Re: Pango draw() patch... messes fonts?

[Luis Rodrigo Gallardo Cruz <rodrigo nul-unu com>]

On Sun, Jan 20, 2008 at 05:41:20PM +0100, Janek Kozicki wrote:
> Andrea Vettorello said:     (by the date of Sun, 20 Jan 2008 15:10:04 +0100)
> 
> > > Janek Kozicki said:     (by the date of Sat, 19 Jan 2008 21:18:50 +0100)
> > >
> > > this screenshot sets a record - selected font is different by about 20
> > > pixels in size from the one used.
> > >
> > > I'm testing this on a debian etch fresh install.
> > 
> > Same on Debian Sid.
> > 
> > As it happens only with bitmap fonts, the first thing i thought was
> > the screen DPI, but starting Xorg with different DPI lead to the same
> > behaviour. I've searched if it's a Pango known bug but found nothing.
> > As this doesn't happen with TTF fonts, i suspect we need to manage
> > bitmap fonts differently from scalable fonts or we are missing
> > something trivial.
> 
> ok. Thanks for testing.
> 
> So I think that better we will wait with this patch until this
> problem will be solved, and apply it in next sawfish release.
 
I've uploaded a new version of the patch to the wiki. I think the font
sizing problems are gone, but I'm not completely positive, since I
don't have the exact fonts that the screenshots display.

Please test, I'd like it if we could add this patch for 1.3.3. That
would make me feel less bad about having a "Fix Rodrigo's bugs" release.

Patch attached for your convenience, although the canonical location
is the wiki.

diff --git a/src/fonts.c b/src/fonts.c
index d4f05d7..3fb7258 100644
--- a/src/fonts.c
+++ b/src/fonts.c
@@ -459,24 +459,29 @@ pango_load (Lisp_Font *f)
     pango_context_set_font_description (pango_context, fontdesc);
     font = pango_context_load_font (pango_context, fontdesc);
 
-    if (!font)
+    if (!font) {
+        pango_font_description_free(fontdesc);
 	return FALSE;
+    }
 
     metrics = pango_font_get_metrics (font, language);
 
-    f->font = font;
     f->ascent = metrics->ascent / PANGO_SCALE;
     f->descent = metrics->descent / PANGO_SCALE;
 
     pango_font_metrics_unref (metrics);
 
+    f->font = fontdesc; // We save the font description, not the font itself!
+                        // That's because it seems we can't recover it perfectly
+                        // later, and the layout routines want a description
+
     return TRUE;
 }
 
 static void
 pango_finalize (Lisp_Font *f)
 {
-    g_object_unref (f->font);
+    pango_font_description_free (f->font);
 }
 
 static int
@@ -486,6 +491,7 @@ pango_measure (Lisp_Font *f, u_char *string, size_t length)
     PangoRectangle rect;
 
     layout = pango_layout_new (pango_context);
+    pango_layout_set_font_description(layout, f->font);
     pango_layout_set_text (layout, string, length);
 
     pango_layout_get_extents (layout, NULL, &rect);
@@ -541,6 +547,7 @@ pango_draw (Lisp_Font *f, u_char *string, size_t length,
     xft_color.color.alpha = fg->alpha;
 
     layout = pango_layout_new (pango_context);
+    pango_layout_set_font_description(layout, f->font);
     pango_layout_set_text (layout, string, length);
     iter = pango_layout_get_iter (layout);

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