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/*! \class vector3 |
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\brief Represents a vector in the 3-dimensional real space. |
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The vector3 class was designed to simplify operations with doubleing |
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The vector3 class was designed to simplify operations with floating |
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point coordinates. To this end many of the common operations have been |
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overloaded for simplicity. Vector addition, subtraction, scalar |
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multiplication, dot product, cross product, magnitude and a number of |
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\warning If length() is very close to zero, but not == 0.0, |
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this method may behave in unexpected ways and return almost |
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random results; details may depend on your particular doubleing |
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random results; details may depend on your particular floating |
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point implementation. The use of this method is therefore |
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highly discouraged, unless you are certain that length() is in |
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a reasonable range, away from 0.0 (Stefan Kebekus) |
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length() of the two vectors is very close to 0.0, but not == |
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0.0, this method may behave in unexpected ways and return |
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almost random results; details may depend on your particular |
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doubleing point implementation. The use of this method is |
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floating point implementation. The use of this method is |
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therefore highly discouraged, unless you are certain that the |
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length()es are in a reasonable range, away from 0.0 (Stefan |
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Kebekus) |
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return((RAD_TO_DEG * acos(dp))); |
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} |
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/*! This function calculates the torsion angle of three vectors, represented |
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by four points A--B--C--D, i.e. B and C are vertexes, but none of A--B, |
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B--C, and C--D are colinear. A "torsion angle" is the amount of "twist" |
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or torsion needed around the B--C axis to bring A--B into the same plane |
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as B--C--D. The torsion is measured by "looking down" the vector B--C so |
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that B is superimposed on C, then noting how far you'd have to rotate |
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A--B to superimpose A over D. Angles are + in the anticlockwise |
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direction. The operation is symmetrical in that if you reverse the image |
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(look from C to B and rotate D over A), you get the same answer. |
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*/ |
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OBAPI double CalcTorsionAngle(const vector3 &a, const vector3 &b, |
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const vector3 &c, const vector3 &d) |
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{ |
