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Subject: [boost] CGL Questions
From: Peter Schregle (p.schregle_at_[hidden])
Date: 2009-11-12 10:16:41

We are thinking about replacing our geometric algorithms with the ones from

We would want to somehow adapt our own geometric primitives so that GGL can
work with them, and with points, line segments and polygons this works
rather nicely.

However, we also have a few other concepts, where we have not found a simple
way to adapt them to GGL.

1) Line
We consider a line being an infinite line in the mathematical sense, i.e. it
does not have endpoints but extends into infinity on both sides. We want to
be able to calculate the distance between such a line and a point, or the
point of intersection ot two lines if it exists.

2) Ray
We consider a ray being a line with one endpoint or origin, and extending
into infinity. Here also we want to be able to calculate the distance
between a ray and a point, or between two rays, or points of intersections

3) Direction
In order to implement a line and a ray as descibed above, we have introduced
the concept of direction (which is basically the same as a direction unit
vector, or an equivalent angle). Is there a concept like this in GGL? How
could we calculate the angle of a line segment in GGL?

Best regards

PS: By the way: I find the acronym GGL unfortunate. For me it feels a bit
awkward, and I was typing it wrong all the time while preparing this text.
Everytime I use it I'm forced to think hard about what it means, in order to
get it right. I would prefer a more descriptive name like geometry or
geolib, or something else that can be memorized better.

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