/// <summary>
/// Orders an array of three ResultPoints in an order [A,B,C] such that AB < AC and
/// BC < AC and the angle between BC and BA is less than 180 degrees.
/// </summary>
public static void orderBestPatterns(ResultPoint[] patterns)
{
// Find distances between pattern centers
float zeroOneDistance = distance(patterns[0], patterns[1]);
float oneTwoDistance = distance(patterns[1], patterns[2]);
float zeroTwoDistance = distance(patterns[0], patterns[2]);
ResultPoint pointA, pointB, pointC;
// Assume one closest to other two is B; A and C will just be guesses at first
if (oneTwoDistance >= zeroOneDistance && oneTwoDistance >= zeroTwoDistance)
{
pointB = patterns[0];
pointA = patterns[1];
pointC = patterns[2];
}
else if (zeroTwoDistance >= oneTwoDistance && zeroTwoDistance >= zeroOneDistance)
{
pointB = patterns[1];
pointA = patterns[0];
pointC = patterns[2];
}
else
{
pointB = patterns[2];
pointA = patterns[0];
pointC = patterns[1];
}
// Use cross product to figure out whether A and C are correct or flipped.
// This asks whether BC x BA has a positive z component, which is the arrangement
// we want for A, B, C. If it's negative, then we've got it flipped around and
// should swap A and C.
if (crossProductZ(pointA, pointB, pointC) < 0.0f)
{
ResultPoint temp = pointA;
pointA = pointC;
pointC = temp;
}
patterns[0] = pointA;
patterns[1] = pointB;
patterns[2] = pointC;
}
/// <returns>
/// distance between two points
/// </returns>
public static float distance(ResultPoint pattern1, ResultPoint pattern2)
{
return(MathUtils.distance(pattern1.x, pattern1.y, pattern2.x, pattern2.y));
}