docs/latex/wx/dc.tex

   1 \section{\class{wxDC}}\label{wxdc}
   2
   3 A wxDC is a {\it device context} onto which graphics and text can be drawn.
   4 It is intended to represent a number of output devices in a generic way,
   5 so a window can have a device context associated with it, and a printer also has a device context.
   6 In this way, the same piece of code may write to a number of different devices,
   7 if the device context is used as a parameter.
   8
   9 Derived types of wxDC have documentation for specific features
  10 only, so refer to this section for most device context information.
  11
  12 \wxheading{Derived from}
  13
  14 \helpref{wxObject}{wxobject}
  15
  16 \wxheading{Include files}
  17
  18 <wx/dc.h>
  19
  20 \wxheading{See also}
  21
  22 \helpref{Overview}{dcoverview}
  23
  24 \latexignore{\rtfignore{\wxheading{Members}}}
  25
  26 \membersection{wxDC::wxDC}
  27
  28 \func{}{wxDC}{\void}
  29
  30 Constructor.
  31
  32 \membersection{wxDC::\destruct{wxDC}}
  33
  34 \func{}{\destruct{wxDC}}{\void}
  35
  36 Destructor.
  37
  38 \membersection{wxDC::BeginDrawing}\label{wxdcbegindrawing}
  39
  40 \func{void}{BeginDrawing}{\void}
  41
  42 Allows optimization of drawing code under MS Windows. Enclose
  43 drawing primitives between {\bf BeginDrawing} and {\bf EndDrawing}\rtfsp
  44 calls.
  45
  46 Drawing to a wxDialog panel device context outside of a
  47 system-generated OnPaint event {\it requires} this pair of calls to
  48 enclose drawing code. This is because a Windows dialog box does not have
  49 a retained device context associated with it, and selections such as pen
  50 and brush settings would be lost if the device context were obtained and
  51 released for each drawing operation.
  52
  53 \membersection{wxDC::Blit}\label{wxdcblit}
  54
  55 \func{bool}{Blit}{\param{wxCoord}{ xdest}, \param{wxCoord}{ ydest}, \param{wxCoord}{ width}, \param{wxCoord}{ height},
  56   \param{wxDC* }{source}, \param{wxCoord}{ xsrc}, \param{wxCoord}{ ysrc}, \param{int}{ logicalFunc = wxCOPY},
  57   \param{bool }{useMask = FALSE}}
  58
  59 Copy from a source DC to this DC, specifying the destination
  60 coordinates, size of area to copy, source DC, source coordinates, and
  61 logical function.
  62
  63 \wxheading{Parameters}
  64
  65 \docparam{xdest}{Destination device context x position.}
  66
  67 \docparam{ydest}{Destination device context y position.}
  68
  69 \docparam{width}{Width of source area to be copied.}
  70
  71 \docparam{height}{Height of source area to be copied.}
  72
  73 \docparam{source}{Source device context.}
  74
  75 \docparam{xsrc}{Source device context x position.}
  76
  77 \docparam{ysrc}{Source device context y position.}
  78
  79 \docparam{logicalFunc}{Logical function to use: see \helpref{wxDC::SetLogicalFunction}{wxdcsetlogicalfunction}.}
  80
  81 \docparam{useMask}{If TRUE, Blit does a transparent blit using the mask that is associated with the bitmap
  82 selected into the source device context. The Windows implementation does the following:
  83
  84 \begin{enumerate}
  85 \item Creates a temporary bitmap and copies the destination area into it.
  86 \item Copies the source area into the temporary bitmap using the specified logical function.
  87 \item Sets the masked area in the temporary bitmap to BLACK by ANDing the
  88 mask bitmap with the temp bitmap with the foreground colour set to WHITE
  89 and the bg colour set to BLACK.
  90 \item Sets the unmasked area in the destination area to BLACK by ANDing the
  91 mask bitmap with the destination area with the foreground colour set to BLACK
  92 and the background colour set to WHITE.
  93 \item ORs the temporary bitmap with the destination area.
  94 \item Deletes the temporary bitmap.
  95 \end{enumerate}
  96
  97 This sequence of operations ensures that the source's transparent area need not be black,
  98 and logical functions are supported.
  99 }
 100
 101 \wxheading{Remarks}
 102
 103 There is partial support for Blit in wxPostScriptDC, under X.
 104
 105 See \helpref{wxMemoryDC}{wxmemorydc} for typical usage.
 106
 107 \wxheading{See also}
 108
 109 \helpref{wxMemoryDC}{wxmemorydc}, \helpref{wxBitmap}{wxbitmap}, \helpref{wxMask}{wxmask}
 110
 111 \membersection{wxDC::Clear}\label{wxdcclear}
 112
 113 \func{void}{Clear}{\void}
 114
 115 Clears the device context using the current background brush.
 116
 117 \membersection{wxDC::CrossHair}\label{wxdccrosshair}
 118
 119 \func{void}{CrossHair}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
 120
 121 Displays a cross hair using the current pen. This is a vertical
 122 and horizontal line the height and width of the window, centred
 123 on the given point.
 124
 125 \membersection{wxDC::DestroyClippingRegion}\label{wxdcdestroyclippingregion}
 126
 127 \func{void}{DestroyClippingRegion}{\void}
 128
 129 Destroys the current clipping region so that none of the DC is clipped.
 130 See also \helpref{wxDC::SetClippingRegion}{wxdcsetclippingregion}.
 131
 132 \membersection{wxDC::DeviceToLogicalX}\label{wxdcdevicetologicalx}
 133
 134 \func{wxCoord}{DeviceToLogicalX}{\param{wxCoord}{ x}}
 135
 136 Convert device X coordinate to logical coordinate, using the current
 137 mapping mode.
 138
 139 \membersection{wxDC::DeviceToLogicalXRel}\label{wxdcdevicetologicalxrel}
 140
 141 \func{wxCoord}{DeviceToLogicalXRel}{\param{wxCoord}{ x}}
 142
 143 Convert device X coordinate to relative logical coordinate, using the current
 144 mapping mode. Use this function for converting a width, for example.
 145
 146 \membersection{wxDC::DeviceToLogicalY}\label{wxdcdevicetologicaly}
 147
 148 \func{wxCoord}{DeviceToLogicalY}{\param{wxCoord}{ y}}
 149
 150 Converts device Y coordinate to logical coordinate, using the current
 151 mapping mode.
 152
 153 \membersection{wxDC::DeviceToLogicalYRel}\label{wxdcdevicetologicalyrel}
 154
 155 \func{wxCoord}{DeviceToLogicalYRel}{\param{wxCoord}{ y}}
 156
 157 Convert device Y coordinate to relative logical coordinate, using the current
 158 mapping mode. Use this function for converting a height, for example.
 159
 160 \membersection{wxDC::DrawArc}\label{wxdcdrawarc}
 161
 162 \func{void}{DrawArc}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}, \param{double}{ xc}, \param{double}{ yc}}
 163
 164 Draws an arc of a circle, centred on ({\it xc, yc}), with starting point ({\it x1, y1})
 165 and ending at ({\it x2, y2}).   The current pen is used for the outline
 166 and the current brush for filling the shape.
 167
 168 The arc is drawn in an anticlockwise direction from the start point to the end point.
 169
 170 \membersection{wxDC::DrawBitmap}\label{wxdcdrawbitmap}
 171
 172 \func{void}{DrawBitmap}{\param{const wxBitmap\&}{ bitmap}, \param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{bool}{ transparent}}
 173
 174 Draw a bitmap on the device context at the specified point. If {\it transparent} is TRUE and the bitmap has
 175 a transparency mask, the bitmap will be drawn transparently.
 176
 177 When drawing a mono-bitmap, the current text foreground colour will be used to draw the foreground
 178 of the bitmap (all bits set to 1), and the current text background colour to draw the background
 179 (all bits set to 0). See also \helpref{SetTextForeground}{wxdcsettextforeground},
 180 \helpref{SetTextBackground}{wxdcsettextbackground} and \helpref{wxMemoryDC}{wxmemorydc}.
 181
 182 \membersection{wxDC::DrawCheckMark}\label{wxdcdrawcheckmark}
 183
 184 \func{void}{DrawCheckMark}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
 185
 186 \func{void}{DrawCheckMark}{\param{const wxRect \&}{rect}}
 187
 188 Draws a check mark inside the given rectangle.
 189
 190 \membersection{wxDC::DrawEllipse}\label{wxdcdrawellipse}
 191
 192 \func{void}{DrawEllipse}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
 193
 194 Draws an ellipse contained in the rectangle with the given top left corner, and with the
 195 given size.  The current pen is used for the outline and the current brush for
 196 filling the shape.
 197
 198 \membersection{wxDC::DrawEllipticArc}\label{wxdcdrawellipticarc}
 199
 200 \func{void}{DrawEllipticArc}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height},
 201  \param{double}{ start}, \param{double}{ end}}
 202
 203 Draws an arc of an ellipse. The current pen is used for drawing the arc and
 204 the current brush is used for drawing the pie. This function is currently only available for
 205 X window and PostScript device contexts.
 206
 207 {\it x} and {\it y} specify the x and y coordinates of the upper-left corner of the rectangle that contains
 208 the ellipse.
 209
 210 {\it width} and {\it height} specify the width and height of the rectangle that contains
 211 the ellipse.
 212
 213 {\it start} and {\it end} specify the start and end of the arc relative to the three-o'clock
 214 position from the center of the rectangle. Angles are specified
 215 in degrees (360 is a complete circle). Positive values mean
 216 counter-clockwise motion. If {\it start} is equal to {\it end}, a
 217 complete ellipse will be drawn.
 218
 219 \membersection{wxDC::DrawIcon}\label{wxdcdrawicon}
 220
 221 \func{void}{DrawIcon}{\param{const wxIcon\&}{ icon}, \param{wxCoord}{ x}, \param{wxCoord}{ y}}
 222
 223 Draw an icon on the display (does nothing if the device context is PostScript).
 224 This can be the simplest way of drawing bitmaps on a window.
 225
 226 \membersection{wxDC::DrawLine}\label{wxdcdrawline}
 227
 228 \func{void}{DrawLine}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}}
 229
 230 Draws a line from the first point to the second. The current pen is used
 231 for drawing the line.
 232
 233 \membersection{wxDC::DrawLines}\label{wxdcdrawlines}
 234
 235 \func{void}{DrawLines}{\param{int}{ n}, \param{wxPoint}{ points[]}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0}}
 236
 237 \func{void}{DrawLines}{\param{wxList *}{points}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0}}
 238
 239 Draws lines using an array of {\it points} of size {\it n}, or list of
 240 pointers to points, adding the optional offset coordinate. The current
 241 pen is used for drawing the lines.  The programmer is responsible for
 242 deleting the list of points.
 243
 244 \pythonnote{The wxPython version of this method accepts a Python list
 245 of wxPoint objects.}
 246
 247 \membersection{wxDC::DrawPolygon}\label{wxdcdrawpolygon}
 248
 249 \func{void}{DrawPolygon}{\param{int}{ n}, \param{wxPoint}{ points[]}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0},\\
 250   \param{int }{fill\_style = wxODDEVEN\_RULE}}
 251
 252 \func{void}{DrawPolygon}{\param{wxList *}{points}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0},\\
 253   \param{int }{fill\_style = wxODDEVEN\_RULE}}
 254
 255 Draws a filled polygon using an array of {\it points} of size {\it n},
 256 or list of pointers to points, adding the optional offset coordinate.
 257
 258 The last argument specifies the fill rule: {\bf wxODDEVEN\_RULE} (the
 259 default) or {\bf wxWINDING\_RULE}.
 260
 261 The current pen is used for drawing the outline, and the current brush
 262 for filling the shape.  Using a transparent brush suppresses filling.
 263 The programmer is responsible for deleting the list of points.
 264
 265 Note that wxWindows automatically closes the first and last points.
 266
 267 \pythonnote{The wxPython version of this method accepts a Python list
 268 of wxPoint objects.}
 269
 270 \membersection{wxDC::DrawPoint}\label{wxdcdrawpoint}
 271
 272 \func{void}{DrawPoint}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
 273
 274 Draws a point using the current pen.
 275
 276 \membersection{wxDC::DrawRectangle}\label{wxdcdrawrectangle}
 277
 278 \func{void}{DrawRectangle}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
 279
 280 Draws a rectangle with the given top left corner, and with the given
 281 size.  The current pen is used for the outline and the current brush
 282 for filling the shape.
 283
 284 \membersection{wxDC::DrawRotatedText}\label{wxdcdrawrotatedtext}
 285
 286 \func{void}{DrawRotatedText}{\param{const wxString\& }{text}, \param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{double}{ angle}}
 287
 288 Draws the text rotated by {\it angle} degrees.
 289
 290 \wxheading{See also}
 291
 292 \helpref{DrawText}{wxdcdrawtext}
 293
 294 \membersection{wxDC::DrawRoundedRectangle}\label{wxdcdrawroundedrectangle}
 295
 296 \func{void}{DrawRoundedRectangle}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}, \param{double}{ radius = 20}}
 297
 298 Draws a rectangle with the given top left corner, and with the given
 299 size.  The corners are quarter-circles using the given radius. The
 300 current pen is used for the outline and the current brush for filling
 301 the shape.
 302
 303 If {\it radius} is positive, the value is assumed to be the
 304 radius of the rounded corner. If {\it radius} is negative,
 305 the absolute value is assumed to be the {\it proportion} of the smallest
 306 dimension of the rectangle. This means that the corner can be
 307 a sensible size relative to the size of the rectangle, and also avoids
 308 the strange effects X produces when the corners are too big for
 309 the rectangle.
 310
 311 \membersection{wxDC::DrawSpline}\label{wxdcdrawspline}
 312
 313 \func{void}{DrawSpline}{\param{wxList *}{points}}
 314
 315 Draws a spline between all given control points, using the current
 316 pen.  Doesn't delete the wxList and contents. The spline is drawn
 317 using a series of lines, using an algorithm taken from the X drawing
 318 program `XFIG'.
 319
 320 \func{void}{DrawSpline}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}, \param{wxCoord}{ x3}, \param{wxCoord}{ y3}}
 321
 322 Draws a three-point spline using the current pen.
 323
 324 \pythonnote{The wxPython version of this method accepts a Python list
 325 of wxPoint objects.}
 326
 327 \membersection{wxDC::DrawText}\label{wxdcdrawtext}
 328
 329 \func{void}{DrawText}{\param{const wxString\& }{text}, \param{wxCoord}{ x}, \param{wxCoord}{ y}}
 330
 331 Draws a text string at the specified point, using the current text font,
 332 and the current text foreground and background colours.
 333
 334 The coordinates refer to the top-left corner of the rectangle bounding
 335 the string. See \helpref{wxDC::GetTextExtent}{wxdcgettextextent} for how
 336 to get the dimensions of a text string, which can be used to position the
 337 text more precisely.
 338
 339 \membersection{wxDC::EndDoc}\label{wxdcenddoc}
 340
 341 \func{void}{EndDoc}{\void}
 342
 343 Ends a document (only relevant when outputting to a printer).
 344
 345 \membersection{wxDC::EndDrawing}\label{wxdcenddrawing}
 346
 347 \func{void}{EndDrawing}{\void}
 348
 349 Allows optimization of drawing code under MS Windows. Enclose
 350 drawing primitives between {\bf BeginDrawing} and {\bf EndDrawing}\rtfsp
 351 calls.
 352
 353 \membersection{wxDC::EndPage}\label{wxdcendpage}
 354
 355 \func{void}{EndPage}{\void}
 356
 357 Ends a document page (only relevant when outputting to a printer).
 358
 359 \membersection{wxDC::FloodFill}\label{wxdcfloodfill}
 360
 361 \func{void}{FloodFill}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxColour *}{colour}, \param{int}{ style=wxFLOOD\_SURFACE}}
 362
 363 Flood fills the device context starting from the given point, in the given colour,
 364 and using a style:
 365
 366 \begin{itemize}\itemsep=0pt
 367 \item wxFLOOD\_SURFACE: the flooding occurs until a colour other than the given colour is encountered.
 368 \item wxFLOOD\_BORDER: the area to be flooded is bounded by the given colour.
 369 \end{itemize}
 370
 371 {\it Note:} this function is available in MS Windows only.
 372
 373 \membersection{wxDC::GetBackground}\label{wxdcgetbackground}
 374
 375 \func{wxBrush\&}{GetBackground}{\void}
 376
 377 Gets the brush used for painting the background (see \helpref{wxDC::SetBackground}{wxdcsetbackground}).
 378
 379 \membersection{wxDC::GetBrush}\label{wxdcgetbrush}
 380
 381 \func{wxBrush\&}{GetBrush}{\void}
 382
 383 Gets the current brush (see \helpref{wxDC::SetBrush}{wxdcsetbrush}).
 384
 385 \membersection{wxDC::GetCharHeight}\label{wxdcgetcharheight}
 386
 387 \func{wxCoord}{GetCharHeight}{\void}
 388
 389 Gets the character height of the currently set font.
 390
 391 \membersection{wxDC::GetCharWidth}\label{wxdcgetcharwidth}
 392
 393 \func{wxCoord}{GetCharWidth}{\void}
 394
 395 Gets the average character width of the currently set font.
 396
 397 \membersection{wxDC::GetClippingBox}\label{wxdcgetclippingbox}
 398
 399 \func{void}{GetClippingBox}{\param{wxCoord}{ *x}, \param{wxCoord}{ *y}, \param{wxCoord}{ *width}, \param{wxCoord}{ *height}}
 400
 401 Gets the rectangle surrounding the current clipping region.
 402
 403 \pythonnote{No arguments are required and the four values defining the
 404 rectangle are returned as a tuple.}
 405
 406 \membersection{wxDC::GetFont}\label{wxdcgetfont}
 407
 408 \func{wxFont\&}{GetFont}{\void}
 409
 410 Gets the current font (see \helpref{wxDC::SetFont}{wxdcsetfont}).
 411
 412 \membersection{wxDC::GetLogicalFunction}\label{wxdcgetlogicalfunction}
 413
 414 \func{int}{GetLogicalFunction}{\void}
 415
 416 Gets the current logical function (see \helpref{wxDC::SetLogicalFunction}{wxdcsetlogicalfunction}).
 417
 418 \membersection{wxDC::GetMapMode}\label{wxdcgetmapmode}
 419
 420 \func{int}{GetMapMode}{\void}
 421
 422 Gets the {\it mapping mode} for the device context (see \helpref{wxDC::SetMapMode}{wxdcsetmapmode}).
 423
 424 \membersection{wxDC::GetOptimization}\label{wxdcgetoptimization}
 425
 426 \func{bool}{GetOptimization}{\void}
 427
 428 Returns TRUE if device context optimization is on.
 429 See \helpref{wxDC::SetOptimization}{wxsetoptimization} for details.
 430
 431 \membersection{wxDC::GetPen}\label{wxdcgetpen}
 432
 433 \func{wxPen\&}{GetPen}{\void}
 434
 435 Gets the current pen (see \helpref{wxDC::SetPen}{wxdcsetpen}).
 436
 437 \membersection{wxDC::GetPixel}\label{wxdcgetpixel}
 438
 439 \func{bool}{GetPixel}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxColour *}{colour}}
 440
 441 Sets {\it colour} to the colour at the specified location. Windows only; an X implementation
 442 is being worked on. Not available for wxPostScriptDC or wxMetafileDC.
 443
 444 \pythonnote{For wxPython the wxColour value is returned and is not
 445 required as a parameter.}
 446
 447 \membersection{wxDC::GetSize}\label{wxdcgetsize}
 448
 449 \func{void}{GetSize}{\param{wxCoord *}{width}, \param{wxCoord *}{height}}
 450
 451 For a PostScript device context, this gets the maximum size of graphics
 452 drawn so far on the device context.
 453
 454 For a Windows printer device context, this gets the horizontal and vertical
 455 resolution. It can be used to scale graphics to fit the page when using
 456 a Windows printer device context. For example, if {\it maxX} and {\it maxY}\rtfsp
 457 represent the maximum horizontal and vertical `pixel' values used in your
 458 application, the following code will scale the graphic to fit on the
 459 printer page:
 460
 461 \begin{verbatim}
 462   wxCoord w, h;
 463   dc.GetSize(&w, &h);
 464   double scaleX=(double)(maxX/w);
 465   double scaleY=(double)(maxY/h);
 466   dc.SetUserScale(min(scaleX,scaleY),min(scaleX,scaleY));
 467 \end{verbatim}
 468
 469 \pythonnote{In place of a single overloaded method name, wxPython
 470 implements the following methods:\par
 471 \indented{2cm}{\begin{twocollist}
 472 \twocolitem{{\bf GetSize()}}{Returns a wxSize}
 473 \twocolitem{{\bf GetSizeTuple()}}{Returns a 2-tuple (width, height)}
 474 \end{twocollist}}
 475 }
 476
 477 \membersection{wxDC::GetTextBackground}\label{wxdcgettextbackground}
 478
 479 \func{wxColour\&}{GetTextBackground}{\void}
 480
 481 Gets the current text background colour (see \helpref{wxDC::SetTextBackground}{wxdcsettextbackground}).
 482
 483 \membersection{wxDC::GetTextExtent}\label{wxdcgettextextent}
 484
 485 \func{void}{GetTextExtent}{\param{const wxString\& }{string}, \param{wxCoord *}{w}, \param{wxCoord *}{h},\\
 486   \param{wxCoord *}{descent = NULL}, \param{wxCoord *}{externalLeading = NULL}, \param{wxFont *}{font = NULL}}
 487
 488 Gets the dimensions of the string using the currently selected font.
 489 \rtfsp{\it string} is the text string to measure, {\it w} and {\it h} are
 490 the total width and height respectively, {\it descent} is the
 491 dimension from the baseline of the font to the bottom of the
 492 descender, and {\it externalLeading} is any extra vertical space added
 493 to the font by the font designer (usually is zero).
 494
 495 The optional parameter {\it font} specifies an alternative
 496 to the currently selected font: but note that this does not
 497 yet work under Windows, so you need to set a font for
 498 the device context first.
 499
 500 See also \helpref{wxFont}{wxfont}, \helpref{wxDC::SetFont}{wxdcsetfont}.
 501
 502 \pythonnote{The following methods are implemented in wxPython:\par
 503 \indented{2cm}{\begin{twocollist}
 504 \twocolitem{{\bf GetTextExtent(string)}}{Returns a 2-tuple, (width, height)}
 505 \twocolitem{{\bf GetFullTextExtent(string, font=NULL)}}{Returns a
 506 4-tuple, (width, height, descent, externalLeading) }
 507 \end{twocollist}}
 508 }
 509
 510 \membersection{wxDC::GetTextForeground}\label{wxdcgettextforeground}
 511
 512 \func{wxColour\&}{GetTextForeground}{\void}
 513
 514 Gets the current text foreground colour (see \helpref{wxDC::SetTextForeground}{wxdcsettextforeground}).
 515
 516
 517 \membersection{wxDC::GetUserScale}\label{wxdcgetuserscale}
 518
 519 \func{void}{GetUserScale}{\param{double}{ *x}, \param{double}{ *y}}
 520
 521 Gets the current user scale factor (set by \helpref{SetUserScale}{wxdcsetuserscale}).
 522
 523
 524 \membersection{wxDC::LogicalToDeviceX}\label{wxdclogicaltodevicex}
 525
 526 \func{wxCoord}{LogicalToDeviceX}{\param{wxCoord}{ x}}
 527
 528 Converts logical X coordinate to device coordinate, using the current
 529 mapping mode.
 530
 531 \membersection{wxDC::LogicalToDeviceXRel}\label{wxdclogicaltodevicexrel}
 532
 533 \func{wxCoord}{LogicalToDeviceXRel}{\param{wxCoord}{ x}}
 534
 535 Converts logical X coordinate to relative device coordinate, using the current
 536 mapping mode. Use this for converting a width, for example.
 537
 538 \membersection{wxDC::LogicalToDeviceY}\label{wxdclogicaltodevicey}
 539
 540 \func{wxCoord}{LogicalToDeviceY}{\param{wxCoord}{ y}}
 541
 542 Converts logical Y coordinate to device coordinate, using the current
 543 mapping mode.
 544
 545 \membersection{wxDC::LogicalToDeviceYRel}\label{wxdclogicaltodeviceyrel}
 546
 547 \func{wxCoord}{LogicalToDeviceYRel}{\param{wxCoord}{ y}}
 548
 549 Converts logical Y coordinate to relative device coordinate, using the current
 550 mapping mode. Use this for converting a height, for example.
 551
 552 \membersection{wxDC::MaxX}\label{wxdcmaxx}
 553
 554 \func{wxCoord}{MaxX}{\void}
 555
 556 Gets the maximum horizontal extent used in drawing commands so far.
 557
 558 \membersection{wxDC::MaxY}\label{wxdcmaxy}
 559
 560 \func{wxCoord}{MaxY}{\void}
 561
 562 Gets the maximum vertical extent used in drawing commands so far.
 563
 564 \membersection{wxDC::MinX}\label{wxdcminx}
 565
 566 \func{wxCoord}{MinX}{\void}
 567
 568 Gets the minimum horizontal extent used in drawing commands so far.
 569
 570 \membersection{wxDC::MinY}\label{wxdcminy}
 571
 572 \func{wxCoord}{MinY}{\void}
 573
 574 Gets the minimum vertical extent used in drawing commands so far.
 575
 576 \membersection{wxDC::Ok}\label{wxdcok}
 577
 578 \func{bool}{Ok}{\void}
 579
 580 Returns TRUE if the DC is ok to use.
 581
 582 \membersection{wxDC::SetDeviceOrigin}\label{wxdcsetdeviceorigin}
 583
 584 \func{void}{SetDeviceOrigin}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
 585
 586 Sets the device origin (i.e., the origin in pixels after scaling has been
 587 applied).
 588
 589 This function may be useful in Windows printing
 590 operations for placing a graphic on a page.
 591
 592 \membersection{wxDC::SetBackground}\label{wxdcsetbackground}
 593
 594 \func{void}{SetBackground}{\param{const wxBrush\& }{brush}}
 595
 596 Sets the current background brush for the DC.
 597
 598 \membersection{wxDC::SetBackgroundMode}\label{wxdcsetbackgroundmode}
 599
 600 \func{void}{SetBackgroundMode}{\param{int}{ mode}}
 601
 602 {\it mode} may be one of wxSOLID and wxTRANSPARENT. This setting determines
 603 whether text will be drawn with a background colour or not.
 604
 605 \membersection{wxDC::SetClippingRegion}\label{wxdcsetclippingregion}
 606
 607 \func{void}{SetClippingRegion}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
 608
 609 \func{void}{SetClippingRegion}{\param{const wxRegion\&}{ region}}
 610
 611 Sets the clipping region for the DC. The clipping region is an area
 612 to which drawing is restricted. Possible uses for the clipping region are for clipping text
 613 or for speeding up window redraws when only a known area of the screen is damaged.
 614
 615 \wxheading{See also}
 616
 617 \helpref{wxDC::DestroyClippingRegion}{wxdcdestroyclippingregion}, \helpref{wxRegion}{wxregion}
 618
 619 \membersection{wxDC::SetPalette}\label{wxdcsetpalette}
 620
 621 \func{void}{SetPalette}{\param{const wxPalette\& }{palette}}
 622
 623 If this is a window DC or memory DC, assigns the given palette to the window
 624 or bitmap associated with the DC. If the argument is wxNullPalette, the current
 625 palette is selected out of the device context, and the original palette
 626 restored.
 627
 628 See \helpref{wxPalette}{wxpalette} for further details.
 629
 630 \membersection{wxDC::SetBrush}\label{wxdcsetbrush}
 631
 632 \func{void}{SetBrush}{\param{const wxBrush\& }{brush}}
 633
 634 Sets the current brush for the DC.
 635
 636 If the argument is wxNullBrush, the current brush is selected out of the device
 637 context, and the original brush restored, allowing the current brush to
 638 be destroyed safely.
 639
 640 See also \helpref{wxBrush}{wxbrush}.
 641
 642 See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours
 643 when drawing into a monochrome bitmap.
 644
 645 \membersection{wxDC::SetFont}\label{wxdcsetfont}
 646
 647 \func{void}{SetFont}{\param{const wxFont\& }{font}}
 648
 649 Sets the current font for the DC.
 650
 651 If the argument is wxNullFont, the current font is selected out of the device
 652 context, and the original font restored, allowing the current font to
 653 be destroyed safely.
 654
 655 See also \helpref{wxFont}{wxfont}.
 656
 657 \membersection{wxDC::SetLogicalFunction}\label{wxdcsetlogicalfunction}
 658
 659 \func{void}{SetLogicalFunction}{\param{int}{ function}}
 660
 661 Sets the current logical function for the device context.  This determines how
 662 a source pixel (from a pen or brush colour, or source device context if
 663 using \helpref{wxDC::Blit}{wxdcblit}) combines with a destination pixel in the
 664 current device context.
 665
 666 The possible values
 667 and their meaning in terms of source and destination pixel values are
 668 as follows:
 669
 670 \begin{verbatim}
 671 wxAND                 src AND dst
 672 wxAND_INVERT          (NOT src) AND dst
 673 wxAND_REVERSE         src AND (NOT dst)
 674 wxCLEAR               0
 675 wxCOPY                src
 676 wxEQUIV               (NOT src) XOR dst
 677 wxINVERT              NOT dst
 678 wxNAND                (NOT src) OR (NOT dst)
 679 wxNOR                 (NOT src) AND (NOT dst)
 680 wxNO_OP               dst
 681 wxOR                  src OR dst
 682 wxOR_INVERT           (NOT src) OR dst
 683 wxOR_REVERSE          src OR (NOT dst)
 684 wxSET                 1
 685 wxSRC_INVERT          NOT src
 686 wxXOR                 src XOR dst
 687 \end{verbatim}
 688
 689 The default is wxCOPY, which simply draws with the current colour.
 690 The others combine the current colour and the background using a
 691 logical operation.  wxINVERT is commonly used for drawing rubber bands or
 692 moving outlines, since drawing twice reverts to the original colour.
 693
 694 \membersection{wxDC::SetMapMode}\label{wxdcsetmapmode}
 695
 696 \func{void}{SetMapMode}{\param{int}{ int}}
 697
 698 The {\it mapping mode} of the device context defines the unit of
 699 measurement used to convert logical units to device units. Note that
 700 in X, text drawing isn't handled consistently with the mapping mode; a
 701 font is always specified in point size. However, setting the {\it
 702 user scale} (see \helpref{wxDC::SetUserScale}{wxdcsetuserscale}) scales the text appropriately. In
 703 Windows, scaleable TrueType fonts are always used; in X, results depend
 704 on availability of fonts, but usually a reasonable match is found.
 705
 706 Note that the coordinate origin should ideally be selectable, but for
 707 now is always at the top left of the screen/printer.
 708
 709 Drawing to a Windows printer device context under UNIX
 710 uses the current mapping mode, but mapping mode is currently ignored for
 711 PostScript output.
 712
 713 The mapping mode can be one of the following:
 714
 715 \begin{twocollist}\itemsep=0pt
 716 \twocolitem{wxMM\_TWIPS}{Each logical unit is 1/20 of a point, or 1/1440 of
 717   an inch.}
 718 \twocolitem{wxMM\_POINTS}{Each logical unit is a point, or 1/72 of an inch.}
 719 \twocolitem{wxMM\_METRIC}{Each logical unit is 1 mm.}
 720 \twocolitem{wxMM\_LOMETRIC}{Each logical unit is 1/10 of a mm.}
 721 \twocolitem{wxMM\_TEXT}{Each logical unit is 1 pixel.}
 722 \end{twocollist}
 723
 724 \membersection{wxDC::SetOptimization}\label{wxsetoptimization}
 725
 726 \func{void}{SetOptimization}{\param{bool }{optimize}}
 727
 728 If {\it optimize} is TRUE (the default), this function sets optimization mode on.
 729 This currently means that under X, the device context will not try to set a pen or brush
 730 property if it is known to be set already. This approach can fall down
 731 if non-wxWindows code is using the same device context or window, for example
 732 when the window is a panel on which the windowing system draws panel items.
 733 The wxWindows device context 'memory' will now be out of step with reality.
 734
 735 Setting optimization off, drawing, then setting it back on again, is a trick
 736 that must occasionally be employed.
 737
 738 \membersection{wxDC::SetPen}\label{wxdcsetpen}
 739
 740 \func{void}{SetPen}{\param{const wxPen\& }{pen}}
 741
 742 Sets the current pen for the DC.
 743
 744 If the argument is wxNullPen, the current pen is selected out of the device
 745 context, and the original pen restored.
 746
 747 See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours
 748 when drawing into a monochrome bitmap.
 749
 750 \membersection{wxDC::SetTextBackground}\label{wxdcsettextbackground}
 751
 752 \func{void}{SetTextBackground}{\param{const wxColour\& }{colour}}
 753
 754 Sets the current text background colour for the DC.
 755
 756 \membersection{wxDC::SetTextForeground}\label{wxdcsettextforeground}
 757
 758 \func{void}{SetTextForeground}{\param{const wxColour\& }{colour}}
 759
 760 Sets the current text foreground colour for the DC.
 761
 762 See also \helpref{wxMemoryDC}{wxmemorydc} for the interpretation of colours
 763 when drawing into a monochrome bitmap.
 764
 765 \membersection{wxDC::SetUserScale}\label{wxdcsetuserscale}
 766
 767 \func{void}{SetUserScale}{\param{double}{ xScale}, \param{double}{ yScale}}
 768
 769 Sets the user scaling factor, useful for applications which require
 770 `zooming'.
 771
 772 \membersection{wxDC::StartDoc}\label{wxdcstartdoc}
 773
 774 \func{bool}{StartDoc}{\param{const wxString\& }{message}}
 775
 776 Starts a document (only relevant when outputting to a printer).
 777 Message is a message to show whilst printing.
 778
 779 \membersection{wxDC::StartPage}\label{wxdcstartpage}
 780
 781 \func{bool}{StartPage}{\void}
 782
 783 Starts a document page (only relevant when outputting to a printer).
 784