math

package
v1.3.334 Latest Latest
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This package is not in the latest version of its module.

 Go to latest Published: Feb 20, 2023 License: Apache-2.0 Imports: 9 Imported by: 0

Documentation

Index

Constants

This section is empty.

Variables

View Source 
var AllOrientations = Orientations{
	Orientation{Right: East(), Down: North()},
	Orientation{Right: East(), Down: South()},
	Orientation{Right: North(), Down: East()},
	Orientation{Right: North(), Down: West()},
	Orientation{Right: South(), Down: East()},
	Orientation{Right: South(), Down: West()},
	Orientation{Right: West(), Down: North()},
	Orientation{Right: West(), Down: South()},
}

Functions

func Div 

func Div(a, b int) int

func Div64 added in v1.2.321 

func Div64(a, b int64) int64

func Mod 

func Mod(a, b int) int

func Mod64 added in v1.2.321 

func Mod64(a, b int64) int64

func Rint 

func Rint(f float64) int

Types

type Delta 

type Delta struct {
	DX, DY int
}

Delta represents a move between two pixel positions.

func East 

func East() Delta

func North 

func North() Delta

func South 

func South() Delta

func West 

func West() Delta

func (Delta) Add 

func (d Delta) Add(d2 Delta) Delta

func (Delta) Div 

func (d Delta) Div(m int) Delta

func (Delta) Dot 

func (d Delta) Dot(d2 Delta) int

func (Delta) IsZero 

func (d Delta) IsZero() bool

func (Delta) Length 

func (d Delta) Length() float64

func (Delta) Length2 

func (d Delta) Length2() int64

func (Delta) LengthFixed 

func (d Delta) LengthFixed() Fixed

func (Delta) MarshalText added in v1.2.217 

func (d Delta) MarshalText() ([]byte, error)

func (Delta) Mod added in v1.1.280 

func (d Delta) Mod(m int) Delta

func (Delta) Mul 

func (d Delta) Mul(n int) Delta

func (Delta) Mul2 

func (d Delta) Mul2(mx, my int) Delta

func (Delta) MulFixed 

func (d Delta) MulFixed(f Fixed) Delta

func (Delta) MulFracFixed 

func (d Delta) MulFracFixed(num, denom Fixed) Delta

func (Delta) Norm0 

func (d Delta) Norm0() int

func (Delta) Norm1 

func (d Delta) Norm1() int

func (Delta) String added in v1.2.356 

func (d Delta) String() string

func (Delta) Sub 

func (d Delta) Sub(d2 Delta) Delta

func (*Delta) UnmarshalText added in v1.2.399 

func (d *Delta) UnmarshalText(text []byte) error

func (Delta) WithLengthFixed 

func (d Delta) WithLengthFixed(f Fixed) Delta

func (Delta) WithMaxLengthFixed 

func (d Delta) WithMaxLengthFixed(f Fixed) Delta

type Fixed 

type Fixed fixedUnderlying
const (
	FixedOne Fixed = 1 << fixedBits
)

func NewFixed 

func NewFixed(i int) Fixed

func NewFixedFloat64 

func NewFixedFloat64(f float64) Fixed

func NewFixedInt64 

func NewFixedInt64(i fixedUnderlying) Fixed

func (Fixed) Div 

func (f Fixed) Div(g Fixed) Fixed

func (Fixed) Float64 

func (f Fixed) Float64() float64

func (Fixed) Mod added in v1.2.321 

func (f Fixed) Mod(g Fixed) Fixed

func (Fixed) Mul 

func (f Fixed) Mul(g Fixed) Fixed

func (Fixed) MulFrac 

func (f Fixed) MulFrac(n, d Fixed) Fixed

func (Fixed) Rint 

func (f Fixed) Rint() int

func (Fixed) Sqrt 

func (f Fixed) Sqrt() Fixed

func (Fixed) String 

func (f Fixed) String() string

type Orientation 

type Orientation struct {
	Right Delta
	Down  Delta
}

Orientation represents a transformation matrix, written as a right and a down vector.

func FlipD 

func FlipD() Orientation

FlipD yields an orientation where X/Y are swapped.

func FlipX 

func FlipX() Orientation

FlipX yields an orientation where X is flipped.

func FlipY 

func FlipY() Orientation

FlipY yields an orientation where Y is flipped.

func Identity 

func Identity() Orientation

Identity yields the default orientation.

func Left 

func Left() Orientation

Left yields an orientation that turns left.

func ParseOrientation 

func ParseOrientation(s string) (Orientation, error)

ParseOrientation parses an orientation from a string. It is given by the right and down directions in that order. 

func Right() Orientation

Right yields an orientation that turns right.

func TurnAround 

func TurnAround() Orientation

Left yields an orientation that turns left.

func (Orientation) Apply 

func (o Orientation) Apply(d Delta) Delta

Apply rotates a delta by an orientation.

func (Orientation) ApplyToRect2 

func (o Orientation) ApplyToRect2(pivot2 Pos, r Rect) Rect

ApplyToRect2 rotates a rectangle by the given orientation, mapping the pivot to itself. The pivot is given in doubled coordinates to support half-pixel pivots. Note: odd numbers are pixel centers, even numbers are pixel corners!

func (Orientation) Concat 

func (o Orientation) Concat(o2 Orientation) Orientation

Concat returns the orientation o * o2 so that o.Concat(o2).Apply(d) == o.Apply(o2.Apply(d)).

func (Orientation) Determinant 

func (o Orientation) Determinant() int

func (Orientation) Inverse 

func (o Orientation) Inverse() Orientation

Inverse returns an orientation so that o.Concat(o.Invert()) == Identity().

func (Orientation) MarshalText added in v1.2.399 

func (o Orientation) MarshalText() ([]byte, error)

func (Orientation) String added in v1.2.356 

func (o Orientation) String() string

func (*Orientation) UnmarshalText added in v1.2.399 

func (o *Orientation) UnmarshalText(text []byte) error

type Orientations added in v1.2.356 

type Orientations []Orientation

func ParseOrientations added in v1.2.4 

func ParseOrientations(s string) (Orientations, error)

func (Orientations) MarshalText added in v1.2.399 

func (o Orientations) MarshalText() ([]byte, error)

func (*Orientations) UnmarshalText added in v1.2.399 

func (o *Orientations) UnmarshalText(text []byte) error

type Pos 

type Pos struct {
	X, Y int
}

Pos represents a pixel position, where X points right and Y points down.

func (Pos) Add 

func (p Pos) Add(d Delta) Pos

Add applies a delta to a position.

func (Pos) Delta 

func (p Pos) Delta(p2 Pos) Delta

func (Pos) Div 

func (p Pos) Div(m int) Pos

func (Pos) FromRectToRect 

func (p Pos) FromRectToRect(a Rect, b Rect) Pos

func (Pos) MarshalText added in v1.2.399 

func (p Pos) MarshalText() ([]byte, error)

func (Pos) Mul 

func (p Pos) Mul(n int) Pos

func (Pos) String added in v1.2.356 

func (p Pos) String() string

func (Pos) Sub 

func (p Pos) Sub(d Delta) Pos

func (*Pos) UnmarshalJSON added in v1.2.399 

func (p *Pos) UnmarshalJSON(text []byte) error

func (*Pos) UnmarshalText added in v1.2.399 

func (p *Pos) UnmarshalText(text []byte) error

type Rect 

type Rect struct {
	// Origin is the origin of the rectangle, typically the top left corner.
	Origin Pos
	// Size is the size of the rectangle, typically positive.
	Size Delta
}

Rect represents a rectangle.

func RectFromPoints 

func RectFromPoints(a, b Pos) Rect

func (Rect) Add added in v1.0.140 

func (r Rect) Add(d Delta) Rect

Add creates a new rectangle moved by the given delta.

func (Rect) Center 

func (r Rect) Center() Pos

Center returns the coordinate in the middle of the rectangle.

func (Rect) Delta 

func (r Rect) Delta(other Rect) Delta

Delta returns the vector between the closest points of two rectangles.

func (Rect) DeltaPos 

func (r Rect) DeltaPos(other Pos) Delta

DeltaPos returns the vector between the closest points of a rectangle and a point.

func (Rect) Foot 

func (r Rect) Foot() Pos

Foot returns the coordinate in the bottom middle of the rectangle.

func (Rect) GridPos added in v1.3.43 

func (r Rect) GridPos(p Pos, nx int, ny int) (int, int)

GridPos converts coordinates of p within the rect into grid coords.

func (Rect) Grow added in v1.2.342 

func (r Rect) Grow(d Delta) Rect

Grow creates a new rectangle grown by the given delta.

func (Rect) MarshalText added in v1.2.399 

func (r Rect) MarshalText() ([]byte, error)

func (Rect) Normalized 

func (r Rect) Normalized() Rect

Normalized returns a rectangle such that its size is nonnegative.

func (Rect) OppositeCorner 

func (r Rect) OppositeCorner() Pos

OppositeCorner returns the coordinate of the opposite corner of the rectangle. Only correct on normalized rectangles.

func (Rect) String added in v1.2.356 

func (r Rect) String() string

func (*Rect) UnmarshalText added in v1.2.399 

func (r *Rect) UnmarshalText(text []byte) error

Source Files

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