ABCpdf uses the standard Adobe PDF coordinate space. The origin
of this space is often at the bottom left of the document
(depending on MediaBox
and/or CropBox).
Distances are measured up and to the right in points. Points are a
traditional measure for print work - there are 72 points in an
inch.
Please note that the bottom-up PDF coordinate space is
different from the top-down coordinate system often used in
Windows. It means that everything is based around the bottom left
of objects - not the top left. If you wish to use a different
coordinate system, you can use the document Units,
TopDown or
Transform
to accomplish this.
ABCpdf uses the XPoint object to
represent positions in space. It uses the XRect object to
represent areas such as the current drawing area or the size of a
page.
The Doc.Rect
property is probably the most important property to be aware of.
Virtually everything happens within the Doc.Rect. If you add
text to a document, it is added within Doc.Rect. If you paint or
frame a rectangle, it is done within Doc.Rect. If you add an image,
it is scaled to fit exactly within Doc.Rect.
The default document size for ABCpdf is 612 by 792. This equates
to a physical page size of 8.5 by 11 inches.
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