Adding use XftFontMatch patch

README.md

@@ -15,6 +15,8 @@ Refer to [https://st.suckless.org/](https://st.suckless.org/) for details on the
 
 ### Changelog:
 
+2022-08-28 - Added the use XftFontMatch patch
+
 2022-08-24 - Added the no window decorations patch
 
 2022-04-11 - Added the background image reload patch
@@ -264,6 +266,10 @@ Refer to [https://st.suckless.org/](https://st.suckless.org/) for details on the
       - allows mouse scroll without modifier keys for regardless of alt screen using the external
         scroll program
 
+   - [use-XftFontMatch](https://git.suckless.org/st/commit/528241aa3835e2f1f052abeeaf891737712955a0.html)
+      - use XftFontMatch in place of FcFontMatch to allow font to scale with Xft.dpi resource
+        setting
+
    - [vertcenter](https://st.suckless.org/patches/vertcenter/)
       - vertically center lines in the space available if you have set a larger chscale in config.h
 

patches.def.h

@@ -373,6 +373,20 @@
  */
 #define UNIVERSCROLL_PATCH 0
 
+/* Use XftFontMatch in place of FcFontMatch.
+ *
+ * XftFontMatch calls XftDefaultSubstitute which configures various match properties according
+ * to the user's configured Xft defaults (xrdb) as well as according to the current display and
+ * screen. Most importantly, the screen DPI is computed [1]. Without this, st uses a "default"
+ * DPI of 75 [2].
+ *
+ * [1]: https://cgit.freedesktop.org/xorg/lib/libXft/tree/src/xftdpy.c?id=libXft-2.3.2#n535
+ * [2]: https://cgit.freedesktop.org/fontconfig/tree/src/fcdefault.c?id=2.11.1#n255
+ *
+ * https://git.suckless.org/st/commit/528241aa3835e2f1f052abeeaf891737712955a0.html
+ */
+#define USE_XFTFONTMATCH_PATCH 0
+
 /* Vertically center lines in the space available if you have set a larger chscale in config.h
  * https://st.suckless.org/patches/vertcenter/
  */

x.c

@@ -1216,7 +1216,11 @@ xloadfont(Font *f, FcPattern *pattern)
 	FcConfigSubstitute(NULL, configured, FcMatchPattern);
 	XftDefaultSubstitute(xw.dpy, xw.scr, configured);
 
+	#if USE_XFTFONTMATCH_PATCH
+	match = XftFontMatch(xw.dpy, xw.scr, pattern, &result);
+	#else
 	match = FcFontMatch(NULL, configured, &result);
+	#endif // USE_XFTFONTMATCH_PATCH
 	if (!match) {
 		FcPatternDestroy(configured);
 		return 1;
@@ -1735,12 +1739,12 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
 					fccharset);
 			FcPatternAddBool(fcpattern, FC_SCALABLE, 1);
 
-			FcConfigSubstitute(0, fcpattern,
-					FcMatchPattern);
+			#if !USE_XFTFONTMATCH_PATCH
+			FcConfigSubstitute(0, fcpattern, FcMatchPattern);
 			FcDefaultSubstitute(fcpattern);
+			#endif // USE_XFTFONTMATCH_PATCH
 
-			fontpattern = FcFontSetMatch(0, fcsets, 1,
-					fcpattern, &fcres);
+			fontpattern = FcFontSetMatch(0, fcsets, 1, fcpattern, &fcres);
 
 			/* Allocate memory for the new cache entry. */
 			if (frclen >= frccap) {