Add OpenType/CFF Subsetting

src/Makefile.am

@@ -1,4 +1,5 @@
 font_subset_sources =				\
+	cairo-cff-subset.c			\
 	cairo-truetype-subset.c			\
 	cairo-type1-fallback.c			\
 	cairo-truetype-subset-private.h		\

src/cairo-pdf-surface.c

@@ -1579,6 +1579,109 @@ _cairo_pdf_surface_write_pages (cairo_pdf_surface_t *surface)
 				 "endobj\r\n");
 }
 
+static cairo_status_t
+_cairo_pdf_surface_emit_cff_font_subset (cairo_pdf_surface_t		*surface,
+                                         cairo_scaled_font_subset_t	*font_subset)
+{
+    cairo_pdf_resource_t stream, descriptor, subset_resource;
+    cairo_status_t status;
+    cairo_pdf_font_t font;
+    cairo_cff_subset_t subset;
+    unsigned long compressed_length;
+    char *compressed;
+    unsigned int i;
+    char name[64];
+
+    snprintf (name, sizeof name, "CairoFont-%d-%d",
+	      font_subset->font_id, font_subset->subset_id);
+    status = _cairo_cff_subset_init (&subset, name, font_subset);
+    if (status)
+	return status;
+
+    compressed = compress_dup (subset.data, subset.data_length, &compressed_length);
+    if (compressed == NULL) {
+	_cairo_cff_subset_fini (&subset);
+	return CAIRO_STATUS_NO_MEMORY;
+    }
+
+    stream = _cairo_pdf_surface_new_object (surface);
+    _cairo_output_stream_printf (surface->output,
+				 "%d 0 obj\r\n"
+				 "<< /Filter /FlateDecode\r\n"
+				 "   /Length %lu\r\n"
+				 "   /Subtype /Type1C\r\n"
+				 ">>\r\n"
+				 "stream\r\n",
+				 stream.id,
+				 compressed_length);
+    _cairo_output_stream_write (surface->output, compressed, compressed_length);
+    _cairo_output_stream_printf (surface->output,
+				 "\r\n"
+				 "endstream\r\n"
+				 "endobj\r\n");
+    free (compressed);
+
+    descriptor = _cairo_pdf_surface_new_object (surface);
+    _cairo_output_stream_printf (surface->output,
+				 "%d 0 obj\r\n"
+				 "<< /Type /FontDescriptor\r\n"
+				 "   /FontName /%s\r\n"
+				 "   /Flags 4\r\n"
+				 "   /FontBBox [ %ld %ld %ld %ld ]\r\n"
+				 "   /ItalicAngle 0\r\n"
+				 "   /Ascent %ld\r\n"
+				 "   /Descent %ld\r\n"
+				 "   /CapHeight 500\r\n"
+				 "   /StemV 80\r\n"
+				 "   /StemH 80\r\n"
+				 "   /FontFile3 %u 0 R\r\n"
+				 ">>\r\n"
+				 "endobj\r\n",
+				 descriptor.id,
+				 subset.base_font,
+				 subset.x_min,
+				 subset.y_min,
+				 subset.x_max,
+				 subset.y_max,
+				 subset.ascent,
+				 subset.descent,
+				 stream.id);
+
+    subset_resource = _cairo_pdf_surface_new_object (surface);
+    _cairo_output_stream_printf (surface->output,
+				 "%d 0 obj\r\n"
+				 "<< /Type /Font\r\n"
+				 "   /Subtype /Type1\r\n"
+				 "   /BaseFont /%s\r\n"
+				 "   /FirstChar 0\r\n"
+				 "   /LastChar %d\r\n"
+				 "   /FontDescriptor %d 0 R\r\n"
+				 "   /Widths [",
+				 subset_resource.id,
+				 subset.base_font,
+				 font_subset->num_glyphs,
+				 descriptor.id);
+
+    for (i = 0; i < font_subset->num_glyphs; i++)
+	_cairo_output_stream_printf (surface->output,
+				     " %d",
+				     subset.widths[i]);
+
+    _cairo_output_stream_printf (surface->output,
+				 " ]\r\n"
+				 ">>\r\n"
+				 "endobj\r\n");
+
+    font.font_id = font_subset->font_id;
+    font.subset_id = font_subset->subset_id;
+    font.subset_resource = subset_resource;
+    _cairo_array_append (&surface->fonts, &font);
+
+    _cairo_cff_subset_fini (&subset);
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
 static cairo_status_t
 _cairo_pdf_surface_emit_type1_font (cairo_pdf_surface_t		*surface,
                                     cairo_scaled_font_subset_t	*font_subset,
@@ -2059,6 +2162,10 @@ _cairo_pdf_surface_emit_font_subset (cairo_scaled_font_subset_t	*font_subset,
     cairo_pdf_surface_t *surface = closure;
     cairo_status_t status;
 
+    status = _cairo_pdf_surface_emit_cff_font_subset (surface, font_subset);
+    if (status != CAIRO_INT_STATUS_UNSUPPORTED)
+	return;
+
 #if CAIRO_HAS_FT_FONT
     status = _cairo_pdf_surface_emit_type1_font_subset (surface, font_subset);
     if (status != CAIRO_INT_STATUS_UNSUPPORTED)

src/cairo-scaled-font-subsets-private.h

@@ -179,6 +179,46 @@ _cairo_scaled_font_subsets_foreach (cairo_scaled_font_subsets_t			*font_subsets,
 				    cairo_scaled_font_subset_callback_func_t	 font_subset_callback,
 				    void					*closure);
 
+typedef struct _cairo_cff_subset {
+    char *base_font;
+    int *widths;
+    long x_min, y_min, x_max, y_max;
+    long ascent, descent;
+    char *data;
+    unsigned long data_length;
+} cairo_cff_subset_t;
+
+/**
+ * _cairo_cff_subset_init:
+ * @cff_subset: a #cairo_cff_subset_t to initialize
+ * @font_subset: the #cairo_scaled_font_subset_t to initialize from
+ *
+ * If possible (depending on the format of the underlying
+ * cairo_scaled_font_t and the font backend in use) generate a
+ * cff file corresponding to @font_subset and initialize
+ * @cff_subset with information about the subset and the cff
+ * data.
+ *
+ * Return value: CAIRO_STATUS_SUCCESS if successful,
+ * CAIRO_INT_STATUS_UNSUPPORTED if the font can't be subset as a
+ * cff file, or an non-zero value indicating an error.  Possible
+ * errors include CAIRO_STATUS_NO_MEMORY.
+ **/
+cairo_private cairo_status_t
+_cairo_cff_subset_init (cairo_cff_subset_t          *cff_subset,
+                        const char                  *name,
+                        cairo_scaled_font_subset_t  *font_subset);
+
+/**
+ * _cairo_cff_subset_fini:
+ * @cff_subset: a #cairo_cff_subset_t
+ *
+ * Free all resources associated with @cff_subset.  After this
+ * call, @cff_subset should not be used again without a
+ * subsequent call to _cairo_cff_subset_init() again first.
+ **/
+cairo_private void
+_cairo_cff_subset_fini (cairo_cff_subset_t *cff_subset);
 
 typedef struct _cairo_truetype_subset {
     char *base_font;

src/cairo-truetype-subset-private.h

@@ -51,6 +51,7 @@
  */
 
 #define MAKE_TT_TAG(a, b, c, d)    (a<<24 | b<<16 | c<<8 | d)
+#define TT_TAG_CFF    MAKE_TT_TAG('C','F','F',' ')
 #define TT_TAG_cmap   MAKE_TT_TAG('c','m','a','p')
 #define TT_TAG_cvt    MAKE_TT_TAG('c','v','t',' ')
 #define TT_TAG_fpgm   MAKE_TT_TAG('f','p','g','m')