1 /*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>
4
5 This software is provided 'as-is', without any express or implied
6 warranty. In no event will the authors be held liable for any damages
7 arising from the use of this software.
8
9 Permission is granted to anyone to use this software for any purpose,
10 including commercial applications, and to alter it and redistribute it
11 freely, subject to the following restrictions:
12
13 1. The origin of this software must not be misrepresented; you must not
14 claim that you wrote the original software. If you use this software
15 in a product, an acknowledgment in the product documentation would be
16 appreciated but is not required.
17 2. Altered source versions must be plainly marked as such, and must not be
18 misrepresented as being the original software.
19 3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../../SDL_internal.h"
22
23 #if SDL_VIDEO_DRIVER_X11
24
25 #include "SDL_x11video.h"
26 #include "SDL_x11framebuffer.h"
27
28
29 #ifndef NO_SHARED_MEMORY
30
31 /* Shared memory error handler routine */
32 static int shm_error;
33 static int (*X_handler)(Display *, XErrorEvent *) = NULL;
shm_errhandler(Display * d,XErrorEvent * e)34 static int shm_errhandler(Display *d, XErrorEvent *e)
35 {
36 if ( e->error_code == BadAccess ) {
37 shm_error = True;
38 return(0);
39 } else
40 return(X_handler(d,e));
41 }
42
have_mitshm(void)43 static SDL_bool have_mitshm(void)
44 {
45 /* Only use shared memory on local X servers */
46 if ( (SDL_strncmp(X11_XDisplayName(NULL), ":", 1) == 0) ||
47 (SDL_strncmp(X11_XDisplayName(NULL), "unix:", 5) == 0) ) {
48 return SDL_X11_HAVE_SHM;
49 }
50 return SDL_FALSE;
51 }
52
53 #endif /* !NO_SHARED_MEMORY */
54
55 int
X11_CreateWindowFramebuffer(_THIS,SDL_Window * window,Uint32 * format,void ** pixels,int * pitch)56 X11_CreateWindowFramebuffer(_THIS, SDL_Window * window, Uint32 * format,
57 void ** pixels, int *pitch)
58 {
59 SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
60 Display *display = data->videodata->display;
61 XGCValues gcv;
62 XVisualInfo vinfo;
63
64 /* Free the old framebuffer surface */
65 X11_DestroyWindowFramebuffer(_this, window);
66
67 /* Create the graphics context for drawing */
68 gcv.graphics_exposures = False;
69 data->gc = X11_XCreateGC(display, data->xwindow, GCGraphicsExposures, &gcv);
70 if (!data->gc) {
71 return SDL_SetError("Couldn't create graphics context");
72 }
73
74 /* Find out the pixel format and depth */
75 if (X11_GetVisualInfoFromVisual(display, data->visual, &vinfo) < 0) {
76 return SDL_SetError("Couldn't get window visual information");
77 }
78
79 *format = X11_GetPixelFormatFromVisualInfo(display, &vinfo);
80 if (*format == SDL_PIXELFORMAT_UNKNOWN) {
81 return SDL_SetError("Unknown window pixel format");
82 }
83
84 /* Calculate pitch */
85 *pitch = (((window->w * SDL_BYTESPERPIXEL(*format)) + 3) & ~3);
86
87 /* Create the actual image */
88 #ifndef NO_SHARED_MEMORY
89 if (have_mitshm()) {
90 XShmSegmentInfo *shminfo = &data->shminfo;
91
92 shminfo->shmid = shmget(IPC_PRIVATE, window->h*(*pitch), IPC_CREAT | 0777);
93 if ( shminfo->shmid >= 0 ) {
94 shminfo->shmaddr = (char *)shmat(shminfo->shmid, 0, 0);
95 shminfo->readOnly = False;
96 if ( shminfo->shmaddr != (char *)-1 ) {
97 shm_error = False;
98 X_handler = X11_XSetErrorHandler(shm_errhandler);
99 X11_XShmAttach(display, shminfo);
100 X11_XSync(display, True);
101 X11_XSetErrorHandler(X_handler);
102 if ( shm_error )
103 shmdt(shminfo->shmaddr);
104 } else {
105 shm_error = True;
106 }
107 shmctl(shminfo->shmid, IPC_RMID, NULL);
108 } else {
109 shm_error = True;
110 }
111 if (!shm_error) {
112 data->ximage = X11_XShmCreateImage(display, data->visual,
113 vinfo.depth, ZPixmap,
114 shminfo->shmaddr, shminfo,
115 window->w, window->h);
116 if (!data->ximage) {
117 X11_XShmDetach(display, shminfo);
118 X11_XSync(display, False);
119 shmdt(shminfo->shmaddr);
120 } else {
121 /* Done! */
122 data->use_mitshm = SDL_TRUE;
123 *pixels = shminfo->shmaddr;
124 return 0;
125 }
126 }
127 }
128 #endif /* not NO_SHARED_MEMORY */
129
130 *pixels = SDL_malloc(window->h*(*pitch));
131 if (*pixels == NULL) {
132 return SDL_OutOfMemory();
133 }
134
135 data->ximage = X11_XCreateImage(display, data->visual,
136 vinfo.depth, ZPixmap, 0, (char *)(*pixels),
137 window->w, window->h, 32, 0);
138 if (!data->ximage) {
139 SDL_free(*pixels);
140 return SDL_SetError("Couldn't create XImage");
141 }
142 return 0;
143 }
144
145 int
X11_UpdateWindowFramebuffer(_THIS,SDL_Window * window,const SDL_Rect * rects,int numrects)146 X11_UpdateWindowFramebuffer(_THIS, SDL_Window * window, const SDL_Rect * rects,
147 int numrects)
148 {
149 SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
150 Display *display = data->videodata->display;
151 int i;
152 int x, y, w ,h;
153 #ifndef NO_SHARED_MEMORY
154 if (data->use_mitshm) {
155 for (i = 0; i < numrects; ++i) {
156 x = rects[i].x;
157 y = rects[i].y;
158 w = rects[i].w;
159 h = rects[i].h;
160
161 if (w <= 0 || h <= 0 || (x + w) <= 0 || (y + h) <= 0) {
162 /* Clipped? */
163 continue;
164 }
165 if (x < 0)
166 {
167 x += w;
168 w += rects[i].x;
169 }
170 if (y < 0)
171 {
172 y += h;
173 h += rects[i].y;
174 }
175 if (x + w > window->w)
176 w = window->w - x;
177 if (y + h > window->h)
178 h = window->h - y;
179
180 X11_XShmPutImage(display, data->xwindow, data->gc, data->ximage,
181 x, y, x, y, w, h, False);
182 }
183 }
184 else
185 #endif /* !NO_SHARED_MEMORY */
186 {
187 for (i = 0; i < numrects; ++i) {
188 x = rects[i].x;
189 y = rects[i].y;
190 w = rects[i].w;
191 h = rects[i].h;
192
193 if (w <= 0 || h <= 0 || (x + w) <= 0 || (y + h) <= 0) {
194 /* Clipped? */
195 continue;
196 }
197 if (x < 0)
198 {
199 x += w;
200 w += rects[i].x;
201 }
202 if (y < 0)
203 {
204 y += h;
205 h += rects[i].y;
206 }
207 if (x + w > window->w)
208 w = window->w - x;
209 if (y + h > window->h)
210 h = window->h - y;
211
212 X11_XPutImage(display, data->xwindow, data->gc, data->ximage,
213 x, y, x, y, w, h);
214 }
215 }
216
217 X11_XSync(display, False);
218
219 return 0;
220 }
221
222 void
X11_DestroyWindowFramebuffer(_THIS,SDL_Window * window)223 X11_DestroyWindowFramebuffer(_THIS, SDL_Window * window)
224 {
225 SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
226 Display *display;
227
228 if (!data) {
229 /* The window wasn't fully initialized */
230 return;
231 }
232
233 display = data->videodata->display;
234
235 if (data->ximage) {
236 XDestroyImage(data->ximage);
237
238 #ifndef NO_SHARED_MEMORY
239 if (data->use_mitshm) {
240 X11_XShmDetach(display, &data->shminfo);
241 X11_XSync(display, False);
242 shmdt(data->shminfo.shmaddr);
243 data->use_mitshm = SDL_FALSE;
244 }
245 #endif /* !NO_SHARED_MEMORY */
246
247 data->ximage = NULL;
248 }
249 if (data->gc) {
250 X11_XFreeGC(display, data->gc);
251 data->gc = NULL;
252 }
253 }
254
255 #endif /* SDL_VIDEO_DRIVER_X11 */
256
257 /* vi: set ts=4 sw=4 expandtab: */
258