SkPathEffect.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 SkPathEffect_DEFINED
#define SkPathEffect_DEFINED

#include "SkFlattenable.h"
#include "SkPath.h"
#include "SkPoint.h"
#include "SkRect.h"

class SkPath;
class SkStrokeRec;

class SK_API SkPathEffect : public SkFlattenable {
public:
    static sk_sp<SkPathEffect> MakeSum(sk_sp<SkPathEffect> first, sk_sp<SkPathEffect> second);

    static sk_sp<SkPathEffect> MakeCompose(sk_sp<SkPathEffect> outer, sk_sp<SkPathEffect> inner);

    virtual bool filterPath(SkPath* dst, const SkPath& src,
                            SkStrokeRec*, const SkRect* cullR) const = 0;

    virtual void computeFastBounds(SkRect* dst, const SkRect& src) const;

    class PointData {
    public:
        PointData()
            : fFlags(0)
            , fPoints(NULL)
            , fNumPoints(0) {
            fSize.set(SK_Scalar1, SK_Scalar1);
            // 'asPoints' needs to initialize/fill-in 'fClipRect' if it sets
            // the kUseClip flag
        }
        ~PointData() {
            delete [] fPoints;
        }

        // TODO: consider using passed-in flags to limit the work asPoints does.
        // For example, a kNoPath flag could indicate don't bother generating
        // stamped solutions.

        // Currently none of these flags are supported.
        enum PointFlags {
            kCircles_PointFlag            = 0x01,   // draw points as circles (instead of rects)
            kUsePath_PointFlag            = 0x02,   // draw points as stamps of the returned path
            kUseClip_PointFlag            = 0x04,   // apply 'fClipRect' before drawing the points
        };

        uint32_t           fFlags;      // flags that impact the drawing of the points
        SkPoint*           fPoints;     // the center point of each generated point
        int                fNumPoints;  // number of points in fPoints
        SkVector           fSize;       // the size to draw the points
        SkRect             fClipRect;   // clip required to draw the points (if kUseClip is set)
        SkPath             fPath;       // 'stamp' to be used at each point (if kUsePath is set)

        SkPath             fFirst;      // If not empty, contains geometry for first point
        SkPath             fLast;       // If not empty, contains geometry for last point
    };

    virtual bool asPoints(PointData* results, const SkPath& src,
                          const SkStrokeRec&, const SkMatrix&,
                          const SkRect* cullR) const;

    enum DashType {
        kNone_DashType, 
        kDash_DashType, 
    };

    struct DashInfo {
        DashInfo() : fIntervals(NULL), fCount(0), fPhase(0) {}
        DashInfo(SkScalar* intervals, int32_t count, SkScalar phase)
            : fIntervals(intervals), fCount(count), fPhase(phase) {}

        SkScalar*   fIntervals;         
                                        //   Even values represent ons, and odds offs
        int32_t     fCount;             
        SkScalar    fPhase;             
                                        //   mod the sum of all intervals
    };

    virtual DashType asADash(DashInfo* info) const;

    SK_TO_STRING_PUREVIRT()
    SK_DEFINE_FLATTENABLE_TYPE(SkPathEffect)

#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
    virtual bool exposedInAndroidJavaAPI() const { return false; }
#endif

    SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()

protected:
    SkPathEffect() {}

private:
    // illegal
    SkPathEffect(const SkPathEffect&);
    SkPathEffect& operator=(const SkPathEffect&);

    typedef SkFlattenable INHERITED;
};

#endif