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1\section{\class{wxDC}}\label{wxdc}
2
3A wxDC is a {\it device context} onto which graphics and text can be drawn.
4It is intended to represent a number of output devices in a generic way,
5so a window can have a device context associated with it, and a printer also has a device context.
6In this way, the same piece of code may write to a number of different devices,
7if the device context is used as a parameter.
8
9Notice that wxDC is an abstract base class and can't be created directly,
10please use \helpref{wxPaintDC}{wxpaintdc}, \helpref{wxClientDC}{wxclientdc},
11\helpref{wxWindowDC}{wxwindowdc}, \helpref{wxScreenDC}{wxscreendc},
12\helpref{wxMemoryDC}{wxmemorydc} or \helpref{wxPrinterDC}{wxprinterdc}.
13
14% VZ: we should really document them instead of this lame excuse, but I don't
15% have time for it now, when it is done please remove this
16Please note that in addition to the versions of the methods documented here,
17there are also versions which accept single {\tt wxPoint} parameter instead of
18two {\tt wxCoord} ones or {\tt wxPoint} and {\tt wxSize} instead of four of
19them.
20
21\wxheading{Support for Transparency / Alpha Channel}
22
23On Mac OS X when using Core Graphics (wx\_MAC\_USE\_CORE\_GRAPHICS set to 1)
24colors with alpha are supported, so instances {\tt wxPen} or {\tt wxBrush} that are built from {\tt wxColour} use
25the color's alpha values when stroking or filling.
26
27Note that beginning with wxWidgets 2.9.0 the entire wxDC code has been
28reorganized. All platform dependent code (actual all drawing code) has
29been moved into backend classes which derive from a common wxDCImpl
30class. The user-visible classes such as wxClientDC and wxPaintDC
31merely forward all calls to the backend implementation.
32
33\wxheading{Derived from}
34
35\helpref{wxObject}{wxobject}
36
37\wxheading{Include files}
38
39<wx/dc.h>
40
41\wxheading{Library}
42
43\helpref{wxCore}{librarieslist}
44
45\wxheading{See also}
46
47\helpref{Overview}{dcoverview}
48
49\latexignore{\rtfignore{\wxheading{Members}}}
50
51
52\membersection{wxDC::Blit}\label{wxdcblit}
53
54\func{bool}{Blit}{\param{wxCoord}{ xdest}, \param{wxCoord}{ ydest}, \param{wxCoord}{ width}, \param{wxCoord}{ height},
55 \param{wxDC* }{source}, \param{wxCoord}{ xsrc}, \param{wxCoord}{ ysrc}, \param{int}{ logicalFunc = wxCOPY},
56 \param{bool }{useMask = false}, \param{wxCoord}{ xsrcMask = -1}, \param{wxCoord}{ ysrcMask = -1}}
57
58Copy from a source DC to this DC, specifying the destination
59coordinates, size of area to copy, source DC, source coordinates,
60logical function, whether to use a bitmap mask, and mask source position.
61
62\wxheading{Parameters}
63
64\docparam{xdest}{Destination device context x position.}
65
66\docparam{ydest}{Destination device context y position.}
67
68\docparam{width}{Width of source area to be copied.}
69
70\docparam{height}{Height of source area to be copied.}
71
72\docparam{source}{Source device context.}
73
74\docparam{xsrc}{Source device context x position.}
75
76\docparam{ysrc}{Source device context y position.}
77
78\docparam{logicalFunc}{Logical function to use: see \helpref{wxDC::SetLogicalFunction}{wxdcsetlogicalfunction}.}
79
80\docparam{useMask}{If true, Blit does a transparent blit using the mask that is associated with the bitmap
81selected into the source device context. The Windows implementation does the following if MaskBlt cannot be used:
82
83\begin{enumerate}
84\item Creates a temporary bitmap and copies the destination area into it.
85\item Copies the source area into the temporary bitmap using the specified logical function.
86\item Sets the masked area in the temporary bitmap to BLACK by ANDing the
87mask bitmap with the temp bitmap with the foreground colour set to WHITE
88and the bg colour set to BLACK.
89\item Sets the unmasked area in the destination area to BLACK by ANDing the
90mask bitmap with the destination area with the foreground colour set to BLACK
91and the background colour set to WHITE.
92\item ORs the temporary bitmap with the destination area.
93\item Deletes the temporary bitmap.
94\end{enumerate}
95
96This sequence of operations ensures that the source's transparent area need not be black,
97and logical functions are supported.
98
99{\bf Note:} on Windows, blitting with masks can be speeded up considerably by compiling
100wxWidgets with the wxUSE\_DC\_CACHE option enabled. You can also influence whether MaskBlt
101or the explicit mask blitting code above is used, by using \helpref{wxSystemOptions}{wxsystemoptions} and
102setting the {\bf no-maskblt} option to 1.
103
104}
105
106\docparam{xsrcMask}{Source x position on the mask. If both xsrcMask and ysrcMask are -1, xsrc and ysrc
107will be assumed for the mask source position. Currently only implemented on Windows.}
108
109\docparam{ysrcMask}{Source y position on the mask. If both xsrcMask and ysrcMask are -1, xsrc and ysrc
110will be assumed for the mask source position. Currently only implemented on Windows.}
111
112
113\wxheading{Remarks}
114
115There is partial support for Blit in wxPostScriptDC, under X.
116
117See \helpref{wxMemoryDC}{wxmemorydc} for typical usage.
118
119\wxheading{See also}
120
121\helpref{wxDC::StretchBlit}{wxdcstretchblit}, \helpref{wxMemoryDC}{wxmemorydc}, \helpref{wxBitmap}{wxbitmap}, \helpref{wxMask}{wxmask}
122
123\begin{comment}
124
125\membersection{wxDC::CacheEnabled}\label{wxdccacheenabled}
126
127\func{static bool}{CacheEnabled}{\void}
128
129On supported platforms (currently only Windows), returns true
130if the DC cache is enabled. The DC cache
131can speed up the \helpref{Blit}{wxdcblit} operation when
132drawing a large number of masked bitmaps.
133
134If using the cache functions in your code, please test for the
135wxUSE\_DC\_CACHEING preprocessor symbol for portability.
136
137\wxheading{See also}
138
139\helpref{wxDC::EnableCache}{wxdcenablecache}, \helpref{wxDC::ClearCache}
140\end{comment}
141
142
143\membersection{wxDC::CalcBoundingBox}\label{wxdccalcboundingbox}
144
145\func{void}{CalcBoundingBox}{\param{wxCoord }{x}, \param{wxCoord }{y}}
146
147Adds the specified point to the bounding box which can be retrieved with
148\helpref{MinX}{wxdcminx}, \helpref{MaxX}{wxdcmaxx} and
149\helpref{MinY}{wxdcminy}, \helpref{MaxY}{wxdcmaxy} functions.
150
151\wxheading{See also}
152
153\helpref{ResetBoundingBox}{wxdcresetboundingbox}
154
155
156\membersection{wxDC::Clear}\label{wxdcclear}
157
158\func{void}{Clear}{\void}
159
160Clears the device context using the current background brush.
161
162\begin{comment}
163
164\membersection{wxDC::ClearCache}\label{wxdcclearcache}
165
166\func{static void}{ClearCache}{\void}
167
168On supported platforms (currently only Windows), clears
169the contents of the DC cache (one bitmap and two Windows device contexts). The DC cache
170can speed up the \helpref{Blit}{wxdcblit} operation when
171drawing a large number of masked bitmaps. You should
172call ClearCache at the end of length DC operations if you wish to only use
173the cache transiently; you should also call it as your application exits.
174
175If using the cache functions in your code, please test for the
176wxUSE\_DC\_CACHEING preprocessor symbol for portability.
177
178\wxheading{See also}
179
180\helpref{wxDC::EnableCache}{wxdcenablecache}, \helpref{wxDC::CacheEnabled}
181\end{comment}
182
183
184\membersection{wxDC::ComputeScaleAndOrigin}\label{wxdccomputescaleandorigin}
185
186\func{virtual void}{ComputeScaleAndOrigin}{\void}
187
188Performs all necessary computations for given platform and context type
189after each change of scale and origin parameters. Usually called automatically
190internally after such changes.
191
192
193\membersection{wxDC::CrossHair}\label{wxdccrosshair}
194
195\func{void}{CrossHair}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
196
197Displays a cross hair using the current pen. This is a vertical
198and horizontal line the height and width of the window, centred
199on the given point.
200
201
202\membersection{wxDC::DestroyClippingRegion}\label{wxdcdestroyclippingregion}
203
204\func{void}{DestroyClippingRegion}{\void}
205
206Destroys the current clipping region so that none of the DC is clipped.
207See also \helpref{wxDC::SetClippingRegion}{wxdcsetclippingregion}.
208
209
210\membersection{wxDC::DeviceToLogicalX}\label{wxdcdevicetologicalx}
211
212\func{virtual wxCoord}{DeviceToLogicalX}{\param{wxCoord}{ x}}
213
214Convert device X coordinate to logical coordinate, using the current
215mapping mode.
216
217
218\membersection{wxDC::DeviceToLogicalXRel}\label{wxdcdevicetologicalxrel}
219
220\func{virtual wxCoord}{DeviceToLogicalXRel}{\param{wxCoord}{ x}}
221
222Convert device X coordinate to relative logical coordinate, using the current
223mapping mode but ignoring the x axis orientation.
224Use this function for converting a width, for example.
225
226
227\membersection{wxDC::DeviceToLogicalY}\label{wxdcdevicetologicaly}
228
229\func{virtual wxCoord}{DeviceToLogicalY}{\param{wxCoord}{ y}}
230
231Converts device Y coordinate to logical coordinate, using the current
232mapping mode.
233
234
235\membersection{wxDC::DeviceToLogicalYRel}\label{wxdcdevicetologicalyrel}
236
237\func{virtual wxCoord}{DeviceToLogicalYRel}{\param{wxCoord}{ y}}
238
239Convert device Y coordinate to relative logical coordinate, using the current
240mapping mode but ignoring the y axis orientation.
241Use this function for converting a height, for example.
242
243
244\membersection{wxDC::DrawArc}\label{wxdcdrawarc}
245
246\func{void}{DrawArc}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}, \param{wxCoord}{ xc}, \param{wxCoord}{ yc}}
247
248Draws an arc of a circle, centred on ({\it xc, yc}), with starting point ({\it x1, y1})
249and ending at ({\it x2, y2}). The current pen is used for the outline
250and the current brush for filling the shape.
251
252The arc is drawn in an anticlockwise direction from the start point to the end point.
253
254
255\membersection{wxDC::DrawBitmap}\label{wxdcdrawbitmap}
256
257\func{void}{DrawBitmap}{\param{const wxBitmap\&}{ bitmap}, \param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{bool}{ transparent}}
258
259Draw a bitmap on the device context at the specified point. If {\it transparent} is true and the bitmap has
260a transparency mask, the bitmap will be drawn transparently.
261
262When drawing a mono-bitmap, the current text foreground colour will be used to draw the foreground
263of the bitmap (all bits set to 1), and the current text background colour to draw the background
264(all bits set to 0). See also \helpref{SetTextForeground}{wxdcsettextforeground},
265\helpref{SetTextBackground}{wxdcsettextbackground} and \helpref{wxMemoryDC}{wxmemorydc}.
266
267
268\membersection{wxDC::DrawCheckMark}\label{wxdcdrawcheckmark}
269
270\func{void}{DrawCheckMark}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
271
272\func{void}{DrawCheckMark}{\param{const wxRect \&}{rect}}
273
274Draws a check mark inside the given rectangle.
275
276
277\membersection{wxDC::DrawCircle}\label{wxdcdrawcircle}
278
279\func{void}{DrawCircle}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ radius}}
280
281\func{void}{DrawCircle}{\param{const wxPoint\&}{ pt}, \param{wxCoord}{ radius}}
282
283Draws a circle with the given centre and radius.
284
285\wxheading{See also}
286
287\helpref{DrawEllipse}{wxdcdrawellipse}
288
289
290\membersection{wxDC::DrawEllipse}\label{wxdcdrawellipse}
291
292\func{void}{DrawEllipse}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
293
294\func{void}{DrawEllipse}{\param{const wxPoint\&}{ pt}, \param{const wxSize\&}{ size}}
295
296\func{void}{DrawEllipse}{\param{const wxRect\&}{ rect}}
297
298Draws an ellipse contained in the rectangle specified either with the given top
299left corner and the given size or directly. The current pen is used for the
300outline and the current brush for filling the shape.
301
302\wxheading{See also}
303
304\helpref{DrawCircle}{wxdcdrawcircle}
305
306
307\membersection{wxDC::DrawEllipticArc}\label{wxdcdrawellipticarc}
308
309\func{void}{DrawEllipticArc}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height},
310 \param{double}{ start}, \param{double}{ end}}
311
312Draws an arc of an ellipse. The current pen is used for drawing the arc and
313the current brush is used for drawing the pie.
314
315{\it x} and {\it y} specify the x and y coordinates of the upper-left corner of the rectangle that contains
316the ellipse.
317
318{\it width} and {\it height} specify the width and height of the rectangle that contains
319the ellipse.
320
321{\it start} and {\it end} specify the start and end of the arc relative to the three-o'clock
322position from the center of the rectangle. Angles are specified
323in degrees (360 is a complete circle). Positive values mean
324counter-clockwise motion. If {\it start} is equal to {\it end}, a
325complete ellipse will be drawn.
326
327
328\membersection{wxDC::DrawIcon}\label{wxdcdrawicon}
329
330\func{void}{DrawIcon}{\param{const wxIcon\&}{ icon}, \param{wxCoord}{ x}, \param{wxCoord}{ y}}
331
332Draw an icon on the display (does nothing if the device context is PostScript).
333This can be the simplest way of drawing bitmaps on a window.
334
335
336\membersection{wxDC::DrawLabel}\label{wxdcdrawlabel}
337
338\func{virtual void}{DrawLabel}{\param{const wxString\&}{ text},
339 \param{const wxBitmap\&}{ image},
340 \param{const wxRect\&}{ rect},
341 \param{int}{ alignment = wxALIGN\_LEFT | wxALIGN\_TOP},
342 \param{int}{ indexAccel = -1},
343 \param{wxRect *}{rectBounding = NULL}}
344
345\func{void}{DrawLabel}{\param{const wxString\&}{ text}, \param{const wxRect\&}{ rect},
346 \param{int}{ alignment = wxALIGN\_LEFT | wxALIGN\_TOP},
347 \param{int}{ indexAccel = -1}}
348
349Draw optional bitmap and the text into the given rectangle and aligns it as specified
350by alignment parameter; it also will emphasize the character with the given index if
351it is != -1 and return the bounding rectangle if required.
352
353
354\membersection{wxDC::DrawLine}\label{wxdcdrawline}
355
356\func{void}{DrawLine}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}}
357
358Draws a line from the first point to the second. The current pen is used
359for drawing the line. Note that the point $(x2, y2)$ is {\emph not} part of the
360line and is not drawn by this function (this is consistent with the behaviour
361of many other toolkits).
362
363
364\membersection{wxDC::DrawLines}\label{wxdcdrawlines}
365
366\func{void}{DrawLines}{\param{int}{ n}, \param{wxPoint}{ points[]}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0}}
367
368Draws lines using an array of {\it points} of size {\it n}
369adding the optional offset coordinate. The current pen is
370used for drawing the lines.
371
372\func{void}{DrawLines}{\param{const wxPointList *}{points}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0}}
373
374This method uses a list of wxPoints, adding the optional offset
375coordinate. The programmer is responsible for deleting the list
376of points.
377
378\pythonnote{The wxPython version of this method accepts a Python list
379of wxPoint objects.}
380
381\perlnote{The wxPerl version of this method accepts
382 as its first parameter a reference to an array
383 of wxPoint objects.}
384
385
386\membersection{wxDC::DrawPolygon}\label{wxdcdrawpolygon}
387
388\func{void}{DrawPolygon}{\param{int}{ n}, \param{wxPoint}{ points[]}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0},\\
389 \param{int }{fill\_style = wxODDEVEN\_RULE}}
390
391Draws a filled polygon using an array of {\it points} of size {\it n},
392adding the optional offset coordinate.
393
394\func{void}{DrawPolygon}{\param{const wxPointList *}{points}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0},\\
395 \param{int }{fill\_style = wxODDEVEN\_RULE}}
396
397This method draws a filled polygon using a list of wxPoints,
398adding the optional offset coordinate.
399
400The last argument specifies the fill rule: {\bf wxODDEVEN\_RULE} (the
401default) or {\bf wxWINDING\_RULE}.
402
403The current pen is used for drawing the outline, and the current brush
404for filling the shape. Using a transparent brush suppresses filling.
405The programmer is responsible for deleting the list of points.
406
407Note that wxWidgets automatically closes the first and last points.
408
409\pythonnote{The wxPython version of this method accepts a Python list
410of wxPoint objects.}
411
412\perlnote{The wxPerl version of this method accepts
413 as its first parameter a reference to an array
414 of wxPoint objects.}
415
416
417\membersection{wxDC::DrawPolyPolygon}\label{wxdcdrawpolypolygon}
418
419\func{void}{DrawPolyPolygon}{\param{int}{ n}, \param{int}{ count[]}, \param{wxPoint}{ points[]}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0},\\
420 \param{int }{fill\_style = wxODDEVEN\_RULE}}
421
422Draws two or more filled polygons using an array of {\it points}, adding the
423optional offset coordinates.
424
425Notice that for the platforms providing a native implementation
426of this function (Windows and PostScript-based wxDC currently), this is more
427efficient than using \helpref{DrawPolygon}{wxdcdrawpolygon} in a loop.
428
429{\it n} specifies the number of polygons to draw, the array {\it count} of size
430{\it n} specifies the number of points in each of the polygons in the
431{\it points} array.
432
433The last argument specifies the fill rule: {\bf wxODDEVEN\_RULE} (the default)
434or {\bf wxWINDING\_RULE}.
435
436The current pen is used for drawing the outline, and the current brush for
437filling the shape. Using a transparent brush suppresses filling.
438
439The polygons maybe disjoint or overlapping. Each polygon specified in a call to
440{\bf DrawPolyPolygon} must be closed. Unlike polygons created by the
441\helpref{DrawPolygon}{wxdcdrawpolygon} member function, the polygons created by
442{\bf DrawPolyPolygon} are not closed automatically.
443
444\pythonnote{Not implemented yet}
445
446\perlnote{Not implemented yet}
447
448
449\membersection{wxDC::DrawPoint}\label{wxdcdrawpoint}
450
451\func{void}{DrawPoint}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
452
453Draws a point using the color of the current pen. Note that the other properties of the pen are not used, such as width etc..
454
455
456\membersection{wxDC::DrawRectangle}\label{wxdcdrawrectangle}
457
458\func{void}{DrawRectangle}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
459
460Draws a rectangle with the given top left corner, and with the given
461size. The current pen is used for the outline and the current brush
462for filling the shape.
463
464
465\membersection{wxDC::DrawRotatedText}\label{wxdcdrawrotatedtext}
466
467\func{void}{DrawRotatedText}{\param{const wxString\& }{text}, \param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{double}{ angle}}
468
469Draws the text rotated by {\it angle} degrees.
470
471{\bf NB:} Under Win9x only TrueType fonts can be drawn by this function. In
472particular, a font different from {\tt wxNORMAL\_FONT} should be used as the
473latter is not a TrueType font. {\tt wxSWISS\_FONT} is an example of a font
474which is.
475
476\wxheading{See also}
477
478\helpref{DrawText}{wxdcdrawtext}
479
480
481\membersection{wxDC::DrawRoundedRectangle}\label{wxdcdrawroundedrectangle}
482
483\func{void}{DrawRoundedRectangle}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}, \param{double}{ radius}}
484
485Draws a rectangle with the given top left corner, and with the given
486size. The corners are quarter-circles using the given radius. The
487current pen is used for the outline and the current brush for filling
488the shape.
489
490If {\it radius} is positive, the value is assumed to be the
491radius of the rounded corner. If {\it radius} is negative,
492the absolute value is assumed to be the {\it proportion} of the smallest
493dimension of the rectangle. This means that the corner can be
494a sensible size relative to the size of the rectangle, and also avoids
495the strange effects X produces when the corners are too big for
496the rectangle.
497
498
499\membersection{wxDC::DrawSpline}\label{wxdcdrawspline}
500
501\func{void}{DrawSpline}{\param{int }{n}, \param{wxPoint }{points[]}}
502
503Draws a spline between all given control points, using the current
504pen.
505
506\func{void}{DrawSpline}{\param{const wxPointList *}{points}}
507
508Draws a spline between all given control points.
509
510\func{void}{DrawSpline}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}, \param{wxCoord}{ x3}, \param{wxCoord}{ y3}}
511
512Draws a three-point spline using the current pen.
513
514\pythonnote{The wxPython version of this method accepts a Python list
515of wxPoint objects.}
516
517\perlnote{The wxPerl version of this method accepts a reference to an array
518 of wxPoint objects.}
519
520
521\membersection{wxDC::DrawText}\label{wxdcdrawtext}
522
523\func{void}{DrawText}{\param{const wxString\& }{text}, \param{wxCoord}{ x}, \param{wxCoord}{ y}}
524
525Draws a text string at the specified point, using the current text font,
526and the current text foreground and background colours.
527
528The coordinates refer to the top-left corner of the rectangle bounding
529the string. See \helpref{wxDC::GetTextExtent}{wxdcgettextextent} for how
530to get the dimensions of a text string, which can be used to position the
531text more precisely.
532
533{\bf NB:} under wxGTK the current
534\helpref{logical function}{wxdcgetlogicalfunction} is used by this function
535but it is ignored by wxMSW. Thus, you should avoid using logical functions
536with this function in portable programs.
537
538\begin{comment}
539
540\membersection{wxDC::EnableCache}\label{wxdcenablecache}
541
542\func{static void}{EnableCache}{\param{bool}{ enableCache}}
543
544On supported platforms (currently only Windows), enables the DC cache
545which can speed up the \helpref{Blit}{wxdcblit} operation when
546drawing a large number of masked bitmaps.
547
548If using the cache functions in your code, please test for the
549wxUSE\_DC\_CACHEING preprocessor symbol for portability.
550
551\wxheading{See also}
552
553\helpref{wxDC::CacheEnabled}{wxdccacheenabled}, \helpref{wxDC::ClearCache}
554\end{comment}
555
556
557\membersection{wxDC::EndDoc}\label{wxdcenddoc}
558
559\func{void}{EndDoc}{\void}
560
561Ends a document (only relevant when outputting to a printer).
562
563
564\membersection{wxDC::EndPage}\label{wxdcendpage}
565
566\func{void}{EndPage}{\void}
567
568Ends a document page (only relevant when outputting to a printer).
569
570
571\membersection{wxDC::FloodFill}\label{wxdcfloodfill}
572
573\func{bool}{FloodFill}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{const wxColour\&}{ colour}, \param{int}{ style=wxFLOOD\_SURFACE}}
574
575Flood fills the device context starting from the given point, using
576the {\it current brush colour}, and using a style:
577
578\begin{itemize}\itemsep=0pt
579\item wxFLOOD\_SURFACE: the flooding occurs until a colour other than the given colour is encountered.
580\item wxFLOOD\_BORDER: the area to be flooded is bounded by the given colour.
581\end{itemize}
582
583Returns false if the operation failed.
584
585{\it Note:} The present implementation for non-Windows platforms may fail to find
586colour borders if the pixels do not match the colour exactly. However the
587function will still return true.
588
589
590\membersection{wxDC::GetBackground}\label{wxdcgetbackground}
591
592\constfunc{const wxBrush\&}{GetBackground}{\void}
593
594Gets the brush used for painting the background (see \helpref{wxDC::SetBackground}{wxdcsetbackground}).
595
596
597\membersection{wxDC::GetBackgroundMode}\label{wxdcgetbackgroundmode}
598
599\constfunc{int}{GetBackgroundMode}{\void}
600
601Returns the current background mode: {\tt wxSOLID} or {\tt wxTRANSPARENT}.
602
603\wxheading{See also}
604
605\helpref{SetBackgroundMode}{wxdcsetbackgroundmode}
606
607
608\membersection{wxDC::GetBrush}\label{wxdcgetbrush}
609
610\constfunc{const wxBrush\&}{GetBrush}{\void}
611
612Gets the current brush (see \helpref{wxDC::SetBrush}{wxdcsetbrush}).
613
614
615\membersection{wxDC::GetCharHeight}\label{wxdcgetcharheight}
616
617\func{wxCoord}{GetCharHeight}{\void}
618
619Gets the character height of the currently set font.
620
621
622\membersection{wxDC::GetCharWidth}\label{wxdcgetcharwidth}
623
624\func{wxCoord}{GetCharWidth}{\void}
625
626Gets the average character width of the currently set font.
627
628
629\membersection{wxDC::GetClippingBox}\label{wxdcgetclippingbox}
630
631\func{void}{GetClippingBox}{\param{wxCoord}{ *x}, \param{wxCoord}{ *y}, \param{wxCoord}{ *width}, \param{wxCoord}{ *height}}
632
633Gets the rectangle surrounding the current clipping region.
634
635\pythonnote{No arguments are required and the four values defining the
636rectangle are returned as a tuple.}
637
638\perlnote{This method takes no arguments and returns a four element list
639{\tt ( x, y, width, height )}}
640
641
642\membersection{wxDC::GetDepth}\label{wxdcgetdepth}
643
644\constfunc{int}{GetDepth}{\void}
645
646Returns the depth (number of bits/pixel) of this DC.
647
648\wxheading{See also}
649
650\helpref{wxDisplayDepth}{wxdisplaydepth}
651
652
653\membersection{wxDC::GetFont}\label{wxdcgetfont}
654
655\constfunc{const wxFont\&}{GetFont}{\void}
656
657Gets the current font. Notice that even although each device context object has
658some default font after creation, this method would return a \texttt{wxNullFont}
659initially and only after calling \helpref{wxDC::SetFont}{wxdcsetfont} a valid
660font is returned.
661
662
663\membersection{wxDC::GetLayoutDirection}\label{wxdcgetlayoutdirection}
664
665\constfunc{wxLayoutDirection}{GetLayoutDirection}{\void}
666
667Gets the current layout direction of the device context. On platforms where RTL layout
668is supported, the return value will either be \texttt{wxLayout\_LeftToRight} or
669\texttt{wxLayout\_RightToLeft}. If RTL layout is not supported, the return value will
670be \texttt{wxLayout\_Default}.
671
672\wxheading{See also}
673
674\helpref{SetLayoutDirection}{wxdcsetlayoutdirection}
675
676
677\membersection{wxDC::GetLogicalFunction}\label{wxdcgetlogicalfunction}
678
679\func{int}{GetLogicalFunction}{\void}
680
681Gets the current logical function (see \helpref{wxDC::SetLogicalFunction}{wxdcsetlogicalfunction}).
682
683
684\membersection{wxDC::GetMapMode}\label{wxdcgetmapmode}
685
686\func{int}{GetMapMode}{\void}
687
688Gets the {\it mapping mode} for the device context (see \helpref{wxDC::SetMapMode}{wxdcsetmapmode}).
689
690
691\membersection{wxDC::GetMultiLineTextExtent}\label{wxdcgetmultilinetextextent}
692
693\constfunc{void}{GetMultiLineTextExtent}{\param{const wxString\& }{string}, \param{wxCoord *}{w},\\
694 \param{wxCoord *}{h}, \param{wxCoord *}{heightLine = NULL}, \param{wxFont *}{font = NULL}}
695
696\constfunc{wxSize}{GetMultiLineTextExtent}{\param{const wxString\& }{string}}
697
698Gets the dimensions of the string using the currently selected font.
699\rtfsp{\it string} is the text string to measure, {\it heightLine}, if non NULL,
700is where to store the height of a single line.
701
702The text extent is returned in {\it w} and {\it h} pointers (first form) or as
703a \helpref{wxSize}{wxsize} object (second form).
704
705If the optional parameter {\it font} is specified and valid, then it is used
706for the text extent calculation. Otherwise the currently selected font is.
707
708Note that this function works both with single-line and multi-line strings.
709
710\wxheading{See also}
711
712\helpref{wxFont}{wxfont},\rtfsp
713\helpref{wxDC::SetFont}{wxdcsetfont},\rtfsp
714\helpref{wxDC::GetPartialTextExtents}{wxdcgetpartialtextextents},\rtfsp
715\helpref{wxDC::GetTextExtent}{wxdcgettextextent}
716
717
718\membersection{wxDC::GetPartialTextExtents}\label{wxdcgetpartialtextextents}
719
720\constfunc{bool}{GetPartialTextExtents}{\param{const wxString\& }{text},
721\param{wxArrayInt\& }{widths}}
722
723Fills the {\it widths} array with the widths from the beginning of
724{\it text} to the corresponding character of {\it text}. The generic
725version simply builds a running total of the widths of each character
726using \helpref{GetTextExtent}{wxdcgettextextent}, however if the
727various platforms have a native API function that is faster or more
728accurate than the generic implementation then it should be used
729instead.
730
731\wxheading{See also}
732
733\helpref{wxDC::GetMultiLineTextExtent}{wxdcgetmultilinetextextent},\rtfsp
734\helpref{wxDC::GetTextExtent}{wxdcgettextextent}
735
736\pythonnote{This method only takes the {\it text} parameter and
737 returns a Python list of integers.}
738
739
740\membersection{wxDC::GetPen}\label{wxdcgetpen}
741
742\constfunc{const wxPen\&}{GetPen}{\void}
743
744Gets the current pen (see \helpref{wxDC::SetPen}{wxdcsetpen}).
745
746
747\membersection{wxDC::GetPixel}\label{wxdcgetpixel}
748
749\func{bool}{GetPixel}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxColour *}{colour}}
750
751Gets in {\it colour} the colour at the specified location.
752Not available for wxPostScriptDC or wxMetafileDC.
753
754Note that setting a pixel can be done using \helpref{DrawPoint}{wxdcdrawpoint}.
755
756\pythonnote{For wxPython the wxColour value is returned and is not
757required as a parameter.}
758
759\perlnote{This method only takes the parameters {\tt x} and {\tt y} and returns
760a Wx::Colour value}
761
762\membersection{wxDC::GetPPI}\label{wxdcgetppi}
763
764\constfunc{wxSize}{GetPPI}{\void}
765
766Returns the resolution of the device in pixels per inch.
767
768\membersection{wxDC::GetSize}\label{wxdcgetsize}
769
770\constfunc{void}{GetSize}{\param{wxCoord *}{width}, \param{wxCoord *}{height}}
771
772\constfunc{wxSize}{GetSize}{\void}
773
774This gets the horizontal and vertical resolution in device units. It can be used to scale graphics to fit the page.
775For example, if {\it maxX} and {\it maxY}\rtfsp
776represent the maximum horizontal and vertical `pixel' values used in your
777application, the following code will scale the graphic to fit on the
778printer page:
779
780\begin{verbatim}
781 wxCoord w, h;
782 dc.GetSize(&w, &h);
783 double scaleX=(double)(maxX/w);
784 double scaleY=(double)(maxY/h);
785 dc.SetUserScale(min(scaleX,scaleY),min(scaleX,scaleY));
786\end{verbatim}
787
788\pythonnote{In place of a single overloaded method name, wxPython
789implements the following methods:\par
790\indented{2cm}{\begin{twocollist}
791\twocolitem{{\bf GetSize()}}{Returns a wxSize}
792\twocolitem{{\bf GetSizeTuple()}}{Returns a 2-tuple (width, height)}
793\end{twocollist}}
794}
795
796\perlnote{In place of a single overloaded method, wxPerl uses:\par
797\indented{2cm}{\begin{twocollist}
798\twocolitem{{\bf GetSize()}}{Returns a Wx::Size}
799\twocolitem{{\bf GetSizeWH()}}{Returns a 2-element list
800 {\tt ( width, height )}}
801\end{twocollist}
802}}
803
804\membersection{wxDC::GetSizeMM}\label{wxdcgetsizemm}
805
806\constfunc{void}{GetSizeMM}{\param{wxCoord *}{width}, \param{wxCoord *}{height}}
807
808\constfunc{wxSize}{GetSizeMM}{\void}
809
810Returns the horizontal and vertical resolution in millimetres.
811
812\membersection{wxDC::GetTextBackground}\label{wxdcgettextbackground}
813
814\constfunc{const wxColour\&}{GetTextBackground}{\void}
815
816Gets the current text background colour (see \helpref{wxDC::SetTextBackground}{wxdcsettextbackground}).
817
818
819\membersection{wxDC::GetTextExtent}\label{wxdcgettextextent}
820
821\constfunc{void}{GetTextExtent}{\param{const wxString\& }{string}, \param{wxCoord *}{w}, \param{wxCoord *}{h},\\
822 \param{wxCoord *}{descent = NULL}, \param{wxCoord *}{externalLeading = NULL}, \param{const wxFont *}{font = NULL}}
823
824\constfunc{wxSize}{GetTextExtent}{\param{const wxString\& }{string}}
825
826Gets the dimensions of the string using the currently selected font.
827\rtfsp{\it string} is the text string to measure, {\it descent} is the
828dimension from the baseline of the font to the bottom of the
829descender, and {\it externalLeading} is any extra vertical space added
830to the font by the font designer (usually is zero).
831
832The text extent is returned in {\it w} and {\it h} pointers (first form) or as
833a \helpref{wxSize}{wxsize} object (second form).
834
835If the optional parameter {\it font} is specified and valid, then it is used
836for the text extent calculation. Otherwise the currently selected font is.
837
838Note that this function only works with single-line strings.
839
840\wxheading{See also}
841
842\helpref{wxFont}{wxfont},\rtfsp
843\helpref{wxDC::SetFont}{wxdcsetfont},\rtfsp
844\helpref{wxDC::GetPartialTextExtents}{wxdcgetpartialtextextents},\rtfsp
845\helpref{wxDC::GetMultiLineTextExtent}{wxdcgetmultilinetextextent}
846
847\pythonnote{The following methods are implemented in wxPython:\par
848\indented{2cm}{\begin{twocollist}
849\twocolitem{{\bf GetTextExtent(string)}}{Returns a 2-tuple, (width, height)}
850\twocolitem{{\bf GetFullTextExtent(string, font=NULL)}}{Returns a
8514-tuple, (width, height, descent, externalLeading) }
852\end{twocollist}}
853}
854
855\perlnote{In wxPerl this method is implemented as
856 {\bf GetTextExtent( string, font = undef )} returning a four element
857 array {\tt ( width, height, descent, externalLeading )}
858}
859
860
861\membersection{wxDC::GetTextForeground}\label{wxdcgettextforeground}
862
863\constfunc{const wxColour\&}{GetTextForeground}{\void}
864
865Gets the current text foreground colour (see \helpref{wxDC::SetTextForeground}{wxdcsettextforeground}).
866
867
868\membersection{wxDC::GetUserScale}\label{wxdcgetuserscale}
869
870\func{void}{GetUserScale}{\param{double}{ *x}, \param{double}{ *y}}
871
872Gets the current user scale factor (set by \helpref{SetUserScale}{wxdcsetuserscale}).
873
874\perlnote{In wxPerl this method takes no arguments and return a two element
875 array {\tt ( x, y )}}
876
877
878\membersection{wxDC::GradientFillConcentric}\label{wxdcgradientfillconcentric}
879
880\func{void}{GradientFillConcentric}{\param{const wxRect\&}{ rect}, \param{const wxColour\&}{ initialColour}, \param{const wxColour\&}{ destColour}}
881
882\func{void}{GradientFillConcentric}{\param{const wxRect\&}{ rect}, \param{const wxColour\&}{ initialColour}, \param{const wxColour\&}{ destColour}, \param{const wxPoint\& }{circleCenter}}
883
884Fill the area specified by rect with a radial gradient, starting from
885\arg{initialColour} at the centre of the circle and fading to \arg{destColour}
886on the circle outside.
887
888\arg{circleCenter} are the relative coordinates of centre of the circle in
889the specified \arg{rect}. If not specified, the cercle is placed at the
890centre of rect.
891
892\textbf{Note: } Currently this function is very slow, don't use it for
893real-time drawing.
894
895
896\membersection{wxDC::GradientFillLinear}\label{wxdcgradientfilllinear}
897
898\func{void}{GradientFillLinear}{\param{const wxRect\&}{ rect}, \param{const wxColour\&}{ initialColour}, \param{const wxColour\&}{ destColour}, \param{wxDirection}{ nDirection = wxEAST}}
899
900Fill the area specified by \arg{rect} with a linear gradient, starting from
901\arg{initialColour} and eventually fading to \arg{destColour}. The
902\arg{nDirection} specifies the direction of the colour change, default is to
903use \arg{initialColour} on the left part of the rectangle and
904\arg{destColour} on the right one.
905
906
907\membersection{wxDC::LogicalToDeviceX}\label{wxdclogicaltodevicex}
908
909\func{virtual wxCoord}{LogicalToDeviceX}{\param{wxCoord}{ x}}
910
911Converts logical X coordinate to device coordinate, using the current
912mapping mode.
913
914
915\membersection{wxDC::LogicalToDeviceXRel}\label{wxdclogicaltodevicexrel}
916
917\func{virtual wxCoord}{LogicalToDeviceXRel}{\param{wxCoord}{ x}}
918
919Converts logical X coordinate to relative device coordinate, using the current
920mapping mode but ignoring the x axis orientation.
921Use this for converting a width, for example.
922
923
924\membersection{wxDC::LogicalToDeviceY}\label{wxdclogicaltodevicey}
925
926\func{virtual wxCoord}{LogicalToDeviceY}{\param{wxCoord}{ y}}
927
928Converts logical Y coordinate to device coordinate, using the current
929mapping mode.
930
931
932\membersection{wxDC::LogicalToDeviceYRel}\label{wxdclogicaltodeviceyrel}
933
934\func{virtual wxCoord}{LogicalToDeviceYRel}{\param{wxCoord}{ y}}
935
936Converts logical Y coordinate to relative device coordinate, using the current
937mapping mode but ignoring the y axis orientation.
938Use this for converting a height, for example.
939
940
941\membersection{wxDC::MaxX}\label{wxdcmaxx}
942
943\func{wxCoord}{MaxX}{\void}
944
945Gets the maximum horizontal extent used in drawing commands so far.
946
947
948\membersection{wxDC::MaxY}\label{wxdcmaxy}
949
950\func{wxCoord}{MaxY}{\void}
951
952Gets the maximum vertical extent used in drawing commands so far.
953
954
955\membersection{wxDC::MinX}\label{wxdcminx}
956
957\func{wxCoord}{MinX}{\void}
958
959Gets the minimum horizontal extent used in drawing commands so far.
960
961
962\membersection{wxDC::MinY}\label{wxdcminy}
963
964\func{wxCoord}{MinY}{\void}
965
966Gets the minimum vertical extent used in drawing commands so far.
967
968
969\membersection{wxDC::IsOk}\label{wxdcisok}
970
971\func{bool}{Ok}{\void}
972
973Returns true if the DC is ok to use.
974
975
976\membersection{wxDC::ResetBoundingBox}\label{wxdcresetboundingbox}
977
978\func{void}{ResetBoundingBox}{\void}
979
980Resets the bounding box: after a call to this function, the bounding box
981doesn't contain anything.
982
983\wxheading{See also}
984
985\helpref{CalcBoundingBox}{wxdccalcboundingbox}
986
987
988\membersection{wxDC::SetAxisOrientation}\label{wxdcsetaxisorientation}
989
990\func{void}{SetAxisOrientation}{\param{bool}{ xLeftRight},
991 \param{bool}{ yBottomUp}}
992
993Sets the x and y axis orientation (i.e., the direction from lowest to
994highest values on the axis). The default orientation is
995x axis from left to right and y axis from top down.
996
997\wxheading{Parameters}
998
999\docparam{xLeftRight}{True to set the x axis orientation to the natural
1000left to right orientation, false to invert it.}
1001
1002\docparam{yBottomUp}{True to set the y axis orientation to the natural
1003bottom up orientation, false to invert it.}
1004
1005
1006\membersection{wxDC::SetBackground}\label{wxdcsetbackground}
1007
1008\func{void}{SetBackground}{\param{const wxBrush\& }{brush}}
1009
1010Sets the current background brush for the DC.
1011
1012
1013\membersection{wxDC::SetBackgroundMode}\label{wxdcsetbackgroundmode}
1014
1015\func{void}{SetBackgroundMode}{\param{int}{ mode}}
1016
1017{\it mode} may be one of wxSOLID and wxTRANSPARENT. This setting determines
1018whether text will be drawn with a background colour or not.
1019
1020
1021\membersection{wxDC::SetBrush}\label{wxdcsetbrush}
1022
1023\func{void}{SetBrush}{\param{const wxBrush\& }{brush}}
1024
1025Sets the current brush for the DC.
1026
1027If the argument is wxNullBrush, the current brush is selected out of the device
1028context (leaving wxDC without any valid brush), allowing the current brush to
1029be destroyed safely.
1030
1031See also \helpref{wxBrush}{wxbrush}.
1032
1033See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours
1034when drawing into a monochrome bitmap.
1035
1036
1037\membersection{wxDC::SetClippingRegion}\label{wxdcsetclippingregion}
1038
1039\func{void}{SetClippingRegion}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
1040
1041\func{void}{SetClippingRegion}{\param{const wxPoint\& }{pt}, \param{const wxSize\& }{sz}}
1042
1043\func{void}{SetClippingRegion}{\param{const wxRect\&}{ rect}}
1044
1045\func{void}{SetClippingRegion}{\param{const wxRegion\&}{ region}}
1046
1047Sets the clipping region for this device context to the intersection of the
1048given region described by the parameters of this method and the previously set
1049clipping region. You should call
1050\helpref{DestroyClippingRegion}{wxdcdestroyclippingregion} if you want to set
1051the clipping region exactly to the region specified.
1052
1053The clipping region is an area to which drawing is restricted. Possible uses
1054for the clipping region are for clipping text or for speeding up window redraws
1055when only a known area of the screen is damaged.
1056
1057\wxheading{See also}
1058
1059\helpref{wxDC::DestroyClippingRegion}{wxdcdestroyclippingregion}, \helpref{wxRegion}{wxregion}
1060
1061
1062\membersection{wxDC::SetDeviceOrigin}\label{wxdcsetdeviceorigin}
1063
1064\func{void}{SetDeviceOrigin}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
1065
1066Sets the device origin (i.e., the origin in pixels after scaling has been
1067applied).
1068
1069This function may be useful in Windows printing
1070operations for placing a graphic on a page.
1071
1072
1073\membersection{wxDC::SetFont}\label{wxdcsetfont}
1074
1075\func{void}{SetFont}{\param{const wxFont\& }{font}}
1076
1077Sets the current font for the DC. It must be a valid font, in particular you
1078should not pass {\tt wxNullFont} to this method.
1079
1080See also \helpref{wxFont}{wxfont}.
1081
1082
1083\membersection{wxDC::SetLayoutDirection}\label{wxdcsetlayoutdirection}
1084
1085\func{void}{SetLayoutDirection}{\param{wxLayoutDirection}{ dir}}
1086
1087Sets the current layout direction for the device context. \arg{dir} may be either
1088\texttt{wxLayout\_Default}, \texttt{wxLayout\_LeftToRight} or \texttt{wxLayout\_RightToLeft}.
1089
1090\wxheading{See also}
1091
1092\helpref{GetLayoutDirection}{wxdcgetlayoutdirection}
1093
1094
1095\membersection{wxDC::SetLogicalFunction}\label{wxdcsetlogicalfunction}
1096
1097\func{void}{SetLogicalFunction}{\param{int}{ function}}
1098
1099Sets the current logical function for the device context. This determines how
1100a source pixel (from a pen or brush colour, or source device context if
1101using \helpref{wxDC::Blit}{wxdcblit}) combines with a destination pixel in the
1102current device context.
1103
1104The possible values
1105and their meaning in terms of source and destination pixel values are
1106as follows:
1107
1108\begin{verbatim}
1109wxAND src AND dst
1110wxAND_INVERT (NOT src) AND dst
1111wxAND_REVERSE src AND (NOT dst)
1112wxCLEAR 0
1113wxCOPY src
1114wxEQUIV (NOT src) XOR dst
1115wxINVERT NOT dst
1116wxNAND (NOT src) OR (NOT dst)
1117wxNOR (NOT src) AND (NOT dst)
1118wxNO_OP dst
1119wxOR src OR dst
1120wxOR_INVERT (NOT src) OR dst
1121wxOR_REVERSE src OR (NOT dst)
1122wxSET 1
1123wxSRC_INVERT NOT src
1124wxXOR src XOR dst
1125\end{verbatim}
1126
1127The default is wxCOPY, which simply draws with the current colour.
1128The others combine the current colour and the background using a
1129logical operation. wxINVERT is commonly used for drawing rubber bands or
1130moving outlines, since drawing twice reverts to the original colour.
1131
1132
1133\membersection{wxDC::SetMapMode}\label{wxdcsetmapmode}
1134
1135\func{void}{SetMapMode}{\param{int}{ int}}
1136
1137The {\it mapping mode} of the device context defines the unit of
1138measurement used to convert logical units to device units. Note that
1139in X, text drawing isn't handled consistently with the mapping mode; a
1140font is always specified in point size. However, setting the {\it
1141user scale} (see \helpref{wxDC::SetUserScale}{wxdcsetuserscale}) scales the text appropriately. In
1142Windows, scalable TrueType fonts are always used; in X, results depend
1143on availability of fonts, but usually a reasonable match is found.
1144
1145The coordinate origin is always at the top left of the screen/printer.
1146
1147Drawing to a Windows printer device context uses the current mapping mode,
1148but mapping mode is currently ignored for PostScript output.
1149
1150The mapping mode can be one of the following:
1151
1152\begin{twocollist}\itemsep=0pt
1153\twocolitem{wxMM\_TWIPS}{Each logical unit is 1/20 of a point, or 1/1440 of
1154 an inch.}
1155\twocolitem{wxMM\_POINTS}{Each logical unit is a point, or 1/72 of an inch.}
1156\twocolitem{wxMM\_METRIC}{Each logical unit is 1 mm.}
1157\twocolitem{wxMM\_LOMETRIC}{Each logical unit is 1/10 of a mm.}
1158\twocolitem{wxMM\_TEXT}{Each logical unit is 1 device pixel.}
1159\end{twocollist}
1160
1161
1162\membersection{wxDC::SetPalette}\label{wxdcsetpalette}
1163
1164\func{void}{SetPalette}{\param{const wxPalette\& }{palette}}
1165
1166If this is a window DC or memory DC, assigns the given palette to the window
1167or bitmap associated with the DC. If the argument is wxNullPalette, the current
1168palette is selected out of the device context, and the original palette
1169restored.
1170
1171See \helpref{wxPalette}{wxpalette} for further details.
1172
1173
1174\membersection{wxDC::SetPen}\label{wxdcsetpen}
1175
1176\func{void}{SetPen}{\param{const wxPen\& }{pen}}
1177
1178Sets the current pen for the DC.
1179
1180If the argument is wxNullPen, the current pen is selected out of the device
1181context (leaving wxDC without any valid pen), allowing the current brush to
1182be destroyed safely.
1183
1184See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours
1185when drawing into a monochrome bitmap.
1186
1187
1188\membersection{wxDC::SetTextBackground}\label{wxdcsettextbackground}
1189
1190\func{void}{SetTextBackground}{\param{const wxColour\& }{colour}}
1191
1192Sets the current text background colour for the DC.
1193
1194
1195\membersection{wxDC::SetTextForeground}\label{wxdcsettextforeground}
1196
1197\func{void}{SetTextForeground}{\param{const wxColour\& }{colour}}
1198
1199Sets the current text foreground colour for the DC.
1200
1201See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours
1202when drawing into a monochrome bitmap.
1203
1204
1205\membersection{wxDC::SetUserScale}\label{wxdcsetuserscale}
1206
1207\func{void}{SetUserScale}{\param{double}{ xScale}, \param{double}{ yScale}}
1208
1209Sets the user scaling factor, useful for applications which require
1210`zooming'.
1211
1212
1213\membersection{wxDC::StartDoc}\label{wxdcstartdoc}
1214
1215\func{bool}{StartDoc}{\param{const wxString\& }{message}}
1216
1217Starts a document (only relevant when outputting to a printer).
1218Message is a message to show while printing.
1219
1220
1221\membersection{wxDC::StartPage}\label{wxdcstartpage}
1222
1223\func{bool}{StartPage}{\void}
1224
1225Starts a document page (only relevant when outputting to a printer).
1226
1227
1228\membersection{wxDC::StretchBlit}\label{wxdcstretchblit}
1229
1230\func{bool}{StretchBlit}{\param{wxCoord}{ xdest}, \param{wxCoord}{ ydest}, \param{wxCoord}{ dstWidth}, \param{wxCoord}{ dstHeight},
1231 \param{wxDC* }{source}, \param{wxCoord}{ xsrc}, \param{wxCoord}{ ysrc}, \param{wxCoord}{ srcWidth}, \param{wxCoord}{ srcHeight},
1232 \param{int}{ logicalFunc = wxCOPY}, \param{bool }{useMask = false}, \param{wxCoord}{ xsrcMask = -1}, \param{wxCoord}{ ysrcMask = -1}}
1233
1234Copy from a source DC to this DC, specifying the destination
1235coordinates, destination size, source DC, source coordinates,
1236size of source area to copy, logical function, whether to use a bitmap mask,
1237and mask source position.
1238
1239\wxheading{Parameters}
1240
1241\docparam{xdest}{Destination device context x position.}
1242
1243\docparam{ydest}{Destination device context y position.}
1244
1245\docparam{dstWidth}{Width of destination area.}
1246
1247\docparam{dstHeight}{Height of destination area.}
1248
1249\docparam{source}{Source device context.}
1250
1251\docparam{xsrc}{Source device context x position.}
1252
1253\docparam{ysrc}{Source device context y position.}
1254
1255\docparam{srcWidth}{Width of source area to be copied.}
1256
1257\docparam{srcHeight}{Height of source area to be copied.}
1258
1259\docparam{logicalFunc}{Logical function to use: see \helpref{wxDC::SetLogicalFunction}{wxdcsetlogicalfunction}.}
1260
1261\docparam{useMask}{If true, Blit does a transparent blit using the mask that is associated with the bitmap
1262selected into the source device context. The Windows implementation does the following if \texttt{MaskBlt} cannot be used:
1263
1264\begin{enumerate}
1265\item Creates a temporary bitmap and copies the destination area into it.
1266\item Copies the source area into the temporary bitmap using the specified logical function.
1267\item Sets the masked area in the temporary bitmap to BLACK by ANDing the
1268mask bitmap with the temp bitmap with the foreground colour set to WHITE
1269and the background colour set to BLACK.
1270\item Sets the unmasked area in the destination area to BLACK by ANDing the
1271mask bitmap with the destination area with the foreground colour set to BLACK
1272and the background colour set to WHITE.
1273\item ORs the temporary bitmap with the destination area.
1274\item Deletes the temporary bitmap.
1275\end{enumerate}
1276
1277This sequence of operations ensures that the source's transparent area need not be black,
1278and logical functions are supported.
1279
1280{\bf Note:} on Windows, blitting with masks can be speeded up considerably by compiling
1281wxWidgets with the \texttt{wxUSE\_DC\_CACHE} option enabled. You can also influence whether \texttt{MaskBlt}
1282or the explicit mask blitting code above is used, by using \helpref{wxSystemOptions}{wxsystemoptions} and
1283setting the {\bf no-maskblt} option to 1.
1284
1285}
1286
1287\docparam{xsrcMask}{Source x position on the mask. If both xsrcMask and ysrcMask are -1, xsrc and ysrc
1288will be assumed for the mask source position. Currently only implemented on Windows.}
1289
1290\docparam{ysrcMask}{Source y position on the mask. If both xsrcMask and ysrcMask are -1, xsrc and ysrc
1291will be assumed for the mask source position. Currently only implemented on Windows.}
1292
1293
1294\wxheading{Remarks}
1295
1296There is partial support for Blit in wxPostScriptDC, under X.
1297
1298wxDC::StretchBlit is only implemented under wxMAC and wxMSW.
1299
1300See \helpref{wxMemoryDC}{wxmemorydc} for typical usage.
1301
1302\newsince{2.9.0}
1303
1304\wxheading{See also}
1305
1306\helpref{wxDC::Blit}{wxdcblit}, \helpref{wxMemoryDC}{wxmemorydc}, \helpref{wxBitmap}{wxbitmap}, \helpref{wxMask}{wxmask}
1307