/*

 * 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.

 */

#include "include/core/SkPath.h"

#include "include/core/SkRegion.h"

#include "include/core/SkStrokeRec.h"

#include "include/effects/Sk2DPathEffect.h"

#include "src/core/SkPathEffectBase.h"

#include "src/core/SkReadBuffer.h"

#include "src/core/SkWriteBuffer.h"

class Sk2DPathEffect : public SkPathEffectBase {

public:

    Sk2DPathEffect(const SkMatrix& mat) : fMatrix(mat) {

        // Calling invert will set the type mask on both matrices, making them thread safe.

        fMatrixIsInvertible = fMatrix.invert(&fInverse);

    }

protected:

    /** New virtual, to be overridden by subclasses.

        This is called once from filterPath, and provides the

        uv parameter bounds for the path. Subsequent calls to

        next() will receive u and v values within these bounds,

        and then a call to end() will signal the end of processing.

    */

    virtual void begin(const SkIRect& uvBounds, SkPath* dst) const {}

    virtual void next(const SkPoint& loc, int u, int v, SkPath* dst) const {}

    virtual void end(SkPath* dst) const {}

    /** Low-level virtual called per span of locations in the u-direction.

        The default implementation calls next() repeatedly with each

        location.

    */

    virtual void nextSpan(int x, int y, int ucount, SkPath* path) const {

        if (!fMatrixIsInvertible) {

            return;

        }

    #if defined(SK_BUILD_FOR_FUZZER)

        if (count > 100) {

            return;

        }

    #endif

        const SkMatrix& mat = this->getMatrix();

        SkPoint src, dst;

        src.set(SkIntToScalar(x) + SK_ScalarHalf, SkIntToScalar(y) + SK_ScalarHalf);

        do {

            mat.mapPoints(&dst, &src, 1);

            this->next(dst, x++, y, path);

            src.fX += SK_Scalar1;

        } while (--ucount > 0);

    }

    const SkMatrix& getMatrix() const { return fMatrix; }

    void flatten(SkWriteBuffer& buffer) const override {

        this->INHERITED::flatten(buffer);

        buffer.writeMatrix(fMatrix);

    }

    bool onFilterPath(SkPath* dst, const SkPath& src, SkStrokeRec* rec,

                      const SkRect* cullRect, const SkMatrix&) const override {

        if (!fMatrixIsInvertible) {

            return false;

        }

        SkPath  tmp;

        SkIRect ir;

        src.transform(fInverse, &tmp);

        tmp.getBounds().round(&ir);

        if (!ir.isEmpty()) {

            this->begin(ir, dst);

            SkRegion rgn;

            rgn.setPath(tmp, SkRegion(ir));

            SkRegion::Iterator iter(rgn);

            for (; !iter.done(); iter.next()) {

                const SkIRect& rect = iter.rect();

                for (int y = rect.fTop; y < rect.fBottom; ++y) {

                    this->nextSpan(rect.fLeft, y, rect.width(), dst);

                }

            }

            this->end(dst);

        }

        return true;

    }

private:

    SkMatrix    fMatrix, fInverse;

    bool        fMatrixIsInvertible;

    // For simplicity, assume fast bounds cannot be computed

    bool computeFastBounds(SkRect*) const override { return false; }

    friend class Sk2DPathEffectBlitter;

    using INHERITED = SkPathEffect;

};

///////////////////////////////////////////////////////////////////////////////

class SkLine2DPathEffectImpl : public Sk2DPathEffect {

public:

    SkLine2DPathEffectImpl(SkScalar width, const SkMatrix& matrix)

        : Sk2DPathEffect(matrix)

        , fWidth(width)

    {

        SkASSERT(width >= 0);

    }

    bool onFilterPath(SkPath* dst, const SkPath& src, SkStrokeRec* rec,

                      const SkRect* cullRect, const SkMatrix& ctm) const override {

        if (this->INHERITED::onFilterPath(dst, src, rec, cullRect, ctm)) {

            rec->setStrokeStyle(fWidth);

            return true;

        }

        return false;

    }

    void nextSpan(int u, int v, int ucount, SkPath* dst) const override {

        if (ucount > 1) {

            SkPoint    src[2], dstP[2];

            src[0].set(SkIntToScalar(u) + SK_ScalarHalf, SkIntToScalar(v) + SK_ScalarHalf);

            src[1].set(SkIntToScalar(u+ucount) + SK_ScalarHalf, SkIntToScalar(v) + SK_ScalarHalf);

            this->getMatrix().mapPoints(dstP, src, 2);

            dst->moveTo(dstP[0]);

            dst->lineTo(dstP[1]);

        }

    }

    static sk_sp<SkFlattenable> CreateProc(SkReadBuffer& buffer) {

        SkMatrix matrix;

        buffer.readMatrix(&matrix);

        SkScalar width = buffer.readScalar();

        return SkLine2DPathEffect::Make(width, matrix);

    }

    void flatten(SkWriteBuffer &buffer) const override {

        buffer.writeMatrix(this->getMatrix());

        buffer.writeScalar(fWidth);

    }

    Factory getFactory() const override { return CreateProc; }

    const char* getTypeName() const override { return "SkLine2DPathEffect"; }

private:

    SkScalar fWidth;

    using INHERITED = Sk2DPathEffect;

};

/////////////////////////////////////////////////////////////////////////////////////////////////

class SK_API SkPath2DPathEffectImpl : public Sk2DPathEffect {

public:

    SkPath2DPathEffectImpl(const SkMatrix& m, const SkPath& p) : INHERITED(m), fPath(p) {}

    void next(const SkPoint& loc, int u, int v, SkPath* dst) const override {

        dst->addPath(fPath, loc.fX, loc.fY);

    }

    static sk_sp<SkFlattenable> CreateProc(SkReadBuffer& buffer) {

        SkMatrix matrix;

        buffer.readMatrix(&matrix);

        SkPath path;

        buffer.readPath(&path);

        return SkPath2DPathEffect::Make(matrix, path);

    }

    void flatten(SkWriteBuffer& buffer) const override {

        buffer.writeMatrix(this->getMatrix());

        buffer.writePath(fPath);

    }

    Factory getFactory() const override { return CreateProc; }

    const char* getTypeName() const override { return "SkPath2DPathEffect"; }

private:

    SkPath  fPath;

    using INHERITED = Sk2DPathEffect;

};

//////////////////////////////////////////////////////////////////////////////////////////////////

sk_sp<SkPathEffect> SkLine2DPathEffect::Make(SkScalar width, const SkMatrix& matrix) {

    if (!(width >= 0)) {

        return nullptr;

    }

    return sk_sp<SkPathEffect>(new SkLine2DPathEffectImpl(width, matrix));

}

sk_sp<SkPathEffect> SkPath2DPathEffect::Make(const SkMatrix& matrix, const SkPath& path) {

    return sk_sp<SkPathEffect>(new SkPath2DPathEffectImpl(matrix, path));

}

void SkLine2DPathEffect::RegisterFlattenables() {

    SK_REGISTER_FLATTENABLE(SkLine2DPathEffectImpl);

}

void SkPath2DPathEffect::RegisterFlattenables() {

    SK_REGISTER_FLATTENABLE(SkPath2DPathEffectImpl);

}