75 lines
1.8 KiB
Go
75 lines
1.8 KiB
Go
package geom
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// RectangleF32 is defined by two points, the minimum and maximum (floating point).
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// Tries to use the same interface as the image. Rectangle but uses float32 instead of int.
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type RectangleF32 struct {
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Min, Max PointF32
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}
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// RectF32 is a shorthand function to create a rectangle.
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func RectF32(x0, y0, x1, y1 float32) RectangleF32 {
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if x0 > x1 {
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x0, x1 = x1, x0
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}
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if y0 > y1 {
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y0, y1 = y1, y0
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}
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return RectangleF32{PtF32(x0, y0), PtF32(x1, y1)}
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}
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// Add translates rectangle r by point p.
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func (r RectangleF32) Add(p PointF32) RectangleF32 {
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return RectangleF32{
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PointF32{r.Min.X + p.X, r.Min.Y + p.Y},
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PointF32{r.Max.X + p.X, r.Max.Y + p.Y},
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}
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}
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// Center returns the center of the rectangle.
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func (r RectangleF32) Center() PointF32 {
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return PointF32{.5 * (r.Min.X + r.Max.X), .5 * (r.Min.Y + r.Max.Y)}
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}
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// Dx returns the width of r.
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func (r RectangleF32) Dx() float32 {
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return r.Max.X - r.Min.X
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}
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// Dy returns the height of r.
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func (r RectangleF32) Dy() float32 {
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return r.Max.Y - r.Min.Y
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}
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// Inset returns the rectangle r inset by n. The resulting rectangle will never have
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// a negative size.
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func (r RectangleF32) Inset(n float32) RectangleF32 {
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if r.Dx() < 2*n {
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r.Min.X = (r.Min.X + r.Max.X) / 2
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r.Max.X = r.Min.X
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} else {
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r.Min.X += n
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r.Max.X -= n
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}
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if r.Dy() < 2*n {
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r.Min.Y = (r.Min.Y + r.Max.Y) / 2
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r.Max.Y = r.Min.Y
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} else {
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r.Min.Y += n
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r.Max.Y -= n
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}
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return r
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}
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// Size returns the size of the rectangle.
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func (r RectangleF32) Size() PointF32 {
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return PointF32{r.Max.X - r.Min.X, r.Max.Y - r.Min.Y}
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}
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// Sub translates rectangle r in the opposite direction of point p.
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func (r RectangleF32) Sub(p PointF32) RectangleF32 {
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return RectangleF32{
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PointF32{r.Min.X - p.X, r.Min.Y - p.Y},
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PointF32{r.Max.X - p.X, r.Max.Y - p.Y},
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}
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}
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