angleLessThanThreshold.cs

/*
MIT License

Copyright (c) 2020 billy brickner

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*/


// A function to determine if the distance between two angles is less than a threshold. 
// Choosing a threshold of 1 will return True for all angles. Choosing threshold of 0 will only return True for an exact match. 
//
// Note: These are floating point operations. Choosing a threshold of 0 is not a good idea because of rounding errors. 
// Instead try a value close to 0.
//
// Author : Billy Brickner
// 
// param[in] angle1 : Angle in radians
// param[in] angle2 : Angle in radians
// param[in] threshold : A float from 0-1. 0 Being an exact match, 1 accepts all angles.
//
// return True if the difference between the angles is less than a threshold. 
bool angle_less_than_threshold(float angle1, float angle2, float threshold){
    # This uses the sin function to evaluate the difference of angles.
    # By having a frequency of 500 milihertz the modified sine function repeats every 2pi radians
    # Sine is also fairly linear when angle differences are close to 0
    float angleDistance = abs(sin((angle1 - angle2)/2));
    return angleDistance < threshold;
}