vcl: support pre-computed glyph items in OutputDevice::ImplLayout()

This allows using the SalLayoutGlyphs obtained from
GenericSalLayout::GetGlyphs() to return early in
GenericSalLayout::LayoutText().

Change-Id: If3a004f983f3578915786668bfcada00227d2eeb
Reviewed-on: https://gerrit.libreoffice.org/59169
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins

1 files changed, 8 insertions, 1 deletions

diff --git a/vcl/source/gdi/CommonSalLayout.cxx b/vcl/source/gdi/CommonSalLayout.cxx
index 32d8e572156a..fc38b33437e1 100644
--- a/vcl/source/gdi/CommonSalLayout.cxx
+++ b/vcl/source/gdi/CommonSalLayout.cxx
@@ -263,12 +263,19 @@ bool GenericSalLayout::HasVerticalAlternate(sal_UCS4 aChar, sal_UCS4 aVariationS
     return hb_set_has(mpVertGlyphs, nGlyphIndex) != 0;
 }
 
-bool GenericSalLayout::LayoutText(ImplLayoutArgs& rArgs)
+bool GenericSalLayout::LayoutText(ImplLayoutArgs& rArgs, const SalLayoutGlyphs* pGlyphs)
 {
     // No need to touch m_GlyphItems at all for an empty string.
     if (rArgs.mnEndCharPos - rArgs.mnMinCharPos <= 0)
         return true;
 
+    if (pGlyphs)
+    {
+        // Work with pre-computed glyph items.
+        m_GlyphItems = *pGlyphs;
+        return true;
+    }
+
     hb_font_t *pHbFont = mpFont->GetHbFont();
     hb_face_t* pHbFace = hb_font_get_face(pHbFont);