sqribe/math.go at master · sqweek/sqribe · GitHub

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package main

import (
	"math"
	"math/big"

	"github.com/sqweek/sqribe/score"
)

var rZero big.Rat

func ratb(beat int, offset *big.Rat) *big.Rat {
	r := big.NewRat(int64(beat), 1)
	r.Add(r, offset)
	return r
}

func Δb(beat1 *score.BeatRef, offset1 *big.Rat, beat2 *score.BeatRef, offset2 *big.Rat) *big.Rat {
	db := beat1.Subtract(beat2)
	t := ratb(db, offset1)
	t.Sub(t, ratb(0, offset2))
	return t
}

func mod(n, d int) int {
	r := n % d
	if r < 0 {
		return d + r
	}
	return r
}

func ceil(n, d int) int {
	q, r := n / d, n % d
	if r == 0 {
		return q
	} else if n < 0 {
		return q
	}
	return q + 1
}

/* divides n by d, rounding away from zero. assumes d is positive */
func divØ(n, d int) int {
	q, r := n / d, n % d
	if r == 0 {
		return q
	} else if n < 0 {
		return q - 1
	}
	return q + 1
}

func slog(s int16) float64 {
	return float64(s)
	if s == 0 {
		return 0.0
	} else if s < 0 {
		return -math.Log(float64(-s))
	} else {
		return math.Log(float64(s))
	}
}

func snapto(x, origin, step int) int {
	d := x - origin
	var sgn int
	if (d < 0) {
		sgn = -1
	} else {
		sgn = 1
	}
	rem := (sgn * d) % step
	if rem < step/2 {
		return x - sgn * rem
	}
	return x + sgn * (step - rem)
}

// returns squared distance between two points
func sqdist(x1, y1, x2, y2 int) int {
	dx, dy := x2 - x1, y2 - y1
	return dx*dx + dy*dy
}