gsk: Make glyph parsing more flexible

It is a bit annoying that one has to specify the glyph width
when specifying glyphs numerically for a text node, since this
information really is part of the font.

Make the parser more flexible, and allow to specify just the glyph
ids, without an explicit width. In this case, the width will be
determined from the font.

With this, glyphs can now be specified in any of the follwing
ways:

glyphs: "ABC";              (ASCII)
glyphs: 23, 45, 1001;       (Glyph IDs)
glyphs: 23 10, 100 11.1;    (Glyph IDs and advance widths)
glyphs: 23 10 1 2 color;    (with offsets and flags)

Tests have been updated to cover these variants.

demos/node-editor/node-format.md

@@ -336,7 +336,7 @@ font that is specified in the string. It can be either a data url containing
 a base64-encoded font file, or a regular url that points to a font file.
 
 Glyphs can be specified as an ASCII string, or as a comma-separated list of
-their glyph ID and advance width. Optionally, x and y offsets and flags can
+their glyph IDs. Optionally, the advance width, x and y offsets and flags can
 be specified as well, like this: 40 10 0 0 color.
 
 If the given font does not exist or the given glyphs are invalid for the given

gsk/gskrendernodeparser.c

@@ -1182,6 +1182,8 @@ clear_font (gpointer inout_font)
   g_clear_object ((PangoFont **) inout_font);
 }
 
+#define GLYPH_NEEDS_WIDTH (1 << 15)
+
 static gboolean
 parse_glyphs (GtkCssParser *parser,
               Context      *context,
@@ -1208,6 +1210,7 @@ parse_glyphs (GtkCssParser *parser,
                   gtk_css_parser_error_value (parser, "Unsupported character %d in string", i);
                 }
               gi.glyph = PANGO_GLYPH_INVALID_INPUT - MAX_ASCII_GLYPH + s[i];
+              *(unsigned int *) &gi.attr |= GLYPH_NEEDS_WIDTH;
               pango_glyph_string_set_size (glyph_string, glyph_string->num_glyphs + 1);
               glyph_string->glyphs[glyph_string->num_glyphs - 1] = gi;
             }
@@ -1216,14 +1219,22 @@ parse_glyphs (GtkCssParser *parser,
         }
       else
         {
-          if (!gtk_css_parser_consume_integer (parser, &i) ||
-              !gtk_css_parser_consume_number (parser, &d))
+          if (!gtk_css_parser_consume_integer (parser, &i))
             {
               pango_glyph_string_free (glyph_string);
               return FALSE;
             }
           gi.glyph = i;
-          gi.geometry.width = (int) (d * PANGO_SCALE);
+
+          if (gtk_css_parser_has_number (parser))
+            {
+              gtk_css_parser_consume_number (parser, &d);
+              gi.geometry.width = (int) (d * PANGO_SCALE);
+            }
+          else
+            {
+              *(unsigned int *) &gi.attr |= GLYPH_NEEDS_WIDTH;
+            }
 
           if (gtk_css_parser_has_number (parser))
             {
@@ -2193,23 +2204,36 @@ unpack_glyphs (PangoFont        *font,
 
   for (i = 0; i < glyphs->num_glyphs; i++)
     {
-      PangoGlyph glyph = glyphs->glyphs[i].glyph;
+      PangoGlyphInfo *gi = &glyphs->glyphs[i];
 
-      if (glyph < PANGO_GLYPH_INVALID_INPUT - MAX_ASCII_GLYPH ||
-          glyph >= PANGO_GLYPH_INVALID_INPUT)
+      if (((*(unsigned int *) &gi->attr) & GLYPH_NEEDS_WIDTH) == 0)
         continue;
 
-      glyph = glyph - (PANGO_GLYPH_INVALID_INPUT - MAX_ASCII_GLYPH) - MIN_ASCII_GLYPH;
+      *(unsigned int *) &gi->attr &= ~GLYPH_NEEDS_WIDTH;
 
-      if (ascii == NULL)
+     if (gi->glyph >= PANGO_GLYPH_INVALID_INPUT - MAX_ASCII_GLYPH &&
+         gi->glyph < PANGO_GLYPH_INVALID_INPUT)
         {
-          ascii = create_ascii_glyphs (font);
-          if (ascii == NULL)
-            return FALSE;
-        }
+          PangoGlyph idx = gi->glyph - (PANGO_GLYPH_INVALID_INPUT - MAX_ASCII_GLYPH) - MIN_ASCII_GLYPH;
 
-      glyphs->glyphs[i].glyph = ascii->glyphs[glyph].glyph;
-      glyphs->glyphs[i].geometry.width = ascii->glyphs[glyph].geometry.width;
+          if (ascii == NULL)
+            {
+              ascii = create_ascii_glyphs (font);
+              if (ascii == NULL)
+                return FALSE;
+            }
+
+          gi->glyph = ascii->glyphs[idx].glyph;
+          gi->geometry.width = ascii->glyphs[idx].geometry.width;
+        }
+      else
+        {
+          PangoRectangle ink_rect;
+
+          pango_font_get_glyph_extents (font, gi->glyph, &ink_rect, NULL);
+
+          gi->geometry.width = ink_rect.width;
+        }
     }
 
   g_clear_pointer (&ascii, pango_glyph_string_free);
@@ -2252,6 +2276,7 @@ parse_text_node (GtkCssParser *parser,
       for (i = 0; i < strlen (text); i++)
         {
           gi.glyph = PANGO_GLYPH_INVALID_INPUT - MAX_ASCII_GLYPH + text[i];
+          *(unsigned int *) &gi.attr |= GLYPH_NEEDS_WIDTH;
           glyphs->glyphs[i] = gi;
         }
     }

testsuite/gsk/nodeparser/text.node

@@ -1,6 +1,6 @@
 text {
   color: rgb(50,50,50);
   font: "Cantarell 14px";
-  glyphs: "N", 430 5, 406 8, 417 7, 772 4, 783 5, 783 5, 793 6 0 0 same-cluster;
+  glyphs: "N", 430, 406, 417 7, 772 4, 783 5, 783 5, 793 6 0 0 same-cluster;
   offset: 0 32.0186;
 }

testsuite/gsk/nodeparser/text.ref.node

@@ -1,6 +1,6 @@
 text {
   color: rgb(50,50,50);
   font: "Cantarell 14px";
-  glyphs: "N", 430 5, 406 8, 417 7, 772 4, 783 5, 783 5, 793 6 0 0 same-cluster;
+  glyphs: "N", 430 5, 406 7, 417 7, 772 4, 783 5, 783 5, 793 6 0 0 same-cluster;
   offset: 0 32.0186;
 }