DynaPDF Manual - Page 750

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Function Reference
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SetMiterLimit
Syntax:
SI32 pdfSetMiterLimit(
const PPDF* IPDF, // Instance pointer
double Value)
// New miter limit
When two line segments meet at a sharp angle and mitered joins have been specified as the line join
style (see SetLineJoinStyle()), it is possible for the miter to extend far beyond the thickness of the line
stroking the path. The miter limit imposes a maximum on the ratio of the miter length to the line
width (see Figure below). When the limit is exceeded, the join is converted from a miter to a bevel.
The ratio of miter length to line width is directly related to the angle φ between the segments in user
space by the formula:
miterLength
1
=
lineWidth
sin(ϕ/2)
For example, a miter limit of 1.414 convert miters to bevels for φ less than 90 degrees, a limit of 2.0
converts them for φ less than 60 degrees, and a limit of 10.0 converts them for φ less than
approximately 11.5 degrees.
Default value = 10.0
Return values:
If the function succeeds the return value is 1. If the function fails the return value is 0.
SetNeedAppearance
Syntax:
LBOOL pdfSetNeedAppearance(
const PPDF* IPDF, // Instance pointer
LBOOL Value)
// Value -> true or false
The global NeedAppearance flag of an Interactive Form specifies whether a PDF viewer should
rebuild the field appearances when opening the file or whether the existing definitions should be
used. DynaPDF creates always appearance streams for all field types. However, in certain cases it
can be useful to let the viewer render fields with their own algorithms because the exact way how
Adobe’s Acrobat builds the field appearances is not documented.
For example, when editing the contents of a text field in Adobe’s Acrobat the viewer rebuilds first
the field appearance before placing the editing cursor into the field. The new appearance created
from Adobe’s Acrobat can be slightly different in comparison to the one that was created by
DynaPDF. The visible contents, especially of text fields, is sometimes not absolutely stable.
 

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