ref: dc0f242f251e59fd2bebf2a1c4dd7a8dc2677f5d
dir: /external/SDL2/src/video/x11/SDL_x11framebuffer.c/
/*
Simple DirectMedia Layer
Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
#include "../../SDL_internal.h"
#if SDL_VIDEO_DRIVER_X11
#include "SDL_x11video.h"
#include "SDL_x11framebuffer.h"
#ifndef NO_SHARED_MEMORY
/* Shared memory error handler routine */
static int shm_error;
static int (*X_handler)(Display *, XErrorEvent *) = NULL;
static int shm_errhandler(Display *d, XErrorEvent *e)
{
if ( e->error_code == BadAccess ) {
shm_error = True;
return(0);
} else
return(X_handler(d,e));
}
static SDL_bool have_mitshm(void)
{
/* Only use shared memory on local X servers */
if ( (SDL_strncmp(X11_XDisplayName(NULL), ":", 1) == 0) ||
(SDL_strncmp(X11_XDisplayName(NULL), "unix:", 5) == 0) ) {
return SDL_X11_HAVE_SHM;
}
return SDL_FALSE;
}
#endif /* !NO_SHARED_MEMORY */
int
X11_CreateWindowFramebuffer(_THIS, SDL_Window * window, Uint32 * format,
void ** pixels, int *pitch)
{
SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
Display *display = data->videodata->display;
XGCValues gcv;
XVisualInfo vinfo;
/* Free the old framebuffer surface */
X11_DestroyWindowFramebuffer(_this, window);
/* Create the graphics context for drawing */
gcv.graphics_exposures = False;
data->gc = X11_XCreateGC(display, data->xwindow, GCGraphicsExposures, &gcv);
if (!data->gc) {
return SDL_SetError("Couldn't create graphics context");
}
/* Find out the pixel format and depth */
if (X11_GetVisualInfoFromVisual(display, data->visual, &vinfo) < 0) {
return SDL_SetError("Couldn't get window visual information");
}
*format = X11_GetPixelFormatFromVisualInfo(display, &vinfo);
if (*format == SDL_PIXELFORMAT_UNKNOWN) {
return SDL_SetError("Unknown window pixel format");
}
/* Calculate pitch */
*pitch = (((window->w * SDL_BYTESPERPIXEL(*format)) + 3) & ~3);
/* Create the actual image */
#ifndef NO_SHARED_MEMORY
if (have_mitshm()) {
XShmSegmentInfo *shminfo = &data->shminfo;
shminfo->shmid = shmget(IPC_PRIVATE, window->h*(*pitch), IPC_CREAT | 0777);
if ( shminfo->shmid >= 0 ) {
shminfo->shmaddr = (char *)shmat(shminfo->shmid, 0, 0);
shminfo->readOnly = False;
if ( shminfo->shmaddr != (char *)-1 ) {
shm_error = False;
X_handler = X11_XSetErrorHandler(shm_errhandler);
X11_XShmAttach(display, shminfo);
X11_XSync(display, False);
X11_XSetErrorHandler(X_handler);
if ( shm_error )
shmdt(shminfo->shmaddr);
} else {
shm_error = True;
}
shmctl(shminfo->shmid, IPC_RMID, NULL);
} else {
shm_error = True;
}
if (!shm_error) {
data->ximage = X11_XShmCreateImage(display, data->visual,
vinfo.depth, ZPixmap,
shminfo->shmaddr, shminfo,
window->w, window->h);
if (!data->ximage) {
X11_XShmDetach(display, shminfo);
X11_XSync(display, False);
shmdt(shminfo->shmaddr);
} else {
/* Done! */
data->use_mitshm = SDL_TRUE;
*pixels = shminfo->shmaddr;
return 0;
}
}
}
#endif /* not NO_SHARED_MEMORY */
*pixels = SDL_malloc(window->h*(*pitch));
if (*pixels == NULL) {
return SDL_OutOfMemory();
}
data->ximage = X11_XCreateImage(display, data->visual,
vinfo.depth, ZPixmap, 0, (char *)(*pixels),
window->w, window->h, 32, 0);
if (!data->ximage) {
SDL_free(*pixels);
return SDL_SetError("Couldn't create XImage");
}
return 0;
}
int
X11_UpdateWindowFramebuffer(_THIS, SDL_Window * window, const SDL_Rect * rects,
int numrects)
{
SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
Display *display = data->videodata->display;
int i;
int x, y, w ,h;
#ifndef NO_SHARED_MEMORY
if (data->use_mitshm) {
for (i = 0; i < numrects; ++i) {
x = rects[i].x;
y = rects[i].y;
w = rects[i].w;
h = rects[i].h;
if (w <= 0 || h <= 0 || (x + w) <= 0 || (y + h) <= 0) {
/* Clipped? */
continue;
}
if (x < 0)
{
x += w;
w += rects[i].x;
}
if (y < 0)
{
y += h;
h += rects[i].y;
}
if (x + w > window->w)
w = window->w - x;
if (y + h > window->h)
h = window->h - y;
X11_XShmPutImage(display, data->xwindow, data->gc, data->ximage,
x, y, x, y, w, h, False);
}
}
else
#endif /* !NO_SHARED_MEMORY */
{
for (i = 0; i < numrects; ++i) {
x = rects[i].x;
y = rects[i].y;
w = rects[i].w;
h = rects[i].h;
if (w <= 0 || h <= 0 || (x + w) <= 0 || (y + h) <= 0) {
/* Clipped? */
continue;
}
if (x < 0)
{
x += w;
w += rects[i].x;
}
if (y < 0)
{
y += h;
h += rects[i].y;
}
if (x + w > window->w)
w = window->w - x;
if (y + h > window->h)
h = window->h - y;
X11_XPutImage(display, data->xwindow, data->gc, data->ximage,
x, y, x, y, w, h);
}
}
X11_XSync(display, False);
return 0;
}
void
X11_DestroyWindowFramebuffer(_THIS, SDL_Window * window)
{
SDL_WindowData *data = (SDL_WindowData *) window->driverdata;
Display *display;
if (!data) {
/* The window wasn't fully initialized */
return;
}
display = data->videodata->display;
if (data->ximage) {
XDestroyImage(data->ximage);
#ifndef NO_SHARED_MEMORY
if (data->use_mitshm) {
X11_XShmDetach(display, &data->shminfo);
X11_XSync(display, False);
shmdt(data->shminfo.shmaddr);
data->use_mitshm = SDL_FALSE;
}
#endif /* !NO_SHARED_MEMORY */
data->ximage = NULL;
}
if (data->gc) {
X11_XFreeGC(display, data->gc);
data->gc = NULL;
}
}
#endif /* SDL_VIDEO_DRIVER_X11 */
/* vi: set ts=4 sw=4 expandtab: */