/*

 * 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 "include/core/SkFlattenable.h"

#include "include/core/SkScalar.h"

// not needed, but some of our clients need it (they don't IWYU)

#include "include/core/SkPath.h"

class SkPath;

struct SkRect;

class SkStrokeRec;

/** \class SkPathEffect

    SkPathEffect is the base class for objects in the SkPaint that affect

    the geometry of a drawing primitive before it is transformed by the

    canvas' matrix and drawn.

    Dashing is implemented as a subclass of SkPathEffect.

*/

class SK_API SkPathEffect : public SkFlattenable {

public:

    /**

     *  Returns a patheffect that apples each effect (first and second) to the original path,

     *  and returns a path with the sum of these.

     *

     *  result = first(path) + second(path)

     *

     */

    static sk_sp<SkPathEffect> MakeSum(sk_sp<SkPathEffect> first, sk_sp<SkPathEffect> second);

    /**

     *  Returns a patheffect that applies the inner effect to the path, and then applies the

     *  outer effect to the result of the inner's.

     *

     *  result = outer(inner(path))

     */

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

    static SkFlattenable::Type GetFlattenableType() {

        return kSkPathEffect_Type;

    }

    // move to base?

    enum DashType {

        kNone_DashType, //!< ignores the info parameter

        kDash_DashType, //!< fills in all of the info parameter

    };

    struct DashInfo {

        DashInfo() : fIntervals(nullptr), fCount(0), fPhase(0) {}

        DashInfo(SkScalar* intervals, int32_t count, SkScalar phase)

            : fIntervals(intervals), fCount(count), fPhase(phase) {}

        SkScalar*   fIntervals;         //!< Length of on/off intervals for dashed lines

                                        //   Even values represent ons, and odds offs

        int32_t     fCount;             //!< Number of intervals in the dash. Should be even number

        SkScalar    fPhase;             //!< Offset into the dashed interval pattern

                                        //   mod the sum of all intervals

    };

    DashType asADash(DashInfo* info) const;

    /**

     *  Given a src path (input) and a stroke-rec (input and output), apply

     *  this effect to the src path, returning the new path in dst, and return

     *  true. If this effect cannot be applied, return false and ignore dst

     *  and stroke-rec.

     *

     *  The stroke-rec specifies the initial request for stroking (if any).

     *  The effect can treat this as input only, or it can choose to change

     *  the rec as well. For example, the effect can decide to change the

     *  stroke's width or join, or the effect can change the rec from stroke

     *  to fill (or fill to stroke) in addition to returning a new (dst) path.

     *

     *  If this method returns true, the caller will apply (as needed) the

     *  resulting stroke-rec to dst and then draw.

     */

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

    /** Version of filterPath that can be called when the CTM is known. */

    bool filterPath(SkPath* dst, const SkPath& src, SkStrokeRec*, const SkRect* cullR,

                    const SkMatrix& ctm) const;

    /** True if this path effect requires a valid CTM */

    bool needsCTM() const;

    static sk_sp<SkPathEffect> Deserialize(const void* data, size_t size,

                                           const SkDeserialProcs* procs = nullptr);

private:

    SkPathEffect() = default;

    friend class SkPathEffectBase;

    using INHERITED = SkFlattenable;

};

#endif