include/wx/graphics.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/graphics.h
   3 // Purpose:     graphics context header
   4 // Author:      Stefan Csomor
   5 // Modified by:
   6 // Created:
   7 // Copyright:   (c) Stefan Csomor
   8 // RCS-ID:      $Id$
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_GRAPHICS_H_
  13 #define _WX_GRAPHICS_H_
  14
  15 #include "wx/defs.h"
  16
  17 #if wxUSE_GRAPHICS_CONTEXT
  18
  19 #include "wx/geometry.h"
  20 #include "wx/dynarray.h"
  21
  22 class WXDLLIMPEXP_FWD_CORE wxWindowDC;
  23 class WXDLLIMPEXP_FWD_CORE wxMemoryDC;
  24 #if wxUSE_PRINTING_ARCHITECTURE
  25 class WXDLLIMPEXP_FWD_CORE wxPrinterDC;
  26 #endif
  27 class WXDLLIMPEXP_FWD_CORE wxGraphicsContext;
  28 class WXDLLIMPEXP_FWD_CORE wxGraphicsPath;
  29 class WXDLLIMPEXP_FWD_CORE wxGraphicsMatrix;
  30 class WXDLLIMPEXP_FWD_CORE wxGraphicsFigure;
  31 class WXDLLIMPEXP_FWD_CORE wxGraphicsRenderer;
  32 class WXDLLIMPEXP_FWD_CORE wxGraphicsPen;
  33 class WXDLLIMPEXP_FWD_CORE wxGraphicsBrush;
  34 class WXDLLIMPEXP_FWD_CORE wxGraphicsFont;
  35 class WXDLLIMPEXP_FWD_CORE wxGraphicsBitmap;
  36
  37 /*
  38  * notes about the graphics context apis
  39  *
  40  * angles : are measured in radians, 0.0 being in direction of positiv x axis, PI/2 being
  41  * in direction of positive y axis.
  42  */
  43
  44 // Base class of all objects used for drawing in the new graphics API, the always point back to their
  45 // originating rendering engine, there is no dynamic unloading of a renderer currently allowed,
  46 // these references are not counted
  47
  48 //
  49 // The data used by objects like graphics pens etc is ref counted, in order to avoid unnecessary expensive
  50 // duplication. Any operation on a shared instance that results in a modified state, uncouples this
  51 // instance from the other instances that were shared - using copy on write semantics
  52 //
  53
  54 class WXDLLIMPEXP_FWD_CORE wxGraphicsObjectRefData;
  55 class WXDLLIMPEXP_FWD_CORE wxGraphicsMatrixData;
  56 class WXDLLIMPEXP_FWD_CORE wxGraphicsPathData;
  57
  58 class WXDLLIMPEXP_CORE wxGraphicsObject : public wxObject
  59 {
  60 public :
  61     wxGraphicsObject() ;
  62     wxGraphicsObject( wxGraphicsRenderer* renderer ) ;
  63     virtual ~wxGraphicsObject() ;
  64
  65     bool IsNull() const ;
  66
  67     // returns the renderer that was used to create this instance, or NULL if it has not been initialized yet
  68     wxGraphicsRenderer* GetRenderer() const ;
  69     wxGraphicsObjectRefData* GetGraphicsData() const ;
  70 protected :
  71     virtual wxObjectRefData* CreateRefData() const;
  72     virtual wxObjectRefData* CloneRefData(const wxObjectRefData* data) const;
  73
  74     DECLARE_DYNAMIC_CLASS(wxGraphicsObject)
  75 } ;
  76
  77 class WXDLLIMPEXP_CORE wxGraphicsPen : public wxGraphicsObject
  78 {
  79 public :
  80     wxGraphicsPen() {}
  81     virtual ~wxGraphicsPen() {}
  82 private :
  83     DECLARE_DYNAMIC_CLASS(wxGraphicsPen)
  84 } ;
  85
  86 extern WXDLLIMPEXP_DATA_CORE(wxGraphicsPen) wxNullGraphicsPen;
  87
  88 class WXDLLIMPEXP_CORE wxGraphicsBrush : public wxGraphicsObject
  89 {
  90 public :
  91     wxGraphicsBrush() {}
  92     virtual ~wxGraphicsBrush() {}
  93 private :
  94     DECLARE_DYNAMIC_CLASS(wxGraphicsBrush)
  95 } ;
  96
  97 extern WXDLLIMPEXP_DATA_CORE(wxGraphicsBrush) wxNullGraphicsBrush;
  98
  99 class WXDLLIMPEXP_CORE wxGraphicsFont : public wxGraphicsObject
 100 {
 101 public :
 102     wxGraphicsFont() {}
 103     virtual ~wxGraphicsFont() {}
 104 private :
 105     DECLARE_DYNAMIC_CLASS(wxGraphicsFont)
 106 } ;
 107
 108 extern WXDLLIMPEXP_DATA_CORE(wxGraphicsFont) wxNullGraphicsFont;
 109
 110 class WXDLLIMPEXP_CORE wxGraphicsBitmap : public wxGraphicsObject
 111 {
 112 public :
 113     wxGraphicsBitmap() {}
 114     virtual ~wxGraphicsBitmap() {}
 115 private :
 116     DECLARE_DYNAMIC_CLASS(wxGraphicsBitmap)
 117 } ;
 118
 119 extern WXDLLIMPEXP_DATA_CORE(wxGraphicsBitmap) wxNullGraphicsBitmap;
 120
 121 class WXDLLIMPEXP_CORE wxGraphicsMatrix : public wxGraphicsObject
 122 {
 123 public :
 124     wxGraphicsMatrix() {}
 125
 126     virtual ~wxGraphicsMatrix() {}
 127
 128     // concatenates the matrix
 129     virtual void Concat( const wxGraphicsMatrix *t );
 130     void Concat( const wxGraphicsMatrix &t ) { Concat( &t ); }
 131
 132     // sets the matrix to the respective values
 133     virtual void Set(wxDouble a=1.0, wxDouble b=0.0, wxDouble c=0.0, wxDouble d=1.0,
 134         wxDouble tx=0.0, wxDouble ty=0.0);
 135
 136     // gets the component valuess of the matrix
 137     virtual void Get(wxDouble* a=NULL, wxDouble* b=NULL,  wxDouble* c=NULL,
 138                      wxDouble* d=NULL, wxDouble* tx=NULL, wxDouble* ty=NULL) const;
 139
 140     // makes this the inverse matrix
 141     virtual void Invert();
 142
 143     // returns true if the elements of the transformation matrix are equal ?
 144     virtual bool IsEqual( const wxGraphicsMatrix* t) const;
 145     bool IsEqual( const wxGraphicsMatrix& t) const { return IsEqual( &t ); }
 146
 147     // return true if this is the identity matrix
 148     virtual bool IsIdentity() const;
 149
 150     //
 151     // transformation
 152     //
 153
 154     // add the translation to this matrix
 155     virtual void Translate( wxDouble dx , wxDouble dy );
 156
 157     // add the scale to this matrix
 158     virtual void Scale( wxDouble xScale , wxDouble yScale );
 159
 160     // add the rotation to this matrix (radians)
 161     virtual void Rotate( wxDouble angle );
 162
 163     //
 164     // apply the transforms
 165     //
 166
 167     // applies that matrix to the point
 168     virtual void TransformPoint( wxDouble *x, wxDouble *y ) const;
 169
 170     // applies the matrix except for translations
 171     virtual void TransformDistance( wxDouble *dx, wxDouble *dy ) const;
 172
 173     // returns the native representation
 174     virtual void * GetNativeMatrix() const;
 175
 176     const wxGraphicsMatrixData* GetMatrixData() const
 177     { return (const wxGraphicsMatrixData*) GetRefData(); }
 178     wxGraphicsMatrixData* GetMatrixData()
 179     { return (wxGraphicsMatrixData*) GetRefData(); }
 180
 181 private :
 182     DECLARE_DYNAMIC_CLASS(wxGraphicsMatrix)
 183 } ;
 184
 185 extern WXDLLIMPEXP_DATA_CORE(wxGraphicsMatrix) wxNullGraphicsMatrix;
 186
 187 class WXDLLIMPEXP_CORE wxGraphicsPath : public wxGraphicsObject
 188 {
 189 public :
 190     wxGraphicsPath()  {}
 191     virtual ~wxGraphicsPath() {}
 192
 193     //
 194     // These are the path primitives from which everything else can be constructed
 195     //
 196
 197     // begins a new subpath at (x,y)
 198     virtual void MoveToPoint( wxDouble x, wxDouble y );
 199     void MoveToPoint( const wxPoint2DDouble& p);
 200
 201     // adds a straight line from the current point to (x,y)
 202     virtual void AddLineToPoint( wxDouble x, wxDouble y );
 203     void AddLineToPoint( const wxPoint2DDouble& p);
 204
 205     // adds a cubic Bezier curve from the current point, using two control points and an end point
 206     virtual void AddCurveToPoint( wxDouble cx1, wxDouble cy1, wxDouble cx2, wxDouble cy2, wxDouble x, wxDouble y ) ;
 207     void AddCurveToPoint( const wxPoint2DDouble& c1, const wxPoint2DDouble& c2, const wxPoint2DDouble& e);
 208
 209     // adds another path
 210     virtual void AddPath( const wxGraphicsPath& path );
 211
 212     // closes the current sub-path
 213     virtual void CloseSubpath() ;
 214
 215     // gets the last point of the current path, (0,0) if not yet set
 216     virtual void GetCurrentPoint( wxDouble* x, wxDouble* y) const;
 217     wxPoint2DDouble GetCurrentPoint() const;
 218
 219     // adds an arc of a circle centering at (x,y) with radius (r) from startAngle to endAngle
 220     virtual void AddArc( wxDouble x, wxDouble y, wxDouble r, wxDouble startAngle, wxDouble endAngle, bool clockwise ) ;
 221     void AddArc( const wxPoint2DDouble& c, wxDouble r, wxDouble startAngle, wxDouble endAngle, bool clockwise);
 222
 223     //
 224     // These are convenience functions which - if not available natively will be assembled
 225     // using the primitives from above
 226     //
 227
 228     // adds a quadratic Bezier curve from the current point, using a control point and an end point
 229     virtual void AddQuadCurveToPoint( wxDouble cx, wxDouble cy, wxDouble x, wxDouble y );
 230
 231     // appends a rectangle as a new closed subpath
 232     virtual void AddRectangle( wxDouble x, wxDouble y, wxDouble w, wxDouble h );
 233
 234     // appends an ellipsis as a new closed subpath fitting the passed rectangle
 235     virtual void AddCircle( wxDouble x, wxDouble y, wxDouble r );
 236
 237     // 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)
 238     virtual void AddArcToPoint( wxDouble x1, wxDouble y1 , wxDouble x2, wxDouble y2, wxDouble r ) ;
 239
 240     // appends an ellipse
 241     virtual void AddEllipse( wxDouble x, wxDouble y, wxDouble w, wxDouble h);
 242
 243     // appends a rounded rectangle
 244     virtual void AddRoundedRectangle( wxDouble x, wxDouble y, wxDouble w, wxDouble h, wxDouble radius);
 245
 246     // returns the native path
 247     virtual void * GetNativePath() const;
 248
 249     // give the native path returned by GetNativePath() back (there might be some deallocations necessary)
 250     virtual void UnGetNativePath(void *p)const;
 251
 252     // transforms each point of this path by the matrix
 253     virtual void Transform( const wxGraphicsMatrix& matrix );
 254
 255     // gets the bounding box enclosing all points (possibly including control points)
 256     virtual void GetBox(wxDouble *x, wxDouble *y, wxDouble *w, wxDouble *h)const;
 257     wxRect2DDouble GetBox()const;
 258
 259     virtual bool Contains( wxDouble x, wxDouble y, int fillStyle = wxODDEVEN_RULE)const;
 260     bool Contains( const wxPoint2DDouble& c, int fillStyle = wxODDEVEN_RULE)const;
 261
 262     const wxGraphicsPathData* GetPathData() const
 263     { return (const wxGraphicsPathData*) GetRefData(); }
 264     wxGraphicsPathData* GetPathData()
 265     { return (wxGraphicsPathData*) GetRefData(); }
 266
 267 private :
 268     DECLARE_DYNAMIC_CLASS(wxGraphicsPath)
 269 } ;
 270
 271 extern WXDLLIMPEXP_DATA_CORE(wxGraphicsPath) wxNullGraphicsPath;
 272
 273
 274 class WXDLLIMPEXP_CORE wxGraphicsContext : public wxGraphicsObject
 275 {
 276 public:
 277     wxGraphicsContext(wxGraphicsRenderer* renderer);
 278
 279     virtual ~wxGraphicsContext();
 280
 281     static wxGraphicsContext* Create( const wxWindowDC& dc) ;
 282     static wxGraphicsContext * Create( const wxMemoryDC& dc) ;
 283 #if wxUSE_PRINTING_ARCHITECTURE
 284     static wxGraphicsContext * Create( const wxPrinterDC& dc) ;
 285 #endif
 286
 287     static wxGraphicsContext* CreateFromNative( void * context ) ;
 288
 289     static wxGraphicsContext* CreateFromNativeWindow( void * window ) ;
 290
 291     static wxGraphicsContext* Create( wxWindow* window ) ;
 292
 293     // create a context that can be used for measuring texts only, no drawing allowed
 294     static wxGraphicsContext * Create();
 295
 296     // begin a new document (relevant only for printing / pdf etc) if there is a progress dialog, message will be shown
 297     virtual bool StartDoc( const wxString& message ) ;
 298
 299     // done with that document (relevant only for printing / pdf etc)
 300     virtual void EndDoc();
 301
 302     // opens a new page  (relevant only for printing / pdf etc) with the given size in points
 303     // (if both are null the default page size will be used)
 304     virtual void StartPage( wxDouble width = 0, wxDouble height = 0 );
 305
 306     // ends the current page  (relevant only for printing / pdf etc)
 307     virtual void EndPage();
 308
 309     // make sure that the current content of this context is immediately visible
 310     virtual void Flush();
 311
 312     wxGraphicsPath CreatePath() const;
 313
 314     virtual wxGraphicsPen CreatePen(const wxPen& pen) const;
 315
 316     virtual wxGraphicsBrush CreateBrush(const wxBrush& brush ) const;
 317
 318     // sets the brush to a linear gradient, starting at (x1,y1) with color c1 to (x2,y2) with color c2
 319     virtual wxGraphicsBrush CreateLinearGradientBrush( wxDouble x1, wxDouble y1, wxDouble x2, wxDouble y2,
 320         const wxColour&c1, const wxColour&c2) const;
 321
 322     // sets the brush to a radial gradient originating at (xo,yc) with color oColor and ends on a circle around (xc,yc)
 323     // with radius r and color cColor
 324     virtual wxGraphicsBrush CreateRadialGradientBrush( wxDouble xo, wxDouble yo, wxDouble xc, wxDouble yc, wxDouble radius,
 325         const wxColour &oColor, const wxColour &cColor) const;
 326
 327     // sets the font
 328     virtual wxGraphicsFont CreateFont( const wxFont &font , const wxColour &col = *wxBLACK ) const;
 329
 330     // create a native bitmap representation
 331     virtual wxGraphicsBitmap CreateBitmap( const wxBitmap &bitmap ) const;
 332
 333     // create a native bitmap representation
 334     virtual wxGraphicsBitmap CreateSubBitmap( const wxGraphicsBitmap &bitmap, wxDouble x, wxDouble y, wxDouble w, wxDouble h  ) const;
 335
 336     // create a 'native' matrix corresponding to these values
 337     virtual wxGraphicsMatrix CreateMatrix( wxDouble a=1.0, wxDouble b=0.0, wxDouble c=0.0, wxDouble d=1.0,
 338         wxDouble tx=0.0, wxDouble ty=0.0) const;
 339
 340     // push the current state of the context, ie the transformation matrix on a stack
 341     virtual void PushState() = 0;
 342
 343     // pops a stored state from the stack
 344     virtual void PopState() = 0;
 345
 346     // clips drawings to the region intersected with the current clipping region
 347     virtual void Clip( const wxRegion &region ) = 0;
 348
 349     // clips drawings to the rect intersected with the current clipping region
 350     virtual void Clip( wxDouble x, wxDouble y, wxDouble w, wxDouble h ) = 0;
 351
 352     // resets the clipping to original extent
 353     virtual void ResetClip() = 0 ;
 354
 355     // returns the native context
 356     virtual void * GetNativeContext() = 0;
 357
 358     // returns the current logical function
 359     virtual int GetLogicalFunction() const { return m_logicalFunction; }
 360
 361     // sets the current logical function, returns true if it supported
 362     virtual bool SetLogicalFunction(int function) ;
 363
 364     // returns the size of the graphics context in device coordinates
 365     virtual void GetSize( wxDouble* width, wxDouble* height);
 366
 367     // returns the resolution of the graphics context in device points per inch
 368     virtual void GetDPI( wxDouble* dpiX, wxDouble* dpiY);
 369
 370 #if 0
 371     // sets the current alpha on this context
 372     virtual void SetAlpha( wxDouble alpha );
 373
 374     // returns the alpha on this context
 375     virtual wxDouble GetAlpha() const;
 376 #endif
 377     //
 378     // transformation : changes the current transformation matrix CTM of the context
 379     //
 380
 381     // translate
 382     virtual void Translate( wxDouble dx , wxDouble dy ) = 0;
 383
 384     // scale
 385     virtual void Scale( wxDouble xScale , wxDouble yScale ) = 0;
 386
 387     // rotate (radians)
 388     virtual void Rotate( wxDouble angle ) = 0;
 389
 390     // concatenates this transform with the current transform of this context
 391     virtual void ConcatTransform( const wxGraphicsMatrix& matrix ) = 0;
 392
 393     // sets the transform of this context
 394     virtual void SetTransform( const wxGraphicsMatrix& matrix ) = 0;
 395
 396     // gets the matrix of this context
 397     virtual wxGraphicsMatrix GetTransform() const = 0;
 398     //
 399     // setting the paint
 400     //
 401
 402     // sets the pen
 403     virtual void SetPen( const wxGraphicsPen& pen );
 404
 405     void SetPen( const wxPen& pen );
 406
 407     // sets the brush for filling
 408     virtual void SetBrush( const wxGraphicsBrush& brush );
 409
 410     void SetBrush( const wxBrush& brush );
 411
 412     // sets the font
 413     virtual void SetFont( const wxGraphicsFont& font );
 414
 415     void SetFont( const wxFont& font, const wxColour& colour );
 416
 417
 418     // strokes along a path with the current pen
 419     virtual void StrokePath( const wxGraphicsPath& path ) = 0;
 420
 421     // fills a path with the current brush
 422     virtual void FillPath( const wxGraphicsPath& path, int fillStyle = wxODDEVEN_RULE ) = 0;
 423
 424     // draws a path by first filling and then stroking
 425     virtual void DrawPath( const wxGraphicsPath& path, int fillStyle = wxODDEVEN_RULE );
 426
 427     //
 428     // text
 429     //
 430
 431     virtual void DrawText( const wxString &str, wxDouble x, wxDouble y ) = 0;
 432
 433     virtual void DrawText( const wxString &str, wxDouble x, wxDouble y, wxDouble angle );
 434
 435     virtual void DrawText( const wxString &str, wxDouble x, wxDouble y, const wxGraphicsBrush& backgroundBrush ) ;
 436
 437     virtual void DrawText( const wxString &str, wxDouble x, wxDouble y, wxDouble angle, const wxGraphicsBrush& backgroundBrush );
 438
 439     virtual void GetTextExtent( const wxString &text, wxDouble *width, wxDouble *height,
 440         wxDouble *descent, wxDouble *externalLeading ) const  = 0;
 441
 442     virtual void GetPartialTextExtents(const wxString& text, wxArrayDouble& widths) const = 0;
 443
 444     //
 445     // image support
 446     //
 447
 448 #ifndef __WXGTK20__
 449     virtual void DrawBitmap( const wxGraphicsBitmap &bmp, wxDouble x, wxDouble y, wxDouble w, wxDouble h ) = 0;
 450 #endif
 451
 452     virtual void DrawBitmap( const wxBitmap &bmp, wxDouble x, wxDouble y, wxDouble w, wxDouble h ) = 0;
 453
 454     virtual void DrawIcon( const wxIcon &icon, wxDouble x, wxDouble y, wxDouble w, wxDouble h ) = 0;
 455
 456     //
 457     // convenience methods
 458     //
 459
 460     // strokes a single line
 461     virtual void StrokeLine( wxDouble x1, wxDouble y1, wxDouble x2, wxDouble y2);
 462
 463     // stroke lines connecting each of the points
 464     virtual void StrokeLines( size_t n, const wxPoint2DDouble *points);
 465
 466     // stroke disconnected lines from begin to end points
 467     virtual void StrokeLines( size_t n, const wxPoint2DDouble *beginPoints, const wxPoint2DDouble *endPoints);
 468
 469     // draws a polygon
 470     virtual void DrawLines( size_t n, const wxPoint2DDouble *points, int fillStyle = wxODDEVEN_RULE );
 471
 472     // draws a polygon
 473     virtual void DrawRectangle( wxDouble x, wxDouble y, wxDouble w, wxDouble h);
 474
 475     // draws an ellipse
 476     virtual void DrawEllipse( wxDouble x, wxDouble y, wxDouble w, wxDouble h);
 477
 478     // draws a rounded rectangle
 479     virtual void DrawRoundedRectangle( wxDouble x, wxDouble y, wxDouble w, wxDouble h, wxDouble radius);
 480
 481      // wrappers using wxPoint2DDouble TODO
 482
 483     // helper to determine if a 0.5 offset should be applied for the drawing operation
 484     virtual bool ShouldOffset() const { return false; }
 485
 486 protected :
 487
 488     wxGraphicsPen m_pen;
 489     wxGraphicsBrush m_brush;
 490     wxGraphicsFont m_font;
 491     int m_logicalFunction;
 492
 493 private :
 494     DECLARE_NO_COPY_CLASS(wxGraphicsContext)
 495     DECLARE_ABSTRACT_CLASS(wxGraphicsContext)
 496 };
 497
 498 #if 0
 499
 500 //
 501 // A graphics figure allows to cache path, pen etc creations, also will be a basis for layering/grouping elements
 502 //
 503
 504 class WXDLLIMPEXP_CORE wxGraphicsFigure : public wxGraphicsObject
 505 {
 506 public :
 507     wxGraphicsFigure(wxGraphicsRenderer* renderer) ;
 508
 509     virtual ~wxGraphicsFigure() ;
 510
 511     void SetPath( wxGraphicsMatrix* matrix );
 512
 513     void SetMatrix( wxGraphicsPath* path);
 514
 515     // draws this object on the context
 516     virtual void Draw( wxGraphicsContext* cg );
 517
 518     // returns the path of this object
 519     wxGraphicsPath* GetPath() { return m_path; }
 520
 521     // returns the transformation matrix of this object, may be null if there is no transformation necessary
 522     wxGraphicsMatrix* GetMatrix() { return m_matrix; }
 523
 524 private :
 525     wxGraphicsMatrix* m_matrix;
 526     wxGraphicsPath* m_path;
 527
 528     DECLARE_DYNAMIC_CLASS(wxGraphicsFigure)
 529 } ;
 530
 531 #endif
 532
 533 //
 534 // The graphics renderer is the instance corresponding to the rendering engine used, eg there is ONE core graphics renderer
 535 // instance on OSX. This instance is pointed back to by all objects created by it. Therefore you can create eg additional
 536 // paths at any point from a given matrix etc.
 537 //
 538
 539 class WXDLLIMPEXP_CORE wxGraphicsRenderer : public wxObject
 540 {
 541 public :
 542     wxGraphicsRenderer() {}
 543
 544     virtual ~wxGraphicsRenderer() {}
 545
 546     static wxGraphicsRenderer* GetDefaultRenderer();
 547
 548     // Context
 549
 550     virtual wxGraphicsContext * CreateContext( const wxWindowDC& dc) = 0 ;
 551     virtual wxGraphicsContext * CreateContext( const wxMemoryDC& dc) = 0 ;
 552 #if wxUSE_PRINTING_ARCHITECTURE
 553     virtual wxGraphicsContext * CreateContext( const wxPrinterDC& dc) = 0 ;
 554 #endif
 555
 556     virtual wxGraphicsContext * CreateContextFromNativeContext( void * context ) = 0;
 557
 558     virtual wxGraphicsContext * CreateContextFromNativeWindow( void * window ) = 0;
 559
 560     virtual wxGraphicsContext * CreateContext( wxWindow* window ) = 0;
 561
 562     // create a context that can be used for measuring texts only, no drawing allowed
 563     virtual wxGraphicsContext * CreateMeasuringContext() = 0;
 564
 565     // Path
 566
 567     virtual wxGraphicsPath CreatePath() = 0;
 568
 569     // Matrix
 570
 571     virtual wxGraphicsMatrix CreateMatrix( wxDouble a=1.0, wxDouble b=0.0, wxDouble c=0.0, wxDouble d=1.0,
 572         wxDouble tx=0.0, wxDouble ty=0.0) = 0;
 573
 574     // Paints
 575
 576     virtual wxGraphicsPen CreatePen(const wxPen& pen) = 0 ;
 577
 578     virtual wxGraphicsBrush CreateBrush(const wxBrush& brush ) = 0 ;
 579
 580     // sets the brush to a linear gradient, starting at (x1,y1) with color c1 to (x2,y2) with color c2
 581     virtual wxGraphicsBrush CreateLinearGradientBrush( wxDouble x1, wxDouble y1, wxDouble x2, wxDouble y2,
 582         const wxColour&c1, const wxColour&c2) = 0;
 583
 584     // sets the brush to a radial gradient originating at (xo,yc) with color oColor and ends on a circle around (xc,yc)
 585     // with radius r and color cColor
 586     virtual wxGraphicsBrush CreateRadialGradientBrush( wxDouble xo, wxDouble yo, wxDouble xc, wxDouble yc, wxDouble radius,
 587         const wxColour &oColor, const wxColour &cColor) = 0;
 588
 589    // sets the font
 590     virtual wxGraphicsFont CreateFont( const wxFont &font , const wxColour &col = *wxBLACK ) = 0;
 591
 592 #ifndef __WXGTK20__
 593     // create a native bitmap representation
 594     virtual wxGraphicsBitmap CreateBitmap( const wxBitmap &bitmap ) = 0;
 595
 596     // create a subimage from a native image representation
 597     virtual wxGraphicsBitmap CreateSubBitmap( const wxGraphicsBitmap &bitmap, wxDouble x, wxDouble y, wxDouble w, wxDouble h  ) = 0;
 598 #endif
 599
 600
 601 private :
 602     DECLARE_NO_COPY_CLASS(wxGraphicsRenderer)
 603     DECLARE_ABSTRACT_CLASS(wxGraphicsRenderer)
 604 } ;
 605
 606 #endif
 607
 608 #endif // _WX_GRAPHICS_H_