prefer DirectWrite for Skia's Windows text rendering

Change-Id: Ibfb6206751126def10905bb22effbe1a947cd6d6
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/91968
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

3 files changed, 91 insertions, 0 deletions

diff --git a/external/skia/UnpackedTarball_skia.mk b/external/skia/UnpackedTarball_skia.mk
index da0a2a7a0547..82fdbc433ece 100644
--- a/external/skia/UnpackedTarball_skia.mk
+++ b/external/skia/UnpackedTarball_skia.mk
@@ -33,6 +33,7 @@ skia_patches := \
     operator-eq-bool.patch.0 \
     fix-without-gl.patch.0 \
     extend-rgb-to-rgba.patch.0 \
+    windows-typeface-directwrite.patch.0 \
 
 $(eval $(call gb_UnpackedTarball_set_patchlevel,skia,1))
 
diff --git a/external/skia/windows-text-gamma.patch.0 b/external/skia/windows-text-gamma.patch.0
index 366b67f15a65..624636b7da99 100644
--- a/external/skia/windows-text-gamma.patch.0
+++ b/external/skia/windows-text-gamma.patch.0
@@ -26,3 +26,45 @@
              RGBToLcd16<false>(src, srcRB, glyph, fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
          }
      }
+--- ./src/ports/SkScalerContext_win_dw.cpp
++++ ./src/ports/SkScalerContext_win_dw.cpp
+@@ -1132,27 +1132,36 @@ void SkScalerContext_DW::generateImage(const SkGlyph& glyph) {
+         BilevelToBW(src, glyph);
+     } else if (!isLCD(fRec)) {
+         if (textureType == DWRITE_TEXTURE_ALIASED_1x1) {
++#if defined(SK_GAMMA_APPLY_TO_A8)
+             if (fPreBlend.isApplicable()) {
+                 GrayscaleToA8<true>(src, glyph, fPreBlend.fG);
+-            } else {
++            } else
++#endif
++            {
+                 GrayscaleToA8<false>(src, glyph, fPreBlend.fG);
+             }
+         } else {
++#if defined(SK_GAMMA_APPLY_TO_A8)
+             if (fPreBlend.isApplicable()) {
+                 RGBToA8<true>(src, glyph, fPreBlend.fG);
+-            } else {
++            } else
++#endif
++            {
+                 RGBToA8<false>(src, glyph, fPreBlend.fG);
+             }
+         }
+     } else {
+         SkASSERT(SkMask::kLCD16_Format == glyph.fMaskFormat);
++#if defined(SK_GAMMA_APPLY_TO_A8)
+         if (fPreBlend.isApplicable()) {
+             if (fRec.fFlags & SkScalerContext::kLCD_BGROrder_Flag) {
+                 RGBToLcd16<true, false>(src, glyph, fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
+             } else {
+                 RGBToLcd16<true, true>(src, glyph, fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
+             }
+-        } else {
++        } else
++#endif
++        {
+             if (fRec.fFlags & SkScalerContext::kLCD_BGROrder_Flag) {
+                 RGBToLcd16<false, false>(src, glyph, fPreBlend.fR, fPreBlend.fG, fPreBlend.fB);
+             } else {
diff --git a/external/skia/windows-typeface-directwrite.patch.0 b/external/skia/windows-typeface-directwrite.patch.0
new file mode 100644
index 000000000000..56e8209cedb4
--- /dev/null
+++ b/external/skia/windows-typeface-directwrite.patch.0
@@ -0,0 +1,48 @@
+--- ./include/ports/SkTypeface_win.h
++++ ./include/ports/SkTypeface_win.h
+@@ -75,5 +75,13 @@ SK_API sk_sp<SkFontMgr> SkFontMgr_New_DirectWriteRenderer(sk_sp<SkRemotableFontM
+  */
+ SK_API sk_sp<SkRemotableFontMgr> SkRemotableFontMgr_New_DirectWrite();
+ 
++struct IDWriteFontFace;
++struct IDWriteFont;
++struct IDWriteFontFamily;
++SK_API SkTypeface* SkCreateTypefaceDirectWrite(sk_sp<SkFontMgr> fontMgr,
++                                               IDWriteFontFace* fontFace,
++                                               IDWriteFont* font,
++                                               IDWriteFontFamily* fontFamily);
++
+ #endif  // SK_BUILD_FOR_WIN
+ #endif  // SkTypeface_win_DEFINED
+--- ./src/ports/SkFontMgr_win_dw.cpp
++++ ./src/ports/SkFontMgr_win_dw.cpp
+@@ -320,6 +320,10 @@ private:
+ 
+     friend class SkFontStyleSet_DirectWrite;
+     friend class FontFallbackRenderer;
++    friend SK_API SkTypeface* SkCreateTypefaceDirectWrite(sk_sp<SkFontMgr> fontMgr,
++                                               IDWriteFontFace* fontFace,
++                                               IDWriteFont* font,
++                                               IDWriteFontFamily* fontFamily);
+ };
+ 
+ class SkFontStyleSet_DirectWrite : public SkFontStyleSet {
+@@ -1215,6 +1219,18 @@ SK_API sk_sp<SkFontMgr> SkFontMgr_New_DirectWrite(IDWriteFactory* factory,
+                                              defaultFamilyName, defaultFamilyNameLen);
+ }
+ 
++SkTypeface* SkCreateTypefaceDirectWrite(sk_sp<SkFontMgr> fontMgr,
++                                        IDWriteFontFace* fontFace,
++                                        IDWriteFont* font,
++                                        IDWriteFontFamily* fontFamily)
++{
++    SkFontMgr_DirectWrite* mgr = dynamic_cast<SkFontMgr_DirectWrite*>(fontMgr.get());
++    if(!mgr)
++        return nullptr;
++    sk_sp<SkTypeface> typeface = mgr->makeTypefaceFromDWriteFont(fontFace, font, fontFamily);
++    return typeface.release();
++}
++
+ #include "include/ports/SkFontMgr_indirect.h"
+ SK_API sk_sp<SkFontMgr> SkFontMgr_New_DirectWriteRenderer(sk_sp<SkRemotableFontMgr> proxy) {
+     sk_sp<SkFontMgr> impl(SkFontMgr_New_DirectWrite());