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
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
|
/* -*- Mode: C; tab-width: 4 -*- */
/* munch --- munching squares */
#if !defined( lint ) && !defined( SABER )
static const char sccsid[] = "@(#)munch.c 5.00 2000/11/01 xlockmore";
#endif
/*-
* Permission to use, copy, modify, and distribute this software and its
* documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appear in all copies and that
* both that copyright notice and this permission notice appear in
* supporting documentation.
*
* This file is provided AS IS with no warranties of any kind. The author
* shall have no liability with respect to the infringement of copyrights,
* trade secrets or any patents by this file or any part thereof. In no
* event will the author be liable for any lost revenue or profits or
* other special, indirect and consequential damages.
*
* Tim Showalter <tjs@andrew.cmu.edu>
*
* Copyright 1997, Tim Showalter
* Permission is granted to copy, modify, and use this as long
* as this notice remains intact. No warranties are expressed or implied.
* CMU Sucks.
*
* Some code stolen from / This is meant to work with
* xscreensaver, Copyright (c) 1992, 1995, 1996
* Jamie Zawinski <jwz@jwz.org>
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation. No representations are made about the suitability of this
* software for any purpose. It is provided "as is" without express or
* implied warranty.
*
* Revision History:
* 01-Nov-2000: Allocation checks
*/
/*-
* Munching Squares is this simplistic, silly screen hack (according to
* HAKMEM, discovered by Jackson Wright in 1962) where you take Y = X XOR T
* and graph it over and over. According to HAKMEM, it takes 5 instructions
* of PDP-1 assembly. This is a little more complicated than that, mostly X's
* fault, but it does some other random things.
* http://www.inwap.com/pdp10/hbaker/hakmem/hacks.html#item146
*/
#ifdef STANDALONE
#define MODE_munch
#define PROGCLASS "Munch"
#define HACK_INIT init_munch
#define HACK_DRAW draw_munch
#define munch_opts xlockmore_opts
#define DEFAULTS "*delay: 5000 \n" \
"*cycles: 7 \n"
#include "xlockmore.h" /* from the xscreensaver distribution */
#else /* !STANDALONE */
#include "xlock.h" /* from the xlockmore distribution */
#endif /* !STANDALONE */
#ifdef MODE_munch
ModeSpecOpt munch_opts =
{0, (XrmOptionDescRec *) NULL, 0, (argtype *) NULL, (OptionStruct *) NULL};
#ifdef USE_MODULES
ModStruct munch_description =
{"munch", "init_munch", "draw_munch", "release_munch",
"init_munch", "init_munch", (char *) NULL, &munch_opts,
5000, 1, 7, 1, 64, 1.0, "",
"Shows munching squares", 0, NULL};
#endif
#ifdef DEBUG
#include <assert.h>
#endif
/* flags for random things. Must be < log2(random's maximum), incidentially. */
#define SHIFT_KX (0x01)
#define SHIFT_KT (0x02)
#define SHIFT_KY (0x04)
#define GRAV (0x08)
typedef struct {
int width, height;
int logminwidth;
int logmaxwidth;
GC gc;
int thiswidth;
int t;
int atX, atY;
int kX, kT, kY;
int grav;
} munchstruct;
static munchstruct *munches = (munchstruct *) NULL;
static void
munchBit(ModeInfo * mi, int width, /* pixels */
int atX, int atY, /* pixels */
int kX, int kT, int kY, /* pixels */
int grav /* 0 or not */ )
{
munchstruct *mp = &munches[MI_SCREEN(mi)];
int x, y;
int drawX, drawY;
#if 0
(void) fprintf(stderr, "Doing width %d at %d %d shift %d %d %d grav %d\n",
width, atX, atY, kX, kT, kY, grav);
#endif
for (x = 0; x < width; x++) {
/* figure out the next point */
y = ((x ^ ((mp->t + kT) % width)) + kY) % width;
drawX = ((x + kX) % width) + atX;
drawY = (grav ? y + atY : atY + width - 1 - y);
/* used to be bugs where it would draw partially offscreen.
while that might be a pretty feature, I didn't want it to do
that yet. if these trigger, please let me know.
*/
#ifdef DEBUG
assert(drawX >= 0 && drawX < MI_WIDTH(mi));
assert(drawY >= 0 && drawY < MI_HEIGHT(mi));
#endif
XDrawPoint(MI_DISPLAY(mi), MI_WINDOW(mi), mp->gc, drawX, drawY);
/* XXX may want to change this to XDrawPoints,
but it's fast enough without it for the moment. */
}
}
/*
* dumb way to get # of digits in number. Probably faster than actually
* doing a log and a division, maybe.
*/
static int
dumb_log_2(int k)
{
int r = -1;
while (k > 0) {
k >>= 1;
r++;
}
return r;
}
void
init_munch(ModeInfo * mi)
{
Display *display = MI_DISPLAY(mi);
munchstruct *mp;
if (munches == NULL) {
if ((munches = (munchstruct *) calloc(MI_NUM_SCREENS(mi),
sizeof (munchstruct))) == NULL)
return;
}
mp = &munches[MI_SCREEN(mi)];
if (mp->gc == None) {
if ((mp->gc = XCreateGC(display, MI_WINDOW(mi),
(unsigned long) 0, (XGCValues *) NULL)) == None)
return;
}
mp->width = MI_WIDTH(mi);
mp->height = MI_HEIGHT(mi);
/* We need a square; limit on screen size? */
/* we want a power of 2 for the width or the munch doesn't fill up. */
mp->logmaxwidth = (int)
dumb_log_2((mp->height < mp->width) ? mp->height : mp->width);
XSetFunction(display, mp->gc, GXxor);
mp->logminwidth = MI_CYCLES(mi);
if (mp->logminwidth < 2 || MI_IS_ICONIC(mi))
mp->logminwidth = 2;
if (mp->logmaxwidth < mp->logminwidth)
mp->logmaxwidth = mp->logminwidth;
mp->t = 0;
MI_CLEARWINDOW(mi);
}
void
draw_munch(ModeInfo * mi)
{
munchstruct *mp;
if (munches == NULL)
return;
mp = &munches[MI_SCREEN(mi)];
if (mp->gc == None)
return;
MI_IS_DRAWN(mi) = True;
if (!mp->t) { /* New one */
int randflags = (int) LRAND();
/* choose size -- power of two */
mp->thiswidth = (int) (1 << (mp->logminwidth +
(LRAND() % (1 + mp->logmaxwidth - mp->logminwidth))));
if (MI_NPIXELS(mi) > 2)
XSetForeground(MI_DISPLAY(mi), mp->gc,
MI_PIXEL(mi, NRAND(MI_NPIXELS(mi))));
else /* Xor'red so WHITE may not be appropriate */
XSetForeground(MI_DISPLAY(mi), mp->gc, 1);
mp->atX = (int) (LRAND() %
((mp->width <= mp->thiswidth) ? 1 : mp->width - mp->thiswidth));
mp->atY = (int) (LRAND() %
((mp->height <= mp->thiswidth) ? 1 : mp->height - mp->thiswidth));
/* wrap-around by these values; no need to %
as we end up doing that later anyway */
mp->kX = (int) ((randflags & SHIFT_KX) ? LRAND() % mp->thiswidth : 0);
mp->kT = (int) ((randflags & SHIFT_KT) ? LRAND() % mp->thiswidth : 0);
mp->kY = (int) ((randflags & SHIFT_KY) ? LRAND() % mp->thiswidth : 0);
/* set the gravity of the munch, or rather,
which direction we draw stuff in. */
mp->grav = randflags & GRAV;
}
/* Finally draw this munching square. */
munchBit(mi,
mp->thiswidth, /* Width, in pixels */
/* draw at this location */
mp->atX, mp->atY, mp->kX, mp->kT, mp->kY, mp->grav);
mp->t++;
if (mp->t == mp->thiswidth)
mp->t = 0;
}
void
release_munch(ModeInfo * mi)
{
if (munches != NULL) {
int screen;
for (screen = 0; screen < MI_NUM_SCREENS(mi); screen++) {
munchstruct *mp = &munches[screen];
if (mp->gc != None)
XFreeGC(MI_DISPLAY(mi), mp->gc);
}
free(munches);
munches = (munchstruct *) NULL;
}
}
#endif /* MODE_munch */
|
