This is purely from my head and so may be very wrong but seems correct.
Anyway, assuming that by center, you mean the centre of the ellipse / arc id do the following (sorry no code) I'd calculate the Tangent Vector at the Start and End Points and then interpolate a set of direction vectors between the two tangents, then scale the direction vectors and apply to the start point as a set of movements. No trig required, I believe. TTFN,Struan, From: delphi-boun...@delphi.org.nz [mailto:delphi-boun...@delphi.org.nz] On Behalf Of Marshland Engineering Sent: Tuesday, 18 January 2011 21:03 To: delphi@delphi.org.nz Subject: [DUG] Arc's Is there an easy way of drawing an arc ? I have center, start and end co-ordinates as XY. >From what I can see, I need to look at least 16 combinations to work out the perimeter size depending in which quadrant the start and ends are in. procedure Arc(X1, Y1, X2, Y2, X3, Y3, X4, Y4: Integer); Use Arc to draw an elliptically curved line with the current Pen. The arc traverses the perimeter of an ellipse that is bounded by the points (X1,Y1) and (X2,Y2). The arc is drawn following the perimeter of the ellipse, counterclockwise, from the starting point to the ending point. The starting point is defined by the intersection of the ellipse and a line defined by the center of the ellipse and (X3,Y3). The ending point is defined by the intersection of the ellipse and a line defined by the center of the ellipse and (X4, Y4). DISCLAIMER: This electronic message together with any attachments is confidential. If you are not the intended recipient, do not copy, disclose or use the contents in any way. Please also advise us by return e-mail that you have received the message in error and then please destroy it together with its attachments. Carter Holt Harvey is not responsible for any changes made to this message and / or any attachments after sending by Carter Holt Harvey. We use virus scanning software but exclude all liability for viruses or anything similar in this email or any attachment.
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