1 /*
2 Simple DirectMedia Layer
3 Copyright (C) 1997-2020 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(Display * dpy)43 static SDL_bool have_mitshm(Display *dpy)
44 {
45 /* Only use shared memory on local X servers */
46 return X11_XShmQueryExtension(dpy) ? SDL_X11_HAVE_SHM : SDL_FALSE;
47 }
48
49 #endif /* !NO_SHARED_MEMORY */
50
51 int
X11_CreateWindowFramebuffer(_THIS,SDL_Window * window,Uint32 * format,void ** pixels,int * pitch)52 X11_CreateWindowFramebuffer(_THIS, SDL_Window * window, Uint32 * format,
53 void ** pixels, int *pitch)
54 {
55 SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
56 Display *display = data->videodata->display;
57 XGCValues gcv;
58 XVisualInfo vinfo;
59
60 /* Free the old framebuffer surface */
61 X11_DestroyWindowFramebuffer(_this, window);
62
63 /* Create the graphics context for drawing */
64 gcv.graphics_exposures = False;
65 data->gc = X11_XCreateGC(display, data->xwindow, GCGraphicsExposures, &gcv);
66 if (!data->gc) {
67 return SDL_SetError("Couldn't create graphics context");
68 }
69
70 /* Find out the pixel format and depth */
71 if (X11_GetVisualInfoFromVisual(display, data->visual, &vinfo) < 0) {
72 return SDL_SetError("Couldn't get window visual information");
73 }
74
75 *format = X11_GetPixelFormatFromVisualInfo(display, &vinfo);
76 if (*format == SDL_PIXELFORMAT_UNKNOWN) {
77 return SDL_SetError("Unknown window pixel format");
78 }
79
80 /* Calculate pitch */
81 *pitch = (((window->w * SDL_BYTESPERPIXEL(*format)) + 3) & ~3);
82
83 /* Create the actual image */
84 #ifndef NO_SHARED_MEMORY
85 if (have_mitshm(display)) {
86 XShmSegmentInfo *shminfo = &data->shminfo;
87
88 shminfo->shmid = shmget(IPC_PRIVATE, window->h*(*pitch), IPC_CREAT | 0777);
89 if ( shminfo->shmid >= 0 ) {
90 shminfo->shmaddr = (char *)shmat(shminfo->shmid, 0, 0);
91 shminfo->readOnly = False;
92 if ( shminfo->shmaddr != (char *)-1 ) {
93 shm_error = False;
94 X_handler = X11_XSetErrorHandler(shm_errhandler);
95 X11_XShmAttach(display, shminfo);
96 X11_XSync(display, False);
97 X11_XSetErrorHandler(X_handler);
98 if ( shm_error )
99 shmdt(shminfo->shmaddr);
100 } else {
101 shm_error = True;
102 }
103 shmctl(shminfo->shmid, IPC_RMID, NULL);
104 } else {
105 shm_error = True;
106 }
107 if (!shm_error) {
108 data->ximage = X11_XShmCreateImage(display, data->visual,
109 vinfo.depth, ZPixmap,
110 shminfo->shmaddr, shminfo,
111 window->w, window->h);
112 if (!data->ximage) {
113 X11_XShmDetach(display, shminfo);
114 X11_XSync(display, False);
115 shmdt(shminfo->shmaddr);
116 } else {
117 /* Done! */
118 data->use_mitshm = SDL_TRUE;
119 *pixels = shminfo->shmaddr;
120 return 0;
121 }
122 }
123 }
124 #endif /* not NO_SHARED_MEMORY */
125
126 *pixels = SDL_malloc(window->h*(*pitch));
127 if (*pixels == NULL) {
128 return SDL_OutOfMemory();
129 }
130
131 data->ximage = X11_XCreateImage(display, data->visual,
132 vinfo.depth, ZPixmap, 0, (char *)(*pixels),
133 window->w, window->h, 32, 0);
134 if (!data->ximage) {
135 SDL_free(*pixels);
136 return SDL_SetError("Couldn't create XImage");
137 }
138 return 0;
139 }
140
141 int
X11_UpdateWindowFramebuffer(_THIS,SDL_Window * window,const SDL_Rect * rects,int numrects)142 X11_UpdateWindowFramebuffer(_THIS, SDL_Window * window, const SDL_Rect * rects,
143 int numrects)
144 {
145 SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
146 Display *display = data->videodata->display;
147 int i;
148 int x, y, w ,h;
149 #ifndef NO_SHARED_MEMORY
150 if (data->use_mitshm) {
151 for (i = 0; i < numrects; ++i) {
152 x = rects[i].x;
153 y = rects[i].y;
154 w = rects[i].w;
155 h = rects[i].h;
156
157 if (w <= 0 || h <= 0 || (x + w) <= 0 || (y + h) <= 0) {
158 /* Clipped? */
159 continue;
160 }
161 if (x < 0)
162 {
163 x += w;
164 w += rects[i].x;
165 }
166 if (y < 0)
167 {
168 y += h;
169 h += rects[i].y;
170 }
171 if (x + w > window->w)
172 w = window->w - x;
173 if (y + h > window->h)
174 h = window->h - y;
175
176 X11_XShmPutImage(display, data->xwindow, data->gc, data->ximage,
177 x, y, x, y, w, h, False);
178 }
179 }
180 else
181 #endif /* !NO_SHARED_MEMORY */
182 {
183 for (i = 0; i < numrects; ++i) {
184 x = rects[i].x;
185 y = rects[i].y;
186 w = rects[i].w;
187 h = rects[i].h;
188
189 if (w <= 0 || h <= 0 || (x + w) <= 0 || (y + h) <= 0) {
190 /* Clipped? */
191 continue;
192 }
193 if (x < 0)
194 {
195 x += w;
196 w += rects[i].x;
197 }
198 if (y < 0)
199 {
200 y += h;
201 h += rects[i].y;
202 }
203 if (x + w > window->w)
204 w = window->w - x;
205 if (y + h > window->h)
206 h = window->h - y;
207
208 X11_XPutImage(display, data->xwindow, data->gc, data->ximage,
209 x, y, x, y, w, h);
210 }
211 }
212
213 X11_XSync(display, False);
214
215 return 0;
216 }
217
218 void
X11_DestroyWindowFramebuffer(_THIS,SDL_Window * window)219 X11_DestroyWindowFramebuffer(_THIS, SDL_Window * window)
220 {
221 SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
222 Display *display;
223
224 if (!data) {
225 /* The window wasn't fully initialized */
226 return;
227 }
228
229 display = data->videodata->display;
230
231 if (data->ximage) {
232 XDestroyImage(data->ximage);
233
234 #ifndef NO_SHARED_MEMORY
235 if (data->use_mitshm) {
236 X11_XShmDetach(display, &data->shminfo);
237 X11_XSync(display, False);
238 shmdt(data->shminfo.shmaddr);
239 data->use_mitshm = SDL_FALSE;
240 }
241 #endif /* !NO_SHARED_MEMORY */
242
243 data->ximage = NULL;
244 }
245 if (data->gc) {
246 X11_XFreeGC(display, data->gc);
247 data->gc = NULL;
248 }
249 }
250
251 #endif /* SDL_VIDEO_DRIVER_X11 */
252
253 /* vi: set ts=4 sw=4 expandtab: */
254