diff options
Diffstat (limited to 'gfx/harfbuzz/src/hb-ot-math-table.hh')
| -rw-r--r-- | gfx/harfbuzz/src/hb-ot-math-table.hh | 33 |
1 files changed, 13 insertions, 20 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-math-table.hh b/gfx/harfbuzz/src/hb-ot-math-table.hh index 32e497aef6..5839059fde 100644 --- a/gfx/harfbuzz/src/hb-ot-math-table.hh +++ b/gfx/harfbuzz/src/hb-ot-math-table.hh @@ -344,27 +344,20 @@ struct MathKern const MathValueRecord* kernValue = mathValueRecordsZ.arrayZ + heightCount; int sign = font->y_scale < 0 ? -1 : +1; - /* The description of the MathKern table is a ambiguous, but interpreting - * "between the two heights found at those indexes" for 0 < i < len as - * - * correctionHeight[i-1] < correction_height <= correctionHeight[i] - * - * makes the result consistent with the limit cases and we can just use the - * binary search algorithm of std::upper_bound: + /* According to OpenType spec (v1.9), except for the boundary cases, the index + * chosen for kern value should be i such that + * correctionHeight[i-1] <= correction_height < correctionHeight[i] + * We can use the binary search algorithm of std::upper_bound(). Or, we can + * use the internal hb_bsearch_impl. */ - unsigned int i = 0; - unsigned int count = heightCount; - while (count > 0) - { - unsigned int half = count / 2; - hb_position_t height = correctionHeight[i + half].get_y_value (font, this); - if (sign * height < sign * correction_height) - { - i += half + 1; - count -= half + 1; - } else - count = half; - } + unsigned int pos; + auto cmp = +[](const void* key, const void* p, + int sign, hb_font_t* font, const MathKern* mathKern) -> int { + return sign * *(hb_position_t*)key - sign * ((MathValueRecord*)p)->get_y_value(font, mathKern); + }; + unsigned int i = hb_bsearch_impl(&pos, correction_height, correctionHeight, + heightCount, MathValueRecord::static_size, + cmp, sign, font, this) ? pos + 1 : pos; return kernValue[i].get_x_value (font, this); } |