Message: 10 Date: Sat, 24 Jan 2004 13:26:05 -0800 From: Richard Gaskin <[EMAIL PROTECTED]> Subject: geometry-challenged To: Rev Discussion List <[EMAIL PROTECTED]> Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="US-ASCII"
It seems I'm geometry-challenged today -- I know this should be simple, but I'm stumped:
I can draw a line object from the loc of one object to the loc of another. But if I want to draw only in the space _between_ objects rather than intersect them, how do I get the points for the location where a line object would meet the edge of the other objects if drawn all the way to their centers, as indicated by the "X"s below:
----------------- | | | button1 | | \ | ----------X------ \ \ ------X---------- | \ | | button2 | | | -----------------
Hint: the diagram above with drawn with a tool I'm working on to make ASCII diagrams for email. If we solve this I'll finish it next week and put it in RevNet.
-- Richard Gaskin Fourth World Media Corporation
Richard,
I'm not sure if this helps, but the function "intersection" below will return the intersection of any two lines. The first line is defined by its end points p1 and p2; the second line is defined by its two endpoints pp1, and pp1 (not the best notation.)
It is part of my Turtle Geometry tools. (Shameless plug: Indispensable tools for doing heavy graphics. From what I understand from Ro at the Developers' conference, Turtle Graphics may be incorporated in future editions of RR. This intersection function is not a traditional component of TG--so it may be included and it may not. In any event, it stands on its own.)
function intersection p1,p2,pp1,pp2
put item 1 of p1 into x1
put item 2 of p1 into y1
put item 1 of p2 into x2
put item 2 of p2 into y2
put item 1 of pp1 into xp1
put item 2 of pp1 into yp1
put item 1 of pp2 into xp2
put item 2 of pp2 into yp2
if x1 = x2 or xp1 = xp2 then
if x1 = x2 then
return x1&comma&yp2 + (x1-xp2)*(yp2-yp1)/(xp2-xp1)
else
return xp2&comma& y2 + (xp1-x2)*(y2-y1)/(x2-x1)
end if
end if
put yp2 - y2 + x2*(y2-y1)/(x2 - x1) - xp2*(yp2 - yp1)/(xp2 - xp1) into numerator
put ((y2 - y1)/(x2 - x1) -(yp2 - yp1)/(xp2-xp1)) into denom
put numerator / denom into x
put y2 + (x-x2) *(y2-y1)/(x2-x1) into y
return x & comma & y
end intersection
Jim _______________________________________________ use-revolution mailing list [EMAIL PROTECTED] http://lists.runrev.com/mailman/listinfo/use-revolution
