mymath.h

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#pragma once
 
#include <InterViews/geometry.h>
 
class Extension;
 
class MyMath {
  public:
    // increase all around in screen coords
    static void extend(Extension&, Coord);
    static void extend(Extension&, const Extension&);
 
    static void minmax(Coord& min, Coord& max);
    static bool inside(Coord x, Coord min, Coord max);
 
    static float min(int count, const float*);
    static float max(int count, const float*);
 
    static bool inside(Coord x, Coord y, Coord left, Coord bottom, Coord right, Coord top);
 
    // within epsilon distance from the infinite line
    static bool near_line(Coord x, Coord y, Coord x1, Coord y1, Coord x2, Coord y2, float epsilon);
 
    // within epsilon distance from the line segment
    static bool
    near_line_segment(Coord x, Coord y, Coord x1, Coord y1, Coord x2, Coord y2, float epsilon);
 
    // returns distance between point and line segment
    static float distance_to_line_segment(Coord x, Coord y, Coord x1, Coord y1, Coord x2, Coord y2);
 
    // returns distance between point and line
    static float distance_to_line(Coord x, Coord y, Coord x1, Coord y1, Coord x2, Coord y2);
 
 
    // returns square norm
    static float norm2(Coord x, Coord y) {
        return x * x + y * y;
    }
 
    // unit length vector perpindicular to vector (x, y)
    static bool unit_normal(Coord x, Coord y, Coord* perp);
 
    // returns range extended to nearest 1.5 digit accuracy.
    // ie. digit is 1, 2, or 5
    static void round_range(Coord x1, Coord x2, double& y1, double& y2, int& ntic);
    static void round_range_down(Coord x1, Coord x2, double& y1, double& y2, int& ntic);
 
    enum { Expand, Contract, Higher, Lower };
    static double round(float& x1, float& x2, int direction, int digits);
 
    static void box(Requisition&, Coord& x1, Coord& y1, Coord& x2, Coord& y2);
 
    static double anint(double);       /* round toward nearest integer */
    static double resolution(double);  // 100, 10, .1,... least significant digit
 
    static bool lt(double x, double y, double e) {
        return x < (y - e);
    }
    static bool le(double x, double y, double e) {
        return x <= (y + e);
    }
    template <typename T>
    static bool eq(T x, T y, T e) {
        return x - y < e && y - x < e;
    }
    static bool eq2(double x, double y, double e) {
        return x - y <= e && y - x <= e;
    }
};
 
inline void MyMath::extend(Extension& e, const Extension& x) {
    e.set_xy(nullptr,
             e.left() + x.left(),
             e.bottom() + x.bottom(),
             e.right() + x.right(),
             e.top() + x.top());
}
 
inline void MyMath::extend(Extension& e, Coord x) {
    e.set_xy(nullptr, e.left() - x, e.bottom() - x, e.right() + x, e.top() + x);
}
 
inline void MyMath::minmax(Coord& x, Coord& y) {
    if (y < x) {
        Coord z = x;
        x = y;
        y = z;
    }
}
 
inline bool MyMath::inside(Coord x, Coord x1, Coord x2) {
    return (x >= x1 && x <= x2);
}
 
inline bool MyMath::inside(Coord x, Coord y, Coord x1, Coord y1, Coord x2, Coord y2) {
    return inside(x, x1, x2) && inside(y, y1, y2);
}