Adding code to calculate Underline Thickness from Font Metrics, this will be useful when Skia is us…

src/core/SkPaint.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPaint.h"
 #include "SkAnnotation.h"
@@ skipping 1278 matching lines @@
     if (scale) {
         metrics->fTop = SkScalarMul(metrics->fTop, scale);
         metrics->fAscent = SkScalarMul(metrics->fAscent, scale);
         metrics->fDescent = SkScalarMul(metrics->fDescent, scale);
         metrics->fBottom = SkScalarMul(metrics->fBottom, scale);
         metrics->fLeading = SkScalarMul(metrics->fLeading, scale);
         metrics->fAvgCharWidth = SkScalarMul(metrics->fAvgCharWidth, scale);
         metrics->fXMin = SkScalarMul(metrics->fXMin, scale);
         metrics->fXMax = SkScalarMul(metrics->fXMax, scale);
         metrics->fXHeight = SkScalarMul(metrics->fXHeight, scale);
+        metrics->fUnderlineThickness = SkScalarMul(metrics->fUnderlineThickness, scale);
+        metrics->fUnderlinePosition = SkScalarMul(metrics->fUnderlinePosition, scale);
     }
     return metrics->fDescent - metrics->fAscent + metrics->fLeading;
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 static void set_bounds(const SkGlyph& g, SkRect* bounds, SkScalar scale) {
     bounds->set(g.fLeft * scale,
                 g.fTop * scale,
                 (g.fLeft + g.fWidth) * scale,
@@ skipping 941 matching lines @@
         this->getMaskFilter()->computeFastBounds(*storage, storage);
     }
 
     if (this->getImageFilter()) {
         this->getImageFilter()->computeFastBounds(*storage, storage);
     }
 
     return *storage;
 }
 
+void SkPaint::FontMetrics::setFontMetricsFlag(FontMetrics::FontMetricsFlags flag) {
+    fFontMetricsFlag |= flag;
+}
+
+void SkPaint::FontMetrics::unsetFontMetricsFlag(FontMetrics::FontMetricsFlags flag) {
+    fFontMetricsFlag &= ~flag;
+}
+
+bool SkPaint::FontMetrics::checkFontMetricsFlag(FontMetrics::FontMetricsFlags flag) const {
+   return SkToBool(fFontMetricsFlag & flag);

[bungeman-skia, 2014/02/20 16:52:46]

If going with the uint32_t version of these, the setters above are still good,
but this would become

SkToBool((fFontMetricsFlag & flag) == flag);

or something equivalent. I do believe that all of these implementations should
be inlined (in SkPaint.h) as they're just named bit twiddles.

+}
+
 #ifdef SK_DEVELOPER
 void SkPaint::toString(SkString* str) const {
     str->append("<dl><dt>SkPaint:</dt><dd><dl>");
 
     SkTypeface* typeface = this->getTypeface();
     if (NULL != typeface) {
         SkDynamicMemoryWStream ostream;
         typeface->serialize(&ostream);
         SkAutoTUnref<SkData> data(ostream.copyToData());
 
@@ skipping 273 matching lines @@
             case SkXfermode::kPlus_Mode:
                 return 0 == this->getAlpha();
             case SkXfermode::kDst_Mode:
                 return true;
             default:
                 break;
         }
     }
     return false;
 }