diff options
| -rw-r--r-- | libs/minikin/Layout.cpp | 47 |
1 files changed, 38 insertions, 9 deletions
diff --git a/libs/minikin/Layout.cpp b/libs/minikin/Layout.cpp index 17ce596..0c8c4ca 100644 --- a/libs/minikin/Layout.cpp +++ b/libs/minikin/Layout.cpp @@ -514,6 +514,29 @@ static size_t getNextWordBreak(const uint16_t* chars, size_t offset, size_t len) return len; } +/** + * Disable certain scripts (mostly those with cursive connection) from having letterspacing + * applied. See https://github.com/behdad/harfbuzz/issues/64 for more details. + */ +static bool isScriptOkForLetterspacing(hb_script_t script) { + return !( + script == HB_SCRIPT_ARABIC || + script == HB_SCRIPT_NKO || + script == HB_SCRIPT_PSALTER_PAHLAVI || + script == HB_SCRIPT_MANDAIC || + script == HB_SCRIPT_MONGOLIAN || + script == HB_SCRIPT_PHAGS_PA || + script == HB_SCRIPT_DEVANAGARI || + script == HB_SCRIPT_BENGALI || + script == HB_SCRIPT_GURMUKHI || + script == HB_SCRIPT_MODI || + script == HB_SCRIPT_SHARADA || + script == HB_SCRIPT_SYLOTI_NAGRI || + script == HB_SCRIPT_TIRHUTA || + script == HB_SCRIPT_OGHAM + ); +} + void Layout::doLayout(const uint16_t* buf, size_t start, size_t count, size_t bufSize, int bidiFlags, const FontStyle &style, const MinikinPaint &paint) { AutoMutex _l(gMinikinLock); @@ -678,15 +701,6 @@ void Layout::doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t double size = ctx->paint.size; double scaleX = ctx->paint.scaleX; - double letterSpace = ctx->paint.letterSpacing * size * scaleX; - double letterSpaceHalfLeft; - if ((ctx->paint.paintFlags & LinearTextFlag) == 0) { - letterSpace = round(letterSpace); - letterSpaceHalfLeft = floor(letterSpace * 0.5); - } else { - letterSpaceHalfLeft = letterSpace * 0.5; - } - double letterSpaceHalfRight = letterSpace - letterSpaceHalfLeft; float x = mAdvance; float y = 0; @@ -716,6 +730,21 @@ void Layout::doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t srunend = srunstart; hb_script_t script = getScriptRun(buf + start, run.end, &srunend); + double letterSpace = 0.0; + double letterSpaceHalfLeft = 0.0; + double letterSpaceHalfRight = 0.0; + + if (ctx->paint.letterSpacing != 0.0 && isScriptOkForLetterspacing(script)) { + letterSpace = ctx->paint.letterSpacing * size * scaleX; + if ((ctx->paint.paintFlags & LinearTextFlag) == 0) { + letterSpace = round(letterSpace); + letterSpaceHalfLeft = floor(letterSpace * 0.5); + } else { + letterSpaceHalfLeft = letterSpace * 0.5; + } + letterSpaceHalfRight = letterSpace - letterSpaceHalfLeft; + } + hb_buffer_clear_contents(buffer); hb_buffer_set_script(buffer, script); hb_buffer_set_direction(buffer, isRtl? HB_DIRECTION_RTL : HB_DIRECTION_LTR); |