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

include/core/SkPaint.h

 
 
 /*
  * 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.
  */
 
 
@@ skipping 724 matching lines @@
         SkScalar    fAscent;    //!< The recommended distance above the baseline (will be <= 0)
         SkScalar    fDescent;   //!< The recommended distance below the baseline (will be >= 0)
         SkScalar    fBottom;    //!< The greatest distance below the baseline for any glyph (will be >= 0)
         SkScalar    fLeading;   //!< The recommended distance to add between lines of text (will be >= 0)
         SkScalar    fAvgCharWidth;  //!< the average charactor width (>= 0)
         SkScalar    fMaxCharWidth;  //!< the max charactor width (>= 0)
         SkScalar    fXMin;      //!< The minimum bounding box x value for all glyphs
         SkScalar    fXMax;      //!< The maximum bounding box x value for all glyphs
         SkScalar    fXHeight;   //!< The height of an 'x' in px, or 0 if no 'x' in face
         SkScalar    fCapHeight;  //!< The cap height (> 0), or 0 if cannot be determined.
+        SkScalar    fUnderlineThickness; //!< underline thickness, or 0 if cannot be determined

[reed1, 2014/02/11 15:59:52]

I suggest a bitfield at the beginning, with some bits defined to identify which
values are unknown (e.g. underline). We may also find other uses besides just
what is valid, but that's all I can think of for now.)

[h.joshi, 2014/02/12 17:20:59]

Added bitfield as per comments, pls check

On 2014/02/11 15:59:52, reed1 wrote:

+        SkScalar    fUnderlinePosition; //!< underline position, or 0 if cannot be determined
     };
 
     /** Return the recommend spacing between lines (which will be
         fDescent - fAscent + fLeading).
         If metrics is not null, return in it the font metrics for the
         typeface/pointsize/etc. currently set in the paint.
         @param metrics      If not null, returns the font metrics for the
                             current typeface/pointsize/etc setting in this
                             paint.
         @param scale        If not 0, return width as if the canvas were scaled
@@ skipping 324 matching lines @@
 #ifdef SK_BUILD_FOR_ANDROID
     SkPaintOptionsAndroid fPaintOptionsAndroid;
 
     // In order for the == operator to work properly this must be the last field
     // in the struct so that we can do a memcmp to this field's offset.
     uint32_t        fGenerationID;
 #endif
 };
 
 #endif