zntg/ui/length.go

package ui

import "opslag.de/schobers/geom"

type Length struct {
	float32
}

func (l *Length) Value() float32 {
	if l == nil {
		return 0
	}
	return l.float32
}

func (l *Length) Zero(value float32) float32 {
	if l == nil {
		return value
	}
	return l.Value()
}

func Fixed(l float32) *Length { return &Length{l} }

func Infinite() *Length { return &Length{geom.NaN32()} }

func ZL() *Length { return &Length{0} }

type SideLengths struct {
	Left   *Length
	Top    *Length
	Right  *Length
	Bottom *Length
}

func (l SideLengths) InsetRect(r geom.RectangleF32) geom.RectangleF32 {
	return Sides{
		Left:   l.Left.Value(),
		Top:    l.Top.Value(),
		Right:  l.Right.Value(),
		Bottom: l.Bottom.Value(),
	}.InsetRect(r)
}

func (l SideLengths) Zero(value float32) Sides {
	return Sides{
		Left:   l.Left.Zero(value),
		Top:    l.Top.Zero(value),
		Right:  l.Right.Zero(value),
		Bottom: l.Bottom.Zero(value),
	}
}

type Sides struct {
	Left   float32
	Top    float32
	Right  float32
	Bottom float32
}

func (s Sides) InsetRect(r geom.RectangleF32) geom.RectangleF32 {
	if r.Dx() < (s.Left + s.Right) {
		r.Min.X += r.Dx() * s.Left / (s.Left + s.Right)
		r.Max.X = r.Min.X
	} else {
		r.Min.X += s.Left
		r.Max.X -= s.Right
	}
	if r.Dy() < (s.Top + s.Bottom) {
		r.Min.Y += r.Dy() * s.Top / (s.Top + s.Bottom)
		r.Max.Y = r.Min.Y
	} else {
		r.Min.Y += s.Top
		r.Max.Y -= s.Bottom
	}
	return r
}