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
|
/* $Id: glxpixmap.c,v 1.2 2000/07/11 16:05:29 brianp Exp $ */
/*
* A demonstration of using the GLXPixmap functions. This program is in
* the public domain.
*
* Brian Paul
*/
#include <GL/gl.h>
#include <GL/glx.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static GLXContext ctx;
static XVisualInfo *visinfo;
static GC gc;
static Window make_rgb_window( Display *dpy,
unsigned int width, unsigned int height )
{
const int sbAttrib[] = { GLX_RGBA,
GLX_RED_SIZE, 1,
GLX_GREEN_SIZE, 1,
GLX_BLUE_SIZE, 1,
None };
const int dbAttrib[] = { GLX_RGBA,
GLX_RED_SIZE, 1,
GLX_GREEN_SIZE, 1,
GLX_BLUE_SIZE, 1,
GLX_DOUBLEBUFFER,
None };
int scrnum;
XSetWindowAttributes attr;
unsigned long mask;
Window root;
Window win;
scrnum = DefaultScreen( dpy );
root = RootWindow( dpy, scrnum );
visinfo = glXChooseVisual( dpy, scrnum, (int *) sbAttrib );
if (!visinfo) {
visinfo = glXChooseVisual( dpy, scrnum, (int *) dbAttrib );
if (!visinfo) {
printf("Error: couldn't get an RGB visual\n");
exit(1);
}
}
/* window attributes */
attr.background_pixel = 0;
attr.border_pixel = 0;
/* TODO: share root colormap if possible */
attr.colormap = XCreateColormap( dpy, root, visinfo->visual, AllocNone);
attr.event_mask = StructureNotifyMask | ExposureMask;
mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
win = XCreateWindow( dpy, root, 0, 0, width, height,
0, visinfo->depth, InputOutput,
visinfo->visual, mask, &attr );
/* make an X GC so we can do XCopyArea later */
gc = XCreateGC( dpy, win, 0, NULL );
/* need indirect context */
ctx = glXCreateContext( dpy, visinfo, NULL, False );
if (!ctx) {
printf("Error: glXCreateContext failed\n");
exit(-1);
}
printf("Direct rendering: %s\n", glXIsDirect(dpy, ctx) ? "Yes" : "No");
return win;
}
static GLXPixmap make_pixmap( Display *dpy, Window win,
unsigned int width, unsigned int height,
Pixmap *pixmap)
{
Pixmap pm;
GLXPixmap glxpm;
XWindowAttributes attr;
pm = XCreatePixmap( dpy, win, width, height, visinfo->depth );
if (!pm) {
printf("Error: XCreatePixmap failed\n");
exit(-1);
}
XGetWindowAttributes( dpy, win, &attr );
/*
* IMPORTANT:
* Use the glXCreateGLXPixmapMESA funtion when using Mesa because
* Mesa needs to know the colormap associated with a pixmap in order
* to render correctly. This is because Mesa allows RGB rendering
* into any kind of visual, not just TrueColor or DirectColor.
*/
#ifdef GLX_MESA_pixmap_colormap
if (strstr(glXQueryExtensionsString(dpy, 0), "GLX_MESA_pixmap_colormap")) {
/* stand-alone Mesa, specify the colormap */
glxpm = glXCreateGLXPixmapMESA( dpy, visinfo, pm, attr.colormap );
}
else {
glxpm = glXCreateGLXPixmap( dpy, visinfo, pm );
}
#else
/* This will work with Mesa too if the visual is TrueColor or DirectColor */
glxpm = glXCreateGLXPixmap( dpy, visinfo, pm );
#endif
if (!glxpm) {
printf("Error: GLXCreateGLXPixmap failed\n");
exit(-1);
}
*pixmap = pm;
return glxpm;
}
static void event_loop( Display *dpy, GLXPixmap pm )
{
XEvent event;
while (1) {
XNextEvent( dpy, &event );
switch (event.type) {
case Expose:
printf("Redraw\n");
/* copy the image from GLXPixmap to window */
XCopyArea( dpy, pm, event.xany.window, /* src, dest */
gc, 0, 0, 300, 300, /* gc, src pos, size */
0, 0 ); /* dest pos */
break;
case ConfigureNotify:
/* nothing */
break;
}
}
}
int main( int argc, char *argv[] )
{
Display *dpy;
Window win;
Pixmap pm;
GLXPixmap glxpm;
dpy = XOpenDisplay(NULL);
win = make_rgb_window( dpy, 300, 300 );
glxpm = make_pixmap( dpy, win, 300, 300, &pm );
glXMakeCurrent( dpy, glxpm, ctx );
printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
/* Render an image into the pixmap */
glShadeModel( GL_FLAT );
glClearColor( 0.5, 0.5, 0.5, 1.0 );
glClear( GL_COLOR_BUFFER_BIT );
glViewport( 0, 0, 300, 300 );
glOrtho( -1.0, 1.0, -1.0, 1.0, -1.0, 1.0 );
glColor3f( 0.0, 1.0, 1.0 );
glRectf( -0.75, -0.75, 0.75, 0.75 );
glFlush();
XMapWindow( dpy, win );
event_loop( dpy, pm );
return 0;
}
|
