geom

package
v0.0.2 Latest Latest
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 Go to latest Published: Jun 26, 2019 License: MIT Imports: 2 Imported by: 0

Documentation

Overview

Package geom contains utilities for working with geometry.

Index

Constants

View Source 
const HalfPi = math.Pi / 2

HalfPi represents PI / 2

View Source 
const QuarterPi = math.Pi / 4

QuarterPi represents PI / 4

View Source 
const TwoPi = 2 * math.Pi

TwoPi represents 2 * PI

Variables

This section is empty.

Functions

func AngleStrictlyBetween 

func AngleStrictlyBetween(angle, low, high float64) bool

AngleStrictlyBetween checks whether the given angle is strictly between two other angles.

func FindBalancedFactors 

func FindBalancedFactors(value int) (int, int)

FindBalancedFactors finds the two factors a and b of the given number such that the difference between a and b is minimal (i.e. a = b = sqrt(value) for square numbers) The return order is a, b such that a <= b

func InnerSquareRadius 

func InnerSquareRadius(r float64) float64

InnerSquareRadius returns the inner radius of a square.

func OuterSquareRadius 

func OuterSquareRadius(r float64) float64

OuterSquareRadius returns the outer radius of a square.

Types

type Point 

type Point struct {
	X, Y float64
}

A Point represents a point using cartesian coordinates.

func Pt 

func Pt(x, y float64) Point

Pt creates a new point from the given coordinates.

func PtFromPolar 

func PtFromPolar(radius, angle float64) Point

PtFromPolar creates a new point from the given polar coordinates.

func (Point) Add 

func (p Point) Add(other Point) Point

Add returns a new point with the given point added.

func (Point) Div 

func (p Point) Div(divisor float64) Point

Div returns a new point divided by the divisor.

func (Point) Mul 

func (p Point) Mul(factor float64) Point

Mul returns a new point multiplied with the factor.

func (Point) Neg 

func (p Point) Neg() Point

Neg returns the negative point

func (Point) Polar 

func (p Point) Polar() (float64, float64)

Polar returns the point in polar form. Return order: radius, angle

func (Point) Rotate 

func (p Point) Rotate(angle float64) Point

Rotate rotates a point counterclockwise around the origin

func (Point) RotateAround 

func (p Point) RotateAround(angle float64, origin Point) Point

RotateAround rotates a point counterclockwise around another point.

func (Point) Scale 

func (p Point) Scale(other Point) Point

Scale multiplies two points component-wise

func (Point) String 

func (p Point) String() string

func (Point) Sub 

func (p Point) Sub(other Point) Point

Sub returns a new point with the given point subtracted.

func (Point) XY 

func (p Point) XY() (float64, float64)

XY returns the x and y coordinates.

type Polygon 

type Polygon struct {
	Vertices []Point
}

A Polygon represents any polygon.

func Poly 

func Poly(points ...Point) Polygon

Poly creates a new polygon containing the given points.

func (Polygon) BoundingRect 

func (pg Polygon) BoundingRect() Rectangle

BoundingRect returns the bounding rectangle

func (Polygon) Center 

func (pg Polygon) Center() Point

Center returns the centroid of the polygon.

func (Polygon) Empty 

func (pg Polygon) Empty() bool

Empty checks whether the polygon contains no points

func (Polygon) Scale 

func (pg Polygon) Scale(factor float64) Polygon

Scale scales the polygon from the origin.

func (Polygon) ScaleFrom 

func (pg Polygon) ScaleFrom(factor float64, origin Point) Polygon

ScaleFrom scales the polygon from a given point.

func (Polygon) ScaleFromCenter 

func (pg Polygon) ScaleFromCenter(factor float64) Polygon

ScaleFromCenter scales the polygon from the center.

func (Polygon) Translate 

func (pg Polygon) Translate(p Point) Polygon

Translate moves the polygon by the given amount.

type Rectangle 

type Rectangle struct {
	Min, Max Point
}

A Rectangle represents a rectangle using 2 corner points. Only rectangles aligned with the coordinate axes can be represented.

func RectContainingPoints 

func RectContainingPoints(points ...Point) Rectangle

RectContainingPoints finds the smallest rectangle containing all given points.

func RectWithSideLengths 

func RectWithSideLengths(p Point) Rectangle

RectWithSideLengths creates a new rectangle with the given size.

func SquareWithSideLen 

func SquareWithSideLen(side float64) Rectangle

SquareWithSideLen creates a new square with the given size.

func (Rectangle) BottomLeft 

func (r Rectangle) BottomLeft() Point

BottomLeft returns the bottom left corner point

func (Rectangle) BottomRight 

func (r Rectangle) BottomRight() Point

BottomRight returns the bottom right corner point

func (Rectangle) Center 

func (r Rectangle) Center() Point

Center returns the center of the rectangle.

func (Rectangle) GrowToContain 

func (r Rectangle) GrowToContain(points ...Point) Rectangle

GrowToContain returns a new rectangle expanded to contain the given points. If the rectangle already contains the points, a copy is returned.

func (Rectangle) Height 

func (r Rectangle) Height() float64

Height returns the height of the rectangle).

func (Rectangle) InnerCenterSquare 

func (r Rectangle) InnerCenterSquare() Rectangle

InnerCenterSquare returns a new square which fits inside of the rectangle.

func (Rectangle) MaxSide 

func (r Rectangle) MaxSide() float64

MaxSide returns the length of the bigger side.

func (Rectangle) MinSide 

func (r Rectangle) MinSide() float64

MinSide return the length of the smaller side.

func (Rectangle) RotateAround 

func (r Rectangle) RotateAround(angle float64, origin Point) Polygon

RotateAround returns the four vertices of the rectangle after a counterclockwise rotation around the given point.

func (Rectangle) RotateAroundCenter 

func (r Rectangle) RotateAroundCenter(angle float64) Polygon

RotateAroundCenter returns the four vertices of the rectangle after a counterclockwise rotation around the center.

func (Rectangle) Scale 

func (r Rectangle) Scale(factor float64) Rectangle

Scale scales the rectangle from the origin.

func (Rectangle) ScaleFrom 

func (r Rectangle) ScaleFrom(factor float64, origin Point) Rectangle

ScaleFrom scales the rectangle from a given point.

func (Rectangle) ScaleFromCenter 

func (r Rectangle) ScaleFromCenter(factor float64) Rectangle

ScaleFromCenter scales the rectangle from the center.

func (Rectangle) String 

func (r Rectangle) String() string

func (Rectangle) TopLeft 

func (r Rectangle) TopLeft() Point

TopLeft returns the top left corner point

func (Rectangle) TopRight 

func (r Rectangle) TopRight() Point

TopRight returns the top right corner point

func (Rectangle) Translate 

func (r Rectangle) Translate(p Point) Rectangle

Translate moves the rectangle around by the given point.

func (Rectangle) Vertices 

func (r Rectangle) Vertices() []Point

Vertices returns a slice containing all four corner points The order is clockwise starting with the top left corner.

func (Rectangle) Width 

func (r Rectangle) Width() float64

Width returns the width of the rectangle.

Source Files

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