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 \membersection{wxDC::DrawEllipse}\label{wxdcdrawellipse}
 178
 179 \func{void}{DrawEllipse}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
 180
 181 Draws an ellipse contained in the rectangle with the given top left corner, and with the
 182 given size.  The current pen is used for the outline and the current brush for
 183 filling the shape.
 184
 185 \membersection{wxDC::DrawEllipticArc}\label{wxdcdrawellipticarc}
 186
 187 \func{void}{DrawEllipticArc}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height},
 188  \param{double}{ start}, \param{double}{ end}}
 189
 190 Draws an arc of an ellipse. The current pen is used for drawing the arc and
 191 the current brush is used for drawing the pie. This function is currently only available for
 192 X window and PostScript device contexts.
 193
 194 {\it x} and {\it y} specify the x and y coordinates of the upper-left corner of the rectangle that contains
 195 the ellipse.
 196
 197 {\it width} and {\it height} specify the width and height of the rectangle that contains
 198 the ellipse.
 199
 200 {\it start} and {\it end} specify the start and end of the arc relative to the three-o'clock
 201 position from the center of the rectangle. Angles are specified
 202 in degrees (360 is a complete circle). Positive values mean
 203 counter-clockwise motion. If {\it start} is equal to {\it end}, a
 204 complete ellipse will be drawn.
 205
 206 \membersection{wxDC::DrawIcon}\label{wxdcdrawicon}
 207
 208 \func{void}{DrawIcon}{\param{const wxIcon\&}{ icon}, \param{wxCoord}{ x}, \param{wxCoord}{ y}}
 209
 210 Draw an icon on the display (does nothing if the device context is PostScript).
 211 This can be the simplest way of drawing bitmaps on a window.
 212
 213 \membersection{wxDC::DrawLine}\label{wxdcdrawline}
 214
 215 \func{void}{DrawLine}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}}
 216
 217 Draws a line from the first point to the second. The current pen is used
 218 for drawing the line.
 219
 220 \membersection{wxDC::DrawLines}\label{wxdcdrawlines}
 221
 222 \func{void}{DrawLines}{\param{int}{ n}, \param{wxPoint}{ points[]}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0}}
 223
 224 \func{void}{DrawLines}{\param{wxList *}{points}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0}}
 225
 226 Draws lines using an array of {\it points} of size {\it n}, or list of
 227 pointers to points, adding the optional offset coordinate. The current
 228 pen is used for drawing the lines.  The programmer is responsible for
 229 deleting the list of points.
 230
 231 \pythonnote{The wxPython version of this method accepts a Python list
 232 of wxPoint objects.}
 233
 234 \membersection{wxDC::DrawPolygon}\label{wxdcdrawpolygon}
 235
 236 \func{void}{DrawPolygon}{\param{int}{ n}, \param{wxPoint}{ points[]}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0},\\
 237   \param{int }{fill\_style = wxODDEVEN\_RULE}}
 238
 239 \func{void}{DrawPolygon}{\param{wxList *}{points}, \param{wxCoord}{ xoffset = 0}, \param{wxCoord}{ yoffset = 0},\\
 240   \param{int }{fill\_style = wxODDEVEN\_RULE}}
 241
 242 Draws a filled polygon using an array of {\it points} of size {\it n},
 243 or list of pointers to points, adding the optional offset coordinate.
 244
 245 The last argument specifies the fill rule: {\bf wxODDEVEN\_RULE} (the
 246 default) or {\bf wxWINDING\_RULE}.
 247
 248 The current pen is used for drawing the outline, and the current brush
 249 for filling the shape.  Using a transparent brush suppresses filling.
 250 The programmer is responsible for deleting the list of points.
 251
 252 Note that wxWindows automatically closes the first and last points.
 253
 254 \pythonnote{The wxPython version of this method accepts a Python list
 255 of wxPoint objects.}
 256
 257 \membersection{wxDC::DrawPoint}\label{wxdcdrawpoint}
 258
 259 \func{void}{DrawPoint}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
 260
 261 Draws a point using the current pen.
 262
 263 \membersection{wxDC::DrawRectangle}\label{wxdcdrawrectangle}
 264
 265 \func{void}{DrawRectangle}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
 266
 267 Draws a rectangle with the given top left corner, and with the given
 268 size.  The current pen is used for the outline and the current brush
 269 for filling the shape.
 270
 271 \membersection{wxDC::DrawRotatedText}\label{wxdcdrawrotatedtext}
 272
 273 \func{void}{DrawRotatedText}{\param{const wxString\& }{text}, \param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{double}{ angle}}
 274
 275 Draws the text rotated by {\it angle} degrees.
 276
 277 \wxheading{See also}
 278
 279 \helpref{DrawText}{wxdcdrawtext}
 280
 281 \membersection{wxDC::DrawRoundedRectangle}\label{wxdcdrawroundedrectangle}
 282
 283 \func{void}{DrawRoundedRectangle}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}, \param{double}{ radius = 20}}
 284
 285 Draws a rectangle with the given top left corner, and with the given
 286 size.  The corners are quarter-circles using the given radius. The
 287 current pen is used for the outline and the current brush for filling
 288 the shape.
 289
 290 If {\it radius} is positive, the value is assumed to be the
 291 radius of the rounded corner. If {\it radius} is negative,
 292 the absolute value is assumed to be the {\it proportion} of the smallest
 293 dimension of the rectangle. This means that the corner can be
 294 a sensible size relative to the size of the rectangle, and also avoids
 295 the strange effects X produces when the corners are too big for
 296 the rectangle.
 297
 298 \membersection{wxDC::DrawSpline}\label{wxdcdrawspline}
 299
 300 \func{void}{DrawSpline}{\param{wxList *}{points}}
 301
 302 Draws a spline between all given control points, using the current
 303 pen.  Doesn't delete the wxList and contents. The spline is drawn
 304 using a series of lines, using an algorithm taken from the X drawing
 305 program `XFIG'.
 306
 307 \func{void}{DrawSpline}{\param{wxCoord}{ x1}, \param{wxCoord}{ y1}, \param{wxCoord}{ x2}, \param{wxCoord}{ y2}, \param{wxCoord}{ x3}, \param{wxCoord}{ y3}}
 308
 309 Draws a three-point spline using the current pen.
 310
 311 \pythonnote{The wxPython version of this method accepts a Python list
 312 of wxPoint objects.}
 313
 314 \membersection{wxDC::DrawText}\label{wxdcdrawtext}
 315
 316 \func{void}{DrawText}{\param{const wxString\& }{text}, \param{wxCoord}{ x}, \param{wxCoord}{ y}}
 317
 318 Draws a text string at the specified point, using the current text font,
 319 and the current text foreground and background colours.
 320
 321 The coordinates refer to the top-left corner of the rectangle bounding
 322 the string. See \helpref{wxDC::GetTextExtent}{wxdcgettextextent} for how
 323 to get the dimensions of a text string, which can be used to position the
 324 text more precisely.
 325
 326 \membersection{wxDC::EndDoc}\label{wxdcenddoc}
 327
 328 \func{void}{EndDoc}{\void}
 329
 330 Ends a document (only relevant when outputting to a printer).
 331
 332 \membersection{wxDC::EndDrawing}\label{wxdcenddrawing}
 333
 334 \func{void}{EndDrawing}{\void}
 335
 336 Allows optimization of drawing code under MS Windows. Enclose
 337 drawing primitives between {\bf BeginDrawing} and {\bf EndDrawing}\rtfsp
 338 calls.
 339
 340 \membersection{wxDC::EndPage}\label{wxdcendpage}
 341
 342 \func{void}{EndPage}{\void}
 343
 344 Ends a document page (only relevant when outputting to a printer).
 345
 346 \membersection{wxDC::FloodFill}\label{wxdcfloodfill}
 347
 348 \func{void}{FloodFill}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxColour *}{colour}, \param{int}{ style=wxFLOOD\_SURFACE}}
 349
 350 Flood fills the device context starting from the given point, in the given colour,
 351 and using a style:
 352
 353 \begin{itemize}\itemsep=0pt
 354 \item wxFLOOD\_SURFACE: the flooding occurs until a colour other than the given colour is encountered.
 355 \item wxFLOOD\_BORDER: the area to be flooded is bounded by the given colour.
 356 \end{itemize}
 357
 358 {\it Note:} this function is available in MS Windows only.
 359
 360 \membersection{wxDC::GetBackground}\label{wxdcgetbackground}
 361
 362 \func{wxBrush\&}{GetBackground}{\void}
 363
 364 Gets the brush used for painting the background (see \helpref{wxDC::SetBackground}{wxdcsetbackground}).
 365
 366 \membersection{wxDC::GetBrush}\label{wxdcgetbrush}
 367
 368 \func{wxBrush\&}{GetBrush}{\void}
 369
 370 Gets the current brush (see \helpref{wxDC::SetBrush}{wxdcsetbrush}).
 371
 372 \membersection{wxDC::GetCharHeight}\label{wxdcgetcharheight}
 373
 374 \func{wxCoord}{GetCharHeight}{\void}
 375
 376 Gets the character height of the currently set font.
 377
 378 \membersection{wxDC::GetCharWidth}\label{wxdcgetcharwidth}
 379
 380 \func{wxCoord}{GetCharWidth}{\void}
 381
 382 Gets the average character width of the currently set font.
 383
 384 \membersection{wxDC::GetClippingBox}\label{wxdcgetclippingbox}
 385
 386 \func{void}{GetClippingBox}{\param{wxCoord}{ *x}, \param{wxCoord}{ *y}, \param{wxCoord}{ *width}, \param{wxCoord}{ *height}}
 387
 388 Gets the rectangle surrounding the current clipping region.
 389
 390 \pythonnote{No arguments are required and the four values defining the
 391 rectangle are returned as a tuple.}
 392
 393 \membersection{wxDC::GetFont}\label{wxdcgetfont}
 394
 395 \func{wxFont\&}{GetFont}{\void}
 396
 397 Gets the current font (see \helpref{wxDC::SetFont}{wxdcsetfont}).
 398
 399 \membersection{wxDC::GetLogicalFunction}\label{wxdcgetlogicalfunction}
 400
 401 \func{int}{GetLogicalFunction}{\void}
 402
 403 Gets the current logical function (see \helpref{wxDC::SetLogicalFunction}{wxdcsetlogicalfunction}).
 404
 405 \membersection{wxDC::GetMapMode}\label{wxdcgetmapmode}
 406
 407 \func{int}{GetMapMode}{\void}
 408
 409 Gets the {\it mapping mode} for the device context (see \helpref{wxDC::SetMapMode}{wxdcsetmapmode}).
 410
 411 \membersection{wxDC::GetOptimization}\label{wxdcgetoptimization}
 412
 413 \func{bool}{GetOptimization}{\void}
 414
 415 Returns TRUE if device context optimization is on.
 416 See \helpref{wxDC::SetOptimization}{wxsetoptimization} for details.
 417
 418 \membersection{wxDC::GetPen}\label{wxdcgetpen}
 419
 420 \func{wxPen\&}{GetPen}{\void}
 421
 422 Gets the current pen (see \helpref{wxDC::SetPen}{wxdcsetpen}).
 423
 424 \membersection{wxDC::GetPixel}\label{wxdcgetpixel}
 425
 426 \func{bool}{GetPixel}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxColour *}{colour}}
 427
 428 Sets {\it colour} to the colour at the specified location. Windows only; an X implementation
 429 is being worked on. Not available for wxPostScriptDC or wxMetafileDC.
 430
 431 \pythonnote{For wxPython the wxColour value is returned and is not
 432 required as a parameter.}
 433
 434 \membersection{wxDC::GetSize}\label{wxdcgetsize}
 435
 436 \func{void}{GetSize}{\param{wxCoord *}{width}, \param{wxCoord *}{height}}
 437
 438 For a PostScript device context, this gets the maximum size of graphics
 439 drawn so far on the device context.
 440
 441 For a Windows printer device context, this gets the horizontal and vertical
 442 resolution. It can be used to scale graphics to fit the page when using
 443 a Windows printer device context. For example, if {\it maxX} and {\it maxY}\rtfsp
 444 represent the maximum horizontal and vertical `pixel' values used in your
 445 application, the following code will scale the graphic to fit on the
 446 printer page:
 447
 448 \begin{verbatim}
 449   wxCoord w, h;
 450   dc.GetSize(&w, &h);
 451   double scaleX=(double)(maxX/w);
 452   double scaleY=(double)(maxY/h);
 453   dc.SetUserScale(min(scaleX,scaleY),min(scaleX,scaleY));
 454 \end{verbatim}
 455
 456 \pythonnote{In place of a single overloaded method name, wxPython
 457 implements the following methods:\par
 458 \indented{2cm}{\begin{twocollist}
 459 \twocolitem{\bf{GetSize()}}{Returns a wxSize}
 460 \twocolitem{\bf{GetSizeTuple()}}{Returns a 2-tuple (width, height)}
 461 \end{twocollist}}
 462 }
 463
 464 \membersection{wxDC::GetTextBackground}\label{wxdcgettextbackground}
 465
 466 \func{wxColour\&}{GetTextBackground}{\void}
 467
 468 Gets the current text background colour (see \helpref{wxDC::SetTextBackground}{wxdcsettextbackground}).
 469
 470 \membersection{wxDC::GetTextExtent}\label{wxdcgettextextent}
 471
 472 \func{void}{GetTextExtent}{\param{const wxString\& }{string}, \param{wxCoord *}{w}, \param{wxCoord *}{h},\\
 473   \param{wxCoord *}{descent = NULL}, \param{wxCoord *}{externalLeading = NULL}, \param{wxFont *}{font = NULL}}
 474
 475 Gets the dimensions of the string using the currently selected font.
 476 \rtfsp{\it string} is the text string to measure, {\it w} and {\it h} are
 477 the total width and height respectively, {\it descent} is the
 478 dimension from the baseline of the font to the bottom of the
 479 descender, and {\it externalLeading} is any extra vertical space added
 480 to the font by the font designer (usually is zero).
 481
 482 The optional parameter {\it font} specifies an alternative
 483 to the currently selected font: but note that this does not
 484 yet work under Windows, so you need to set a font for
 485 the device context first.
 486
 487 See also \helpref{wxFont}{wxfont}, \helpref{wxDC::SetFont}{wxdcsetfont}.
 488
 489 \pythonnote{The following methods are implemented in wxPython:\par
 490 \indented{2cm}{\begin{twocollist}
 491 \twocolitem{\bf{GetTextExtent(string)}}{Returns a 2-tuple, (width, height)}
 492 \twocolitem{\bf{GetFullTextExtent(string, font=NULL)}}{Returns a
 493 4-tuple, (width, height, descent, externalLeading) }
 494 \end{twocollist}}
 495 }
 496
 497 \membersection{wxDC::GetTextForeground}\label{wxdcgettextforeground}
 498
 499 \func{wxColour\&}{GetTextForeground}{\void}
 500
 501 Gets the current text foreground colour (see \helpref{wxDC::SetTextForeground}{wxdcsettextforeground}).
 502
 503
 504 \membersection{wxDC::GetUserScale}\label{wxdcgetuserscale}
 505
 506 \func{void}{GetUserScale}{\param{double}{ *x}, \param{double}{ *y}}
 507
 508 Gets the current user scale factor (set by \helpref{SetUserScale}{wxdcsetuserscale}).
 509
 510
 511 \membersection{wxDC::LogicalToDeviceX}\label{wxdclogicaltodevicex}
 512
 513 \func{wxCoord}{LogicalToDeviceX}{\param{wxCoord}{ x}}
 514
 515 Converts logical X coordinate to device coordinate, using the current
 516 mapping mode.
 517
 518 \membersection{wxDC::LogicalToDeviceXRel}\label{wxdclogicaltodevicexrel}
 519
 520 \func{wxCoord}{LogicalToDeviceXRel}{\param{wxCoord}{ x}}
 521
 522 Converts logical X coordinate to relative device coordinate, using the current
 523 mapping mode. Use this for converting a width, for example.
 524
 525 \membersection{wxDC::LogicalToDeviceY}\label{wxdclogicaltodevicey}
 526
 527 \func{wxCoord}{LogicalToDeviceY}{\param{wxCoord}{ y}}
 528
 529 Converts logical Y coordinate to device coordinate, using the current
 530 mapping mode.
 531
 532 \membersection{wxDC::LogicalToDeviceYRel}\label{wxdclogicaltodeviceyrel}
 533
 534 \func{wxCoord}{LogicalToDeviceYRel}{\param{wxCoord}{ y}}
 535
 536 Converts logical Y coordinate to relative device coordinate, using the current
 537 mapping mode. Use this for converting a height, for example.
 538
 539 \membersection{wxDC::MaxX}\label{wxdcmaxx}
 540
 541 \func{wxCoord}{MaxX}{\void}
 542
 543 Gets the maximum horizontal extent used in drawing commands so far.
 544
 545 \membersection{wxDC::MaxY}\label{wxdcmaxy}
 546
 547 \func{wxCoord}{MaxY}{\void}
 548
 549 Gets the maximum vertical extent used in drawing commands so far.
 550
 551 \membersection{wxDC::MinX}\label{wxdcminx}
 552
 553 \func{wxCoord}{MinX}{\void}
 554
 555 Gets the minimum horizontal extent used in drawing commands so far.
 556
 557 \membersection{wxDC::MinY}\label{wxdcminy}
 558
 559 \func{wxCoord}{MinY}{\void}
 560
 561 Gets the minimum vertical extent used in drawing commands so far.
 562
 563 \membersection{wxDC::Ok}\label{wxdcok}
 564
 565 \func{bool}{Ok}{\void}
 566
 567 Returns TRUE if the DC is ok to use.
 568
 569 \membersection{wxDC::SetDeviceOrigin}\label{wxdcsetdeviceorigin}
 570
 571 \func{void}{SetDeviceOrigin}{\param{wxCoord}{ x}, \param{wxCoord}{ y}}
 572
 573 Sets the device origin (i.e., the origin in pixels after scaling has been
 574 applied).
 575
 576 This function may be useful in Windows printing
 577 operations for placing a graphic on a page.
 578
 579 \membersection{wxDC::SetBackground}\label{wxdcsetbackground}
 580
 581 \func{void}{SetBackground}{\param{const wxBrush\& }{brush}}
 582
 583 Sets the current background brush for the DC.
 584
 585 \membersection{wxDC::SetBackgroundMode}\label{wxdcsetbackgroundmode}
 586
 587 \func{void}{SetBackgroundMode}{\param{int}{ mode}}
 588
 589 {\it mode} may be one of wxSOLID and wxTRANSPARENT. This setting determines
 590 whether text will be drawn with a background colour or not.
 591
 592 \membersection{wxDC::SetClippingRegion}\label{wxdcsetclippingregion}
 593
 594 \func{void}{SetClippingRegion}{\param{wxCoord}{ x}, \param{wxCoord}{ y}, \param{wxCoord}{ width}, \param{wxCoord}{ height}}
 595
 596 \func{void}{SetClippingRegion}{\param{const wxRegion\&}{ region}}
 597
 598 Sets the clipping region for the DC. The clipping region is an area
 599 to which drawing is restricted. Possible uses for the clipping region are for clipping text
 600 or for speeding up window redraws when only a known area of the screen is damaged.
 601
 602 \wxheading{See also}
 603
 604 \helpref{wxDC::DestroyClippingRegion}{wxdcdestroyclippingregion}, \helpref{wxRegion}{wxregion}
 605
 606 \membersection{wxDC::SetPalette}\label{wxdcsetpalette}
 607
 608 \func{void}{SetPalette}{\param{const wxPalette\& }{palette}}
 609
 610 If this is a window DC or memory DC, assigns the given palette to the window
 611 or bitmap associated with the DC. If the argument is wxNullPalette, the current
 612 palette is selected out of the device context, and the original palette
 613 restored.
 614
 615 See \helpref{wxPalette}{wxpalette} for further details.
 616
 617 \membersection{wxDC::SetBrush}\label{wxdcsetbrush}
 618
 619 \func{void}{SetBrush}{\param{const wxBrush\& }{brush}}
 620
 621 Sets the current brush for the DC.
 622
 623 If the argument is wxNullBrush, the current brush is selected out of the device
 624 context, and the original brush restored, allowing the current brush to
 625 be destroyed safely.
 626
 627 See also \helpref{wxBrush}{wxbrush}.
 628
 629 \membersection{wxDC::SetFont}\label{wxdcsetfont}
 630
 631 \func{void}{SetFont}{\param{const wxFont\& }{font}}
 632
 633 Sets the current font for the DC.
 634
 635 If the argument is wxNullFont, the current font is selected out of the device
 636 context, and the original font restored, allowing the current font to
 637 be destroyed safely.
 638
 639 See also \helpref{wxFont}{wxfont}.
 640
 641 \membersection{wxDC::SetLogicalFunction}\label{wxdcsetlogicalfunction}
 642
 643 \func{void}{SetLogicalFunction}{\param{int}{ function}}
 644
 645 Sets the current logical function for the device context.  This determines how
 646 a source pixel (from a pen or brush colour, or source device context if
 647 using \helpref{wxDC::Blit}{wxdcblit}) combines with a destination pixel in the
 648 current device context.
 649
 650 The possible values
 651 and their meaning in terms of source and destination pixel values are
 652 as follows:
 653
 654 \begin{verbatim}
 655 wxAND                 src AND dst
 656 wxAND_INVERT          (NOT src) AND dst
 657 wxAND_REVERSE         src AND (NOT dst)
 658 wxCLEAR               0
 659 wxCOPY                src
 660 wxEQUIV               (NOT src) XOR dst
 661 wxINVERT              NOT dst
 662 wxNAND                (NOT src) OR (NOT dst)
 663 wxNOR                 (NOT src) AND (NOT dst)
 664 wxNO_OP               dst
 665 wxOR                  src OR dst
 666 wxOR_INVERT           (NOT src) OR dst
 667 wxOR_REVERSE          src OR (NOT dst)
 668 wxSET                 1
 669 wxSRC_INVERT          NOT src
 670 wxXOR                 src XOR dst
 671 \end{verbatim}
 672
 673 The default is wxCOPY, which simply draws with the current colour.
 674 The others combine the current colour and the background using a
 675 logical operation.  wxINVERT is commonly used for drawing rubber bands or
 676 moving outlines, since drawing twice reverts to the original colour.
 677
 678 \membersection{wxDC::SetMapMode}\label{wxdcsetmapmode}
 679
 680 \func{void}{SetMapMode}{\param{int}{ int}}
 681
 682 The {\it mapping mode} of the device context defines the unit of
 683 measurement used to convert logical units to device units. Note that
 684 in X, text drawing isn't handled consistently with the mapping mode; a
 685 font is always specified in point size. However, setting the {\it
 686 user scale} (see \helpref{wxDC::SetUserScale}{wxdcsetuserscale}) scales the text appropriately. In
 687 Windows, scaleable TrueType fonts are always used; in X, results depend
 688 on availability of fonts, but usually a reasonable match is found.
 689
 690 Note that the coordinate origin should ideally be selectable, but for
 691 now is always at the top left of the screen/printer.
 692
 693 Drawing to a Windows printer device context under UNIX
 694 uses the current mapping mode, but mapping mode is currently ignored for
 695 PostScript output.
 696
 697 The mapping mode can be one of the following:
 698
 699 \begin{twocollist}\itemsep=0pt
 700 \twocolitem{wxMM\_TWIPS}{Each logical unit is 1/20 of a point, or 1/1440 of
 701   an inch.}
 702 \twocolitem{wxMM\_POINTS}{Each logical unit is a point, or 1/72 of an inch.}
 703 \twocolitem{wxMM\_METRIC}{Each logical unit is 1 mm.}
 704 \twocolitem{wxMM\_LOMETRIC}{Each logical unit is 1/10 of a mm.}
 705 \twocolitem{wxMM\_TEXT}{Each logical unit is 1 pixel.}
 706 \end{twocollist}
 707
 708 \membersection{wxDC::SetOptimization}\label{wxsetoptimization}
 709
 710 \func{void}{SetOptimization}{\param{bool }{optimize}}
 711
 712 If {\it optimize} is TRUE (the default), this function sets optimization mode on.
 713 This currently means that under X, the device context will not try to set a pen or brush
 714 property if it is known to be set already. This approach can fall down
 715 if non-wxWindows code is using the same device context or window, for example
 716 when the window is a panel on which the windowing system draws panel items.
 717 The wxWindows device context 'memory' will now be out of step with reality.
 718
 719 Setting optimization off, drawing, then setting it back on again, is a trick
 720 that must occasionally be employed.
 721
 722 \membersection{wxDC::SetPen}\label{wxdcsetpen}
 723
 724 \func{void}{SetPen}{\param{const wxPen\& }{pen}}
 725
 726 Sets the current pen for the DC.
 727
 728 If the argument is wxNullPen, the current pen is selected out of the device
 729 context, and the original pen restored.
 730
 731 \membersection{wxDC::SetTextBackground}\label{wxdcsettextbackground}
 732
 733 \func{void}{SetTextBackground}{\param{const wxColour\& }{colour}}
 734
 735 Sets the current text background colour for the DC.
 736
 737 \membersection{wxDC::SetTextForeground}\label{wxdcsettextforeground}
 738
 739 \func{void}{SetTextForeground}{\param{const wxColour\& }{colour}}
 740
 741 Sets the current text foreground colour for the DC.
 742
 743 \membersection{wxDC::SetUserScale}\label{wxdcsetuserscale}
 744
 745 \func{void}{SetUserScale}{\param{double}{ xScale}, \param{double}{ yScale}}
 746
 747 Sets the user scaling factor, useful for applications which require
 748 `zooming'.
 749
 750 \membersection{wxDC::StartDoc}\label{wxdcstartdoc}
 751
 752 \func{bool}{StartDoc}{\param{const wxString\& }{message}}
 753
 754 Starts a document (only relevant when outputting to a printer).
 755 Message is a message to show whilst printing.
 756
 757 \membersection{wxDC::StartPage}\label{wxdcstartpage}
 758
 759 \func{bool}{StartPage}{\void}
 760
 761 Starts a document page (only relevant when outputting to a printer).
 762