diff options
author | Caolán McNamara <caolanm@redhat.com> | 2019-09-04 10:57:06 +0100 |
---|---|---|
committer | Caolán McNamara <caolanm@redhat.com> | 2019-09-04 13:45:10 +0200 |
commit | df4a6f977843dbf4eb8bb5998b090d92c454611b (patch) | |
tree | 62331cf1d820907c6d8baa4d870c469acb9bb449 | |
parent | 4b3a648a2fd7d733674f95bb7f20670c57e99252 (diff) |
tdf#127189 FreeType <= 2.8 will fail to render stretched horizontal brace...
glyphs in starmath at a fairly low stretch ratio. The failure will set
CAIRO_STATUS_FREETYPE_ERROR on the surface which cannot be cleared, so all
further painting to the surface fails.
This appears fixed in 2.9 with
https://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=91015cb41d8f56777f93394f5a60914bc0c0f330
"Improve complex rendering at high ppem"
Change-Id: I8cbf8347ccd29beda4057b14f2e68678f6030bf4
Reviewed-on: https://gerrit.libreoffice.org/78587
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
-rw-r--r-- | vcl/inc/unx/glyphcache.hxx | 7 | ||||
-rw-r--r-- | vcl/unx/generic/gdi/cairotextrender.cxx | 20 | ||||
-rw-r--r-- | vcl/unx/generic/glyphs/freetype_glyphcache.cxx | 20 |
3 files changed, 47 insertions, 0 deletions
diff --git a/vcl/inc/unx/glyphcache.hxx b/vcl/inc/unx/glyphcache.hxx index 0331d7e9f86e..ccb25cab87e2 100644 --- a/vcl/inc/unx/glyphcache.hxx +++ b/vcl/inc/unx/glyphcache.hxx @@ -117,6 +117,13 @@ public: FreetypeFontInstance* GetFontInstance() const { return mpFontInstance.get(); } void SetFontVariationsOnHBFont(hb_font_t* pHbFace) const; + + // tdf#127189 FreeType <= 2.8 will fail to render stretched horizontal brace glyphs + // in starmath at a fairly low stretch ratio. This appears fixed in 2.9 with + // https://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=91015cb41d8f56777f93394f5a60914bc0c0f330 + // "Improve complex rendering at high ppem" + static bool AlmostHorizontalDrainsRenderingPool(); + private: friend class GlyphCache; friend class FreetypeFontInstance; diff --git a/vcl/unx/generic/gdi/cairotextrender.cxx b/vcl/unx/generic/gdi/cairotextrender.cxx index 8b55ab6da58d..0b24cbf32d63 100644 --- a/vcl/unx/generic/gdi/cairotextrender.cxx +++ b/vcl/unx/generic/gdi/cairotextrender.cxx @@ -204,6 +204,22 @@ void CairoTextRender::DrawTextLayout(const GenericSalLayout& rLayout, const SalG if (nWidth == 0 || nHeight == 0) return; + int nRatio = nWidth * 10 / nHeight; + if (nRatio > 100 && rFSD.maTargetName == "OpenSymbol" && FreetypeFont::AlmostHorizontalDrainsRenderingPool()) + { + // tdf#127189 FreeType <= 2.8 will fail to render stretched horizontal + // brace glyphs in starmath at a fairly low stretch ratio. The failure + // will set CAIRO_STATUS_FREETYPE_ERROR on the surface which cannot be + // cleared, so all further painting to the surface fails. + + // This appears fixed in >= freetype 2.9 + + // Restrict this bodge to a stretch ratio > ~10 of the OpenSymbol font + // where it has been seen in practice. + SAL_WARN("vcl", "rendering text would fail with stretch ratio of: " << nRatio << ", with FreeType <= 2.8"); + return; + } + /* * It might be ideal to cache surface and cairo context between calls and * only destroy it when the drawable changes, but to do that we need to at @@ -330,6 +346,10 @@ void CairoTextRender::DrawTextLayout(const GenericSalLayout& rLayout, const SalG cairo_set_font_matrix(cr, &m); cairo_show_glyphs(cr, &cairo_glyphs[nStartIndex], nLen); + if (cairo_status(cr) != CAIRO_STATUS_SUCCESS) + { + SAL_WARN("vcl", "rendering text failed with stretch ratio of: " << nRatio << ", " << cairo_status_to_string(cairo_status(cr))); + } #if OSL_DEBUG_LEVEL > 2 //draw origin diff --git a/vcl/unx/generic/glyphs/freetype_glyphcache.cxx b/vcl/unx/generic/glyphs/freetype_glyphcache.cxx index 1b3532ceee1b..525da6e52b43 100644 --- a/vcl/unx/generic/glyphs/freetype_glyphcache.cxx +++ b/vcl/unx/generic/glyphs/freetype_glyphcache.cxx @@ -324,6 +324,26 @@ void GlyphCache::InitFreetype() (void)vclFontFileList::get(); } +namespace +{ + bool DoesAlmostHorizontalDrainRenderingPool() + { + FT_Int nMajor, nMinor, nPatch; + FT_Library_Version(aLibFT, &nMajor, &nMinor, &nPatch); + if (nMajor > 2) + return false; + if (nMajor == 2 && nMinor <= 8) + return true; + return false; + } +} + +bool FreetypeFont::AlmostHorizontalDrainsRenderingPool() +{ + static bool bAlmostHorizontalDrainsRenderingPool = DoesAlmostHorizontalDrainRenderingPool(); + return bAlmostHorizontalDrainsRenderingPool; +} + FT_Face FreetypeFont::GetFtFace() const { FT_Activate_Size( maSizeFT ); |