include/cppcanvas/canvasgraphic.hxx

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  19
  20 #ifndef INCLUDED_CPPCANVAS_CANVASGRAPHIC_HXX
  21 #define INCLUDED_CPPCANVAS_CANVASGRAPHIC_HXX
  22
  23 #include <sal/types.h>
  24
  25 #include <boost/shared_ptr.hpp>
  26 #include <cppcanvas/color.hxx>
  27 #include <cppcanvas/canvas.hxx>
  28
  29 namespace basegfx
  30 {
  31     class B2DHomMatrix;
  32     class B2DPolyPolygon;
  33 }
  34
  35
  36 /* Definition of CanvasGraphic interface */
  37
  38 namespace cppcanvas
  39 {
  40     // forward declaration, since tools::PolyPolygon also derives from CanvasGraphic
  41     typedef ::boost::shared_ptr< class PolyPolygon > PolyPolygonSharedPtr;
  42
  43
  44     /** This interface defines basic properties of
  45         objects that can be painted on a Canvas
  46      */
  47     class CanvasGraphic
  48     {
  49     public:
  50
  51         /** These enums determine how the primitive color is combined
  52             with the background. When performing this calculations, it
  53             is assumed that all color values are premultiplied with
  54             the corresponding alpha values (if no alpha is specified,
  55             1.0 is assumed). Then, the following general compositing
  56             operation is performed:
  57
  58             C = Ca * Fa + Cb * Fb
  59
  60             where C is the result color, Ca and Cb are the input
  61             colors, premultiplied with alpha, and Fa and Fb are
  62             described for the different composite modes (wherein Aa
  63             and Ab denote source and destination alpha, respectively).
  64         */
  65         enum CompositeOp
  66         {
  67             /// Clear destination. Fa = Fb = 0.
  68             CLEAR,
  69
  70             /// Copy source as-is to destination. Fa = 1, Fb = 0.
  71             SOURCE,
  72
  73             /// Leave destination as-is.  Fa = 0, Fb = 1.
  74             DESTINATION,
  75
  76             /// Copy source over destination. Fa = 1, Fb = 1-Aa.
  77             OVER,
  78
  79             /// Copy source under destination. Fa = 1-Ab, Fb = 1.
  80             UNDER,
  81
  82             /// Copy source to destination, but limited to where the destination is. Fa = Ab, Fb = 0.
  83             INSIDE,
  84
  85             /// Leave destination as is, but only where source was. Fa = 0, Fb = Aa.
  86             INSIDE_REVERSE,
  87
  88             /// Copy source to destination, but limited to where destination is not. Fa = 1-Ab, Fb = 0.
  89             OUTSIDE,
  90
  91             /// Leave destination as is, but only where source has not been. Fa = 0, Fb = 1-Aa.
  92             OUTSIDE_REVERSE,
  93
  94             /// Copy source over destination, but only where destination is. Keep destination. Fa = Ab, Fb = 1-Aa.
  95             ATOP,
  96
  97             /// Copy destination over source, but only where source is. Keep source. Fa = 1-Ab, Fb = Aa.
  98             ATOP_REVERSE,
  99
 100             /// Take only parts where either source or destination, but not both are. Fa = 1-Ab, Fb = 1-Aa.
 101             XOR,
 102
 103             /** simply add contributions of both source and destination. The
 104                 resulting color values are limited to the permissible color
 105                 range, and clipped to the maximal value, if exceeded. Fa = 1, Fb = 1.
 106             */
 107             ADD,
 108
 109             /// Fa = min(1,(1-Ab)/Aa), Fb = 1
 110             SATURATE
 111         };
 112
 113         virtual ~CanvasGraphic() {}
 114
 115         /** Set object transformation matrix
 116          */
 117         virtual void                             setTransformation( const ::basegfx::B2DHomMatrix& rMatrix ) = 0;
 118         /** Get object transformation matrix
 119          */
 120         virtual ::basegfx::B2DHomMatrix          getTransformation() const = 0;
 121
 122         /** Set object clipping polygon
 123          */
 124         virtual void                             setClip( const ::basegfx::B2DPolyPolygon& rClipPoly ) = 0;
 125         /** Clear object clipping polygon
 126          */
 127         virtual void                             setClip() = 0;
 128         /** Get object clipping polygon
 129
 130             @return NULL, if no clip is set; otherwise, the current clip poly-polygon is returned
 131          */
 132         virtual ::basegfx::B2DPolyPolygon const* getClip() const = 0;
 133
 134         /** Set object composite mode
 135          */
 136         virtual void                             setCompositeOp( CompositeOp aOp ) = 0;
 137         /** Get object composite mode
 138          */
 139         virtual CompositeOp                      getCompositeOp() const = 0;
 140
 141         /** Render to parent canvas
 142
 143             This method renders the content to the parent canvas,
 144             i.e. the canvas this object was constructed for.
 145
 146             @return whether the rendering finished successfully.
 147          */
 148         virtual bool draw() const = 0;
 149
 150     };
 151
 152     typedef ::boost::shared_ptr< ::cppcanvas::CanvasGraphic > CanvasGraphicSharedPtr;
 153 }
 154
 155 #endif // INCLUDED_CPPCANVAS_CANVASGRAPHIC_HXX
 156
 157 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */