cache: switch to gradual cache clearing

Advantages over the old algorithm consist of the following.
 * There are no glitches due to full cache clearing.
   Items are arranged into linked list ordered by time of last use.
   Only the oldest items get deleted at the clearing event.
 * Each item now keeps track of number of references.
   Referenced cache values are immune to clearing.
 * Reduced amount of total cache memory for the same performance.
 * Reduced number of memory allocations per cache item.

1 files changed, 1 insertions, 1 deletions

diff --git a/libass/ass_font.h b/libass/ass_font.h
index 9fc4532..3035654 100644
--- a/libass/ass_font.h
+++ b/libass/ass_font.h
@@ -74,7 +74,7 @@ uint32_t ass_font_index_magic(FT_Face face, uint32_t symbol);
 FT_Glyph ass_font_get_glyph(ASS_Font *font,
                             uint32_t ch, int face_index, int index,
                             ASS_Hinting hinting, int deco);
-void ass_font_free(ASS_Font *font);
+void ass_font_clear(ASS_Font *font);
 
 void outline_translate(const ASS_Outline *outline, FT_Pos dx, FT_Pos dy);
 void outline_transform(const ASS_Outline *outline, const FT_Matrix *matrix);