Bug 694851: enhance fz_load_system_font

For SumatraPDF, the following changes are required:
* fz_load_system_font is called from pdf_load_builtin_font as well so
  that Arial, Courier New, etc. can be loaded from the system instead
  of their Nimbus replacements. In order to distinguish between calls
  from pdf_load_builtin_font and pdf_load_substitute_font, an
  is_substitute argument is added.
* fz_load_system_cjk_font is added and called from
  pdf_load_substitute_cjk_font so that a better replacement font can
  be loaded instead of DroidSansFallback.
* Both fz_load_system_font and fz_load_system_cjk_font return fz_font*
  instead of fz_buffer* so that implementers aren't required to load
  fonts into memory (SumatraPDF uses fz_new_font_from_file for system
  fonts).

In addition to that, fz_load_system_font_func is renamed to
fz_load_system_font_funcs since it now accepts two functions, and the
PDF_ROS_* constants are renamed to FZ_ADOBE_* (collection names aren't
passed as const char* so that implementers know which collections to
expect). For convenience, fz_load_*_font also never throws since
currently all callers have further fallbacks available.

1 files changed, 29 insertions, 27 deletions

diff --git a/source/pdf/pdf-font.c b/source/pdf/pdf-font.c
index efb1eee6..11b009b3 100644
--- a/source/pdf/pdf-font.c
+++ b/source/pdf/pdf-font.c
@@ -175,17 +175,22 @@ static int lookup_mre_code(char *name)
 static void
 pdf_load_builtin_font(fz_context *ctx, pdf_font_desc *fontdesc, char *fontname)
 {
-	unsigned char *data;
-	unsigned int len;
 	FT_Face face;
 
-	fontname = clean_font_name(fontname);
+	fontdesc->font = fz_load_system_font(ctx, fontname, 0);
+	if (!fontdesc->font)
+	{
+		unsigned char *data;
+		unsigned int len;
+
+		fontname = clean_font_name(fontname);
 
-	data = pdf_lookup_builtin_font(fontname, &len);
-	if (!data)
-		fz_throw(ctx, FZ_ERROR_GENERIC, "cannot find builtin font: '%s'", fontname);
+		data = pdf_lookup_builtin_font(fontname, &len);
+		if (!data)
+			fz_throw(ctx, FZ_ERROR_GENERIC, "cannot find builtin font: '%s'", fontname);
 
-	fontdesc->font = fz_new_font_from_memory(ctx, fontname, data, len, 0, 1);
+		fontdesc->font = fz_new_font_from_memory(ctx, fontname, data, len, 0, 1);
+	}
 
 	if (!strcmp(fontname, "Symbol") || !strcmp(fontname, "ZapfDingbats"))
 		fontdesc->flags |= PDF_FD_SYMBOLIC;
@@ -198,15 +203,8 @@ pdf_load_builtin_font(fz_context *ctx, pdf_font_desc *fontdesc, char *fontname)
 static void
 pdf_load_substitute_font(fz_context *ctx, pdf_font_desc *fontdesc, char *fontname, int mono, int serif, int bold, int italic)
 {
-	fz_buffer *buffer;
-
-	buffer = fz_load_system_font(ctx, fontname);
-	if (buffer)
-	{
-		fontdesc->font = fz_new_font_from_buffer(ctx, fontname, buffer, 0, 1);
-		fz_drop_buffer(ctx, buffer);
-	}
-	else
+	fontdesc->font = fz_load_system_font(ctx, fontname, 1);
+	if (!fontdesc->font)
 	{
 		unsigned char *data;
 		unsigned int len;
@@ -226,15 +224,19 @@ pdf_load_substitute_font(fz_context *ctx, pdf_font_desc *fontdesc, char *fontnam
 static void
 pdf_load_substitute_cjk_font(fz_context *ctx, pdf_font_desc *fontdesc, char *fontname, int ros, int serif)
 {
-	unsigned char *data;
-	unsigned int len;
+	fontdesc->font = fz_load_system_cjk_font(ctx, fontname, ros, serif);
+	if (!fontdesc->font)
+	{
+		unsigned char *data;
+		unsigned int len;
 
-	data = pdf_lookup_substitute_cjk_font(ros, serif, &len);
-	if (!data)
-		fz_throw(ctx, FZ_ERROR_GENERIC, "cannot find builtin CJK font");
+		data = pdf_lookup_substitute_cjk_font(ros, serif, &len);
+		if (!data)
+			fz_throw(ctx, FZ_ERROR_GENERIC, "cannot find builtin CJK font");
 
-	/* a glyph bbox cache is too big for droid sans fallback (51k glyphs!) */
-	fontdesc->font = fz_new_font_from_memory(ctx, fontname, data, len, 0, 0);
+		/* a glyph bbox cache is too big for droid sans fallback (51k glyphs!) */
+		fontdesc->font = fz_new_font_from_memory(ctx, fontname, data, len, 0, 0);
+	}
 
 	fontdesc->font->ft_substitute = 1;
 }
@@ -266,13 +268,13 @@ pdf_load_system_font(fz_context *ctx, pdf_font_desc *fontdesc, char *fontname, c
 	if (collection)
 	{
 		if (!strcmp(collection, "Adobe-CNS1"))
-			pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, PDF_ROS_CNS, serif);
+			pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, FZ_ADOBE_CNS_1, serif);
 		else if (!strcmp(collection, "Adobe-GB1"))
-			pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, PDF_ROS_GB, serif);
+			pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, FZ_ADOBE_GB_1, serif);
 		else if (!strcmp(collection, "Adobe-Japan1"))
-			pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, PDF_ROS_JAPAN, serif);
+			pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, FZ_ADOBE_JAPAN_1, serif);
 		else if (!strcmp(collection, "Adobe-Korea1"))
-			pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, PDF_ROS_KOREA, serif);
+			pdf_load_substitute_cjk_font(ctx, fontdesc, fontname, FZ_ADOBE_KOREA_1, serif);
 		else
 		{
 			if (strcmp(collection, "Adobe-Identity") != 0)