Introduce bitmap runs

Prepare for run-based rendering. In the parser, increment a run id
according to relevant style changes (color, border, shadow, etc.) to
mark the points where a new bitmap needs to be started. Modify the line
wrapper to increment the run ids of each glyph after a break.
Add functions to calculate the render size of runs for rasterization.

1 files changed, 5 insertions, 0 deletions

diff --git a/libass/ass_render.h b/libass/ass_render.h
index 80ec394..a204145 100644
--- a/libass/ass_render.h
+++ b/libass/ass_render.h
@@ -123,6 +123,8 @@ typedef struct {
     double fax, fay;            // text shearing
     unsigned italic;
 
+    int bm_run_id;
+
     BitmapHashKey hash_key;
 } GlyphInfo;
 
@@ -187,6 +189,9 @@ typedef struct {
     int effect_timing;
     int effect_skip_timing;
 
+    // bitmap run id (used for final bitmap rendering)
+    int bm_run_id;
+
     enum {
         SCROLL_LR,              // left-to-right
         SCROLL_RL,