class Eagle::RigidBody2D

Overview

A body moved by the physics simulation: it falls, bounces, stacks and gets pushed.

Don't set its position every frame. Push it with forces and impulses instead, or set #velocity directly for arcade-style control.

ball = RigidBody2D.new(position: v2(400, 0)).circle(16)
ball.restitution = 0.7 # bouncy
ball.friction = 0.2
ball.apply_impulse(v2(200, -300)) # kick it up and to the right
ball.on_body_entered { |other| puts "bonk" }
SceneTree.root.add(ball)

Defined in:

eagle/nodes/physics_nodes.cr

Constructors

Instance Method Summary

Instance methods inherited from class Eagle::CollisionObject2D

add_shape(s : Physics2D::Shape) : self add_shape, body : Physics2D::Body body, body_entered : Eagle::Emitter(CollisionObject2D) body_entered, body_exited : Eagle::Emitter(CollisionObject2D) body_exited, box(w : Number, h : Number, offset : Vec2 = Vec2::ZERO) : self box, circle(radius : Number, offset : Vec2 = Vec2::ZERO) : self circle, debug=(debug : Bool) debug=, debug? : Bool debug?, draw(g : Graphics) : Nil draw, emit_body_entered(*args) : Nil emit_body_entered, emit_body_exited(*args) : Nil emit_body_exited, enter_tree : Nil enter_tree, exit_tree : Nil exit_tree, layer : UInt32 layer, layer=(v : UInt32) layer=, mask : UInt32 mask, mask=(v : UInt32) mask=, on_body_entered(&block : CollisionObject2D -> Nil) : Proc(CollisionObject2D, Nil) on_body_entered, on_body_exited(&block : CollisionObject2D -> Nil) : Proc(CollisionObject2D, Nil) on_body_exited, overlapping : Array(CollisionObject2D) overlapping, overlaps?(other : CollisionObject2D) : Bool overlaps?, physics_process(dt : Float32) : Nil physics_process, polygon(points : Array(Vec2)) : self polygon, pull_transform : Nil pull_transform, push_transform : Nil push_transform, world : Physics2D::World world, world=(world : Physics2D::World) world=

Constructor methods inherited from class Eagle::CollisionObject2D

new(type : Physics2D::BodyType, name : String = "", position : Vec2 = Vec2::ZERO, shape : Physics2D::Shape | Nil = nil) new

Instance methods inherited from class Eagle::Node2D

direction_to(other : Node2D) : Vec2 direction_to, distance_to(other : Node2D) : Float32 distance_to, down : Vec2 down, forward : Vec2 forward, global_position : Vec2 global_position, global_position=(p : Vec2) global_position=, global_rotation : Float32 global_rotation, global_scale : Vec2 global_scale, global_transform : Transform2D global_transform, look_at(target : Vec2) : Nil look_at, modulate : Color modulate, modulate=(modulate : Color) modulate=, parent_2d : Node2D | Nil parent_2d, position : Vec2 position, position=(p : Vec2) position=, right : Vec2 right, rotate(rad : Number) : Nil rotate, rotation : Float32 rotation, rotation=(rotation : Float32) rotation=, rotation_degrees : Float32 rotation_degrees, rotation_degrees=(d : Number) rotation_degrees=, scale : Vec2 scale, scale=(s : Vec2)
scale=(s : Number) scale=, to_global(local : Vec2) : Vec2 to_global, to_local(global : Vec2) : Vec2 to_local, top_level=(top_level : Bool) top_level=, top_level? : Bool top_level?, transform : Transform2D transform, transform=(t : Transform2D) transform=, translate(x : Number, y : Number) : Nil
translate(v : Vec2) : Nil translate, x : Float32 x, x=(v : Number) x=, y : Float32 y, y=(v : Number) y=

Constructor methods inherited from class Eagle::Node2D

new(name : String = "", position : Eagle::Vec2 = Vec2::ZERO, rotation : Float32 = 0_f32, scale : Eagle::Vec2 = Vec2::ONE) new

Instance methods inherited from class Eagle::Node

<<(child : Node) : self <<, [](path : String) : Node [], []?(path : String) : Node | Nil []?, add(child : Node) : Node
add(*children : Node) : Nil add, add_child(child : Node) : Node add_child, add_to_group(group : String) : self add_to_group, ancestor_of?(node : Node) : Bool ancestor_of?, can_process? : Bool can_process?, child?(name : String) : Node | Nil child?, child_added : Eagle::Emitter(Node) child_added, child_count : Int32 child_count, child_removed : Eagle::Emitter(Node) child_removed, children : Array(Eagle::Node) children, children_of(type : T.class) : Array(T) forall T children_of, clear_children : Nil clear_children, draw(g : Graphics) : Nil draw, dump(io : IO = STDOUT, indent = 0) : Nil dump, each_ancestor(& : Node -> ) : Nil each_ancestor, each_child(& : Node -> ) : Nil each_child, each_descendant(&block : Node -> ) : Nil each_descendant, emit_child_added(*args) : Nil emit_child_added, emit_child_removed(*args) : Nil emit_child_removed, emit_tree_entered(*args) : Nil emit_tree_entered, emit_tree_exited(*args) : Nil emit_tree_exited, enter_tree : Nil enter_tree, exit_tree : Nil exit_tree, find(name : String) : Node | Nil find, find_all(type : T.class) : Array(T) forall T find_all, first_child : Node | Nil first_child, free : Nil free, get_node(path : String, type : T.class) : T forall T
get_node(path : String) : Node get_node, get_node?(path : String) : Node | Nil get_node?, groups : Set(String) groups, in_group?(group : String) : Bool in_group?, in_tree? : Bool in_tree?, input(event : Event) : Nil input, name : String name, name=(name : String) name=, on_child_added(&block : Node -> Nil) : Proc(Node, Nil) on_child_added, on_child_removed(&block : Node -> Nil) : Proc(Node, Nil) on_child_removed, on_tree_entered(&block : -> Nil) : Proc(Nil) on_tree_entered, on_tree_exited(&block : -> Nil) : Proc(Nil) on_tree_exited, parent : Node | Nil parent, path : String path, physics_process(dt : Float32) : Nil physics_process, process(dt : Float32) : Nil process, process_mode : Eagle::Node::ProcessMode process_mode, process_mode=(process_mode : Eagle::Node::ProcessMode) process_mode=, queue_free : Nil queue_free, queued_free? : Bool queued_free?, ready : Nil ready, ready_called? : Bool ready_called?, remove(child : Node) : Nil remove, remove_child(child : Node) : Nil remove_child, remove_from_group(group : String) : Nil remove_from_group, remove_from_parent : Nil remove_from_parent, resized(width : Int32, height : Int32) : Nil resized, root : Node root, to_s(io : IO) : Nil to_s, tree_entered : Eagle::Emitter() tree_entered, tree_exited : Eagle::Emitter() tree_exited, visible=(visible : Bool) visible=, visible? : Bool visible?, z_index : Int32 z_index, z_index=(z_index : Int32) z_index=

Constructor methods inherited from class Eagle::Node

new(name : String = "") new

Constructor Detail

def self.new(name : String = "", position : Vec2 = Vec2::ZERO, shape : Physics2D::Shape | Nil = nil) #

Creates a dynamic body.


Instance Method Detail

def angular_velocity : Float32 #

Spin in radians per second.


def angular_velocity=(v : Number) #

Sets the spin.


def apply_force(f : Vec2, point : Vec2 | Nil = nil) #

Pushes continuously during the next step. Call it every physics frame for thrust or wind. Applied at point in world space, it also causes spin.


def apply_impulse(i : Vec2, point : Vec2 | Nil = nil) #

Changes velocity instantly, for jumps, kicks and explosions. Applied at point, it also causes spin.


def apply_torque(t : Number) #

Spins the body during the next step.


def fixed_rotation=(v : Bool) #

Stops the body from rotating, which is useful for characters driven by physics.


def friction=(f : Number) #

Surface grip from 0 (ice) upward. 0.5 is a good default.


def gravity_scale=(s : Number) #

Multiplies gravity for this body. 0 makes it float.


def linear_damping=(d : Number) #

Drag that slows the body over time, like air resistance.


def mass : Float32 #

Mass. Heavier bodies push lighter ones around.


def mass=(m : Number) #

Sets the mass. Inertia follows the shapes.


def restitution=(r : Number) #

Bounciness from 0 (dead stop) to 1 (bounces back at full speed).


def velocity : Vec2 #

Linear velocity in pixels per second.


def velocity=(v : Vec2) #

Sets the linear velocity.