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
|
/************************************************************************
*
* Purpose: Program to randomly change the root window colour on X Displays.
*
* Description.
* The program randomly selects a target colour and then
* performs a basic interpolation to move from the current
* colour to the target colour. When the target has been
* reached, a new target is selected and the process is
* repeated.
*
* Notes: 1) No attempt is made to see if the client supports colour.
* 2) Other applications may cause problems if they have allocated
* all the available colour cells in the colour map.
* 3) Use the following command to compile.
*
* gcc root_col.c -lX11
* 4) Tested on Linux running XFree386 and FVWM
* and SunOS 4.1.3 running X11R5 and Motif.
*
* Author: M.J. Leslie
*
* Date: 26-Mar-95
*
************************************************************************/
/****************** Includes ********************************************/
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xos.h>
#include <stdio.h>
#include <stdlib.h>
/************************************************************************/
#define INC 512 /* Increments between colours. */
#define MAX_COL 65536 /* Max number of colours. */
#define SECONDS 2 /* # of seconds between updates */
/****************** Functions *******************************************/
void help(char * proganme); /* Give some help on syntax. */
/* Used to see if a colour gun has
* reached its required intensity
*/
int reached_target( unsigned short colour, unsigned short target_colour);
void root_colour(int seconds); /* Where the real work starts. */
/* Change the colour of the
* root window */
void change_colour(Display * display,
Window root,
Colormap colormap,
XColor colour);
/************************************************************************/
main(int argc, char * argv[])
{
int seconds=SECONDS;
/* Have we got cmd line parms? */
if (argc > 1 )
{
/* Yes. Is Help Required? */
if ( !strcmp(argv[1], "-h"))
{
help(argv[0]); /* Yes. */
exit(0);
}
/* Do we have an integer. */
if (!sscanf(argv[1], "%u", &seconds))
{
help(argv[0]); /* No. */
exit(0);
}
}
root_colour(seconds); /* Start colouring the
* root window.
* 'seconds' is the # of seconds
* between updates. */
}
/************************************************************************/
void root_colour(int seconds)
{
Display * display;
int screen;
char * display_name=NULL;
Window root;
Colormap colormap;
XColor colour, target_colour;
/****************************************
*
* Initalise the X environment.
*
****************************************/
/* Connect to X display server. */
display=XOpenDisplay(display_name);
/* Get screen ID */
screen=DefaultScreen(display);
root=RootWindow(display, screen);
/* Load the default colour map */
colormap = DefaultColormap(display, screen);
/* Starting colour - Grey */
colour.red=MAX_COL/2; colour.green=MAX_COL/2; colour.blue=MAX_COL/2;
colour.flags = DoRed|DoGreen|DoBlue;
/****************************************
*
* Loop forever.
*
****************************************/
while(1)
{
/* Increments used to go from the current
* colour to the target colour. */
int red_inc, green_inc, blue_inc;
/* Flags used to show when the target
* colour has been reached.
*
* 0 = Arrived at the target colour.
* 1 = Not arrived at the target colour.
* */
int red=1, green=1, blue=1;
/* Random selection of a new target
* colour */
target_colour.red=rand()%MAX_COL;
target_colour.green=rand()%MAX_COL;
target_colour.blue=rand()%MAX_COL;
/* Calculate the direction to go in
* to reach the new target colour. */
red_inc = ( target_colour.red > colour.red ) ? INC : INC * -1;
green_inc = ( target_colour.green > colour.green) ? INC : INC * -1;
blue_inc = ( target_colour.blue > colour.blue ) ? INC : INC * -1;
/* Loop until all three colours have
* reached their required value. */
while(red || green || blue)
{
/* Change the colour of the root window */
change_colour(display, root, colormap, colour);
/* Increment onto the next colour. */
if ( red=reached_target(colour.red, target_colour.red))
colour.red += red_inc;
if (green=reached_target(colour.green, target_colour.green))
colour.green += green_inc;
if ( blue=reached_target(colour.blue, target_colour.blue))
colour.blue += blue_inc;
sleep(seconds); /* Pause...... */
}
}
XCloseDisplay(display);
}
/************************************************************************/
int reached_target( unsigned short colour, unsigned short target_colour)
{
return (( colour >= target_colour-INC && colour <= target_colour+INC) ?0:1);
}
/************************************************************************/
void change_colour(Display * display,
Window root,
Colormap colormap,
XColor colour)
{
/* Reserve a cell in the colour map */
XAllocColorCells(display, colormap, False, NULL, 0, &colour.pixel, 1);
/* Place the required colour in the map.*/
XStoreColor(display, colormap, &colour);
/* Free the cell so it can be reused. */
XFreeColors(display, colormap, &colour.pixel, 1, 0);
/* Set the root window colour. */
XSetWindowBackground(display, root, colour.pixel);
/* Refresh the root window (with the new
* colour). */
XClearWindow(display, root);
}
/************************************************************************/
void help(char * progname)
{
printf("\n%s information\n\n", progname);
puts(" This program randomly changes the color of the screen background.");
puts("\n Syntax:\n");
printf("\t%s \tRun the program with with a default update time\n", progname);
printf("\t\t \tof %d seconds.\n", SECONDS);
printf("\t%s 3\tRun the program specifing the delay between updates.\n", progname);
printf("\t%s -h\tHelp. you are reading it.\n\n", progname);
}
|
