e2ab54a896f822fa85f785f5426dd69186185f55 — Elias Naur 14 days ago b25af47
ui/f32: document

Signed-off-by: Elias Naur <mail@eliasnaur.com>
1 files changed, 22 insertions(+), 0 deletions(-)

M ui/f32/f32.go
M ui/f32/f32.go => ui/f32/f32.go +22 -0
@@ 1,39 1,55 @@ // SPDX-License-Identifier: Unlicense OR MIT
+ /*
+ Package f32 is a float32 implementation of package image's
+ Point and Rectangle
  
+ The coordinate space has the origin in the top left
+ corner with the axes extending right and down.
+ */
  package f32
  
+ // A Point is a two dimensional point.
  type Point struct {
  	X, Y float32
  }
  
+ // A Rectangle contains the points (X, Y) where Min.X <= X < Max.X,
+ // Min.Y <= Y < Max.Y.
  type Rectangle struct {
  	Min, Max Point
  }
  
+ // Add return the point p+p2.
  func (p Point) Add(p2 Point) Point {
  	return Point{X: p.X + p2.X, Y: p.Y + p2.Y}
  }
  
+ // Sub returns the vector p-p2.
  func (p Point) Sub(p2 Point) Point {
  	return Point{X: p.X - p2.X, Y: p.Y - p2.Y}
  }
  
+ // Mul returns p scaled by s.
  func (p Point) Mul(s float32) Point {
  	return Point{X: p.X * s, Y: p.Y * s}
  }
  
+ // Size returns r's width and height.
  func (r Rectangle) Size() Point {
  	return Point{X: r.Dx(), Y: r.Dy()}
  }
  
+ // Dx returns r's width.
  func (r Rectangle) Dx() float32 {
  	return r.Max.X - r.Min.X
  }
  
+ // Dy returns r's Height.
  func (r Rectangle) Dy() float32 {
  	return r.Max.Y - r.Min.Y
  }
  
+ // Intersect returns the intersection of r and s.
  func (r Rectangle) Intersect(s Rectangle) Rectangle {
  	if r.Min.X < s.Min.X {
  		r.Min.X = s.Min.X


@@ 50,6 66,7 @@ return r
  }
  
+ // Union returns the union of r and s.
  func (r Rectangle) Union(s Rectangle) Rectangle {
  	if r.Min.X > s.Min.X {
  		r.Min.X = s.Min.X


@@ 66,6 83,8 @@ return r
  }
  
+ // Canon returns the canonical version of r, where Min is to
+ // the upper left of Max.
  func (r Rectangle) Canon() Rectangle {
  	if r.Max.X < r.Min.X {
  		r.Min.X, r.Max.X = r.Max.X, r.Min.X


@@ 76,10 95,12 @@ return r
  }
  
+ // Empty reports whether r represents the empty area.
  func (r Rectangle) Empty() bool {
  	return r.Min.X >= r.Max.X || r.Min.Y >= r.Max.Y
  }
  
+ // Add offsets r with the vector p.
  func (r Rectangle) Add(p Point) Rectangle {
  	return Rectangle{
  		Point{r.Min.X + p.X, r.Min.Y + p.Y},


@@ 87,6 108,7 @@ }
  }
  
+ // Sub offsets r with the vector -p.
  func (r Rectangle) Sub(p Point) Rectangle {
  	return Rectangle{
  		Point{r.Min.X - p.X, r.Min.Y - p.Y},