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x11: If XRandR isn't available, add a generic display. 

We can get _some_ of the info we need out of standard Xlib and report a
single display (which might actually be multiple physical displays mushed
into a single desktop). This is better than nothing, but you should really
just build with XRandR support and get a better X server.  :)
This commit is contained in:
Ryan C. Gordon 2022-04-26 23:14:44 -04:00
parent ccc70e644b
commit 05bd225a80
No known key found for this signature in database
GPG Key ID: FA148B892AB48044
1 changed files with 122 additions and 30 deletions
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148
src/video/x11/SDL_x11modes.c
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@ -148,6 +148,30 @@ X11_GetPixelFormatFromVisualInfo(Display * display, XVisualInfo * vinfo)
return SDL_PIXELFORMAT_UNKNOWN;
}
static int
GetXftDPI(Display* dpy)
{
char* xdefault_resource;
int xft_dpi, err;
xdefault_resource = X11_XGetDefault(dpy, "Xft", "dpi");
if(!xdefault_resource) {
return 0;
}
/*
* It's possible for SDL_atoi to call SDL_strtol, if it fails due to a
* overflow or an underflow, it will return LONG_MAX or LONG_MIN and set
* errno to ERANGE. So we need to check for this so we dont get crazy dpi
* values
*/
xft_dpi = SDL_atoi(xdefault_resource);
err = errno;
return err == ERANGE ? 0 : xft_dpi;
}
#if SDL_VIDEO_DRIVER_X11_XRANDR
static SDL_bool
CheckXRandR(Display * display, int *major, int *minor)
@ -289,30 +313,6 @@ SetXRandRDisplayName(Display *dpy, Atom EDID, char *name, const size_t namelen,
#endif
}
static int
GetXftDPI(Display* dpy)
{
char* xdefault_resource;
int xft_dpi, err;
xdefault_resource = X11_XGetDefault(dpy, "Xft", "dpi");
if(!xdefault_resource) {
return 0;
}
/*
* It's possible for SDL_atoi to call SDL_strtol, if it fails due to a
* overflow or an underflow, it will return LONG_MAX or LONG_MIN and set
* errno to ERANGE. So we need to check for this so we dont get crazy dpi
* values
*/
xft_dpi = SDL_atoi(xdefault_resource);
err = errno;
return err == ERANGE ? 0 : xft_dpi;
}
static int
X11_InitModes_XRandR(_THIS)
{
@ -478,16 +478,107 @@ X11_InitModes_XRandR(_THIS)
}
#endif /* SDL_VIDEO_DRIVER_X11_XRANDR */
/* This is used if there's no better functionality--like XRandR--to use.
It won't attempt to supply different display modes at all, but it can
enumerate the current displays and their current sizes. */
static int X11_InitModes_StdXlib(_THIS)
{
/* !!! FIXME: a lot of copy/paste from X11_InitModes_XRandR in this function. */
SDL_VideoData *data = (SDL_VideoData *) _this->driverdata;
Display *dpy = data->display;
const int default_screen = DefaultScreen(dpy);
Screen *screen = ScreenOfDisplay(dpy, default_screen);
int display_mm_width, display_mm_height, xft_dpi, scanline_pad, n, i;
SDL_DisplayModeData *modedata;
SDL_DisplayData *displaydata;
SDL_DisplayMode mode;
XPixmapFormatValues *pixmapformats;
Uint32 pixelformat;
XVisualInfo vinfo;
SDL_VideoDisplay display;
/* note that generally even if you have a multiple physical monitors, ScreenCount(dpy) still only reports ONE screen. */
if (get_visualinfo(dpy, default_screen, &vinfo) < 0) {
return SDL_SetError("Failed to find an X11 visual for the primary display");
}
pixelformat = X11_GetPixelFormatFromVisualInfo(dpy, &vinfo);
if (SDL_ISPIXELFORMAT_INDEXED(pixelformat)) {
return SDL_SetError("Palettized video modes are no longer supported");
}
SDL_zero(mode);
mode.w = WidthOfScreen(screen);
mode.h = HeightOfScreen(screen);
mode.format = pixelformat;
mode.refresh_rate = 0; /* don't know it, sorry. */
displaydata = (SDL_DisplayData *) SDL_calloc(1, sizeof(*displaydata));
if (!displaydata) {
return SDL_OutOfMemory();
}
modedata = (SDL_DisplayModeData *) SDL_calloc(1, sizeof(SDL_DisplayModeData));
if (!modedata) {
SDL_free(displaydata);
return SDL_OutOfMemory();
}
mode.driverdata = modedata;
display_mm_width = WidthMMOfScreen(screen);
display_mm_height = HeightMMOfScreen(screen);
displaydata->screen = default_screen;
displaydata->visual = vinfo.visual;
displaydata->depth = vinfo.depth;
displaydata->hdpi = display_mm_width ? (((float) mode.w) * 25.4f / display_mm_width) : 0.0f;
displaydata->vdpi = display_mm_height ? (((float) mode.h) * 25.4f / display_mm_height) : 0.0f;
displaydata->ddpi = SDL_ComputeDiagonalDPI(mode.w, mode.h, ((float) display_mm_width) / 25.4f,((float) display_mm_height) / 25.4f);
xft_dpi = GetXftDPI(dpy);
if(xft_dpi > 0) {
displaydata->hdpi = (float)xft_dpi;
displaydata->vdpi = (float)xft_dpi;
}
scanline_pad = SDL_BYTESPERPIXEL(pixelformat) * 8;
pixmapformats = X11_XListPixmapFormats(dpy, &n);
if (pixmapformats) {
for (i = 0; i < n; ++i) {
if (pixmapformats[i].depth == vinfo.depth) {
scanline_pad = pixmapformats[i].scanline_pad;
break;
}
}
X11_XFree(pixmapformats);
}
displaydata->scanline_pad = scanline_pad;
displaydata->x = 0;
displaydata->y = 0;
displaydata->use_xrandr = SDL_FALSE;
SDL_zero(display);
display.name = (char *) "Generic X11 Display"; /* this is just copied and thrown away, it's safe to cast to char* here. */
display.desktop_mode = mode;
display.current_mode = mode;
display.driverdata = displaydata;
SDL_AddVideoDisplay(&display, SDL_FALSE);
return 0;
}
int
X11_InitModes(_THIS)
{
SDL_VideoData *data = (SDL_VideoData *) _this->driverdata;
/* XRandR is the One True Modern Way to do this on X11. If this
/* XRandR is the One True Modern Way to do this on X11. If this
fails, we just won't report any display modes except the current
desktop size. */
#if SDL_VIDEO_DRIVER_X11_XRANDR
{
SDL_VideoData *data = (SDL_VideoData *) _this->driverdata;
int xrandr_major, xrandr_minor;
/* require at least XRandR v1.3 */
if (CheckXRandR(data->display, &xrandr_major, &xrandr_minor) &&
@ -497,7 +588,8 @@ X11_InitModes(_THIS)
}
#endif /* SDL_VIDEO_DRIVER_X11_XRANDR */
return 0;
/* still here? Just set up an extremely basic display. */
return X11_InitModes_StdXlib(_this);
}
void