(scaleBiasSelect);
glutAddMenuEntry("+25% bias", mask | 1);
glutAddMenuEntry("-25% bias", mask | 2);
glutAddMenuEntry("+25% scale", mask | 3);
glutAddMenuEntry("-25% scale", mask | 4);
return menu;
}
int
main(int argc, char *argv[])
{
int mainMenu, redMenu, greenMenu, blueMenu;
glutInitWindowSize(680, 440);
glutInit(&argc, argv);
splatConfig = splatDefault;
glutCreateWindow("splatlogo");
glutReshapeFunc(reshape);
glutDisplayFunc(display);
glutMouseFunc(mouse);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glAlphaFunc(GL_GEQUAL, 0.5);
glDisable(GL_ALPHA_TEST);
glEnable(GL_DITHER);
glClearColor(1.0, 1.0, 1.0, 0.0);
redMenu = glutScaleBiasMenu(0 << 4);
greenMenu = glutScaleBiasMenu(1 << 4);
blueMenu = glutScaleBiasMenu(2 << 4);
mainMenu = glutCreateMenu(mainSelect);
glutAddMenuEntry("Reset splays", 0);
glutAddMenuEntry("Reset splat config", 1);
glutAddSubMenu("Red control", redMenu);
glutAddSubMenu("Green control", greenMenu);
glutAddSubMenu("Blue control", blueMenu);
glutAddMenuEntry("+25% zoom", 2);
glutAddMenuEntry("-25% zoom", 3);
glutAddMenuEntry("X flip", 4);
glutAddMenuEntry("Y flip", 5);
glutAddMenuEntry("Enable alpha test", 6);
glutAddMenuEntry("Disable alpha test", 7);
glutSetMenu(mainMenu);
glutAddMenuEntry("Query raster position", 411);
glutAddMenuEntry("Quit", 666);
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutMainLoop();
return 0; /* Never reached; make ANSI C happy. */
}
|
