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, 9 insertions, 3 deletions

diff --git a/include/mupdf/fitz/font.h b/include/mupdf/fitz/font.h
index ffba996c..c5e72f05 100644
--- a/include/mupdf/fitz/font.h
+++ b/include/mupdf/fitz/font.h
@@ -61,13 +61,19 @@ struct fz_font_s
 	int *width_table; /* in 1000 units */
 };
 
+/* common CJK font collections */
+enum { FZ_ADOBE_CNS_1, FZ_ADOBE_GB_1, FZ_ADOBE_JAPAN_1, FZ_ADOBE_KOREA_1 };
+
 void fz_new_font_context(fz_context *ctx);
 fz_font_context *fz_keep_font_context(fz_context *ctx);
 void fz_drop_font_context(fz_context *ctx);
 
-typedef fz_buffer *(*fz_load_system_font_func)(fz_context *ctx, const char *name);
-void fz_install_load_system_font_func(fz_context *ctx, fz_load_system_font_func f);
-fz_buffer *fz_load_system_font(fz_context *ctx, const char *name);
+typedef fz_font *(*fz_load_system_font_func)(fz_context *ctx, const char *name, int is_substitute);
+typedef fz_font *(*fz_load_system_cjk_font_func)(fz_context *ctx, const char *name, int ros, int serif);
+void fz_install_load_system_font_funcs(fz_context *ctx, fz_load_system_font_func f, fz_load_system_cjk_font_func f_cjk);
+/* fz_load_*_font returns NULL if no font could be loaded (also on error) */
+fz_font *fz_load_system_font(fz_context *ctx, const char *name, int is_substitute);
+fz_font *fz_load_system_cjk_font(fz_context *ctx, const char *name, int ros, int serif);
 
 fz_font *fz_new_type3_font(fz_context *ctx, const char *name, const fz_matrix *matrix);