i'm looking for write a special API to generate PDF, so... i'm using the text atributes/commands to build a pdf document through a simple text file.
I've already downloaded the pdf references manual, but i didn't found what i looking for.
What the standard pdf scale?
I need know the standard pdf scale to measure my line lenght, and change my width of "MediaBox".
The MediaBox, CropBox, BleedBox, TrimBox, and ArtBox are rectangles expressed in default user space units, cf. Table 30 – Entries in a page object in ISO 32000-1.
The size of this unit is defined by another Page dictionary entry (cf. the same table):
UserUnit number (Optional; PDF 1.6) A positive number that shall give the size of default user space units, in multiples of 1 ⁄ 72 inch. The range of supported values shall be implementation-dependent. Default value: 1.0 (user space unit is 1 ⁄ 72 inch).
The UserUnit is only used very rarely. Thus, most of the time the unit you are after is 1/72th inch.
BTW, it is called default user space unit because in a content stream you can constantly change the size of a unit in user space by using appropriate changes of the transformation and/or text matrices; thus, in the context of content streams this 1/72th inch is merely a starting value.