Bounding Box of an Arc

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Article #153

#153

From: Brad Myers
Date: Thu, 02 Dec 1993 15:51

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Can someone send me the formula for computing the bounding box that just
fits around an arc of a circle?  For example, for:

		   / \ C
		  /  /
	       A / / B
		// 
	     P ._______________ Horiz

(Line C is actually rounded (part of a circle centered at P)).  A and B are
both of length R (radius of the circle).  The arc is defined by P,
ANGLE1 which is from Horiz to B, and ANGLE2 which goes from B to A.
Note that the arc is not necessarily in the first quadrant (ANGLE1 can be up
to 360), and ANGLE2 can also be between 0 and 360.

What makes this harder is that for some orientations of the arc, the circular
part of C extends beyond the ends of B and A in either X or Y, so the
bounding box of the lines A and B often do not include all of the arc C.

Thanks!
Brad Myers

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From: bam+@BAM.GARNET.CS.CMU.EDU (Brad Myers)
Subject: Bounding Box of an Arc
Message-ID: <CHF02C.7C5.1@cs.cmu.edu>
Originator: bam@BAM.GARNET.CS.CMU.EDU
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Organization: School of Computer Science, Carnegie Mellon
Date: Thu, 2 Dec 1993 10:51:44 -0500
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