/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

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 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/.

 *

 * This file incorporates work covered by the following license notice:

 *

 *   Licensed to the Apache Software Foundation (ASF) under one or more

 *   contributor license agreements. See the NOTICE file distributed

 *   with this work for additional information regarding copyright

 *   ownership. The ASF licenses this file to you under the Apache

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 *   except in compliance with the License. You may obtain a copy of

 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .

 */

#include <svgclippathnode.hxx>

#include <drawinglayer/primitive2d/transformprimitive2d.hxx>

#include <drawinglayer/primitive2d/maskprimitive2d.hxx>

#include <basegfx/matrix/b2dhommatrixtools.hxx>

#include <drawinglayer/geometry/viewinformation2d.hxx>

#include <drawinglayer/processor2d/contourextractor2d.hxx>

#include <basegfx/polygon/b2dpolypolygoncutter.hxx>

#include <basegfx/polygon/b2dpolygontools.hxx>

#include <o3tl/string_view.hxx>

namespace svgio::svgreader

{

        SvgClipPathNode::SvgClipPathNode(

            SvgDocument& rDocument,

            SvgNode* pParent)

        :   SvgNode(SVGToken::ClipPathNode, rDocument, pParent),

            maSvgStyleAttributes(*this),

            maClipPathUnits(SvgUnits::userSpaceOnUse)

        {

        }

        SvgClipPathNode::~SvgClipPathNode()

        {

        }

        const SvgStyleAttributes* SvgClipPathNode::getSvgStyleAttributes() const

        {

            return &maSvgStyleAttributes;

        }

        void SvgClipPathNode::parseAttribute(SVGToken aSVGToken, const OUString& aContent)

        {

            // call parent

            SvgNode::parseAttribute(aSVGToken, aContent);

            // read style attributes

            maSvgStyleAttributes.parseStyleAttribute(aSVGToken, aContent);

            // parse own

            switch(aSVGToken)

            {

                case SVGToken::Style:

                {

                    readLocalCssStyle(aContent);

                    break;

                }

                case SVGToken::Transform:

                {

                    const basegfx::B2DHomMatrix aMatrix(readTransform(aContent, *this));

                    if(!aMatrix.isIdentity())

                    {

                        setTransform(aMatrix);

                    }

                    break;

                }

                case SVGToken::ClipPathUnits:

                {

                    if(!aContent.isEmpty())

                    {

                        if(o3tl::equalsIgnoreAsciiCase(o3tl::trim(aContent), commonStrings::aStrUserSpaceOnUse))

                        {

                            setClipPathUnits(SvgUnits::userSpaceOnUse);

                        }

                        else if(o3tl::equalsIgnoreAsciiCase(o3tl::trim(aContent), commonStrings::aStrObjectBoundingBox))

                        {

                            setClipPathUnits(SvgUnits::objectBoundingBox);

                        }

                    }

                    break;

                }

                default:

                {

                    break;

                }

            }

        }

        void SvgClipPathNode::decomposeSvgNode(drawinglayer::primitive2d::Primitive2DContainer& rTarget, bool bReferenced) const

        {

            drawinglayer::primitive2d::Primitive2DContainer aNewTarget;

            // decompose children

            SvgNode::decomposeSvgNode(aNewTarget, bReferenced);

            if(aNewTarget.empty())

                return;

            if(getTransform())

            {

                // create embedding group element with transformation

                const drawinglayer::primitive2d::Primitive2DReference xRef(

                    new drawinglayer::primitive2d::TransformPrimitive2D(

                        *getTransform(),

                        std::move(aNewTarget)));

                rTarget.push_back(xRef);

            }

            else

            {

                // append to current target

                rTarget.append(std::move(aNewTarget));

            }

        }

        void SvgClipPathNode::apply(

            drawinglayer::primitive2d::Primitive2DContainer& rContent,

            const std::optional<basegfx::B2DHomMatrix>& pTransform) const

        {

            if (rContent.empty() || Display::None == getDisplay())

                return;

            const drawinglayer::geometry::ViewInformation2D aViewInformation2D;

            drawinglayer::primitive2d::Primitive2DContainer aClipTarget;

            basegfx::B2DPolyPolygon aClipPolyPolygon;

            // get clipPath definition as primitives

            decomposeSvgNode(aClipTarget, true);

            if(!aClipTarget.empty())

            {

                // extract filled polygons as base for a mask PolyPolygon

                drawinglayer::processor2d::ContourExtractor2D aExtractor(aViewInformation2D, true);

                aExtractor.process(aClipTarget);

                const basegfx::B2DPolyPolygonVector& rResult(aExtractor.getExtractedContour());

                const sal_uInt32 nSize(rResult.size());

                if(nSize > 1)

                {

                    // merge to single clipPolyPolygon

                    aClipPolyPolygon = basegfx::utils::mergeToSinglePolyPolygon(rResult);

                }

                else if (nSize != 0)

                {

                    aClipPolyPolygon = rResult[0];

                }

            }

            if(aClipPolyPolygon.count())

            {

                if (SvgUnits::objectBoundingBox == getClipPathUnits())

                {

                    // clip is object-relative, transform using content transformation

                    const basegfx::B2DRange aContentRange(rContent.getB2DRange(aViewInformation2D));

                    aClipPolyPolygon.transform(

                        basegfx::utils::createScaleTranslateB2DHomMatrix(

                            aContentRange.getRange(),

                            aContentRange.getMinimum()));

                }

                else // userSpaceOnUse

                {

                    // #i124852#

                    if(pTransform)

                    {

                        aClipPolyPolygon.transform(*pTransform);

                    }

                }

                // #i124313# try to avoid creating an embedding to a MaskPrimitive2D if

                // possible; MaskPrimitive2D processing is potentially expensive

                bool bCreateEmbedding(true);

                bool bAddContent(true);

                if(basegfx::utils::isRectangle(aClipPolyPolygon))

                {

                    // ClipRegion is a rectangle, thus it is not expensive to tell

                    // if the content is completely inside or outside of it; get ranges

                    const basegfx::B2DRange aClipRange(aClipPolyPolygon.getB2DRange());

                    const basegfx::B2DRange aContentRange(

                        rContent.getB2DRange(

                            aViewInformation2D));

                    if(aClipRange.isInside(aContentRange))

                    {

                        // completely contained, no need to clip at all, so no need for embedding

                        bCreateEmbedding = false;

                    }

                    else if(aClipRange.overlaps(aContentRange))

                    {

                        // overlap; embedding needed. ClipRegion can be minimized by using

                        // the intersection of the ClipRange and the ContentRange. Minimizing

                        // the ClipRegion potentially enhances further processing since

                        // usually clip operations are expensive.

                        basegfx::B2DRange aCommonRange(aContentRange);

                        aCommonRange.intersect(aClipRange);

                        aClipPolyPolygon = basegfx::B2DPolyPolygon(basegfx::utils::createPolygonFromRect(aCommonRange));

                    }

                    else

                    {

                        // not inside and no overlap -> completely outside

                        // no need for embedding, no need for content at all

                        bCreateEmbedding = false;

                        bAddContent = false;

                    }

                }

                else

                {

                    // ClipRegion is not a simple rectangle, it would be possible but expensive to

                    // tell if the content needs clipping or not. It is also dependent of

                    // the content's decomposition. To do this, a processor would be needed that

                    // is capable if processing the given sequence of primitives and decide

                    // if all is inside or all is outside. Such a ClipProcessor could be written,

                    // but for now just create the embedding

                }

                if(bCreateEmbedding)

                {

                    // redefine target. Use MaskPrimitive2D with created clip

                    // geometry. Using the automatically set mbIsClipPathContent at

                    // SvgStyleAttributes the clip definition is without fill, stroke,

                    // and strokeWidth and forced to black

                    rContent = drawinglayer::primitive2d::Primitive2DContainer {

                            new drawinglayer::primitive2d::MaskPrimitive2D(

                                std::move(aClipPolyPolygon),

                                std::move(rContent))

                    };

                }

                else

                {

                    if(!bAddContent)

                    {

                        rContent.clear();

                    }

                }

            }

            else

            {

                // An empty clipping path will completely clip away the element that had

                // the clip-path property applied. (Svg spec)

                rContent.clear();

            }

        }

} // end of namespace svgio::svgreader

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