vcl/inc/impglyphitem.hxx | 1 +
vcl/source/gdi/impglyphitem.cxx | 30 ++++++++++++++++++++++++++----
2 files changed, 27 insertions(+), 4 deletions(-)
New commits:
commit 5caa7f44b861876afa5b3b8f71e3848abd8875e6
Author: Luboš Luňák <l.lu...@collabora.com>
AuthorDate: Wed May 11 16:32:52 2022 +0200
Commit: Luboš Luňák <l.lu...@collabora.com>
CommitDate: Wed May 11 19:00:42 2022 +0200
fix HB_GLYPH_FLAG_UNSAFE_TO_BREAK for RTL in cloneCharRange() (tdf#148954)
I got the meaning wrong, when the docs talk about beginning of a cluster,
that refers to text, not glyphs, so this needs to be backwards too.
Change-Id: I12ef775b033100405e3332d5611844cefb6b5a85
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/134173
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lu...@collabora.com>
diff --git a/vcl/inc/impglyphitem.hxx b/vcl/inc/impglyphitem.hxx
index e86c2652100a..18764cede500 100644
--- a/vcl/inc/impglyphitem.hxx
+++ b/vcl/inc/impglyphitem.hxx
@@ -153,6 +153,7 @@ public:
#endif
private:
+ bool isSafeToBreak(const_iterator pos, bool rtl) const;
rtl::Reference<LogicalFontInstance> m_rFontInstance;
SalLayoutFlags mnFlags = SalLayoutFlags::NONE;
};
diff --git a/vcl/source/gdi/impglyphitem.cxx b/vcl/source/gdi/impglyphitem.cxx
index 43f102102210..648696a55107 100644
--- a/vcl/source/gdi/impglyphitem.cxx
+++ b/vcl/source/gdi/impglyphitem.cxx
@@ -128,9 +128,7 @@ SalLayoutGlyphsImpl*
SalLayoutGlyphsImpl::cloneCharRange(sal_Int32 index, sal_In
// (for non-RTL charPos is always the start of a multi-character glyph).
if (rtl && pos->charPos() + pos->charCount() > beginPos + 1)
return nullptr;
- // Don't create a subset if it's not safe to break at the beginning or end
of the sequence
- // (https://harfbuzz.github.io/harfbuzz-hb-buffer.html#hb-glyph-flags-t).
- if (pos->IsUnsafeToBreak() || (pos->IsInCluster() &&
!pos->IsClusterStart()))
+ if (!isSafeToBreak(pos, rtl))
return nullptr;
// LinearPos needs adjusting to start at xOffset/yOffset for the first
item,
// that's how it's computed in GenericSalLayout::LayoutText().
@@ -163,7 +161,7 @@ SalLayoutGlyphsImpl*
SalLayoutGlyphsImpl::cloneCharRange(sal_Int32 index, sal_In
// that we're not cutting in the middle of a multi-character glyph.
if (rtl ? pos->charPos() + pos->charCount() != endPos + 1 :
pos->charPos() != endPos)
return nullptr;
- if (pos->IsUnsafeToBreak() || (pos->IsInCluster() &&
!pos->IsClusterStart()))
+ if (!isSafeToBreak(pos, rtl))
return nullptr;
}
// HACK: If mode is se to be RTL, but the last glyph is a non-RTL space,
@@ -179,6 +177,30 @@ SalLayoutGlyphsImpl*
SalLayoutGlyphsImpl::cloneCharRange(sal_Int32 index, sal_In
return copy.release();
}
+bool SalLayoutGlyphsImpl::isSafeToBreak(const_iterator pos, bool rtl) const
+{
+ if (rtl)
+ {
+ // RTL is more complicated, because HB_GLYPH_FLAG_UNSAFE_TO_BREAK
talks about beginning
+ // of a cluster, which refers to the text, not glyphs. This function
is called
+ // for the first glyph of the subset and the first glyph after the
subset, but since
+ // the glyphs are backwards, and we need the beginning of cluster at
the start of the text
+ // and beginning of the cluster after the text, we need to check
glyphs before this position.
+ if (pos == begin())
+ return true;
+ --pos;
+ while (pos >= begin() && (pos->IsInCluster() &&
!pos->IsClusterStart()))
+ --pos;
+ if (pos < begin())
+ return true;
+ }
+ // Don't create a subset if it's not safe to break at the beginning or end
of the sequence
+ // (https://harfbuzz.github.io/harfbuzz-hb-buffer.html#hb-glyph-flags-t).
+ if (pos->IsUnsafeToBreak() || (pos->IsInCluster() &&
!pos->IsClusterStart()))
+ return false;
+ return true;
+}
+
#ifdef DBG_UTIL
bool SalLayoutGlyphsImpl::isEqual(const SalLayoutGlyphsImpl* other) const
{
