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Re: [ft] Font units to pixels in line height
From: |
Werner LEMBERG |
Subject: |
Re: [ft] Font units to pixels in line height |
Date: |
Sat, 31 Dec 2016 15:37:46 +0100 (CET) |
> I want to convert the "height" value from FT_FaceRec to pixels. IIUC
> this can be done like this:
>
> double lineHeight =
> (double) FT_MulFix(face->height,
> face->size->metrics.y_scale) / (double) 64;
>
> Is that right?
Yes.
> Since the value will typically be a fractional value I was also
> wondering whether I should apply any rounding using floor() or
> ceil() here. For example, when opening Arial in 28pt, the above
> formula yields 32.203125 pixels. So should I use 32 pixels or 33
> pixels as the line height in this case?
I suggest simple rounding; the above then changes to
double lineHeight =
(double) (FT_MulFix(face->height,
face->size->metrics.y_scale) +32)
/ (double) 64;
Werner