PDFlib Text Extraction Toolkit (TET) Manual

Glyph calculations for vertical writing mode.
the end point calculation works as follows:
For CJK text with vertical writing mode
x end = x
y end = y - fontsize
The upper left and lower right corners of the glyph box can be calculated as follows (for
beta=0):
ulx = x - width/2 * cos(alpha)
uly = y - width/2 * sin(alpha)
lrx = ulx + width * cos(alpha) + dir * fontsize * sin(alpha)
lry = uly + width * sin(alpha) - dir * fontsize * cos(alpha)
with dir=1 in the default case topdown={output=false} and dir=-1 if topdown={output=
true} (see »Top-down coordinate system«, page 73).
78 Chapter 6: Text Extraction