text: /////////////////////////////////////////////////////////////////////////////
  // Name:        wx/graphics.h
  // Purpose:     graphics context header
  // Author:      Stefan Csomor
  // Modified by:
  // Created:
  // Copyright:   (c) Stefan Csomor
  // Licence:     wxWindows licence
  /////////////////////////////////////////////////////////////////////////////
  
  #ifndef _WX_GRAPHICS_H_
  #define _WX_GRAPHICS_H_
  
  #include "wx/defs.h"
  
  #if wxUSE_GRAPHICS_CONTEXT
  
  #include "wx/affinematrix2d.h"
  #include "wx/geometry.h"
  #include "wx/colour.h"
  #include "wx/dynarray.h"
  #include "wx/font.h"
  #include "wx/image.h"
  #include "wx/peninfobase.h"
  #include "wx/vector.h"
  
  enum wxAntialiasMode
  {
      wxANTIALIAS_NONE, // should be 0
      wxANTIALIAS_DEFAULT
  };
  
  enum wxInterpolationQuality
  {
      // default interpolation
      wxINTERPOLATION_DEFAULT,
      // no interpolation
      wxINTERPOLATION_NONE,
      // fast interpolation, suited for interactivity
      wxINTERPOLATION_FAST,
      // better quality
      wxINTERPOLATION_GOOD,
      // best quality, not suited for interactivity
      wxINTERPOLATION_BEST
  };
  
  enum wxCompositionMode
  {
      // R = Result, S = Source, D = Destination, premultiplied with alpha
      // Ra, Sa, Da their alpha components
  
      // classic Porter-Duff compositions
      // http://keithp.com/~keithp/porterduff/p253-porter.pdf
  
      wxCOMPOSITION_INVALID = -1, /* indicates invalid/unsupported mode */
      wxCOMPOSITION_CLEAR, /* R = 0 */
      wxCOMPOSITION_SOURCE, /* R = S */
      wxCOMPOSITION_OVER, /* R = S + D*(1 - Sa) */
      wxCOMPOSITION_IN, /* R = S*Da */
      wxCOMPOSITION_OUT, /* R = S*(1 - Da) */
      wxCOMPOSITION_ATOP, /* R = S*Da + D*(1 - Sa) */
  
      wxCOMPOSITION_DEST, /* R = D, essentially a noop */
      wxCOMPOSITION_DEST_OVER, /* R = S*(1 - Da) + D */
      wxCOMPOSITION_DEST_IN, /* R = D*Sa */
      wxCOMPOSITION_DEST_OUT, /* R = D*(1 - Sa) */
      wxCOMPOSITION_DEST_ATOP, /* R = S*(1 - Da) + D*Sa */
      wxCOMPOSITION_XOR, /* R = S*(1 - Da) + D*(1 - Sa) */
  
      // mathematical compositions
      wxCOMPOSITION_ADD /* R = S + D */
  };
  
  enum wxGradientType
  {
      wxGRADIENT_NONE,
      wxGRADIENT_LINEAR,
      wxGRADIENT_RADIAL
  };
  
  
  class WXDLLIMPEXP_FWD_CORE wxDC;
  class WXDLLIMPEXP_FWD_CORE wxWindowDC;
  class WXDLLIMPEXP_FWD_CORE wxMemoryDC;
  #if wxUSE_PRINTING_ARCHITECTURE
  class WXDLLIMPEXP_FWD_CORE wxPrinterDC;
  #endif
  #ifdef __WXMSW__
  #if wxUSE_ENH_METAFILE
  class WXDLLIMPEXP_FWD_CORE wxEnhMetaFileDC;
  #endif
  #endif
  class WXDLLIMPEXP_FWD_CORE wxGraphicsContext;
  class WXDLLIMPEXP_FWD_CORE wxGraphicsPath;
  class WXDLLIMPEXP_FWD_CORE wxGraphicsMatrix;
  class WXDLLIMPEXP_FWD_CORE wxGraphicsFigure;
  class WXDLLIMPEXP_FWD_CORE wxGraphicsRenderer;
  class WXDLLIMPEXP_FWD_CORE wxGraphicsPen;
  class WXDLLIMPEXP_FWD_CORE wxGraphicsBrush;
  class WXDLLIMPEXP_FWD_CORE wxGraphicsFont;
  class WXDLLIMPEXP_FWD_CORE wxGraphicsBitmap;
  
  
  /*
   * notes about the graphics context apis
   *
   * angles : are measured in radians, 0.0 being in direction of positive x axis, PI/2 being
   * in direction of positive y axis.
   */
  
  // Base class of all objects used for drawing in the new graphics API, the always point back to their
  // originating rendering engine, there is no dynamic unloading of a renderer currently allowed,
  // these references are not counted
  
  //
  // The data used by objects like graphics pens etc is ref counted, in order to avoid unnecessary expensive
  // duplication. Any operation on a shared instance that results in a modified state, uncouples this
  // instance from the other instances that were shared - using copy on write semantics
  //
  
  class WXDLLIMPEXP_FWD_CORE wxGraphicsObjectRefData;
  class WXDLLIMPEXP_FWD_CORE wxGraphicsBitmapData;
  class WXDLLIMPEXP_FWD_CORE wxGraphicsMatrixData;
  class WXDLLIMPEXP_FWD_CORE wxGraphicsPathData;
  
  class WXDLLIMPEXP_CORE wxGraphicsObject : public wxObject
  {
  public:
      wxGraphicsObject();
      wxGraphicsObject( wxGraphicsRenderer* renderer );
      virtual ~wxGraphicsObject();
  
      bool IsNull() const;
  
      // returns the renderer that was used to create this instance, or NULL if it has not been initialized yet
      wxGraphicsRenderer* GetRenderer() const;
      wxGraphicsObjectRefData* GetGraphicsData() const;
  protected:
      virtual wxObjectRefData* CreateRefData() const wxOVERRIDE;
      virtual wxObjectRefData* CloneRefData(const wxObjectRefData* data) const wxOVERRIDE;
  
      wxDECLARE_DYNAMIC_CLASS(wxGraphicsObject);
  };
  
  
  
  class WXDLLIMPEXP_CORE wxGraphicsPen : public wxGraphicsObject
  {
  public:
      wxGraphicsPen() {}
      virtual ~wxGraphicsPen() {}
  private:
      wxDECLARE_DYNAMIC_CLASS(wxGraphicsPen);
  };
  
  extern WXDLLIMPEXP_DATA_CORE(wxGraphicsPen) wxNullGraphicsPen;
  
  class WXDLLIMPEXP_CORE wxGraphicsBrush : public wxGraphicsObject
  {
  public:
      wxGraphicsBrush() {}
      virtual ~wxGraphicsBrush() {}
  private:
      wxDECLARE_DYNAMIC_CLASS(wxGraphicsBrush);
  };
  
  extern WXDLLIMPEXP_DATA_CORE(wxGraphicsBrush) wxNullGraphicsBrush;
  
  class WXDLLIMPEXP_CORE wxGraphicsFont : public wxGraphicsObject
  {
  public:
      wxGraphicsFont() {}
      virtual ~wxGraphicsFont() {}
  private:
      wxDECLARE_DYNAMIC_CLASS(wxGraphicsFont);
  };
  
  extern WXDLLIMPEXP_DATA_CORE(wxGraphicsFont) wxNullGraphicsFont;
  
  class WXDLLIMPEXP_CORE wxGraphicsBitmap : public wxGraphicsObject
  {
  public:
      wxGraphicsBitmap() {}
      virtual ~wxGraphicsBitmap() {}
  
      // Convert bitmap to wxImage: this is more efficient than converting to
      // wxBitmap first and then to wxImage and also works without X server
      // connection under Unix that wxBitmap requires.
  #if wxUSE_IMAGE
      wxImage ConvertToImage() const;
  #endif // wxUSE_IMAGE
  
      void* GetNativeBitmap() const;
  
      const wxGraphicsBitmapData* GetBitmapData() const
      { return (const wxGraphicsBitmapData*) GetRefData(); }
      wxGraphicsBitmapData* GetBitmapData()
      { return (wxGraphicsBitmapData*) GetRefData(); }
  
  private:
      wxDECLARE_DYNAMIC_CLASS(wxGraphicsBitmap);
  };
  
  extern WXDLLIMPEXP_DATA_CORE(wxGraphicsBitmap) wxNullGraphicsBitmap;
  
  class WXDLLIMPEXP_CORE wxGraphicsMatrix : public wxGraphicsObject
  {
  public:
      wxGraphicsMatrix() {}
  
      virtual ~wxGraphicsMatrix() {}
  
      // concatenates the matrix
      virtual void Concat( const wxGraphicsMatrix *t );
      void Concat( const wxGraphicsMatrix &t ) { Concat( &t ); }
  
      // sets the matrix to the respective values
      virtual void Set(wxDouble a=1.0, wxDouble b=0.0, wxDouble c=0.0, wxDouble d=1.0,
          wxDouble tx=0.0, wxDouble ty=0.0);
  
      // gets the component values of the matrix
      virtual void Get(wxDouble* a=NULL, wxDouble* b=NULL,  wxDouble* c=NULL,
                       wxDouble* d=NULL, wxDouble* tx=NULL, wxDouble* ty=NULL) const;
  
      // makes this the inverse matrix
      virtual void Invert();
  
      // returns true if the elements of the transformation matrix are equal ?
      virtual bool IsEqual( const wxGraphicsMatrix* t) const;
      bool IsEqual( const wxGraphicsMatrix& t) const { return IsEqual( &t ); }
  
      // return true if this is the identity matrix
      virtual bool IsIdentity() const;
  
      //
      // transformation
      //
  
      // add the translation to this matrix
      virtual void Translate( wxDouble dx , wxDouble dy );
  
      // add the scale to this matrix
      virtual void Scale( wxDouble xScale , wxDouble yScale );
  
      // add the rotation to this matrix (radians)
      virtual void Rotate( wxDouble angle );
  
      //
      // apply the transforms
      //
  
      // applies that matrix to the point
      virtual void TransformPoint( wxDouble *x, wxDouble *y ) const;
  
      // applies the matrix except for translations
      virtual void TransformDistance( wxDouble *dx, wxDouble *dy ) const;
  
      // returns the native representation
      virtual void * GetNativeMatrix() const;
  
      const wxGraphicsMatrixData* GetMatrixData() const
      { return (const wxGraphicsMatrixData*) GetRefData(); }
      wxGraphicsMatrixData* GetMatrixData()
      { return (wxGraphicsMatrixData*) GetRefData(); }
  
  private:
      wxDECLARE_DYNAMIC_CLASS(wxGraphicsMatrix);
  };
  
  extern WXDLLIMPEXP_DATA_CORE(wxGraphicsMatrix) wxNullGraphicsMatrix;
  
  // ----------------------------------------------------------------------------
  // wxGradientStop and wxGradientStops: Specify what intermediate colors are used
  // and how they are spread out in a gradient
  // ----------------------------------------------------------------------------
  
  // gcc 9 gives a nonsensical warning about implicitly generated move ctor not
  // throwing but not being noexcept, suppress it.
  #if wxCHECK_GCC_VERSION(9, 1) && !wxCHECK_GCC_VERSION(10, 0)
  wxGCC_WARNING_SUPPRESS(noexcept)
  #endif
  
  // Describes a single gradient stop.
  class wxGraphicsGradientStop
  {
  public:
      wxGraphicsGradientStop(wxColour col = wxTransparentColour,
                             float pos = 0.0f)
          : m_col(col),
            m_pos(pos)
      {
      }
  
      // default copy ctor, assignment operator and dtor are ok
  
      const wxColour& GetColour() const { return m_col; }
      void SetColour(const wxColour& col) { m_col = col; }
  
      float GetPosition() const { return m_pos; }
      void SetPosition(float pos)
      {
          wxASSERT_MSG( pos >= 0 && pos <= 1, "invalid gradient stop position" );
  
          m_pos = pos;
      }
  
  private:
      // The colour of this gradient band.
      wxColour m_col;
  
      // Its starting position: 0 is the beginning and 1 is the end.
      float m_pos;
  };
  
  #if wxCHECK_GCC_VERSION(9, 1) && !wxCHECK_GCC_VERSION(10, 0)
  wxGCC_WARNING_RESTORE(noexcept)
  #endif
  
  // A collection of gradient stops ordered by their positions (from lowest to
  // highest). The first stop (index 0, position 0.0) is always the starting
  // colour and the last one (index GetCount() - 1, position 1.0) is the end
  // colour.
  class WXDLLIMPEXP_CORE wxGraphicsGradientStops
  {
  public:
      wxGraphicsGradientStops(wxColour startCol = wxTransparentColour,
                              wxColour endCol = wxTransparentColour)
      {
          // we can't use Add() here as it relies on having start/end stops as
          // first/last array elements so do it manually
          m_stops.push_back(wxGraphicsGradientStop(startCol, 0.f));
          m_stops.push_back(wxGraphicsGradientStop(endCol, 1.f));
      }
  
      // default copy ctor, assignment operator and dtor are ok for this class
  
  
      // Add a stop in correct order.
      void Add(const wxGraphicsGradientStop& stop);
      void Add(wxColour col, float pos) { Add(wxGraphicsGradientStop(col, pos)); }
  
      // Get the number of stops.
      size_t GetCount() const { return m_stops.size(); }
  
      // Return the stop at the given index (which must be valid).
      wxGraphicsGradientStop Item(unsigned n) const { return m_stops.at(n); }
  
      // Get/set start and end colours.
      void SetStartColour(wxColour col)
          { m_stops[0].SetColour(col); }
      wxColour GetStartColour() const
          { return m_stops[0].GetColour(); }
      void SetEndColour(wxColour col)
          { m_stops[m_stops.size() - 1].SetColour(col); }
      wxColour GetEndColour() const
          { return m_stops[m_stops.size() - 1].GetColour(); }
  
  private:
      // All the stops stored in ascending order of positions.
      wxVector<wxGraphicsGradientStop> m_stops;
  };
  
  // ----------------------------------------------------------------------------
  // wxGraphicsPenInfo describes a wxGraphicsPen
  // ----------------------------------------------------------------------------
  
  class wxGraphicsPenInfo : public wxPenInfoBase<wxGraphicsPenInfo>
  {
  public:
      explicit wxGraphicsPenInfo(const wxColour& colour = wxColour(),
                                 wxDouble width = 1.0,
                                 wxPenStyle style = wxPENSTYLE_SOLID)
          : wxPenInfoBase<wxGraphicsPenInfo>(colour, style)
      {
          m_width = width;
          m_gradientType = wxGRADIENT_NONE;
      }
  
      // Setters
  
      wxGraphicsPenInfo& Width(wxDouble width)
      { m_width = width; return *this; }
  
      wxGraphicsPenInfo&
      LinearGradient(wxDouble x1, wxDouble y1, wxDouble x2, wxDouble y2,
                     const wxColour& c1, const wxColour& c2,
                     const wxGraphicsMatrix& matrix = wxNullGraphicsMatrix)
      {
          m_gradientType = wxGRADIENT_LINEAR;
          m_x1 = x1;
          m_y1 = y1;
          m_x2 = x2;
          m_y2 = y2;
          m_stops.SetStartColour(c1);
          m_stops.SetEndColour(c2);
          m_matrix = matrix;
          return *this;
      }
  
      wxGraphicsPenInfo&
      LinearGradient(wxDouble x1, wxDouble y1, wxDouble x2, wxDouble y2,
                     const wxGraphicsGradientStops& stops,
                     const wxGraphicsMatrix& matrix = wxNullGraphicsMatrix)
      {
          m_gradientType = wxGRADIENT_LINEAR;
          m_x1 = x1;
          m_y1 = y1;
          m_x2 = x2;
          m_y2 = y2;
          m_stops = stops;
          m_matrix = matrix;
          return *this;
      }
  
      wxGraphicsPenInfo&
      RadialGradient(wxDouble startX, wxDouble startY,
                     wxDouble endX, wxDouble endY, wxDouble radius,
                     const wxColour& oColor, const wxColour& cColor,
                     const wxGraphicsMatrix& matrix = wxNullGraphicsMatrix)
      {
          m_gradientType = wxGRADIENT_RADIAL;
          m_x1 = startX;
          m_y1 = startY;
          m_x2 = endX;
          m_y2 = endY;
          m_radius = radius;
          m_stops.SetStartColour(oColor);
          m_stops.SetEndColour(cColor);
          m_matrix = matrix;
          return *this;
      }
  
      wxGraphicsPenInfo&
      RadialGradient(wxDouble startX, wxDouble startY,
                     wxDouble endX, wxDouble endY,
                     wxDouble radius, const wxGraphicsGradientStops& stops,
                     const wxGraphicsMatrix& matrix = wxNullGraphicsMatrix)
      {
          m_gradientType = wxGRADIENT_RADIAL;
          m_x1 = startX;
          m_y1 = startY;
          m_x2 = endX;
          m_y2 = endY;
          m_radius = radius;
          m_stops = stops;
          m_matrix = matrix;
          return *this;
      }
  
      // Accessors
  
      wxDouble GetWidth() const { return m_width; }
      wxGradientType GetGradientType() const { return m_gradientType; }
      wxDouble GetX1() const { return m_x1; }
      wxDouble GetY1() const { return m_y1; }
      wxDouble GetX2() const { return m_x2; }
      wxDouble GetY2() const { return m_y2; }
      wxDouble GetStartX() const { return m_x1; }
      wxDouble GetStartY() const { return m_y1; }
      wxDouble GetEndX() const { return m_x2; }
      wxDouble GetEndY() const { return m_y2; }
      wxDouble GetRadius() const { return m_radius; }
      const wxGraphicsGradientStops& GetStops() const { return m_stops; }
      const wxGraphicsMatrix& GetMatrix() const { return m_matrix; }
  
  private:
      wxDouble m_width;
      wxGradientType m_gradientType;
      wxDouble m_x1, m_y1, m_x2, m_y2; // also used for m_xo, m_yo, m_xc, m_yc
      wxDouble m_radius;
      wxGraphicsGradientStops m_stops;
      wxGraphicsMatrix m_matrix;
  };
  
  
  
  class WXDLLIMPEXP_CORE wxGraphicsPath : public wxGraphicsObject
  {
  public:
      wxGraphicsPath()  {}
      virtual ~wxGraphicsPath() {}
  
      //
      // These are the path primitives from which everything else can be constructed
      //
  
      // begins a new subpath at (x,y)
      virtual void MoveToPoint( wxDouble x, wxDouble y );
      void MoveToPoint( const wxPoint2DDouble& p);
  
      // adds a straight line from the current point to (x,y)
      virtual void AddLineToPoint( wxDouble x, wxDouble y );
      void AddLineToPoint( const wxPoint2DDouble& p);
  
      // adds a cubic Bezier curve from the current point, using two control points and an end point
      virtual void AddCurveToPoint( wxDouble cx1, wxDouble cy1, wxDouble cx2, wxDouble cy2, wxDouble x, wxDouble y );
      void AddCurveToPoint( const wxPoint2DDouble& c1, const wxPoint2DDouble& c2, const wxPoint2DDouble& e);
  
      // adds another path
      virtual void AddPath( const wxGraphicsPath& path );
  
      // closes the current sub-path
      virtual void CloseSubpath();
  
      // gets the last point of the current path, (0,0) if not yet set
      virtual void GetCurrentPoint( wxDouble* x, wxDouble* y) const;
      wxPoint2DDouble GetCurrentPoint() const;
  
      // adds an arc of a circle centering at (x,y) with radius (r) from startAngle to endAngle
      virtual void AddArc( wxDouble x, wxDouble y, wxDouble r, wxDouble startAngle, wxDouble endAngle, bool clockwise );
      void AddArc( const wxPoint2DDouble& c, wxDouble r, wxDouble startAngle, wxDouble endAngle, bool clockwise);
  
      //
      // These are convenience functions which - if not available natively will be assembled
      // using the primitives from above
      //
  
      // adds a quadratic Bezier curve from the current point, using a control point and an end point
      virtual void AddQuadCurveToPoint( wxDouble cx, wxDouble cy, wxDouble x, wxDouble y );
  
      // appends a rectangle as a new closed subpath
      virtual void AddRectangle( wxDouble x, wxDouble y, wxDouble w, wxDouble h );
  
      // appends an ellipsis as a new closed subpath fitting the passed rectangle
      virtual void AddCircle( wxDouble x, wxDouble y, wxDouble r );
  
      // appends a an arc to two tangents connecting (current) to (x1,y1) and (x1,y1) to (x2,y2), also a straight line from (current) to (x1,y1)
      virtual void AddArcToPoint( wxDouble x1, wxDouble y1 , wxDouble x2, wxDouble y2, wxDouble r );
  
      // appends an ellipse
      virtual void AddEllipse( wxDouble x, wxDouble y, wxDouble w, wxDouble h);
  
      // appends a rounded rectangle
      virtual void AddRoundedRectangle( wxDouble x, wxDouble y, wxDouble w, wxDouble h, wxDouble radius);
  
      // returns the native path
      virtual void * GetNativePath() const;
  
      // give the native path returned by GetNativePath() back (there might be some deallocations necessary)
      virtual void UnGetNativePath(void *p)const;
  
      // transforms each point of this path by the matrix
      virtual void Transform( const wxGraphicsMatrix& matrix );
  
      // gets the bounding box enclosing all points (possibly including control points)
      virtual void GetBox(wxDouble *x, wxDouble *y, wxDouble *w, wxDouble *h)const;
      wxRect2DDouble GetBox()const;
  
      virtual bool Contains( wxDouble x, wxDouble y, wxPolygonFillMode fillStyle = wxODDEVEN_RULE)const;
      bool Contains( const wxPoint2DDouble& c, wxPolygonFillMode fillStyle = wxODDEVEN_RULE)const;
  
      const wxGraphicsPathData* GetPathData() const
      { return (const wxGraphicsPathData*) GetRefData(); }
      wxGraphicsPathData* GetPathData()
      { return (wxGraphicsPathData*) GetRefData(); }
  
  private:
      wxDECLARE_DYNAMIC_CLASS(wxGraphicsPath);
  };
  
  extern WXDLLIMPEXP_DATA_CORE(wxGraphicsPath) wxNullGraphicsPath;
  
  
  class WXDLLIMPEXP_CORE wxGraphicsContext : public wxGraphicsObject
  {
  public:
      wxGraphicsContext(wxGraphicsRenderer* renderer, wxWindow* window = NULL);
  
      virtual ~wxGraphicsContext();
  
      static wxGraphicsContext* Create( const wxWindowDC& dc);
      static wxGraphicsContext * Create( const wxMemoryDC& dc);
  #if wxUSE_PRINTING_ARCHITECTURE
      static wxGraphicsContext * Create( const wxPrinterDC& dc);
  #endif
  #ifdef __WXMSW__
  #if wxUSE_ENH_METAFILE
      static wxGraphicsContext * Create( const wxEnhMetaFileDC& dc);
  #endif
  #endif
  
      // Create a context from a DC of unknown type, if supported, returns NULL otherwise
      static wxGraphicsContext* CreateFromUnknownDC(const wxDC& dc);
  
      static wxGraphicsContext* CreateFromNative( void * context );
  
      static wxGraphicsContext* CreateFromNativeWindow( void * window );
  
  #ifdef __WXMSW__
      static wxGraphicsContext* CreateFromNativeHDC(WXHDC dc);
  #endif
  
      static wxGraphicsContext* Create( wxWindow* window );
  
  #if wxUSE_IMAGE
      // Create a context for drawing onto a wxImage. The image life time must be
      // greater than that of the context itself as when the context is destroyed
      // it will copy its contents to the specified image.
      static wxGraphicsContext* Create(wxImage& image);
  #endif // wxUSE_IMAGE
  
      // create a context that can be used for measuring texts only, no drawing allowed
      static wxGraphicsContext * Create();
  
      // Return the window this context is associated with, if any.
      wxWindow* GetWindow() const { return m_window; }
  
      // begin a new document (relevant only for printing / pdf etc) if there is a progress dialog, message will be shown
      virtual bool StartDoc( const wxString& message );
  
      // done with that document (relevant only for printing / pdf etc)
      virtual void EndDoc();
  
      // opens a new page  (relevant only for printing / pdf etc) with the given size in points
      // (if both are null the default page size will be used)
      virtual void StartPage( wxDouble width = 0, wxDouble height = 0 );
  
      // ends the current page  (relevant only for printing / pdf etc)
      virtual void EndPage();
  
      // make sure that the current content of this context is immediately visible
      virtual void Flush();
  
      wxGraphicsPath CreatePath() const;
  
      wxGraphicsPen CreatePen(const wxPen& pen) const;
  
      wxGraphicsPen CreatePen(const wxGraphicsPenInfo& info) const
          { return DoCreatePen(info); }
  
      virtual wxGraphicsBrush CreateBrush(const wxBrush& brush ) const;
  
      // sets the brush to a linear gradient, starting at (x1,y1) and ending at
      // (x2,y2) with the given boundary colours or the specified stops
      wxGraphicsBrush
      CreateLinearGradientBrush(wxDouble x1, wxDouble y1,
                                wxDouble x2, wxDouble y2,
                                const wxColour& c1, const wxColour& c2,
                                const wxGraphicsMatrix& matrix = wxNullGraphicsMatrix) const;
      wxGraphicsBrush
      CreateLinearGradientBrush(wxDouble x1, wxDouble y1,
                                wxDouble x2, wxDouble y2,
                                const wxGraphicsGradientStops& stops,
                                const wxGraphicsMatrix& matrix = wxNullGraphicsMatrix) const;
  
      // sets the brush to a radial gradient originating at (xo,yc) and ending
      // on a circle around (xc,yc) with the given radius; the colours may be
      // specified by just the two extremes or the full array of gradient stops
      wxGraphicsBrush
      CreateRadialGradientBrush(wxDouble startX, wxDouble startY,
                                wxDouble endX, wxDouble endY, wxDouble radius,
                                const wxColour& oColor, const wxColour& cColor,
                                const wxGraphicsMatrix& matrix = wxNullGraphicsMatrix) const;
  
      wxGraphicsBrush
      CreateRadialGradientBrush(wxDouble startX, wxDouble startY,
                                wxDouble endX, wxDouble endY, wxDouble radius,
                                const wxGraphicsGradientStops& stops,
                                const wxGraphicsMatrix& matrix = wxNullGraphicsMatrix) const;
  
      // creates a font
      virtual wxGraphicsFont CreateFont( const wxFont &font , const wxColour &col = *wxBLACK ) const;
      virtual wxGraphicsFont CreateFont(double sizeInPixels,
                                        const wxString& facename,
                                        int flags = wxFONTFLAG_DEFAULT,
                                        const wxColour& col = *wxBLACK) const;
  
      // create a native bitmap representation
      virtual wxGraphicsBitmap CreateBitmap( const wxBitmap &bitmap ) const;
  #if wxUSE_IMAGE
      wxGraphicsBitmap CreateBitmapFromImage(const wxImage& image) const;
  #endif // wxUSE_IMAGE
  
      // create a native bitmap representation
      virtual wxGraphicsBitmap CreateSubBitmap( const wxGraphicsBitmap &bitmap, wxDouble x, wxDouble y, wxDouble w, wxDouble h  ) const;
  
      // create a 'native' matrix corresponding to these values
      virtual wxGraphicsMatrix CreateMatrix( wxDouble a=1.0, wxDouble b=0.0, wxDouble c=0.0, wxDouble d=1.0,
          wxDouble tx=0.0, wxDouble ty=0.0) const;
  
      wxGraphicsMatrix CreateMatrix( const wxAffineMatrix2DBase& mat ) const
      {
          wxMatrix2D mat2D;
          wxPoint2DDouble tr;
          mat.Get(&mat2D, &tr);
  
          return CreateMatrix(mat2D.m_11, mat2D.m_12, mat2D.m_21, mat2D.m_22,
                              tr.m_x, tr.m_y);
      }
  
      // push the current state of the context, ie the transformation matrix on a stack
      virtual void PushState() = 0;
  
      // pops a stored state from the stack
      virtual void PopState() = 0;
  
      // clips drawings to the region intersected with the current clipping region
      virtual void Clip( const wxRegion &region ) = 0;
  
      // clips drawings to the rect intersected with the current clipping region
      virtual void Clip( wxDouble x, wxDouble y, wxDouble w, wxDouble h ) = 0;
  
      // resets the clipping to original extent
      virtual void ResetClip() = 0;
  
      // returns bounding box of the clipping region
      virtual void GetClipBox(wxDouble* x, wxDouble* y, wxDouble* w, wxDouble* h) = 0;
  
      // returns the native context
      virtual void * GetNativeContext() = 0;
  
      // returns the current shape antialiasing mode
      virtual wxAntialiasMode GetAntialiasMode() const { return m_antialias; }
  
      // sets the antialiasing mode, returns true if it supported
      virtual bool SetAntialiasMode(wxAntialiasMode antialias) = 0;
  
      // returns the current interpolation quality
      virtual wxInterpolationQuality GetInterpolationQuality() const { return m_interpolation; }
  
      // sets the interpolation quality, returns true if it supported
      virtual bool SetInterpolationQuality(wxInterpolationQuality interpolation) = 0;
  
      // returns the current compositing operator
      virtual wxCompositionMode GetCompositionMode() const { return m_composition; }
  
      // sets the compositing operator, returns true if it supported
      virtual bool SetCompositionMode(wxCompositionMode op) = 0;
  
      // returns the size of the graphics context in device coordinates
      void GetSize(wxDouble* width, wxDouble* height) const
      {
          if ( width )
              *width = m_width;
          if ( height )
              *height = m_height;
      }
  
      // returns the resolution of the graphics context in device points per inch
      virtual void GetDPI( wxDouble* dpiX, wxDouble* dpiY) const;
  
  #if 0
      // sets the current alpha on this context
      virtual void SetAlpha( wxDouble alpha );
  
      // returns the alpha on this context
      virtual wxDouble GetAlpha() const;
  #endif
  
      // all rendering is done into a fully transparent temporary context
      virtual void BeginLayer(wxDouble opacity) = 0;
  
      // composites back the drawings into the context with the opacity given at
      // the BeginLayer call
      virtual void EndLayer() = 0;
  
      //
      // transformation : changes the current transformation matrix CTM of the context
      //
  
      // translate
      virtual void Translate( wxDouble dx , wxDouble dy ) = 0;
  
      // scale
      virtual void Scale( wxDouble xScale , wxDouble yScale ) = 0;
  
      // rotate (radians)
      virtual void Rotate( wxDouble angle ) = 0;
  
      // concatenates this transform with the current transform of this context
      virtual void ConcatTransform( const wxGraphicsMatrix& matrix ) = 0;
  
      // sets the transform of this context
      virtual void SetTransform( const wxGraphicsMatrix& matrix ) = 0;
  
      // gets the matrix of this context
      virtual wxGraphicsMatrix GetTransform() const = 0;
      //
      // setting the paint
      //
  
      // sets the pen
      virtual void SetPen( const wxGraphicsPen& pen );
  
      void SetPen( const wxPen& pen );
  
      // sets the brush for filling
      virtual void SetBrush( const wxGraphicsBrush& brush );
  
      void SetBrush( const wxBrush& brush );
  
      // sets the font
      virtual void SetFont( const wxGraphicsFont& font );
  
      void SetFont( const wxFont& font, const wxColour& colour );
  
  
      // strokes along a path with the current pen
      virtual void StrokePath( const wxGraphicsPath& path ) = 0;
  
      // fills a path with the current brush
      virtual void FillPath( const wxGraphicsPath& path, wxPolygonFillMode fillStyle = wxODDEVEN_RULE ) = 0;
  
      // draws a path by first filling and then stroking
      virtual void DrawPath( const wxGraphicsPath& path, wxPolygonFillMode fillStyle = wxODDEVEN_RULE );
  
      // paints a transparent rectangle (only useful for bitmaps or windows)
      virtual void ClearRectangle(wxDouble x, wxDouble y, wxDouble w, wxDouble h);
  
      //
      // text
      //
  
      void DrawText( const wxString &str, wxDouble x, wxDouble y )
          { DoDrawText(str, x, y); }
  
      void DrawText( const wxString &str, wxDouble x, wxDouble y, wxDouble angle )
          { DoDrawRotatedText(str, x, y, angle); }
  
      void DrawText( const wxString &str, wxDouble x, wxDouble y,
                     const wxGraphicsBrush& backgroundBrush )
          { DoDrawFilledText(str, x, y, backgroundBrush); }
  
      void DrawText( const wxString &str, wxDouble x, wxDouble y,
                     wxDouble angle, const wxGraphicsBrush& backgroundBrush )
          { DoDrawRotatedFilledText(str, x, y, angle, backgroundBrush); }
  
  
      virtual void GetTextExtent( const wxString &text, wxDouble *width, wxDouble *height,
          wxDouble *descent = NULL, wxDouble *externalLeading = NULL ) const  = 0;
  
      virtual void GetPartialTextExtents(const wxString& text, wxArrayDouble& widths) const = 0;
  
      //
      // image support
      //
  
      virtual void DrawBitmap( const wxGraphicsBitmap &bmp, wxDouble x, wxDouble y, wxDouble w, wxDouble h ) = 0;
  
      virtual void DrawBitmap( const wxBitmap &bmp, wxDouble x, wxDouble y, wxDouble w, wxDouble h ) = 0;
  
      virtual void DrawIcon( const wxIcon &icon, wxDouble x, wxDouble y, wxDouble w, wxDouble h ) = 0;
  
      //
      // convenience methods
      //
  
      // strokes a single line
      virtual void StrokeLine( wxDouble x1, wxDouble y1, wxDouble x2, wxDouble y2);
  
      // stroke lines connecting each of the points
      virtual void StrokeLines( size_t n, const wxPoint2DDouble *points);
  
      // stroke disconnected lines from begin to end points
      virtual void StrokeLines( size_t n, const wxPoint2DDouble *beginPoints, const wxPoint2DDouble *endPoints);
  
      // draws a polygon
      virtual void DrawLines( size_t n, const wxPoint2DDouble *points, wxPolygonFillMode fillStyle = wxODDEVEN_RULE );
  
      // draws a rectangle
      virtual void DrawRectangle( wxDouble x, wxDouble y, wxDouble w, wxDouble h);
  
      // draws an ellipse
      virtual void DrawEllipse( wxDouble x, wxDouble y, wxDouble w, wxDouble h);
  
      // draws a rounded rectangle
      virtual void DrawRoundedRectangle( wxDouble x, wxDouble y, wxDouble w, wxDouble h, wxDouble radius);
  
       // wrappers using wxPoint2DDouble TODO
  
      // helper to determine if a 0.5 offset should be applied for the drawing operation
      virtual bool ShouldOffset() const { return false; }
  
      // indicates whether the context should try to offset for pixel boundaries, this only makes sense on
      // bitmap devices like screen, by default this is turned off
      virtual void EnableOffset(bool enable = true);
  
      void DisableOffset() { EnableOffset(false); }
      bool OffsetEnabled() { return m_enableOffset; }
  
  protected:
      // These fields must be initialized in the derived class ctors.
      wxDouble m_width,
               m_height;
  
      wxGraphicsPen m_pen;
      wxGraphicsBrush m_brush;
      wxGraphicsFont m_font;
      wxAntialiasMode m_antialias;
      wxCompositionMode m_composition;
      wxInterpolationQuality m_interpolation;
      bool m_enableOffset;
  
  protected:
      // implementations of overloaded public functions: we use different names
      // for them to avoid the virtual function hiding problems in the derived
      // classes
      virtual wxGraphicsPen DoCreatePen(const wxGraphicsPenInfo& info) const;
  
      virtual void DoDrawText(const wxString& str, wxDouble x, wxDouble y) = 0;
      virtual void DoDrawRotatedText(const wxString& str, wxDouble x, wxDouble y,
                                     wxDouble angle);
      virtual void DoDrawFilledText(const wxString& str, wxDouble x, wxDouble y,
                                    const wxGraphicsBrush& backgroundBrush);
      virtual void DoDrawRotatedFilledText(const wxString& str,
                                           wxDouble x, wxDouble y,
                                           wxDouble angle,
                                           const wxGraphicsBrush& backgroundBrush);
  
  private:
      // The associated window, if any, i.e. if one was passed directly to
      // Create() or the associated window of the wxDC this context was created
      // from.
      wxWindow* const m_window;
  
      wxDECLARE_NO_COPY_CLASS(wxGraphicsContext);
      wxDECLARE_ABSTRACT_CLASS(wxGraphicsContext);
  };
  
  #if 0
  
  //
  // A graphics figure allows to cache path, pen etc creations, also will be a basis for layering/grouping elements
  //
  
  class WXDLLIMPEXP_CORE wxGraphicsFigure : public wxGraphicsObject
  {
  public:
      wxGraphicsFigure(wxGraphicsRenderer* renderer);
  
      virtual ~wxGraphicsFigure();
  
      void SetPath( wxGraphicsMatrix* matrix );
  
      void SetMatrix( wxGraphicsPath* path);
  
      // draws this object on the context
      virtual void Draw( wxGraphicsContext* cg );
  
      // returns the path of this object
      wxGraphicsPath* GetPath() { return m_path; }
  
      // returns the transformation matrix of this object, may be null if there is no transformation necessary
      wxGraphicsMatrix* GetMatrix() { return m_matrix; }
  
  private:
      wxGraphicsMatrix* m_matrix;
      wxGraphicsPath* m_path;
  
      wxDECLARE_DYNAMIC_CLASS(wxGraphicsFigure);
  };
  
  #endif
  
  //
  // The graphics renderer is the instance corresponding to the rendering engine used, eg there is ONE core graphics renderer
  // instance on OSX. This instance is pointed back to by all objects created by it. Therefore you can create eg additional
  // paths at any point from a given matrix etc.
  //
  
  class WXDLLIMPEXP_CORE wxGraphicsRenderer : public wxObject
  {
  public:
      wxGraphicsRenderer() {}
  
      virtual ~wxGraphicsRenderer() {}
  
      static wxGraphicsRenderer* GetDefaultRenderer();
  
      static wxGraphicsRenderer* GetCairoRenderer();
  
  #ifdef __WXMSW__
  #if wxUSE_GRAPHICS_GDIPLUS
      static wxGraphicsRenderer* GetGDIPlusRenderer();
  #endif
  
  #if wxUSE_GRAPHICS_DIRECT2D
      static wxGraphicsRenderer* GetDirect2DRenderer();
  #endif
  #endif
  
      // Context
  
      virtual wxGraphicsContext * CreateContext( const wxWindowDC& dc) = 0;
      virtual wxGraphicsContext * CreateContext( const wxMemoryDC& dc) = 0;
  #if wxUSE_PRINTING_ARCHITECTURE
      virtual wxGraphicsContext * CreateContext( const wxPrinterDC& dc) = 0;
  #endif
  #ifdef __WXMSW__
  #if wxUSE_ENH_METAFILE
      virtual wxGraphicsContext * CreateContext( const wxEnhMetaFileDC& dc) = 0;
  #endif
  #endif
  
      wxGraphicsContext* CreateContextFromUnknownDC(const wxDC& dc);
  
      virtual wxGraphicsContext * CreateContextFromNativeContext( void * context ) = 0;
  
      virtual wxGraphicsContext * CreateContextFromNativeWindow( void * window ) = 0;
  
  #ifdef __WXMSW__
      virtual wxGraphicsContext * CreateContextFromNativeHDC(WXHDC dc) = 0;
  #endif
  
      virtual wxGraphicsContext * CreateContext( wxWindow* window ) = 0;
  
  #if wxUSE_IMAGE
      virtual wxGraphicsContext * CreateContextFromImage(wxImage& image) = 0;
  #endif // wxUSE_IMAGE
  
      // create a context that can be used for measuring texts only, no drawing allowed
      virtual wxGraphicsContext * CreateMeasuringContext() = 0;
  
      // Path
  
      virtual wxGraphicsPath CreatePath() = 0;
  
      // Matrix
  
      virtual wxGraphicsMatrix CreateMatrix( wxDouble a=1.0, wxDouble b=0.0, wxDouble c=0.0, wxDouble d=1.0,
          wxDouble tx=0.0, wxDouble ty=0.0) = 0;
  
      // Paints
  
      virtual wxGraphicsPen CreatePen(const wxGraphicsPenInfo& info) = 0;
  
      virtual wxGraphicsBrush CreateBrush(const wxBrush& brush ) = 0;
  
      // Gradient brush creation functions may not honour all the stops specified
      // stops and use just its boundary colours (this is currently the case
      // under OS X)
      virtual wxGraphicsBrush
      CreateLinearGradientBrush(wxDouble x1, wxDouble y1,
                                wxDouble x2, wxDouble y2,
                                const wxGraphicsGradientStops& stops,
                                const wxGraphicsMatrix& matrix = wxNullGraphicsMatrix) = 0;
  
      virtual wxGraphicsBrush
      CreateRadialGradientBrush(wxDouble startX, wxDouble startY,
                                wxDouble endX, wxDouble endY,
                                wxDouble radius,
                                const wxGraphicsGradientStops& stops,
                                const wxGraphicsMatrix& matrix = wxNullGraphicsMatrix) = 0;
  
      // sets the font
      virtual wxGraphicsFont CreateFont( const wxFont &font , const wxColour &col = *wxBLACK ) = 0;
      virtual wxGraphicsFont CreateFont(double sizeInPixels,
                                        const wxString& facename,
                                        int flags = wxFONTFLAG_DEFAULT,
                                        const wxColour& col = *wxBLACK) = 0;
      virtual wxGraphicsFont CreateFontAtDPI(const wxFont& font,
                                             const wxRealPoint& dpi,
                                             const wxColour& col = *wxBLACK) = 0;
  
      // create a native bitmap representation
      virtual wxGraphicsBitmap CreateBitmap( const wxBitmap &bitmap ) = 0;
  #if wxUSE_IMAGE
      virtual wxGraphicsBitmap CreateBitmapFromImage(const wxImage& image) = 0;
      virtual wxImage CreateImageFromBitmap(const wxGraphicsBitmap& bmp) = 0;
  #endif // wxUSE_IMAGE
  
      // create a graphics bitmap from a native bitmap
      virtual wxGraphicsBitmap CreateBitmapFromNativeBitmap( void* bitmap ) = 0;
  
      // create a subimage from a native image representation
      virtual wxGraphicsBitmap CreateSubBitmap( const wxGraphicsBitmap &bitmap, wxDouble x, wxDouble y, wxDouble w, wxDouble h  ) = 0;
  
      virtual wxString GetName() const = 0;
      virtual void
      GetVersion(int* major, int* minor = NULL, int* micro = NULL) const = 0;
  
  private:
      wxDECLARE_NO_COPY_CLASS(wxGraphicsRenderer);
      wxDECLARE_ABSTRACT_CLASS(wxGraphicsRenderer);
  };
  
  
  #if wxUSE_IMAGE
  inline
  wxImage wxGraphicsBitmap::ConvertToImage() const
  {
      wxGraphicsRenderer* renderer = GetRenderer();
      return renderer ? renderer->CreateImageFromBitmap(*this) : wxNullImage;
  }
  #endif // wxUSE_IMAGE
  
  #endif // wxUSE_GRAPHICS_CONTEXT
  
  #endif // _WX_GRAPHICS_H_
  