fix Skia Windows text rendering

There are two cases in WinSalGraphics::DrawTextLayout(), with and
without cached glyphs:
- Cached case DeferredTextDraw() gets data as BGRA with the glyph
drawn in white, it just needs to be modulated to the proper color
and drawn.
- Uncached case DrawTextMask() gets data as BGRA with A invalid,
it must be used as mask for the color to drawn, but without
the inverse alpha VCL idiosyncracy that DrawMask() handles.

Change-Id: I05dcec994df68d5986cd85cffa42a8f9f23c42c4

2 files changed, 7 insertions, 4 deletions

diff --git a/vcl/inc/win/salgdi.h b/vcl/inc/win/salgdi.h
index f7fb206624b5..fc12bc823b93 100644
--- a/vcl/inc/win/salgdi.h
+++ b/vcl/inc/win/salgdi.h
@@ -138,11 +138,14 @@ public:
     /// Base texture class (OpenGL and Skia will provide their implementations).
     struct Texture;
 
-    /// Obtain the texture.
-    virtual std::unique_ptr<Texture> getTexture() { abort(); };
+    /// Obtain the texture in format for WinSalGraphicsImplBase::DrawTextMask().
+    virtual std::unique_ptr<Texture> getAsMaskTexture() { abort(); };
 
     /// Copy bitmap data to the texture. Texture must be initialized and the correct size to hold the bitmap.
     virtual bool copyToTexture(Texture& /*aTexture*/) { abort(); };
+
+    /// Return true if text glyphs should be drawn as white instead of black.
+    virtual bool wantsTextColorWhite() const { return false; }
 };
 
 struct CompatibleDC::Texture
diff --git a/vcl/inc/win/wingdiimpl.hxx b/vcl/inc/win/wingdiimpl.hxx
index 2264eecf353d..84884220318f 100644
--- a/vcl/inc/win/wingdiimpl.hxx
+++ b/vcl/inc/win/wingdiimpl.hxx
@@ -39,8 +39,8 @@ public:
     virtual bool UseTextDraw() const { return false; }
     virtual void PreDrawText() {}
     virtual void PostDrawText() {}
-    virtual void DrawMask(CompatibleDC::Texture* /*rTexture*/, Color /*nMaskColor*/,
-                          const SalTwoRect& /*rPosAry*/)
+    virtual void DrawTextMask(CompatibleDC::Texture* /*rTexture*/, Color /*nMaskColor*/,
+                              const SalTwoRect& /*rPosAry*/)
     {
         abort();
     };