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st-background-image-0.9.3.diff (11260B)

---

 From b43b4842d62d800da712ef7d6244967daa4ff096 Mon Sep 17 00:00:00 2001
 From: Matthias Schoth <mschoth@gmail.com>
 Date: Tue, 18 Aug 2026 19:32:18 +0200
 Subject: [PATCH] Add background image support via root window pixmap
 
 Add a background image to st by tiling a server-side pixmap set as the
 _ST_BACKGROUND_IMAGE root window property. st watches the root window
 for property changes, so re-running the stbg setter updates all running
 st instances immediately.
 
 The pixmap is shared between all instances and no composite manager is
 required. A pseudotransparency config option fixes the tile coordinates
 to the screen origin so the terminal backgrounds line up with the
 wallpaper behind the window.
 
 stbg reads a farbfeld image from a file or stdin (using -) and sets the
 property. It is not built by default; compile separately with:
 
     cc -o stbg stbg.c -lX11
 ---
  config.def.h |   6 +++
  st.c         |   2 +-
  st.h         |   1 +
  stbg.c       | 122 +++++++++++++++++++++++++++++++++++++++++++++++++
  x.c          | 127 +++++++++++++++++++++++++++++++++++++++++++++++----
  5 files changed, 248 insertions(+), 10 deletions(-)
  create mode 100644 stbg.c
 
 diff --git a/config.def.h b/config.def.h
 index 2cd740a..3d98c87 100644
 --- a/config.def.h
 +++ b/config.def.h
 @@ -8,6 +8,12 @@
  static char *font = "Liberation Mono:pixelsize=12:antialias=true:autohint=true";
  static int borderpx = 2;
  
 +/*
 + * pseudo transparency fixes coordinates to the screen origin
 + * requires _ST_BACKGROUND_IMAGE root window property (set via stbg)
 + */
 +static const int pseudotransparency = 0;
 +
  /*
   * What program is execed by st depends of these precedence rules:
   * 1: program passed with -e
 diff --git a/st.c b/st.c
 index 8e57991..2663816 100644
 --- a/st.c
 +++ b/st.c
 @@ -194,7 +194,7 @@ static void tsetscroll(int, int);
  static void tswapscreen(void);
  static void tsetmode(int, int, const int *, int);
  static int twrite(const char *, int, int);
 -static void tfulldirt(void);
 +void tfulldirt(void);
  static void tcontrolcode(uchar );
  static void tdectest(char );
  static void tdefutf8(char);
 diff --git a/st.h b/st.h
 index fd3b0d8..a716a73 100644
 --- a/st.h
 +++ b/st.h
 @@ -89,6 +89,7 @@ void toggleprinter(const Arg *);
  int tattrset(int);
  void tnew(int, int);
  void tresize(int, int);
 +void tfulldirt(void);
  void tsetdirtattr(int);
  void ttyhangup(void);
  int ttynew(const char *, char *, const char *, char **);
 diff --git a/stbg.c b/stbg.c
 new file mode 100644
 index 0000000..80bc4cf
 --- /dev/null
 +++ b/stbg.c
 @@ -0,0 +1,122 @@
 +/* See LICENSE file for copyright and license details. */
 +/* Build: cc -o stbg stbg.c -lX11 */
 +#include <errno.h>
 +#include <stdarg.h>
 +#include <stdio.h>
 +#include <stdlib.h>
 +#include <stdint.h>
 +#include <string.h>
 +#include <arpa/inet.h>
 +#include <X11/Xlib.h>
 +#include <X11/Xutil.h>
 +#include <X11/Xatom.h>
 +
 +static char *argv0;
 +
 +static void
 +die(const char *errstr, ...)
 +{
 +	va_list ap;
 +
 +	fprintf(stderr, "%s: ", argv0);
 +	va_start(ap, errstr);
 +	vfprintf(stderr, errstr, ap);
 +	va_end(ap);
 +	exit(1);
 +}
 +
 +static void
 +usage(void)
 +{
 +	die("usage: %s file.ff\n       %s - < file.ff\n", argv0, argv0);
 +}
 +
 +int
 +main(int argc, char *argv[])
 +{
 +	uint32_t i, hdr[4], w, h, size;
 +	uint64_t *data;
 +	uint32_t *data32;
 +	FILE *f;
 +	int fromstdin;
 +	Pixmap pmap;
 +	Display *dpy;
 +	Window root;
 +	int scr;
 +	Atom atom_stbg;
 +	GC gc;
 +	XGCValues gcvalues;
 +	XImage *xi;
 +
 +	argv0 = argv[0];
 +
 +	if (argc != 2)
 +		usage();
 +
 +	if (!(dpy = XOpenDisplay(NULL)))
 +		die("can't open display\n");
 +
 +	scr = DefaultScreen(dpy);
 +	root = RootWindow(dpy, scr);
 +
 +	fromstdin = !strcmp(argv[1], "-");
 +	f = fromstdin ? stdin : fopen(argv[1], "rb");
 +	if (!fromstdin && !f)
 +		die("can't open %s\n", argv[1]);
 +
 +	if (fread(hdr, sizeof(*hdr), 4, f) != 4)
 +		die("fread: unexpected end of file\n");
 +
 +	if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1))
 +		die("invalid farbfeld magic\n");
 +
 +	w = ntohl(hdr[2]);
 +	h = ntohl(hdr[3]);
 +	if (w == 0 || h == 0)
 +		die("invalid farbfeld dimensions\n");
 +	size = w * h;
 +
 +	data = malloc(size * sizeof(uint64_t));
 +	if (!data)
 +		die("malloc: %s\n", strerror(errno));
 +
 +	if (fread(data, sizeof(uint64_t), size, f) != size)
 +		die("fread: unexpected end of file\n");
 +	if (!fromstdin)
 +		fclose(f);
 +
 +	data32 = malloc(size * sizeof(uint32_t));
 +	if (!data32)
 +		die("malloc: %s\n", strerror(errno));
 +
 +	for (i = 0; i < size; i++) {
 +		uint64_t p = data[i];
 +		data32[i] = (p & 0x00000000000000FF) << 16 |
 +		            (p & 0x0000000000FF0000) >> 8  |
 +		            (p & 0x000000FF00000000) >> 32;
 +	}
 +	free(data);
 +
 +	xi = XCreateImage(dpy, DefaultVisual(dpy, scr),
 +	                  DefaultDepth(dpy, scr), ZPixmap, 0,
 +	                  (char *)data32, w, h, 32, w * 4);
 +
 +	pmap = XCreatePixmap(dpy, root, w, h, DefaultDepth(dpy, scr));
 +
 +	memset(&gcvalues, 0, sizeof(gcvalues));
 +	gcvalues.graphics_exposures = False;
 +	gc = XCreateGC(dpy, pmap, GCGraphicsExposures, &gcvalues);
 +
 +	XPutImage(dpy, pmap, gc, xi, 0, 0, 0, 0, w, h);
 +	XDestroyImage(xi);
 +	XFreeGC(dpy, gc);
 +
 +	atom_stbg = XInternAtom(dpy, "_ST_BACKGROUND_IMAGE", False);
 +	XChangeProperty(dpy, root, atom_stbg, XA_PIXMAP, 32,
 +	                PropModeReplace, (unsigned char *)&pmap, 1);
 +	XSetCloseDownMode(dpy, RetainPermanent);
 +
 +	XSync(dpy, False);
 +
 +	return 0;
 +}
 diff --git a/x.c b/x.c
 index d73152b..bee9d35 100644
 --- a/x.c
 +++ b/x.c
 @@ -81,6 +81,7 @@ typedef XftGlyphFontSpec GlyphFontSpec;
  typedef struct {
  	int tw, th; /* tty width and height */
  	int w, h; /* window width and height */
 +	int x, y; /* window location */
  	int ch; /* char height */
  	int cw; /* char width  */
  	int mode; /* window state/mode flags */
 @@ -101,6 +102,9 @@ typedef struct {
  		XVaNestedList spotlist;
  	} ime;
  	Draw draw;
 +	GC bggc;          /* Graphics Context for background */
 +	Atom stbg_atom;   /* _ST_BACKGROUND_IMAGE atom */
 +	Atom netwmstate_atom; /* _NET_WM_STATE atom */
  	Visual *vis;
  	XSetWindowAttributes attrs;
  	int scr;
 @@ -151,6 +155,9 @@ static void ximinstantiate(Display *, XPointer, XPointer);
  static void ximdestroy(XIM, XPointer, XPointer);
  static int xicdestroy(XIC, XPointer, XPointer);
  static void xinit(int, int);
 +static void updatexy(void);
 +static void bginit(void);
 +static Pixmap bginitfromroot(void);
  static void cresize(int, int);
  static void xresize(int, int);
  static void xhints(void);
 @@ -220,6 +227,7 @@ static DC dc;
  static XWindow xw;
  static XSelection xsel;
  static TermWindow win;
 +static int posdirty = 1; /* window may have moved; re-sync tile origin */
  
  /* Font Ring Cache */
  enum {
 @@ -515,6 +523,17 @@ propnotify(XEvent *e)
  			 xpev->atom == clipboard)) {
  		selnotify(e);
  	}
 +
 +	if (xpev->atom == xw.stbg_atom) {
 +		bginit();
 +		redraw();
 +		return;
 +	}
 +
 +	if (pseudotransparency &&
 +	    e->xproperty.atom == xw.netwmstate_atom) {
 +		redraw();
 +	}
  }
  
  void
 @@ -545,7 +564,8 @@ selnotify(XEvent *e)
  			return;
  		}
  
 -		if (e->type == PropertyNotify && nitems == 0 && rem == 0) {
 +		if (e->type == PropertyNotify && nitems == 0 && rem == 0 &&
 +		    !pseudotransparency) {
  			/*
  			 * If there is some PropertyNotify with no data, then
  			 * this is the signal of the selection owner that all
 @@ -563,9 +583,11 @@ selnotify(XEvent *e)
  			 * when the selection owner does send us the next
  			 * chunk of data.
  			 */
 -			MODBIT(xw.attrs.event_mask, 1, PropertyChangeMask);
 -			XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask,
 +			if (!pseudotransparency) {
 +				MODBIT(xw.attrs.event_mask, 1, PropertyChangeMask);
 +				XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask,
  					&xw.attrs);
 +			}
  
  			/*
  			 * Deleting the property is the transfer start signal.
 @@ -851,9 +873,9 @@ xsetcolorname(int x, const char *name)
  void
  xclear(int x1, int y1, int x2, int y2)
  {
 -	XftDrawRect(xw.draw,
 -			&dc.col[IS_SET(MODE_REVERSE)? defaultfg : defaultbg],
 -			x1, y1, x2-x1, y2-y1);
 +	if (pseudotransparency)
 +		XSetTSOrigin(xw.dpy, xw.bggc, -win.x, -win.y);
 +	XFillRectangle(xw.dpy, xw.buf, xw.bggc, x1, y1, x2-x1, y2-y1);
  }
  
  void
 @@ -1242,6 +1264,77 @@ xinit(int cols, int rows)
  		xsel.xtarget = XA_STRING;
  }
  
 +void
 +updatexy(void)
 +{
 +	Window child;
 +	XTranslateCoordinates(xw.dpy, xw.win, DefaultRootWindow(xw.dpy), 0, 0,
 +	                      &win.x, &win.y, &child);
 +}
 +
 +/*
 + * initialize background image from root window _ST_BACKGROUND_IMAGE
 + */
 +static Pixmap
 +bginitfromroot(void)
 +{
 +	Atom prop, atom_type;
 +	int format;
 +	unsigned long nitems, after;
 +	unsigned char *data;
 +	Pixmap pmap;
 +
 +	prop = XInternAtom(xw.dpy, "_ST_BACKGROUND_IMAGE", True);
 +	if (prop == None)
 +		return None;
 +
 +	if (XGetWindowProperty(xw.dpy, DefaultRootWindow(xw.dpy), prop,
 +	                       0, 1, False, AnyPropertyType, &atom_type,
 +	                       &format, &nitems, &after, &data) != Success)
 +		return None;
 +
 +	if (atom_type != XA_PIXMAP || format != 32 || nitems < 1) {
 +		XFree(data);
 +		return None;
 +	}
 +
 +	pmap = *(Pixmap *)data;
 +	XFree(data);
 +
 +	XSetTile(xw.dpy, xw.bggc, pmap);
 +	XSetFillStyle(xw.dpy, xw.bggc, FillTiled);
 +	return pmap;
 +}
 +
 +void
 +bginit(void)
 +{
 +	XGCValues gcvalues;
 +	Pixmap bgpmap;
 +
 +	if (xw.bggc)
 +		XFreeGC(xw.dpy, xw.bggc);
 +
 +	memset(&gcvalues, 0, sizeof(gcvalues));
 +	xw.bggc = XCreateGC(xw.dpy, xw.win, 0, &gcvalues);
 +
 +	bgpmap = bginitfromroot();
 +
 +	if (bgpmap == None) {
 +		XSetForeground(xw.dpy, xw.bggc, dc.col[defaultbg].pixel);
 +		XSetFillStyle(xw.dpy, xw.bggc, FillSolid);
 +	}
 +
 +	if (pseudotransparency) {
 +		MODBIT(xw.attrs.event_mask, 1, PropertyChangeMask);
 +		XChangeWindowAttributes(xw.dpy, xw.win, CWEventMask, &xw.attrs);
 +	}
 +
 +	xw.stbg_atom = XInternAtom(xw.dpy, "_ST_BACKGROUND_IMAGE", False);
 +	xw.netwmstate_atom = XInternAtom(xw.dpy, "_NET_WM_STATE", False);
 +	XSelectInput(xw.dpy, DefaultRootWindow(xw.dpy), PropertyChangeMask);
 +}
 +
  int
  xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x, int y)
  {
 @@ -1482,7 +1575,10 @@ xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, i
  		xclear(winx, winy + win.ch, winx + width, win.h);
  
  	/* Clean up the region we want to draw to. */
 -	XftDrawRect(xw.draw, bg, winx, winy, width, win.ch);
 +	if (bg == &dc.col[defaultbg])
 +		xclear(winx, winy, winx + width, winy + win.ch);
 +	else
 +		XftDrawRect(xw.draw, bg, winx, winy, width, win.ch);
  
  	/* Set the clip region because Xft is sometimes dirty. */
  	r.x = 0;
 @@ -1651,6 +1747,12 @@ xsettitle(char *p)
  int
  xstartdraw(void)
  {
 +	if (pseudotransparency && IS_SET(MODE_VISIBLE)) {
 +		if (posdirty) {
 +			updatexy();
 +			posdirty = 0;
 +		}
 +	}
  	return IS_SET(MODE_VISIBLE);
  }
  
 @@ -1914,9 +2016,15 @@ cmessage(XEvent *e)
  void
  resize(XEvent *e)
  {
 -	if (e->xconfigure.width == win.w && e->xconfigure.height == win.h)
 -		return;
 +	if (pseudotransparency &&
 +	    (e->xconfigure.x != win.x || e->xconfigure.y != win.y))
 +		posdirty = 1;
  
 +	if (e->xconfigure.width == win.w && e->xconfigure.height == win.h) {
 +		if (pseudotransparency && posdirty)
 +			tfulldirt();
 +		return;
 +	}
  	cresize(e->xconfigure.width, e->xconfigure.height);
  }
  
 @@ -2100,6 +2208,7 @@ run:
  	rows = MAX(rows, 1);
  	tnew(cols, rows);
  	xinit(cols, rows);
 +	bginit();
  	xsetenv();
  	selinit();
  	run();
 -- 
 2.55.0