Documentation
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Index ¶
- func Div(a, b int) int
- func Mod(a, b int) int
- func Rint(f float64) int
- type Delta
- func (d Delta) Add(d2 Delta) Delta
- func (d Delta) Div(m int) Delta
- func (d Delta) Dot(d2 Delta) int
- func (d Delta) IsZero() bool
- func (d Delta) Length() float64
- func (d Delta) Length2() int64
- func (d Delta) LengthFixed() Fixed
- func (d Delta) Mul(n int) Delta
- func (d Delta) Mul2(mx, my int) Delta
- func (d Delta) MulFixed(f Fixed) Delta
- func (d Delta) MulFracFixed(num, denom Fixed) Delta
- func (d Delta) Norm0() int
- func (d Delta) Norm1() int
- func (d Delta) Sub(d2 Delta) Delta
- func (d Delta) WithLengthFixed(f Fixed) Delta
- func (d Delta) WithMaxLengthFixed(f Fixed) Delta
- type Fixed
- type Orientation
- type Pos
- type Rect
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
Types ¶
type Delta ¶
type Delta struct {
DX, DY int
}
Delta represents a move between two pixel positions.
func (Delta) LengthFixed ¶
func (Delta) MulFracFixed ¶
func (Delta) WithLengthFixed ¶
func (Delta) WithMaxLengthFixed ¶
type Fixed ¶
type Fixed fixedUnderlying
const (
FixedOne Fixed = 1 << fixedBits
)
func NewFixedFloat64 ¶
func NewFixedInt64 ¶
func NewFixedInt64(i fixedUnderlying) Fixed
type Orientation ¶
Orientation represents a transformation matrix, written as a right and a down vector.
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 (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().
type Pos ¶
type Pos struct {
X, Y int
}
Pos represents a pixel position, where X points right and Y points down.
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 (Rect) DeltaPos ¶
DeltaPos returns the vector between the closest points of a rectangle and a point.
func (Rect) Normalized ¶
Normalized returns a rectangle such that its size is nonnegative.
func (Rect) OppositeCorner ¶
OppositeCorner returns the coordinate of the opposite corner of the rectangle. Only correct on normalized rectangles.
Source Files