From 512444c15e69a78ae82a8e9ff0e7bdef9f93bbcf Mon Sep 17 00:00:00 2001
From: Oleg Oshmyan <chortos@inbox.lv>
Date: Mon, 19 Oct 2020 16:25:58 +0300
Subject: Improve \kf position rounding

---
 libass/ass_parse.c  | 12 ++++++------
 libass/ass_render.c |  2 +-
 libass/ass_render.h |  4 ++--
 3 files changed, 9 insertions(+), 9 deletions(-)

(limited to 'libass')

diff --git a/libass/ass_parse.c b/libass/ass_parse.c
index ef4b0e0..9107545 100644
--- a/libass/ass_parse.c
+++ b/libass/ass_parse.c
@@ -1006,12 +1006,12 @@ void process_karaoke_effects(ASS_Renderer *render_priv)
 
         int x;
         if (tm_current < tm_start)
-            x = -1000000;
+            x = -100000000;
         else if (tm_current >= tm_end)
-            x = 1000000;
+            x = 100000000;
         else {
-            int x_start = d6_to_int(start->pos.x);
-            int x_end = d6_to_int(end[-1].pos.x + end[-1].advance.x);
+            int x_start = start->pos.x;
+            int x_end = end[-1].pos.x + end[-1].advance.x;
             double dt = (double) (tm_current - tm_start) / (tm_end - tm_start);
             double frz = fmod(start->frz, 360);
             if (frz > 90 && frz < 270) {
@@ -1023,12 +1023,12 @@ void process_karaoke_effects(ASS_Renderer *render_priv)
                     info->c[1] = tmp;
                 }
             }
-            x = x_start + (x_end - x_start) * dt;
+            x = x_start + lrint((x_end - x_start) * dt);
         }
 
         for (GlyphInfo *info = start; info < end; info++) {
             info->effect_type = effect_type;
-            info->effect_timing = x - d6_to_int(info->pos.x);
+            info->effect_timing = x - info->pos.x;
         }
     }
 }
diff --git a/libass/ass_render.c b/libass/ass_render.c
index e8254f2..fbe2765 100644
--- a/libass/ass_render.c
+++ b/libass/ass_render.c
@@ -2417,7 +2417,7 @@ static void render_and_combine_glyphs(ASS_Renderer *render_priv,
         }
 
         if (info->effect_type == EF_KARAOKE_KF)
-            info->effect_timing += d6_to_int(info->leftmost_x);
+            info->effect_timing = d6_to_int(info->leftmost_x + info->effect_timing);
 
         for (int j = 0; j < info->bitmap_count; j++) {
             info->bitmaps[j].pos.x -= info->x;
diff --git a/libass/ass_render.h b/libass/ass_render.h
index 9796841..803b577 100644
--- a/libass/ass_render.h
+++ b/libass/ass_render.h
@@ -100,7 +100,7 @@ typedef struct {
     uint32_t c[4];              // colors
     Effect effect_type;
 
-    // during render_and_combine_glyphs: distance in pixels from the karaoke origin.
+    // during render_and_combine_glyphs: distance in subpixels from the karaoke origin.
     // after render_and_combine_glyphs: screen coordinate in pixels.
     // part of the glyph to the left of it is displayed in a different color.
     int effect_timing;
@@ -147,7 +147,7 @@ typedef struct glyph_info {
     ASS_Vector cluster_advance;
     Effect effect_type;
     int effect_timing;          // time duration of current karaoke word
-    // after process_karaoke_effects: distance in pixels from the karaoke origin.
+    // after process_karaoke_effects: distance in subpixels from the karaoke origin.
     // part of the glyph to the left of it is displayed in a different color.
     int effect_skip_timing;     // delay after the end of last karaoke word
     int asc, desc;              // font max ascender and descender
-- 
cgit v1.2.3