wxDC

A wxDC is a device context onto which graphics and text can be drawn. It is intended to represent a number of output devices in a generic way, so a window can have a device context associated with it, and a printer also has a device context. In this way, the same piece of code may write to a number of different devices, if the device context is used as a parameter.

Derived types of wxDC have documentation for specific features only, so refer to this section for most device context information.

Please note that in addition to the versions of the methods documented here, there are also versions which accept single wxPoint parameter instead of two wxCoord ones or wxPoint and wxSize instead of four of them.

Derived from

wxObject

Include files

<wx/dc.h>

See also

Overview



wxDC::wxDC



wxDC(void)

Constructor.



wxDC::~wxDC



~wxDC(void)

Destructor.



wxDC::BeginDrawing



void BeginDrawing(void)

Allows optimization of drawing code under MS Windows. Enclose drawing primitives between BeginDrawing and EndDrawing calls.

Drawing to a wxDialog panel device context outside of a system-generated OnPaint event requires this pair of calls to enclose drawing code. This is because a Windows dialog box does not have a retained device context associated with it, and selections such as pen and brush settings would be lost if the device context were obtained and released for each drawing operation.



wxDC::Blit



bool Blit(wxCoord xdest, wxCoord ydest, wxCoord width, wxCoord height, wxDC* source, wxCoord xsrc, wxCoord ysrc, int logicalFunc = wxCOPY, bool useMask = false, wxCoord xsrcMask = -1, wxCoord ysrcMask = -1)

Copy from a source DC to this DC, specifying the destination coordinates, size of area to copy, source DC, source coordinates, logical function, whether to use a bitmap mask, and mask source position.

Parameters

xdest
Destination device context x position.

ydest
Destination device context y position.

width
Width of source area to be copied.

height
Height of source area to be copied.

source
Source device context.

xsrc
Source device context x position.

ysrc
Source device context y position.

logicalFunc
Logical function to use: see wxDC::SetLogicalFunction.

useMask
If true, Blit does a transparent blit using the mask that is associated with the bitmap selected into the source device context. The Windows implementation does the following if MaskBlt cannot be used:

  1. Creates a temporary bitmap and copies the destination area into it.
  2. Copies the source area into the temporary bitmap using the specified logical function.
  3. Sets the masked area in the temporary bitmap to BLACK by ANDing the mask bitmap with the temp bitmap with the foreground colour set to WHITE and the bg colour set to BLACK.
  4. Sets the unmasked area in the destination area to BLACK by ANDing the mask bitmap with the destination area with the foreground colour set to BLACK and the background colour set to WHITE.
  5. ORs the temporary bitmap with the destination area.
  6. Deletes the temporary bitmap.

This sequence of operations ensures that the source's transparent area need not be black, and logical functions are supported.

Note: on Windows, blitting with masks can be speeded up considerably by compiling wxWidgets with the wxUSE_DC_CACHE option enabled. You can also influence whether MaskBlt or the explicit mask blitting code above is used, by using wxSystemOptions and setting the no-maskblt option to 1.

xsrcMask
Source x position on the mask. If both xsrcMask and ysrcMask are -1, xsrc and ysrc will be assumed for the mask source position. Currently only implemented on Windows.

ysrcMask
Source y position on the mask. If both xsrcMask and ysrcMask are -1, xsrc and ysrc will be assumed for the mask source position. Currently only implemented on Windows.

Remarks

There is partial support for Blit in wxPostScriptDC, under X.

See wxMemoryDC for typical usage.

See also

wxMemoryDC, wxBitmap, wxMask



wxDC::CalcBoundingBox



void CalcBoundingBox(wxCoord x, wxCoord y)

Adds the specified point to the bounding box which can be retrieved with MinX, MaxX and MinY, MaxY functions.

See also

ResetBoundingBox



wxDC::Clear



void Clear(void)

Clears the device context using the current background brush.



wxDC::ComputeScaleAndOrigin



virtual void ComputeScaleAndOrigin(void)

Performs all necessary computations for given platform and context type after each change of scale and origin parameters. Usually called automatically internally after such changes.



wxDC::CrossHair



void CrossHair(wxCoord x, wxCoord y)

Displays a cross hair using the current pen. This is a vertical and horizontal line the height and width of the window, centred on the given point.



wxDC::DestroyClippingRegion



void DestroyClippingRegion(void)

Destroys the current clipping region so that none of the DC is clipped. See also wxDC::SetClippingRegion.



wxDC::DeviceToLogicalX



wxCoord DeviceToLogicalX(wxCoord x)

Convert device X coordinate to logical coordinate, using the current mapping mode.



wxDC::DeviceToLogicalXRel



wxCoord DeviceToLogicalXRel(wxCoord x)

Convert device X coordinate to relative logical coordinate, using the current mapping mode but ignoring the x axis orientation. Use this function for converting a width, for example.



wxDC::DeviceToLogicalY



wxCoord DeviceToLogicalY(wxCoord y)

Converts device Y coordinate to logical coordinate, using the current mapping mode.



wxDC::DeviceToLogicalYRel



wxCoord DeviceToLogicalYRel(wxCoord y)

Convert device Y coordinate to relative logical coordinate, using the current mapping mode but ignoring the y axis orientation. Use this function for converting a height, for example.



wxDC::DrawArc



void DrawArc(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2, wxCoord xc, wxCoord yc)

Draws an arc of a circle, centred on (xc, yc), with starting point (x1, y1) and ending at (x2, y2). The current pen is used for the outline and the current brush for filling the shape.

The arc is drawn in an anticlockwise direction from the start point to the end point.



wxDC::DrawBitmap



void DrawBitmap(const wxBitmap& bitmap, wxCoord x, wxCoord y, bool transparent)

Draw a bitmap on the device context at the specified point. If transparent is true and the bitmap has a transparency mask, the bitmap will be drawn transparently.

When drawing a mono-bitmap, the current text foreground colour will be used to draw the foreground of the bitmap (all bits set to 1), and the current text background colour to draw the background (all bits set to 0). See also SetTextForeground, SetTextBackground and wxMemoryDC.



wxDC::DrawCheckMark



void DrawCheckMark(wxCoord x, wxCoord y, wxCoord width, wxCoord height)



void DrawCheckMark(const wxRect & rect)

Draws a check mark inside the given rectangle.



wxDC::DrawCircle



void DrawCircle(wxCoord x, wxCoord y, wxCoord radius)



void DrawCircle(const wxPoint& pt, wxCoord radius)

Draws a circle with the given centre and radius.

See also

DrawEllipse



wxDC::DrawEllipse



void DrawEllipse(wxCoord x, wxCoord y, wxCoord width, wxCoord height)



void DrawEllipse(const wxPoint& pt, const wxSize& size)



void DrawEllipse(const wxRect& rect)

Draws an ellipse contained in the rectangle specified either with the given top left corner and the given size or directly. The current pen is used for the outline and the current brush for filling the shape.

See also

DrawCircle



wxDC::DrawEllipticArc



void DrawEllipticArc(wxCoord x, wxCoord y, wxCoord width, wxCoord height, double start, double end)

Draws an arc of an ellipse. The current pen is used for drawing the arc and the current brush is used for drawing the pie.

x and y specify the x and y coordinates of the upper-left corner of the rectangle that contains the ellipse.

width and height specify the width and height of the rectangle that contains the ellipse.

start and end specify the start and end of the arc relative to the three-o'clock position from the center of the rectangle. Angles are specified in degrees (360 is a complete circle). Positive values mean counter-clockwise motion. If start is equal to end, a complete ellipse will be drawn.



wxDC::DrawIcon



void DrawIcon(const wxIcon& icon, wxCoord x, wxCoord y)

Draw an icon on the display (does nothing if the device context is PostScript). This can be the simplest way of drawing bitmaps on a window.



wxDC::DrawLabel



virtual void DrawLabel(const wxString& text, const wxBitmap& image, const wxRect& rect, int alignment = wxALIGN_LEFT | wxALIGN_TOP, int indexAccel = -1, wxRect * rectBounding = NULL)



void DrawLabel(const wxString& text, const wxRect& rect, int alignment = wxALIGN_LEFT | wxALIGN_TOP, int indexAccel = -1)

Draw optional bitmap and the text into the given rectangle and aligns it as specified by alignment parameter; it also will emphasize the character with the given index if it is != -1 and return the bounding rectangle if required.



wxDC::DrawLine



void DrawLine(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2)

Draws a line from the first point to the second. The current pen is used for drawing the line. Note that the point $(x2, y2)$ is not part of the line and is not drawn by this function (this is consistent with the behaviour of many other toolkits).



wxDC::DrawLines



void DrawLines(int n, wxPoint points[], wxCoord xoffset = 0, wxCoord yoffset = 0)



void DrawLines(wxList * points, wxCoord xoffset = 0, wxCoord yoffset = 0)

Draws lines using an array of points of size n, or list of pointers to points, adding the optional offset coordinate. The current pen is used for drawing the lines. The programmer is responsible for deleting the list of points.

wxPython での注意点: The wxPython version of this method accepts a Python list of wxPoint objects.

wxPerl での注意点: The wxPerl version of this method accepts as its first parameter a reference to an array of wxPoint objects.



wxDC::DrawPolygon



void DrawPolygon(int n, wxPoint points[], wxCoord xoffset = 0, wxCoord yoffset = 0,
int fill_style = wxODDEVEN_RULE)



void DrawPolygon(wxList * points, wxCoord xoffset = 0, wxCoord yoffset = 0,
int fill_style = wxODDEVEN_RULE)

Draws a filled polygon using an array of points of size n, or list of pointers to points, adding the optional offset coordinate.

The last argument specifies the fill rule: wxODDEVEN_RULE (the default) or wxWINDING_RULE.

The current pen is used for drawing the outline, and the current brush for filling the shape. Using a transparent brush suppresses filling. The programmer is responsible for deleting the list of points.

Note that wxWidgets automatically closes the first and last points.

wxPython での注意点: The wxPython version of this method accepts a Python list of wxPoint objects.

wxPerl での注意点: The wxPerl version of this method accepts as its first parameter a reference to an array of wxPoint objects.



wxDC::DrawPolyPolygon



void DrawPolyPolygon(int n, int count[], wxPoint points[], wxCoord xoffset = 0, wxCoord yoffset = 0,
int fill_style = wxODDEVEN_RULE)

Draws two or more filled polygons using an array of points, adding the optional offset coordinates.

Notice that for the platforms providing a native implementation of this function (Windows and PostScript-based wxDC currently), this is more efficient than using DrawPolygon in a loop.

n specifies the number of polygons to draw, the array count of size n specifies the number of points in each of the polygons in the points array.

The last argument specifies the fill rule: wxODDEVEN_RULE (the default) or wxWINDING_RULE.

The current pen is used for drawing the outline, and the current brush for filling the shape. Using a transparent brush suppresses filling.

The polygons maybe disjoint or overlapping. Each polygon specified in a call to DrawPolyPolygon must be closed. Unlike polygons created by the DrawPolygon member function, the polygons created by DrawPolyPolygon are not closed automatically.

wxPython での注意点: Not implemented yet

wxPerl での注意点: Not implemented yet



wxDC::DrawPoint



void DrawPoint(wxCoord x, wxCoord y)

Draws a point using the color of the current pen. Note that the other properties of the pen are not used, such as width etc..



wxDC::DrawRectangle



void DrawRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height)

Draws a rectangle with the given top left corner, and with the given size. The current pen is used for the outline and the current brush for filling the shape.



wxDC::DrawRotatedText



void DrawRotatedText(const wxString& text, wxCoord x, wxCoord y, double angle)

Draws the text rotated by angle degrees.

NB: Under Win9x only TrueType fonts can be drawn by this function. In particular, a font different from wxNORMAL_FONT should be used as the latter is not a TrueType font. wxSWISS_FONT is an example of a font which is.

See also

DrawText



wxDC::DrawRoundedRectangle



void DrawRoundedRectangle(wxCoord x, wxCoord y, wxCoord width, wxCoord height, double radius = 20)

Draws a rectangle with the given top left corner, and with the given size. The corners are quarter-circles using the given radius. The current pen is used for the outline and the current brush for filling the shape.

If radius is positive, the value is assumed to be the radius of the rounded corner. If radius is negative, the absolute value is assumed to be the proportion of the smallest dimension of the rectangle. This means that the corner can be a sensible size relative to the size of the rectangle, and also avoids the strange effects X produces when the corners are too big for the rectangle.



wxDC::DrawSpline



void DrawSpline(int n, wxPoint points[])

Draws a spline between all given control points, using the current pen.



void DrawSpline(wxList * points)

Draws a spline between all given control points, using the current pen. Doesn't delete the wxList and contents.



void DrawSpline(wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2, wxCoord x3, wxCoord y3)

Draws a three-point spline using the current pen.

wxPython での注意点: The wxPython version of this method accepts a Python list of wxPoint objects.

wxPerl での注意点: The wxPerl version of this method accepts a reference to an array of wxPoint objects.



wxDC::DrawText



void DrawText(const wxString& text, wxCoord x, wxCoord y)

Draws a text string at the specified point, using the current text font, and the current text foreground and background colours.

The coordinates refer to the top-left corner of the rectangle bounding the string. See wxDC::GetTextExtent for how to get the dimensions of a text string, which can be used to position the text more precisely.

NB: under wxGTK the current logical function is used by this function but it is ignored by wxMSW. Thus, you should avoid using logical functions with this function in portable programs.



wxDC::EndDoc



void EndDoc(void)

Ends a document (only relevant when outputting to a printer).



wxDC::EndDrawing



void EndDrawing(void)

Allows optimization of drawing code under MS Windows. Enclose drawing primitives between BeginDrawing and EndDrawing calls.



wxDC::EndPage



void EndPage(void)

Ends a document page (only relevant when outputting to a printer).



wxDC::FloodFill



bool FloodFill(wxCoord x, wxCoord y, const wxColour& colour, int style=wxFLOOD_SURFACE)

Flood fills the device context starting from the given point, using the current brush colour, and using a style:

Returns false if the operation failed.

Note: The present implementation for non-Windows platforms may fail to find colour borders if the pixels do not match the colour exactly. However the function will still return true.



wxDC::GetBackground

const wxBrush& GetBackground(void) const

Gets the brush used for painting the background (see wxDC::SetBackground).



wxDC::GetBackgroundMode

int GetBackgroundMode(void) const

Returns the current background mode: wxSOLID or wxTRANSPARENT.

See also

SetBackgroundMode



wxDC::GetBrush

const wxBrush& GetBrush(void) const

Gets the current brush (see wxDC::SetBrush).



wxDC::GetCharHeight



wxCoord GetCharHeight(void)

Gets the character height of the currently set font.



wxDC::GetCharWidth



wxCoord GetCharWidth(void)

Gets the average character width of the currently set font.



wxDC::GetClippingBox



void GetClippingBox(wxCoord *x, wxCoord *y, wxCoord *width, wxCoord *height)

Gets the rectangle surrounding the current clipping region.

wxPython での注意点: No arguments are required and the four values defining the rectangle are returned as a tuple.

wxPerl での注意点: This method takes no arguments and returns a four element list ( x, y, width, height )



wxDC::GetFont

const wxFont& GetFont(void) const

Gets the current font (see wxDC::SetFont).



wxDC::GetLogicalFunction



int GetLogicalFunction(void)

Gets the current logical function (see wxDC::SetLogicalFunction).



wxDC::GetMapMode



int GetMapMode(void)

Gets the mapping mode for the device context (see wxDC::SetMapMode).



wxDC::GetPartialTextExtents

bool GetPartialTextExtents(const wxString& text, wxArrayInt& widths) const

Fills the widths array with the widths from the beginning of text to the corresponding character of text. The generic version simply builds a running total of the widths of each character using GetTextExtent, however if the various platforms have a native API function that is faster or more accurate than the generic implementation then it should be used instead.

wxPython での注意点: This method only takes the text parameter and returns a Python list of integers.



wxDC::GetPen

const wxPen& GetPen(void) const

Gets the current pen (see wxDC::SetPen).



wxDC::GetPixel



bool GetPixel(wxCoord x, wxCoord y, wxColour * colour)

Sets colour to the colour at the specified location. Not available for wxPostScriptDC or wxMetafileDC.

Note that setting a pixel can be done using DrawPoint.

wxPython での注意点: For wxPython the wxColour value is returned and is not required as a parameter.

wxPerl での注意点: This method only takes the parameters x and y and returns a Wx::Colour value



wxDC::GetPPI

wxSize GetPPI(void) const

Returns the resolution of the device in pixels per inch.



wxDC::GetSize

void GetSize(wxCoord * width, wxCoord * height) const

wxSize GetSize(void) const

This gets the horizontal and vertical resolution in device units. It can be used to scale graphics to fit the page. For example, if maxX and maxY represent the maximum horizontal and vertical `pixel' values used in your application, the following code will scale the graphic to fit on the printer page:

  wxCoord w, h;
  dc.GetSize(&w, &h);
  double scaleX=(double)(maxX/w);
  double scaleY=(double)(maxY/h);
  dc.SetUserScale(min(scaleX,scaleY),min(scaleX,scaleY));

wxPython での注意点: In place of a single overloaded method name, wxPython implements the following methods:

2cm
GetSize() Returns a wxSize
GetSizeTuple() Returns a 2-tuple (width, height)

wxPerl での注意点: In place of a single overloaded method, wxPerl uses:

2cm
GetSize() Returns a Wx::Size
GetSizeWH() Returns a 2-element list ( width, height )



wxDC::GetSizeMM

void GetSizeMM(wxCoord * width, wxCoord * height) const

wxSize GetSizeMM(void) const

Returns the horizontal and vertical resolution in millimetres.



wxDC::GetTextBackground

const wxColour& GetTextBackground(void) const

Gets the current text background colour (see wxDC::SetTextBackground).



wxDC::GetTextExtent



void GetTextExtent(const wxString& string, wxCoord * w, wxCoord * h,
wxCoord * descent = NULL, wxCoord * externalLeading = NULL, wxFont * font = NULL)

Gets the dimensions of the string using the currently selected font. string is the text string to measure, w and h are the total width and height respectively, descent is the dimension from the baseline of the font to the bottom of the descender, and externalLeading is any extra vertical space added to the font by the font designer (usually is zero).

The optional parameter font specifies an alternative to the currently selected font: but note that this does not yet work under Windows, so you need to set a font for the device context first.

See also wxFont, wxDC::SetFont.

wxPython での注意点: The following methods are implemented in wxPython:

2cm
GetTextExtent(string) Returns a 2-tuple, (width, height)
GetFullTextExtent(string, font=NULL) Returns a 4-tuple, (width, height, descent, externalLeading)

wxPerl での注意点: In wxPerl this method is implemented as GetTextExtent( string, font = undef ) returning a four element array ( width, height, descent, externalLeading )



wxDC::GetTextForeground

const wxColour& GetTextForeground(void) const

Gets the current text foreground colour (see wxDC::SetTextForeground).



wxDC::GetUserScale



void GetUserScale(double *x, double *y)

Gets the current user scale factor (set by SetUserScale).

wxPerl での注意点: In wxPerl this method takes no arguments and return a two element array ( x, y )



wxDC::LogicalToDeviceX



wxCoord LogicalToDeviceX(wxCoord x)

Converts logical X coordinate to device coordinate, using the current mapping mode.



wxDC::LogicalToDeviceXRel



wxCoord LogicalToDeviceXRel(wxCoord x)

Converts logical X coordinate to relative device coordinate, using the current mapping mode but ignoring the x axis orientation. Use this for converting a width, for example.



wxDC::LogicalToDeviceY



wxCoord LogicalToDeviceY(wxCoord y)

Converts logical Y coordinate to device coordinate, using the current mapping mode.



wxDC::LogicalToDeviceYRel



wxCoord LogicalToDeviceYRel(wxCoord y)

Converts logical Y coordinate to relative device coordinate, using the current mapping mode but ignoring the y axis orientation. Use this for converting a height, for example.



wxDC::MaxX



wxCoord MaxX(void)

Gets the maximum horizontal extent used in drawing commands so far.



wxDC::MaxY



wxCoord MaxY(void)

Gets the maximum vertical extent used in drawing commands so far.



wxDC::MinX



wxCoord MinX(void)

Gets the minimum horizontal extent used in drawing commands so far.



wxDC::MinY



wxCoord MinY(void)

Gets the minimum vertical extent used in drawing commands so far.



wxDC::Ok



bool Ok(void)

Returns true if the DC is ok to use.



wxDC::ResetBoundingBox



void ResetBoundingBox(void)

Resets the bounding box: after a call to this function, the bounding box doesn't contain anything.

See also

CalcBoundingBox



wxDC::SetAxisOrientation



void SetAxisOrientation(bool xLeftRight, bool yBottomUp)

Sets the x and y axis orientation (i.e., the direction from lowest to highest values on the axis). The default orientation is x axis from left to right and y axis from top down.

Parameters

xLeftRight
True to set the x axis orientation to the natural left to right orientation, false to invert it.

yBottomUp
True to set the y axis orientation to the natural bottom up orientation, false to invert it.



wxDC::SetBackground



void SetBackground(const wxBrush& brush)

Sets the current background brush for the DC.



wxDC::SetBackgroundMode



void SetBackgroundMode(int mode)

mode may be one of wxSOLID and wxTRANSPARENT. This setting determines whether text will be drawn with a background colour or not.



wxDC::SetBrush



void SetBrush(const wxBrush& brush)

Sets the current brush for the DC.

If the argument is wxNullBrush, the current brush is selected out of the device context, and the original brush restored, allowing the current brush to be destroyed safely.

See also wxBrush.

See also wxMemoryDC for the interpretation of colours when drawing into a monochrome bitmap.



wxDC::SetClippingRegion



void SetClippingRegion(wxCoord x, wxCoord y, wxCoord width, wxCoord height)



void SetClippingRegion(const wxPoint& pt, const wxSize& sz)



void SetClippingRegion(const wxRect& rect)



void SetClippingRegion(const wxRegion& region)

Sets the clipping region for this device context to the intersection of the given region described by the parameters of this method and the previously set clipping region. You should call DestroyClippingRegion if you want to set the clipping region exactly to the region specified.

The clipping region is an area to which drawing is restricted. Possible uses for the clipping region are for clipping text or for speeding up window redraws when only a known area of the screen is damaged.

See also

wxDC::DestroyClippingRegion, wxRegion



wxDC::SetDeviceOrigin



void SetDeviceOrigin(wxCoord x, wxCoord y)

Sets the device origin (i.e., the origin in pixels after scaling has been applied).

This function may be useful in Windows printing operations for placing a graphic on a page.



wxDC::SetFont



void SetFont(const wxFont& font)

Sets the current font for the DC. It must be a valid font, in particular you should not pass wxNullFont to this method.

See also wxFont.



wxDC::SetLogicalFunction



void SetLogicalFunction(int function)

Sets the current logical function for the device context. This determines how a source pixel (from a pen or brush colour, or source device context if using wxDC::Blit) combines with a destination pixel in the current device context.

The possible values and their meaning in terms of source and destination pixel values are as follows:

wxAND                 src AND dst
wxAND_INVERT          (NOT src) AND dst
wxAND_REVERSE         src AND (NOT dst)
wxCLEAR               0
wxCOPY                src
wxEQUIV               (NOT src) XOR dst
wxINVERT              NOT dst
wxNAND                (NOT src) OR (NOT dst)
wxNOR                 (NOT src) AND (NOT dst)
wxNO_OP               dst
wxOR                  src OR dst
wxOR_INVERT           (NOT src) OR dst
wxOR_REVERSE          src OR (NOT dst)
wxSET                 1
wxSRC_INVERT          NOT src
wxXOR                 src XOR dst

The default is wxCOPY, which simply draws with the current colour. The others combine the current colour and the background using a logical operation. wxINVERT is commonly used for drawing rubber bands or moving outlines, since drawing twice reverts to the original colour.



wxDC::SetMapMode



void SetMapMode(int int)

The mapping mode of the device context defines the unit of measurement used to convert logical units to device units. Note that in X, text drawing isn't handled consistently with the mapping mode; a font is always specified in point size. However, setting the user scale (see wxDC::SetUserScale) scales the text appropriately. In Windows, scalable TrueType fonts are always used; in X, results depend on availability of fonts, but usually a reasonable match is found.

The coordinate origin is always at the top left of the screen/printer.

Drawing to a Windows printer device context uses the current mapping mode, but mapping mode is currently ignored for PostScript output.

The mapping mode can be one of the following:

wxMM_TWIPS Each logical unit is 1/20 of a point, or 1/1440 of an inch.
wxMM_POINTS Each logical unit is a point, or 1/72 of an inch.
wxMM_METRIC Each logical unit is 1 mm.
wxMM_LOMETRIC Each logical unit is 1/10 of a mm.
wxMM_TEXT Each logical unit is 1 pixel.



wxDC::SetPalette



void SetPalette(const wxPalette& palette)

If this is a window DC or memory DC, assigns the given palette to the window or bitmap associated with the DC. If the argument is wxNullPalette, the current palette is selected out of the device context, and the original palette restored.

See wxPalette for further details.



wxDC::SetPen



void SetPen(const wxPen& pen)

Sets the current pen for the DC.

If the argument is wxNullPen, the current pen is selected out of the device context, and the original pen restored.

See also wxMemoryDC for the interpretation of colours when drawing into a monochrome bitmap.



wxDC::SetTextBackground



void SetTextBackground(const wxColour& colour)

Sets the current text background colour for the DC.



wxDC::SetTextForeground



void SetTextForeground(const wxColour& colour)

Sets the current text foreground colour for the DC.

See also wxMemoryDC for the interpretation of colours when drawing into a monochrome bitmap.



wxDC::SetUserScale



void SetUserScale(double xScale, double yScale)

Sets the user scaling factor, useful for applications which require `zooming'.



wxDC::StartDoc



bool StartDoc(const wxString& message)

Starts a document (only relevant when outputting to a printer). Message is a message to show while printing.



wxDC::StartPage



bool StartPage(void)

Starts a document page (only relevant when outputting to a printer).

ymasuda 平成17年11月19日