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Topic: Text Width Calculation Confusion
Conf: (P-PDF) Engineering, Msg: 147960
From: ved_jai
Date: 3/23/2006 04:19 PM

Hello people

I have already posted a similar question but I am very confused in this
matter. So I am seeking help again from the experts to guide me
through the math.

I would like to know about the math involved for calculation of the width
of a complete text run which includes calculation using Tc, Tw, TD, Td,
Tm, along with individual character widths.

When I am doing the calculation of width of a text run, I find the width of
each character (given by the /Widths or /W array) and add them up
properly to find out the width.
(formula used : width of each char * current_fontsize / 1000)

Then I use this summed up width and add it simply to the Value of Tc
and length of the text run i.e.
Width += Tc*length_of_text_run.

Next I add the word spacing if present i.e.
Width += Tw*number_of_words

I would like to know if Tc and Tw calculation is correct or the
multiplication should be wrt Tm, i.e.
Width += Tm.a * Tc * length_of_text_run
and
Width += Tm.a * Tw * number_of_words

Also when we get TD, I find the new x and y location by the formula -
new_x = (Tm.a * TD.x) + (Tm.c * TD.y) + Tm.e and then assign this
same value to Tm.e
new_y = (Tm.b * TD.x) + (Tm.d * TD.y) + Tm.f and then assign this
same value to Tm.f

Please let me know if this calculation is also correct or not ?

Please help me with this regards.

Thanks
Jai Praful Ved