Point represents a point in ℝ².
type Point struct {
X, Y float64
}
func (p Point) Add(op Point) Point
Add returns the sum of p and op.
func (p Point) Cross(op Point) float64
Cross returns the cross product of p and op.
func (p Point) Dot(op Point) float64
Dot returns the dot product between p and op.
func (p Point) Mul(m float64) Point
Mul returns the scalar product of p and m.
func (p Point) Norm() float64
Norm returns the vector's norm.
func (p Point) Normalize() Point
Normalize returns a unit point in the same direction as p.
func (p Point) Ortho() Point
Ortho returns a counterclockwise orthogonal point with the same norm.
func (p Point) String() string
func (p Point) Sub(op Point) Point
Sub returns the difference of p and op.
Rect represents a closed axis-aligned rectangle in the (x,y) plane.
type Rect struct {
X, Y r1.Interval
}
func EmptyRect() Rect
EmptyRect constructs the canonical empty rectangle. Use IsEmpty() to test for empty rectangles, since they have more than one representation. A Rect{} is not the same as the EmptyRect.
func RectFromCenterSize(center, size Point) Rect
RectFromCenterSize constructs a rectangle with the given center and size. Both dimensions of size must be non-negative.
func RectFromPoints(pts ...Point) Rect
RectFromPoints constructs a rect that contains the given points.
func (r Rect) AddPoint(p Point) Rect
AddPoint expands the rectangle to include the given point. The rectangle is expanded by the minimum amount possible.
func (r Rect) AddRect(other Rect) Rect
AddRect expands the rectangle to include the given rectangle. This is the same as replacing the rectangle by the union of the two rectangles, but is more efficient.
func (r Rect) ApproxEqual(r2 Rect) bool
ApproxEqual returns true if the x- and y-intervals of the two rectangles are the same up to the given tolerance.
func (r Rect) Center() Point
Center returns the center of the rectangle in (x,y)-space
func (r Rect) ClampPoint(p Point) Point
ClampPoint returns the closest point in the rectangle to the given point. The rectangle must be non-empty.
func (r Rect) Contains(other Rect) bool
Contains reports whether the rectangle contains the given rectangle.
func (r Rect) ContainsPoint(p Point) bool
ContainsPoint reports whether the rectangle contains the given point. Rectangles are closed regions, i.e. they contain their boundary.
func (r Rect) Expanded(margin Point) Rect
Expanded returns a rectangle that has been expanded in the x-direction by margin.X, and in y-direction by margin.Y. If either margin is empty, then shrink the interval on the corresponding sides instead. The resulting rectangle may be empty. Any expansion of an empty rectangle remains empty.
func (r Rect) ExpandedByMargin(margin float64) Rect
ExpandedByMargin returns a Rect that has been expanded by the amount on all sides.
func (r Rect) Hi() Point
Hi returns the high corner of the rect.
func (r Rect) InteriorContains(other Rect) bool
InteriorContains reports whether the interior of this rectangle contains all of the points of the given other rectangle (including its boundary).
func (r Rect) InteriorContainsPoint(p Point) bool
InteriorContainsPoint returns true iff the given point is contained in the interior of the region (i.e. the region excluding its boundary).
func (r Rect) InteriorIntersects(other Rect) bool
InteriorIntersects reports whether the interior of this rectangle intersects any point (including the boundary) of the given other rectangle.
func (r Rect) Intersection(other Rect) Rect
Intersection returns the smallest rectangle containing the intersection of this rectangle and the given rectangle.
func (r Rect) Intersects(other Rect) bool
Intersects reports whether this rectangle and the other rectangle have any points in common.
func (r Rect) IsEmpty() bool
IsEmpty reports whether the rectangle is empty.
func (r Rect) IsValid() bool
IsValid reports whether the rectangle is valid. This requires the width to be empty iff the height is empty.
func (r Rect) Lo() Point
Lo returns the low corner of the rect.
func (r Rect) Size() Point
Size returns the width and height of this rectangle in (x,y)-space. Empty rectangles have a negative width and height.
func (r Rect) String() string
func (r Rect) Union(other Rect) Rect
Union returns the smallest rectangle containing the union of this rectangle and the given rectangle.
func (r Rect) VertexIJ(i, j int) Point
VertexIJ returns the vertex in direction i along the X-axis (0=left, 1=right) and direction j along the Y-axis (0=down, 1=up).
func (r Rect) Vertices() [4]Point
Vertices returns all four vertices of the rectangle. Vertices are returned in CCW direction starting with the lower left corner.