thick stroke Beziers

src/core/SkStroke.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.
  */
 
 #ifndef SkStroke_DEFINED
 #define SkStroke_DEFINED
 
 #include "SkPath.h"
 #include "SkPoint.h"
 #include "SkPaint.h"
+#include "SkStrokerPriv.h"
+
+// set to 1 to use experimental outset stroking with quads
+#ifndef QUAD_STROKE_APPROXIMATION
+#define QUAD_STROKE_APPROXIMATION 0
+#endif
+
+#if QUAD_STROKE_APPROXIMATION && defined(SK_DEBUG)
+extern bool gDebugStrokerErrorSet;
+extern SkScalar gDebugStrokerError;
+
+extern int gMaxRecursion[];
+#endif
 
 /** \class SkStroke
     SkStroke is the utility class that constructs paths by stroking
     geometries (lines, rects, ovals, roundrects, paths). This is
     invoked when a geometry or text is drawn in a canvas with the
     kStroke_Mask bit set in the paint.
 */
 class SkStroke {
 public:
     SkStroke();
     SkStroke(const SkPaint&);
     SkStroke(const SkPaint&, SkScalar width);   // width overrides paint.getStrokeWidth()
 
     SkPaint::Cap    getCap() const { return (SkPaint::Cap)fCap; }
     void        setCap(SkPaint::Cap);
 
     SkPaint::Join   getJoin() const { return (SkPaint::Join)fJoin; }
     void        setJoin(SkPaint::Join);
 
+#if QUAD_STROKE_APPROXIMATION
+    void    setError(SkScalar);
+#endif
     void    setMiterLimit(SkScalar);
     void    setWidth(SkScalar);
 
     bool    getDoFill() const { return SkToBool(fDoFill); }
     void    setDoFill(bool doFill) { fDoFill = SkToU8(doFill); }
 
     /**
      *  Stroke the specified rect, winding it in the specified direction..
      */
     void    strokeRect(const SkRect& rect, SkPath* result,
                        SkPath::Direction = SkPath::kCW_Direction) const;
     void    strokePath(const SkPath& path, SkPath*) const;
 
     ////////////////////////////////////////////////////////////////
 
 private:
+#if QUAD_STROKE_APPROXIMATION
+    SkScalar    fError;
+#endif
     SkScalar    fWidth, fMiterLimit;
     uint8_t     fCap, fJoin;
     SkBool8     fDoFill;
 
     friend class SkPaint;
 };
 
 #endif