QD Geometry
Given 2 points in global QuickDraw coordinates (originPt, terminalPt), I would
like to draw an arrow. For a simple line, I would do the following:
MoveTo(originPt.h, originPt.v);
LineTo(terminalPt.h, terminalPt.v);
Getting the correct angle in QuickDraw coordinates for the "head" is what I'm
wondering about…
The terminalPt is the origin for the "head", whose angles should be 40 degrees
from the main line; the "length" of the head lines should be about one fifth as
long as the main line. In "ASCII art", the lines would look something like
this:
<—
—>
/\
|
|
|
/\
/
/
/
Horizontal and vertical arrows are not a problem; I'm just wondering what
the best way is to handle drawing when the arrow is not horizontal or
vertical. Do I need to resort to trig. functions, or is there a better way?
Thanks for any help,
Patrick