class Eagle::Physics2D::Polygon

Overview

A convex polygon collision shape. Points can be in either winding order. Concave input isn't supported; split it into several convex polygons.

Physics2D::Polygon.box(32, 48)
Physics2D::Polygon.new([v2(0, -20), v2(15, 10), v2(-15, 10)]) # triangle

eagle/physics/shapes2d.cr

.box(w : Number, h : Number, offset : Vec2 = Vec2::ZERO) : Polygon
A w by h box centered on offset.
.new(points : Array(Vec2), offset : Vec2 = Vec2::ZERO)
Creates a polygon from convex points.
.regular(sides : Int32, radius : Number, offset : Vec2 = Vec2::ZERO) : Polygon
A regular polygon with sides corners.

#aabb : Rect
Bounds in world space.
#area : Float32
Area of the polygon.
#centroid : Vec2
The polygon's center of mass.
#contains?(p : Vec2) : Bool
True when p is inside the polygon.
#inertia_factor : Float32
Inertia per unit mass.
#local_aabb : Rect
Bounds in local space.
#normals : Array(Vec2)
Outward edge normals.
#points : Array(Vec2)
Vertices in local space, stored clockwise.
#support(d : Vec2) : Vec2
The vertex furthest in direction d, used by collision tests.
#transformed(t : Transform2D) : Shape
A world-space copy.

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def self.box(w : Number, h : Number, offset : Vec2 = Vec2::ZERO) : Polygon #

A w by h box centered on offset.

def self.new(points : Array(Vec2), offset : Vec2 = Vec2::ZERO) #

Creates a polygon from convex points.

def self.regular(sides : Int32, radius : Number, offset : Vec2 = Vec2::ZERO) : Polygon #

A regular polygon with sides corners.

def aabb : Rect #

Bounds in world space.

def area : Float32 #

Area of the polygon.

def centroid : Vec2 #

The polygon's center of mass.

def contains?(p : Vec2) : Bool #

True when p is inside the polygon.

def inertia_factor : Float32 #

Inertia per unit mass.

def local_aabb : Rect #

Bounds in local space.

def normals : Array(Vec2) #

Outward edge normals.

def points : Array(Vec2) #

Vertices in local space, stored clockwise.

def support(d : Vec2) : Vec2 #

The vertex furthest in direction d, used by collision tests.

def transformed(t : Transform2D) : Shape #

A world-space copy.