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#1 |
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Funkalicious
Join Date: Nov 2006
Location: Nijmegen, Netherlands
Posts: 599
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intersection points of line on a circle
Hi all,
I have a bit of an algebraic problem, and my lack of attention during math is starting to show. I was experimenting with hit detection based on lines for a simple shooting game, and the enemies bieng circulair. I already have a function to check the distance from the line to the circles centre, so I already know that there is a intersection (or hit). I also would like to know where it intersects, for graphics and some extra physics. So here's what I got: Known: r m b so these can be considered constant Equitions so far y = mx+b r^2 = y^2 + x^2 this gives: r^2 = (mx+b)^2 + x^2 And then my troubles begin, because writing that out would give: r^2 + b^2 = x^2 + mx^2 + 2mbx Googling around tells me that this is the way to go, and you should get a quadratic function, but I don't know how to solve this kind of equation. Can anybody help out? I hope to finish a prototype soon. Tnx in advance, TO Last edited by TOdorus; 06-26-2007 at 08:49 PM. |
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#2 | |
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Member
Join Date: Jun 2007
Posts: 36
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Quote:
Like so, r^2 = x^2 + mx^2 + 2mbx+ b^2 or alternatively, r^2 - b^2 = x^2 + mx^2 + 2mbx |
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#3 |
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Funkalicious
Join Date: Nov 2006
Location: Nijmegen, Netherlands
Posts: 599
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I noticed that too, this morning. I geuss it was kinda getting late.
I wanted it on the left side to have my known variables on one side. |
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#4 |
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Member
Join Date: Jun 2007
Posts: 36
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and did you get that equation solved? or do you still need some help with it?
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#5 |
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Funkalicious
Join Date: Nov 2006
Location: Nijmegen, Netherlands
Posts: 599
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I think so, but I haven't tried it yet. It's in another forum:
http://www.physicsforums.com/showthr...53#post1365553 |
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