commit ac007669ee7145fdd2c9a91d609ccaa7064bc953
author Ben Wagner <bungeman@google.com> Tue May 19 14:03:27 2020 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Tue May 19 20:44:07 2020 +0000
tree 8e27a1bed7d55a1792348ed8fdf8e99a57da0b09
parent 3298baf6a5a203009b651c0c7f911daf106c6851

Avoid GDI measuring modes with CBDT fonts.

This fixes the scaledemoji_rendering GM CBDT font test for native fonts
with DirectWrite.

Change-Id: I60aaf4fe015e08192b4ac16ddd4436499d4a74ee
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/290820
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>

src/ports/SkScalerContext_win_dw.cpp

diff --git a/src/ports/SkScalerContext_win_dw.cpp b/src/ports/SkScalerContext_win_dw.cpp
index b820890..f95f6c6 100644
--- a/src/ports/SkScalerContext_win_dw.cpp
+++ b/src/ports/SkScalerContext_win_dw.cpp
@@ -368,6 +368,15 @@
         fTextSizeMeasure = realTextSize;
         fMeasuringMode = DWRITE_MEASURING_MODE_NATURAL;
     }
+
+    // The GDI measuring modes don't seem to work well with CBDT fonts (DWrite.dll 10.0.18362.836).
+    if (fMeasuringMode != DWRITE_MEASURING_MODE_NATURAL) {
+        constexpr UINT32 CBDTTag = DWRITE_MAKE_OPENTYPE_TAG('C','B','D','T');
+        AutoDWriteTable CBDT(typeface->fDWriteFontFace.get(), CBDTTag);
+        if (CBDT.fExists) {
+            fMeasuringMode = DWRITE_MEASURING_MODE_NATURAL;
+        }
+    }
 }
 
 SkScalerContext_DW::~SkScalerContext_DW() {