ginger/gim/geo/round.go

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package geo
import (
"fmt"
"math"
)
// Rounder describes how a floating point number should be converted to an int
type Rounder int
const (
// Round will round up or down depending on the number itself
Round Rounder = iota
// Floor will use the math.Floor function
Floor
// Ceil will use the math.Ceil function
Ceil
)
// Round64 converts a float to an in64 based on the rounding function indicated
// by the Rounder's value
func (r Rounder) Round64(f float64) int64 {
switch r {
case Round:
if f < 0 {
f = math.Ceil(f - 0.5)
}
f = math.Floor(f + 0.5)
case Floor:
f = math.Floor(f)
case Ceil:
f = math.Ceil(f)
default:
panic(fmt.Sprintf("invalid Rounder: %#v", r))
}
return int64(f)
}
// Round is like Round64 but convers the int64 to an int
func (r Rounder) Round(f float64) int {
return int(r.Round64(f))
}