1 /*
2 * Mesa 3-D graphics library
3 * Version: 6.5.2
4 *
5 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25
26 /*
27 * This program opens two GLX windows, renders into one and uses
28 * glCopyPixels to copy the image from the first window into the
29 * second by means of the GLX 1.3 function glxMakeContextCurrent().
30 * This function works just like the glXMakeCurrentReadSGI() function
31 * in the GLX_SGI_make_current_read extension.
32 */
33
34
35 #define GL_GLEXT_PROTOTYPES
36 #define GLX_GLXEXT_PROTOTYPES
37 #include <GL/gl.h>
38 #include <GL/glx.h>
39 #include <X11/keysym.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44
45
46 #ifdef GLX_VERSION_1_3
47
48
49 static Display *Dpy;
50 static int ScrNum;
51 static GLXContext Context;
52 static Window Win[2]; /* Win[0] = source, Win[1] = dest */
53 static GLint Width[2], Height[2];
54 static GLboolean TestClipping = GL_FALSE;
55 static GLfloat Angle = 0.0;
56
57 static GLboolean DrawFront = GL_FALSE;
58
59 PFNGLXMAKECURRENTREADSGIPROC make_context_current = NULL;
60
61 static Window
CreateWindow(Display * dpy,int scrnum,XVisualInfo * visinfo,int xpos,int ypos,int width,int height,const char * name)62 CreateWindow(Display *dpy, int scrnum, XVisualInfo *visinfo,
63 int xpos, int ypos, int width, int height,
64 const char *name)
65 {
66 Window win;
67 XSetWindowAttributes attr;
68 unsigned long mask;
69 Window root;
70
71 root = RootWindow(dpy, scrnum);
72
73 /* window attributes */
74 attr.background_pixel = 0;
75 attr.border_pixel = 0;
76 attr.colormap = XCreateColormap(dpy, root, visinfo->visual, AllocNone);
77 attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
78 mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
79
80 win = XCreateWindow(dpy, root, xpos, ypos, width, height,
81 0, visinfo->depth, InputOutput,
82 visinfo->visual, mask, &attr);
83 if (win) {
84 XSizeHints sizehints;
85 sizehints.x = xpos;
86 sizehints.y = ypos;
87 sizehints.width = width;
88 sizehints.height = height;
89 sizehints.flags = USSize | USPosition;
90 XSetNormalHints(dpy, win, &sizehints);
91 XSetStandardProperties(dpy, win, name, name,
92 None, (char **)NULL, 0, &sizehints);
93
94 XMapWindow(dpy, win);
95 }
96 return win;
97 }
98
99
100 static void
Redraw(void)101 Redraw(void)
102 {
103 /* make the first window the current one */
104 if (! (*make_context_current)(Dpy, Win[0], Win[0], Context)) {
105 printf("glXMakeContextCurrent failed in Redraw()\n");
106 return;
107 }
108
109 Angle += 1.0;
110
111 if (DrawFront) {
112 glDrawBuffer(GL_FRONT);
113 glReadBuffer(GL_FRONT);
114 }
115 else {
116 glDrawBuffer(GL_BACK);
117 glReadBuffer(GL_BACK);
118 }
119
120 glViewport(0, 0, Width[0], Height[0]);
121 glMatrixMode(GL_PROJECTION);
122 glLoadIdentity();
123 glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
124 glMatrixMode(GL_MODELVIEW);
125
126 glShadeModel(GL_FLAT);
127 glClearColor(0.5, 0.5, 0.5, 0.0);
128 glClear(GL_COLOR_BUFFER_BIT);
129
130 /* draw blue quad */
131 glColor3f(0.3, 0.3, 1.0);
132 glPushMatrix();
133 glRotatef(Angle, 0, 0, 1);
134 glBegin(GL_POLYGON);
135 glVertex2f(-0.5, -0.25);
136 glVertex2f( 0.5, -0.25);
137 glVertex2f( 0.5, 0.25);
138 glVertex2f(-0.5, 0.25);
139 glEnd();
140 glPopMatrix();
141
142 if (DrawFront)
143 glFinish();
144 else
145 glXSwapBuffers(Dpy, Win[0]);
146
147
148 /* copy image from window 0 to window 1 */
149 if (!(*make_context_current)(Dpy, Win[1], Win[0], Context)) {
150 printf("glXMakeContextCurrent failed in Redraw()\n");
151 return;
152 }
153
154 /* copy the image between windows */
155 glClearColor(0.0, 0.0, 0.0, 0.0);
156 glClear(GL_COLOR_BUFFER_BIT);
157
158 if (TestClipping) {
159 glWindowPos2iARB(-2, -2);
160 glCopyPixels(-2, -2, Width[0] + 4, Height[0] + 4, GL_COLOR);
161 }
162 else {
163 glWindowPos2iARB(0, 0);
164 glCopyPixels(0, 0, Width[0], Height[0], GL_COLOR);
165 }
166
167 if (DrawFront)
168 glFinish();
169 else
170 glXSwapBuffers(Dpy, Win[1]);
171 }
172
173
174
175 static void
Resize(Window win,unsigned int width,unsigned int height)176 Resize(Window win, unsigned int width, unsigned int height)
177 {
178 int i;
179 if (win == Win[0]) {
180 i = 0;
181 }
182 else {
183 i = 1;
184 }
185 Width[i] = width;
186 Height[i] = height;
187 if (!glXMakeCurrent(Dpy, Win[i], Context)) {
188 printf("glXMakeCurrent failed in Resize()\n");
189 return;
190 }
191 }
192
193
194
195 static void
EventLoop(void)196 EventLoop(void)
197 {
198 XEvent event;
199 while (1) {
200 if (XPending(Dpy) > 0) {
201 XNextEvent( Dpy, &event );
202 switch (event.type) {
203 case Expose:
204 Redraw();
205 break;
206 case ConfigureNotify:
207 Resize(event.xany.window, event.xconfigure.width, event.xconfigure.height);
208 break;
209 case KeyPress:
210 {
211 char buf[100];
212 KeySym keySym;
213 XComposeStatus stat;
214 XLookupString(&event.xkey, buf, sizeof(buf), &keySym, &stat);
215 if (keySym == XK_Escape) {
216 /* exit */
217 return;
218 }
219 else if (buf[0] == 'f') {
220 DrawFront = !DrawFront;
221 printf("Drawing to %s buffer\n",
222 DrawFront ? "GL_FRONT" : "GL_BACK");
223 }
224 }
225 break;
226 default:
227 /*no-op*/ ;
228 }
229 }
230 else {
231 /* animate */
232 Redraw();
233 }
234 }
235 }
236
237
238 static void
Init(void)239 Init(void)
240 {
241 XVisualInfo *visinfo;
242 int attrib[] = { GLX_RGBA,
243 GLX_RED_SIZE, 1,
244 GLX_GREEN_SIZE, 1,
245 GLX_BLUE_SIZE, 1,
246 GLX_DOUBLEBUFFER,
247 None };
248 int major, minor;
249
250 Dpy = XOpenDisplay(NULL);
251 if (!Dpy) {
252 printf("Couldn't open default display!\n");
253 exit(1);
254 }
255
256 ScrNum = DefaultScreen(Dpy);
257
258 glXQueryVersion(Dpy, &major, &minor);
259
260 if (major * 100 + minor >= 103) {
261 make_context_current = (PFNGLXMAKECURRENTREADSGIPROC)
262 glXGetProcAddressARB( (GLubyte *) "glXMakeContextCurrent" );
263 }
264 else {
265 const char * const glxExtensions = glXQueryExtensionsString(Dpy, ScrNum);
266 const char * ext = strstr( glxExtensions, "GLX_SGI_make_current_read" );
267 const size_t len = strlen( "GLX_SGI_make_current_read" );
268
269 if ( (ext != NULL)
270 && ((ext[len] == ' ') || (ext[len] == '\0')) ) {
271 make_context_current = (PFNGLXMAKECURRENTREADSGIPROC)
272 glXGetProcAddressARB( (GLubyte *) "glXMakeCurrentReadSGI" );
273 }
274 }
275
276 if (make_context_current == NULL) {
277 fprintf(stderr, "Sorry, this program requires either GLX 1.3 "
278 "or GLX_SGI_make_current_read.\n");
279 exit(1);
280 }
281
282 visinfo = glXChooseVisual(Dpy, ScrNum, attrib);
283 if (!visinfo) {
284 printf("Unable to find RGB, double-buffered visual\n");
285 exit(1);
286 }
287
288 Context = glXCreateContext(Dpy, visinfo, NULL, True);
289 if (!Context) {
290 printf("Couldn't create GLX context\n");
291 exit(1);
292 }
293
294
295 Win[0] = CreateWindow(Dpy, ScrNum, visinfo,
296 0, 0, 300, 300, "source window");
297
298 Win[1] = CreateWindow(Dpy, ScrNum, visinfo,
299 350, 0, 300, 300, "dest window");
300
301 printf("Press Esc to exit\n");
302 printf("Press 'f' to toggle front/back buffer drawing\n");
303 }
304
305
306 int
main(int argc,char * argv[])307 main(int argc, char *argv[])
308 {
309 if (argc > 1 && strcmp(argv[1], "-clip") == 0)
310 TestClipping = GL_TRUE;
311 Init();
312 EventLoop();
313 return 0;
314 }
315
316
317 #else
318
319
320 int
main(int argc,char * argv[])321 main(int argc, char *argv[])
322 {
323 printf("This program requires GLX 1.3!\n");
324 return 0;
325 }
326
327
328 #endif /* GLX_VERSION_1_3 */
329