50 lines
1.2 KiB
Go
50 lines
1.2 KiB
Go
package koboldsim
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import (
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"math"
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"golang.org/x/exp/constraints"
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)
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// Generic helper functions not directly attached to Card Sim Engine mechanics.
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// Mean calculates the mathematical mean of its arguments (the sum, divided
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// by the number of elements). If it is called with no arguments, it returns
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// NaN ("not a number"). If there are contradictory infinities among the
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// arguments, it also returns NaN. Overflowing or underflowing can create an
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// infinity.
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func Mean(vals ...float64) float64 {
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if len(vals) == 0 {
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return math.NaN()
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}
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total := 0.0
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for _, x := range vals {
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total += x
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}
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return total / float64(len(vals))
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}
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// clamp returns the middle of the three provided values. It doesn't
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// matter which order the values are in. This function is known as `mid` in
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// Pico-8's library, among others. It is usually used to clamp a value to a
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// range, and it doesn't care which order the range is written in.
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func clamp[T constraints.Ordered](a, b, c T) T {
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if a <= b && a <= c {
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// `a` is least; mid is lower of `b` or `c`
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if b <= c {
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return b
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}
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return c
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}
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if a >= b && a >= c {
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// `a` is most; mid is greater of `b` or `c`
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if b >= c {
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return b
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}
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return c
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}
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// `a` is neither most nor least; therefore, `a` is mid
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return a
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}
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