package f32

import "gioui.org/f32"

Package f32 is a float32 implementation of package image's Point and affine transformations.

The coordinate space has the origin in the top left corner with the axes extending right and down.

Index ¶

• type Affine2D
• func NewAffine2D(sx, hx, ox, hy, sy, oy float32) Affine2D
• func (a Affine2D) Elems() (sx, hx, ox, hy, sy, oy float32)
• func (a Affine2D) Invert() Affine2D
• func (A Affine2D) Mul(B Affine2D) (r Affine2D)
• func (a Affine2D) Offset(offset Point) Affine2D
• func (a Affine2D) Rotate(origin Point, radians float32) Affine2D
• func (a Affine2D) Scale(origin, factor Point) Affine2D
• func (a Affine2D) Shear(origin Point, radiansX, radiansY float32) Affine2D
• func (a *Affine2D) Split() (srs Affine2D, offset Point)
• func (a Affine2D) String() string
• func (a Affine2D) Transform(p Point) Point
• type Point
• func Pt(x, y float32) Point
• func (p Point) Add(p2 Point) Point
• func (p Point) Div(s float32) Point
• func (p Point) Mul(s float32) Point
• func (p Point) Round() image.Point
• func (p Point) String() string
• func (p Point) Sub(p2 Point) Point

Types ¶

type Affine2D ¶

type Affine2D struct {
	// contains filtered or unexported fields
}

Affine2D represents an affine 2D transformation. The zero value of Affine2D represents the identity transform.

func NewAffine2D ¶

func NewAffine2D(sx, hx, ox, hy, sy, oy float32) Affine2D

NewAffine2D creates a new Affine2D transform from the matrix elements in row major order. The rows are: [sx, hx, ox], [hy, sy, oy], [0, 0, 1].

func (Affine2D) Elems ¶

func (a Affine2D) Elems() (sx, hx, ox, hy, sy, oy float32)

Elems returns the matrix elements of the transform in row-major order. The rows are: [sx, hx, ox], [hy, sy, oy], [0, 0, 1].

func (Affine2D) Invert ¶

func (a Affine2D) Invert() Affine2D

Invert the transformation. Note that if the matrix is close to singular numerical errors may become large or infinity.

func (Affine2D) Mul ¶

func (A Affine2D) Mul(B Affine2D) (r Affine2D)

Mul returns A*B.

func (Affine2D) Offset ¶

func (a Affine2D) Offset(offset Point) Affine2D

Offset the transformation.

func (Affine2D) Rotate ¶

func (a Affine2D) Rotate(origin Point, radians float32) Affine2D

Rotate the transformation by the given angle (in radians) counter clockwise around the given origin.

func (Affine2D) Scale ¶

func (a Affine2D) Scale(origin, factor Point) Affine2D

Scale the transformation around the given origin.

func (Affine2D) Shear ¶

func (a Affine2D) Shear(origin Point, radiansX, radiansY float32) Affine2D

Shear the transformation by the given angle (in radians) around the given origin.

func (*Affine2D) Split ¶

func (a *Affine2D) Split() (srs Affine2D, offset Point)

Split a transform into two parts, one which is pure offset and the other representing the scaling, shearing and rotation part.

func (Affine2D) String ¶

func (a Affine2D) String() string

func (Affine2D) Transform ¶

func (a Affine2D) Transform(p Point) Point

Transform p by returning a*p.

type Point ¶

type Point struct {
	X, Y float32
}

A Point is a two dimensional point.

func Pt ¶

func Pt(x, y float32) Point

Pt is shorthand for Point{X: x, Y: y}.

func (Point) Add ¶

func (p Point) Add(p2 Point) Point

Add return the point p+p2.

func (Point) Div ¶

func (p Point) Div(s float32) Point

Div returns the vector p/s.

func (Point) Mul ¶

func (p Point) Mul(s float32) Point

Mul returns p scaled by s.

func (Point) Round ¶

func (p Point) Round() image.Point

Round returns the integer point closest to p.

func (Point) String ¶

func (p Point) String() string

String return a string representation of p.

func (Point) Sub ¶

func (p Point) Sub(p2 Point) Point

Sub returns the vector p-p2.

Source Files ¶

affine.go f32.go