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
|
/* XCB application drawing an updating bitmap in a window
*
* Inspired by the xcb black rectangle in a window example
*
* Copyright 2010 V. R. Sanders, released under the MIT licence
*/
/* compile with:
* gcc -Wall -lxcb-icccm -lxcb -lxcb-image -o disp disp.c
*/
#include <string.h>
#include <xcb/xcb.h>
#include <xcb/xcb_image.h>
#include <xcb/xcb_atom.h>
#include <xcb/xcb_icccm.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
static xcb_format_t *
find_format (xcb_connection_t * c, uint8_t depth, uint8_t bpp)
{
const xcb_setup_t *setup = xcb_get_setup(c);
xcb_format_t *fmt = xcb_setup_pixmap_formats(setup);
xcb_format_t *fmtend = fmt + xcb_setup_pixmap_formats_length(setup);
for(; fmt != fmtend; ++fmt)
if((fmt->depth == depth) && (fmt->bits_per_pixel == bpp)) {
/* printf("fmt %p has pad %d depth %d, bpp %d\n",
fmt,fmt->scanline_pad, depth,bpp); */
return fmt;
}
return 0;
}
void
fillimage(unsigned char *p, int width, int height)
{
int i, j;
for(j=0; j < height; j++)
{
for(i=0; i < width; i++)
{
if((i < 256)&&(j < 256))
{
*p++=rand()%256; // blue
*p++=rand()%256; // green
*p++=rand()%256; // red
} else {
*p++=i%256; // blue
*p++=j%256; // green
if(i < 256)
*p++=i%256; // red
else if(j < 256)
*p++=j%256; // red
else
*p++=(256-j)%256; // red
}
p++; /* unused byte */
}
}
}
xcb_image_t *
CreateTrueColorImage(xcb_connection_t *c,
int width,
int height)
{
const xcb_setup_t *setup = xcb_get_setup(c);
unsigned char *image32=(unsigned char *)malloc(width*height*4);
xcb_format_t *fmt = find_format(c, 24, 32);
if (fmt == NULL)
return NULL;
fillimage(image32, width, height);
return xcb_image_create(width,
height,
XCB_IMAGE_FORMAT_Z_PIXMAP,
fmt->scanline_pad,
fmt->depth,
fmt->bits_per_pixel,
0,
setup->image_byte_order,
XCB_IMAGE_ORDER_LSB_FIRST,
image32,
width*height*4,
image32);
}
int
main (int argc, char **argv)
{
xcb_connection_t *c;
xcb_screen_t *s;
xcb_window_t w;
xcb_pixmap_t pmap;
xcb_gcontext_t gc;
xcb_generic_event_t *e;
uint32_t mask;
uint32_t values[2];
int done=0;
xcb_image_t *image;
uint8_t *image32;
xcb_expose_event_t *ee;
char *title="Hello World!";
xcb_size_hints_t *hints;
/* open connection with the server */
c = xcb_connect (NULL, NULL);
if (!c) {
printf ("Cannot open display\n");
exit (1);
}
s = xcb_setup_roots_iterator (xcb_get_setup (c)).data;
/* printf("root depth %d\n",s->root_depth); */
/* create image */
image = CreateTrueColorImage(c, 640, 480);
if (image == NULL) {
printf ("Cannot create iamge\n");
xcb_disconnect(c);
return 1;
}
image32 = image->data;
/* create window */
mask = XCB_CW_BACK_PIXEL | XCB_CW_EVENT_MASK;
values[0] = s->white_pixel;
values[1] = XCB_EVENT_MASK_EXPOSURE |
XCB_EVENT_MASK_KEY_PRESS |
XCB_EVENT_MASK_BUTTON_PRESS;
w = xcb_generate_id (c);
xcb_create_window (c, XCB_COPY_FROM_PARENT, w, s->root,
10, 10, image->width, image->height, 1,
XCB_WINDOW_CLASS_INPUT_OUTPUT,
s->root_visual,
mask, values);
/*[> set size hits on window <]*/
/*hints = xcb_alloc_size_hints();*/
/*xcb_size_hints_set_max_size(hints, image->width,image->height);*/
/*xcb_size_hints_set_min_size(hints, image->width,image->height);*/
/*xcb_set_wm_size_hints(c, w, WM_NORMAL_HINTS, hints);*/
/* create backing pixmap */
pmap = xcb_generate_id(c);
xcb_create_pixmap(c, 24, pmap, w, image->width, image->height);
/* create pixmap plot gc */
mask = XCB_GC_FOREGROUND | XCB_GC_BACKGROUND;
values[0] = s->black_pixel;
values[1] = 0xffffff;
gc = xcb_generate_id (c);
xcb_create_gc (c, gc, pmap, mask, values);
/* put the image into the pixmap */
xcb_image_put(c, pmap, gc, image, 0, 0, 0);
/* show the window */
xcb_map_window (c, w);
xcb_flush (c);
/* event loop */
while (!done && (e = xcb_wait_for_event (c))) {
switch (e->response_type) {
case XCB_EXPOSE:
ee=(xcb_expose_event_t *)e;
/* printf ("expose %d,%d - %d,%d\n",
ee->x,ee->y,ee->width,ee->height); */
xcb_copy_area(c, pmap, w, gc,
ee->x,
ee->y,
ee->x,
ee->y,
ee->width,
ee->height);
xcb_flush (c);
image32+=16;
break;
/*case XCB_KEY_PRESS:*/
/*[> exit on keypress <]*/
/*done = 1;*/
/*break;*/
case XCB_BUTTON_PRESS:
fillimage(image->data, image->width, image->height);
memset(image->data, 0, image32 - image->data);
xcb_image_put(c, pmap, gc, image, 0, 0, 0);
xcb_copy_area(c, pmap, w, gc, 0,0,0,0,image->width,image->height);
xcb_flush (c);
break;
}
free (e);
}
/* free pixmap */
xcb_free_pixmap(c, pmap);
/* close connection to server */
xcb_disconnect (c);
return 0;
}
|
