DynaPDF Manual - Page 215

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Function Reference
Page 215 of 777
The sequential flow of an article is defined by an article thread; the individual content items that
make up the article are called beads on the thread. PDF viewer applications such as Adobe’s Acrobat
provide navigation facilities to allow the user to follow a thread from one bead to the next.
Due to a bug in Acrobat 6 articles can cause a zoom out. The pages of a document appear then as
small thumb nails. It is highly recommended to test your articles with Acrobat 6.
This function is implemented in an Ansi and Unicode compatible version. The Ansi Version
supports Ansi strings of the code page 1252 only. To create an article thread in an arbitrary encoding
convert the string to Unicode with the function ConvToIncode() first and use the Unicode version to
create the article thread.
Return values:
If the function succeeds the return value is the handle of the article thread, a value greater or equal
zero. If the function fails the return value is a negative error code.
SI32 pdfCreateAxialShading(
const PPDF* IPDF, // Instance pointer
double sX,
// X-Coordinate of the start point
double sY,
// Y-Coordinate of the start point
double eX,
// X-Coordinate of the end point
double eY,
// Y-Coordinate of the end point
double SCenter,
// Shading center
UI32 SColor,
// Start color
UI32 EColor,
// End color
LBOOL Extend1,
// Extend the shading beyond the start point
LBOOL Extend2)
// Extend the shading beyond the end point
Axial shadings define a color blend or gradient that varies along a linear axis between two endpoints
and extends indefinitely perpendicular to that axis. The shading may optionally be extended beyond
either or both endpoints by continuing the boundary colors indefinitely.
The shading center defines the point from where the first color will blend into the other. A value of 1
determines the exact center between the starting and ending point of the shading. Smaller values
shift the shading center in direction to the start point, greater values in the direction to the end point.
Axial shadings can be drawn into a clipping path to restrict painting into this path. If the shading is
drawn outside of a clipping path it is applied to the entire page. Not that extended shadings are
opaque, objects behind the shading becomes invisible if they are overprinted by the shading.
Shadings are drawn by using the current coordinate system. It is recommended to understand that
shadings have its own dimension like a normal shape. The parameters Extend1 and Extend2 extend
the shading beyond its dimension. If the shading is extended it must normally be drawn into a
clipping path to avoid overprinting of other objects.

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