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Pathfinder optimization, fixes #3541.

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Simplify the math of Geometry::TestRayAASquare.

This was SVN commit r17500.
This commit is contained in:
elexis 2015-12-18 15:05:33 +00:00
parent 659606b83e
commit abce6cb737
1 changed files with 8 additions and 20 deletions
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28
source/simulation2/helpers/Geometry.cpp
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@ -239,38 +239,26 @@ bool Geometry::TestRaySquare(const CFixedVector2D& a, const CFixedVector2D& b, c
return false;
}
// Exactly like TestRaySquare with u=(1,0), v=(0,1)
bool Geometry::TestRayAASquare(const CFixedVector2D& a, const CFixedVector2D& b, const CFixedVector2D& halfSize)
{
// Exactly like TestRaySquare with u=(1,0), v=(0,1)
// Assume the compiler is clever enough to inline and simplify all this
// (TODO: stop assuming that)
CFixedVector2D u (fixed::FromInt(1), fixed::Zero());
CFixedVector2D v (fixed::Zero(), fixed::FromInt(1));
fixed hw = halfSize.X;
fixed hh = halfSize.Y;
fixed au = a.Dot(u);
fixed av = a.Dot(v);
if (-hw <= au && au <= hw && -hh <= av && av <= hh)
if (-hw <= a.X && a.X <= hw && -hh <= a.Y && a.Y <= hh)
return false; // a is inside
fixed bu = b.Dot(u);
fixed bv = b.Dot(v);
if (-hw <= bu && bu <= hw && -hh <= bv && bv <= hh) // TODO: isn't this subsumed by the next checks?
if (-hw <= b.X && b.X <= hw && -hh <= b.Y && b.Y <= hh) // TODO: isn't this subsumed by the next checks?
return true; // a is outside, b is inside
if ((au < -hw && bu < -hw) || (au > hw && bu > hw) || (av < -hh && bv < -hh) || (av > hh && bv > hh))
if ((a.X < -hw && b.X < -hw) || (a.X > hw && b.X > hw) || (a.Y < -hh && b.Y < -hh) || (a.Y > hh && b.Y > hh))
return false; // ab is entirely above/below/side the square
CFixedVector2D abp = (b - a).Perpendicular();
fixed s0 = abp.Dot((u.Multiply(hw) + v.Multiply(hh)) - a);
fixed s1 = abp.Dot((u.Multiply(hw) - v.Multiply(hh)) - a);
fixed s2 = abp.Dot((-u.Multiply(hw) - v.Multiply(hh)) - a);
fixed s3 = abp.Dot((-u.Multiply(hw) + v.Multiply(hh)) - a);
fixed s0 = abp.Dot(CFixedVector2D(hw, hh) - a);
fixed s1 = abp.Dot(CFixedVector2D(hw, -hh) - a);
fixed s2 = abp.Dot(CFixedVector2D(-hw, -hh) - a);
fixed s3 = abp.Dot(CFixedVector2D(-hw, hh) - a);
if (s0.IsZero() || s1.IsZero() || s2.IsZero() || s3.IsZero())
return true; // ray intersects the corner