Precision (accuracy)

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   I've just started playing around with the library (DLL) and simply added one word 10 mm from the top edge and 10mm from the left edge. To my surprise it ended up only ~7 mm down.. - Why would that be?
I've been looking high and low for an obvious explanation (setting/margin or something), but didn't find any yet. SetPrecision don't make any difference, and I've yet to see another possibly relevant function to try..

Edited by Autodidact

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Autodidact Members Profile Find Members Posts Team Player Joined: 03 Feb 06 Status: Offline Points: 21	Post Options Post Reply Quote Autodidact Report Post Thanks(0) Quote Reply Topic: Precision (accuracy) Posted: 03 Feb 06 at 7:15PM
	I've just started playing around with the library (DLL) and simply added one word 10 mm from the top edge and 10mm from the left edge. To my surprise it ended up only ~7 mm down.. - Why would that be? I've been looking high and low for an obvious explanation (setting/margin or something), but didn't find any yet. SetPrecision don't make any difference, and I've yet to see another possibly relevant function to try.. Edited by Autodidact

DELBEKE Members Profile Find Members Posts Debenu Quick PDF Library Expert Joined: 31 Oct 05 Location: France Status: Offline Points: 151	Post Options Post Reply Quote DELBEKE Report Post Thanks(0) Quote Reply Posted: 04 Feb 06 at 12:31AM
	Not sure of that, but perhaps the mesurements are for the base line of the text. Try with differents font size

Autodidact Members Profile Find Members Posts Team Player Joined: 03 Feb 06 Status: Offline Points: 21	Post Options Post Reply Quote Autodidact Report Post Thanks(0) Quote Reply Posted: 04 Feb 06 at 4:44AM
	Indeed it is.. And it's actually stated so in the parameter description ("in tiny writing" ;). How could I miss that. By trying another font (and smaller size) it shows clearly that it is the baseline point that ends up at 10 mm since the top of the word "changes location". Thank you very much for your suggestion!

Autodidact Members Profile Find Members Posts Team Player Joined: 03 Feb 06 Status: Offline Points: 21	Post Options Post Reply Quote Autodidact Report Post Thanks(0) Quote Reply Posted: 04 Feb 06 at 8:08AM
	Doing some homework, and posting it for the sake of easy learning for others; The [DrawText] Y-position refers to the baseline of the text. The baseline is the imaginary line upon which a line of text rests. It is also the point from which other elements of type are measured including x-height and leading. To reference the top-left location of the word (font), one can use the following two ways: Find the difference between [GetTextHeight] and [GetTextBound] (top) and then substract the difference from the returned [GetTextBound] value and use it for positioning. Or.. the easier and probably (slightly) more accurate(?) way: Use [GetTextAscent] to retrieve the height from the baseline to the top, not counting in any accents, and applying it to the measure; Ypos + Ascent value. Edited by Autodidact