unifiedtransparenceprimitive2d.cxx

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#include <drawinglayer/primitive2d/unifiedtransparenceprimitive2d.hxx>
#include <basegfx/polygon/b2dpolygon.hxx>
#include <basegfx/polygon/b2dpolygontools.hxx>
#include <basegfx/color/bcolor.hxx>
#include <drawinglayer/primitive2d/PolygonHairlinePrimitive2D.hxx>
#include <drawinglayer/primitive2d/PolyPolygonColorPrimitive2D.hxx>
#include <drawinglayer/primitive2d/transparenceprimitive2d.hxx>
#include <drawinglayer/primitive2d/drawinglayer_primitivetypes2d.hxx>
 
 
using namespace com::sun::star;
 
 
namespace drawinglayer::primitive2d
{
        UnifiedTransparencePrimitive2D::UnifiedTransparencePrimitive2D(
            Primitive2DContainer&& aChildren,
            double fTransparence)
        :   GroupPrimitive2D(std::move(aChildren)),
            mfTransparence(fTransparence)
        {
        }
 
        bool UnifiedTransparencePrimitive2D::operator==(const BasePrimitive2D& rPrimitive) const
        {
            if(GroupPrimitive2D::operator==(rPrimitive))
            {
                const UnifiedTransparencePrimitive2D& rCompare = static_cast<const UnifiedTransparencePrimitive2D&>(rPrimitive);
 
                return (getTransparence() == rCompare.getTransparence());
            }
 
            return false;
        }
 
        basegfx::B2DRange UnifiedTransparencePrimitive2D::getB2DRange(const geometry::ViewInformation2D& rViewInformation) const
        {
            // do not use the fallback to decomposition here since for a correct BoundRect we also
            // need invisible (1.0 == getTransparence()) geometry; these would be deleted in the decomposition
            return getChildren().getB2DRange( rViewInformation);
        }
 
        void UnifiedTransparencePrimitive2D::get2DDecomposition(Primitive2DDecompositionVisitor& rVisitor, const geometry::ViewInformation2D& rViewInformation) const
        {
            if(0.0 == getTransparence())
            {
                // no transparence used, so just use the content
                getChildren(rVisitor);
            }
            else if(getTransparence() > 0.0 && getTransparence() < 1.0)
            {
                // The idea is to create a TransparencePrimitive2D with transparent content using a fill color
                // corresponding to the transparence value. Problem is that in most systems, the right
                // and bottom pixel array is not filled when filling polygons, thus this would not
                // always produce a complete transparent bitmap. There are some solutions:
 
                // - Grow the used polygon range by one discrete unit in X and Y. This
                // will make the decomposition view-dependent.
 
                // - For all filled polygon renderings, draw the polygon outline extra. This
                // would lead to unwanted side effects when using concatenated polygons.
 
                // - At this decomposition, add a filled polygon and a hairline polygon. This
                // solution stays view-independent.
 
                // I will take the last one here. The small overhead of two primitives will only be
                // used when UnifiedTransparencePrimitive2D is not handled directly.
                const basegfx::B2DRange aPolygonRange(getChildren().getB2DRange(rViewInformation));
                basegfx::B2DPolygon aPolygon(basegfx::utils::createPolygonFromRect(aPolygonRange));
                const basegfx::BColor aGray(getTransparence(), getTransparence(), getTransparence());
                Primitive2DContainer aTransparenceContent(2);
 
                aTransparenceContent[0] = Primitive2DReference(new PolyPolygonColorPrimitive2D(basegfx::B2DPolyPolygon(aPolygon), aGray));
                aTransparenceContent[1] = Primitive2DReference(new PolygonHairlinePrimitive2D(std::move(aPolygon), aGray));
 
                // create sub-transparence group with a gray-colored rectangular fill polygon
                rVisitor.visit(new TransparencePrimitive2D(Primitive2DContainer(getChildren()), std::move(aTransparenceContent)));
            }
            else
            {
                // completely transparent or invalid definition, add nothing
            }
        }
 
        // provide unique ID
        sal_uInt32 UnifiedTransparencePrimitive2D::getPrimitive2DID() const
        {
            return PRIMITIVE2D_ID_UNIFIEDTRANSPARENCEPRIMITIVE2D;
        }
 
} // end of namespace
 
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