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

src/core/SkPaint.cpp

Index: src/core/SkPaint.cpp
diff --git a/src/core/SkPaint.cpp b/src/core/SkPaint.cpp
index c3f217cefc60e5501e08a88755b5f537dbcb956c..fae4fc49d89c68f3c60bfabc5294e2d267dd285a 100644
--- a/src/core/SkPaint.cpp
+++ b/src/core/SkPaint.cpp
@@ -1296,6 +1296,8 @@ SkScalar SkPaint::getFontMetrics(FontMetrics* metrics, SkScalar zoom) const {
         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;
 }
@@ -2257,6 +2259,21 @@ const SkRect& SkPaint::doComputeFastBounds(const SkRect& origSrc,
     return *storage;
 }
 
+void SkPaint::FontMetrics::setFontMetricsFlag(FontMetrics::FontMetricsFlags flag)
+{

[bungeman-skia, 2014/02/19 15:39:17]

Style nit: we usually put this '{' at the end of the line above.

[h.joshi, 2014/02/19 17:12:03]

Will make changes
On 2014/02/19 15:39:17, bungeman1 wrote:

+    this->fFontMetricsFlag = this->fFontMetricsFlag | flag;

[bungeman-skia, 2014/02/19 15:39:17]

This might be clearer like

fFontMetricsFlag |= flag;

[h.joshi, 2014/02/19 17:12:03]

Will make changes
On 2014/02/19 15:39:17, bungeman1 wrote:

+}
+
+void SkPaint::FontMetrics::unsetFontMetricsFlag(FontMetrics::FontMetricsFlags flag)
+{
+    this->fFontMetricsFlag = this->fFontMetricsFlag ^ flag;

[bungeman-skia, 2014/02/19 15:39:17]

This will toggle, not unset. Also, since members begin with the 'f' prefix in
Skia, the 'this->' is unnecessary.

fFontMetricsFlag &= ~flag;

[h.joshi, 2014/02/19 17:12:03]

Will make changes
On 2014/02/19 15:39:17, bungeman1 wrote:

+}
+
+bool SkPaint::FontMetrics::checkFontMetricsFlag(FontMetrics::FontMetricsFlags flag) const
+{
+   return SkToBool(this->fFontMetricsFlag & flag);
+}
+
 #ifdef SK_DEVELOPER
 void SkPaint::toString(SkString* str) const {
     str->append("<dl><dt>SkPaint:</dt><dd><dl>");