Do not use color when font attributes are supported

If fontconfig gives us a font without the attributes we asked for,
display an alternative color instead.

2 files changed, 35 insertions, 13 deletions

diff --git a/config.def.h b/config.def.h
index c2e4ffd..7f465d1 100644
--- a/config.def.h
+++ b/config.def.h
@@ -138,12 +138,10 @@ static unsigned int mousefg = 7;
 static unsigned int mousebg = 0;
 
 /*
- * Colors used, when the specific fg == defaultfg. So in reverse mode this
- * will reverse too. Another logic would only make the simple feature too
- * complex.
+ * Color used to display font attributes when fontconfig selected a font which
+ * doesn't match the ones requested.
  */
-static unsigned int defaultitalic = 11;
-static unsigned int defaultunderline = 7;
+static unsigned int defaultattr = 11;
 
 /*
  * Internal mouse shortcuts.
diff --git a/st.c b/st.c
index c67623f..4d44388 100644
--- a/st.c
+++ b/st.c
@@ -354,6 +354,8 @@ typedef struct {
         int width;
         int ascent;
         int descent;
+        int badslant;
+        int badweight;
         short lbearing;
         short rbearing;
         XftFont *match;
@@ -3373,6 +3375,7 @@ xloadfont(Font *f, FcPattern *pattern)
         FcPattern *match;
         FcResult result;
         XGlyphInfo extents;
+        int wantattr, haveattr;
 
         match = XftFontMatch(xw.dpy, xw.scr, pattern, &result);
         if (!match)
@@ -3383,6 +3386,28 @@ xloadfont(Font *f, FcPattern *pattern)
                 return 1;
         }
 
+        if ((XftPatternGetInteger(pattern, "slant", 0, &wantattr) ==
+            XftResultMatch)) {
+                /*
+                 * Check if xft was unable to find a font with the appropriate
+                 * slant but gave us one anyway. Try to mitigate.
+                 */
+                if ((XftPatternGetInteger(f->match->pattern, "slant", 0,
+                    &haveattr) != XftResultMatch) || haveattr < wantattr) {
+                        f->badslant = 1;
+                        fputs("st: font slant does not match\n", stderr);
+                }
+        }
+
+        if ((XftPatternGetInteger(pattern, "weight", 0, &wantattr) ==
+            XftResultMatch)) {
+                if ((XftPatternGetInteger(f->match->pattern, "weight", 0,
+                    &haveattr) != XftResultMatch) || haveattr != wantattr) {
+                        f->badweight = 1;
+                        fputs("st: font weight does not match\n", stderr);
+                }
+        }
+
         XftTextExtentsUtf8(xw.dpy, f->match,
                 (const FcChar8 *) ascii_printable,
                 strlen(ascii_printable), &extents);
@@ -3780,14 +3805,13 @@ xdrawglyphfontspecs(const XftGlyphFontSpec *specs, Glyph base, int len, int x, i
         XRenderColor colfg, colbg;
         XRectangle r;
 
-        /* Determine foreground and background colors based on mode. */
-        if (base.fg == defaultfg) {
-                if (base.mode & ATTR_ITALIC)
-                        base.fg = defaultitalic;
-                else if ((base.mode & ATTR_ITALIC) && (base.mode & ATTR_BOLD))
-                        base.fg = defaultitalic;
-                else if (base.mode & ATTR_UNDERLINE)
-                        base.fg = defaultunderline;
+        /* Fallback on color display for attributes not supported by the font */
+        if (base.mode & ATTR_ITALIC && base.mode & ATTR_BOLD) {
+                if (dc.ibfont.badslant || dc.ibfont.badweight)
+                        base.fg = defaultattr;
+        } else if ((base.mode & ATTR_ITALIC && dc.ifont.badslant) ||
+            (base.mode & ATTR_BOLD && dc.bfont.badweight)) {
+                base.fg = defaultattr;
         }
 
         if (IS_TRUECOL(base.fg)) {