[dev] [st] [PATCH] query pixel size from matched font

[Eon S. Jeon]

On Tue, 17 Dec 2013 10:06:22 +0100
Nils Reuße <n.reu...@hxgn.net> wrote:

(Originally: [dev] [st] parse relative font size instead of pixelsize)

Hello,

> I prefer size over pixelsize because size scales to the current
> display resolution, while pixelsize has to be increased (either in
> config.h or on starting st), e.g. if you switch between a non-hd
> (home) and hd screen (work).

It should be a good thing to support point size. AFAIK,
FontConfig converts point size to pixel size using DPI, though I heard
that FC does not always use screen DPI.

> What do you think?

I found that your patch breaks zooming when used with pixel size. Since
FC calculates pixel size for us, I wrote a patch that retrieves pixel
size from matched font.

Note that I changed the types of usedfontsize(global) and
fontsize(xloadfonts) to double, because converted pixel sizes are
usually non-integer.

Sincerely,
Eon


diff --git a/st.c b/st.c
index f883ac1..67f9469 100644
--- a/st.c
+++ b/st.c
@@ -398,7 +398,7 @@ static void xinit(void);
 static void xloadcols(void);
 static int xsetcolorname(int, const char *);
 static int xloadfont(Font *, FcPattern *);
-static void xloadfonts(char *, int);
+static void xloadfonts(char *, double);
 static int xloadfontset(Font *);
 static void xsettitle(char *);
 static void xresettitle(void);
@@ -478,7 +478,7 @@ static char *opt_font = NULL;
 static int oldbutton = 3; /* button event on startup: 3 = release */
 
 static char *usedfont = NULL;
-static int usedfontsize = 0;
+static double usedfontsize = 0;
 
 /* Font Ring Cache */
 enum {
@@ -2826,9 +2826,9 @@ xloadfont(Font *f, FcPattern *pattern) {
 }
 
 void
-xloadfonts(char *fontstr, int fontsize) {
+xloadfonts(char *fontstr, double fontsize) {
        FcPattern *pattern;
-       FcResult result;
+       FcResult r_sz, r_psz;
        double fontval;
 
        if(fontstr[0] == '-') {
@@ -2842,12 +2842,16 @@ xloadfonts(char *fontstr, int fontsize) {
 
        if(fontsize > 0) {
                FcPatternDel(pattern, FC_PIXEL_SIZE);
+               FcPatternDel(pattern, FC_SIZE);
                FcPatternAddDouble(pattern, FC_PIXEL_SIZE,
(double)fontsize); usedfontsize = fontsize;
        } else {
-               result = FcPatternGetDouble(pattern, FC_PIXEL_SIZE, 0,
&fontval);
-               if(result == FcResultMatch) {
-                       usedfontsize = (int)fontval;
+               r_psz = FcPatternGetDouble(pattern, FC_PIXEL_SIZE, 0,
&fontval);
+               r_sz = FcPatternGetDouble(pattern, FC_SIZE, 0,
&fontval);
+               if(r_psz == FcResultMatch) {
+                       usedfontsize = fontval;
+               } else if(r_sz == FcResultMatch) {
+                       usedfontsize = -1;
                } else {
                        /*
                         * Default font size is 12, if none given.
This is to @@ -2864,6 +2868,12 @@ xloadfonts(char *fontstr, int
fontsize) { if(xloadfont(&dc.font, pattern))
                die("st: can't open font %s\n", fontstr);
 
+       if(usedfontsize < 0) {
+               FcPatternGetDouble(dc.font.match->pattern,
+                                  FC_PIXEL_SIZE, 0, &fontval);
+               usedfontsize = fontval;
+       }
+
        /* Setting character width and height. */
        xw.cw = CEIL(dc.font.width * cwscale);
        xw.ch = CEIL(dc.font.height * chscale);

I found that your patch breaks zooming when used with pixel size. Since