also tdf#137440 and tdf#102780
EMF files with pre-shaped text (e.g. Arabic) use ETO_GLYPH_INDEX in
EMR_EXTTEXTOUTW records. The string data in these records contains
font-specific glyph indices (16-bit IDs), not Unicode codepoints.
Previously, emfio read these glyph indices as Unicode text via
read_uInt16s_ToOUString, then passed them to DrawText which creates
a MetaTextArrayAction. On playback, VCL/HarfBuzz would shape these
fake "characters" again, producing double-shaped garbage output.
Fix this by detecting ETO_GLYPH_INDEX and rendering the pre-shaped
glyphs as filled polypolygon outlines, bypassing text shaping entirely.
Implementation:
- Add OutputDevice::GetGlyphOutlines() as a new VCL public API that
takes raw glyph IDs and returns per-glyph B2DPolyPolygon outlines
by calling LogicalFontInstance::GetGlyphOutline() directly. This is
needed because LogicalFontInstance is in VCL's private headers and
not accessible from emfio.
- Add MtfTools::DrawGlyphs() in emfio that mirrors the DrawText()
setup (position/DX/DY mapping, font/color/alignment MetaActions)
but instead of emitting MetaTextArrayAction, it obtains glyph
outlines via GetGlyphOutlines() on a VirtualDevice, positions each
glyph using the DX/DY array, and emits the combined result as a
filled MetaPolyPolygonAction with the text color.
- Branch in emfreader.cxx: when ETO_GLYPH_INDEX is set on the Unicode
variant (EMR_EXTTEXTOUTW), read glyph indices as sal_uInt16 values
and call DrawGlyphs() instead of DrawText().
- Since glyph indices are font-specific, DrawGlyphs() checks font
availability via IsFontAvailable() before rendering. If the required
font is not installed, it returns false and the code falls back to
the standard DrawText() path (same as before this change).
- Remove the stale SAL_WARN_IF for ETO_PDY|ETO_GLYPH_INDEX, since
both flags are now handled.
Change-Id: Ib6e0a0b1accfe61ff871c391d02f4c529764438c
Reviewed-on: https://gerrit.collaboraoffice.com/c/core/+/318
Tested-by: Jenkins CPCI <releng@collaboraoffice.com>
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
(cherry picked from commit b260c2a6d8313c80720e34a366f01bcd0e429f47)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/204245
Reviewed-by: Xisco Fauli <xiscofauli@libreoffice.org>
Tested-by: Jenkins
Andras Timar
5db6c203f3