ExtCreatePen function (wingdi.h)

Article
10/13/2021

The ExtCreatePen function creates a logical cosmetic or geometric pen that has the specified style, width, and brush attributes.

Syntax

HPEN ExtCreatePen(
  [in] DWORD          iPenStyle,
  [in] DWORD          cWidth,
  [in] const LOGBRUSH *plbrush,
  [in] DWORD          cStyle,
  [in] const DWORD    *pstyle
);

Parameters

[in] iPenStyle

A combination of type, style, end cap, and join attributes. The values from each category are combined by using the bitwise OR operator ( | ).

The pen type can be one of the following values.

Value	Meaning
PS_GEOMETRIC	The pen is geometric.
PS_COSMETIC	The pen is cosmetic.

The pen style can be one of the following values.

Value	Meaning
PS_ALTERNATE	The pen sets every other pixel. (This style is applicable only for cosmetic pens.)
PS_SOLID	The pen is solid.
PS_DASH	The pen is dashed.
PS_DOT	The pen is dotted.
PS_DASHDOT	The pen has alternating dashes and dots.
PS_DASHDOTDOT	The pen has alternating dashes and double dots.
PS_NULL	The pen is invisible.
PS_USERSTYLE	The pen uses a styling array supplied by the user.
PS_INSIDEFRAME	The pen is solid. When this pen is used in any GDI drawing function that takes a bounding rectangle, the dimensions of the figure are shrunk so that it fits entirely in the bounding rectangle, taking into account the width of the pen. This applies only to geometric pens.

The end cap is only specified for geometric pens. The end cap can be one of the following values.

Value	Meaning
PS_ENDCAP_ROUND	End caps are round.
PS_ENDCAP_SQUARE	End caps are square.
PS_ENDCAP_FLAT	End caps are flat.

The join is only specified for geometric pens. The join can be one of the following values.

Value	Meaning
PS_JOIN_BEVEL	Joins are beveled.
PS_JOIN_MITER	Joins are mitered when they are within the current limit set by the SetMiterLimit function. If it exceeds this limit, the join is beveled.
PS_JOIN_ROUND	Joins are round.

[in] cWidth

The width of the pen. If the dwPenStyle parameter is PS_GEOMETRIC, the width is given in logical units. If dwPenStyle is PS_COSMETIC, the width must be set to 1.

[in] plbrush

A pointer to a LOGBRUSH structure. If dwPenStyle is PS_COSMETIC, the lbColor member specifies the color of the pen and the lpStyle member must be set to BS_SOLID. If dwPenStyle is PS_GEOMETRIC, all members must be used to specify the brush attributes of the pen.

[in] cStyle

The length, in DWORD units, of the lpStyle array. This value must be zero if dwPenStyle is not PS_USERSTYLE.

The style count is limited to 16.

[in] pstyle

A pointer to an array. The first value specifies the length of the first dash in a user-defined style, the second value specifies the length of the first space, and so on. This pointer must be NULL if dwPenStyle is not PS_USERSTYLE.

If the lpStyle array is exceeded during line drawing, the pointer is reset to the beginning of the array. When this happens and dwStyleCount is an even number, the pattern of dashes and spaces repeats. However, if dwStyleCount is odd, the pattern reverses when the pointer is reset -- the first element of lpStyle now refers to spaces, the second refers to dashes, and so forth.

Return value

If the function succeeds, the return value is a handle that identifies a logical pen.

If the function fails, the return value is zero.

Remarks

A geometric pen can have any width and can have any of the attributes of a brush, such as dithers and patterns. A cosmetic pen can only be a single pixel wide and must be a solid color, but cosmetic pens are generally faster than geometric pens.

The width of a geometric pen is always specified in world units. The width of a cosmetic pen is always 1.

End caps and joins are only specified for geometric pens.

After an application creates a logical pen, it can select that pen into a device context by calling the SelectObject function. After a pen is selected into a device context, it can be used to draw lines and curves.

If dwPenStyle is PS_COSMETIC and PS_USERSTYLE, the entries in the lpStyle array specify lengths of dashes and spaces in style units. A style unit is defined by the device where the pen is used to draw a line.

If dwPenStyle is PS_GEOMETRIC and PS_USERSTYLE, the entries in the lpStyle array specify lengths of dashes and spaces in logical units.

If dwPenStyle is PS_ALTERNATE, the style unit is ignored and every other pixel is set.

If the lbStyle member of the LOGBRUSH structure pointed to by lplb is BS_PATTERN, the bitmap pointed to by the lbHatch member of that structure cannot be a DIB section. A DIB section is a bitmap created by CreateDIBSection. If that bitmap is a DIB section, the ExtCreatePen function fails.

When an application no longer requires a specified pen, it should call the DeleteObject function to delete the pen.

ICM: No color management is done at pen creation. However, color management is performed when the pen is selected into an ICM-enabled device context.

Examples

For an example, see Using Pens.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	wingdi.h (include Windows.h)
Library	Gdi32.lib
DLL	Gdi32.dll

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