B2.createMouseJointDef

From GiderosMobile
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.


Available since: Gideros 2011.6
Class: b2

Description

Creates and returns a mouse joint definition table with the bodies, world target point, maxForce and optional frequencyHz and dampingRatio.

(Please refer to b2.World:createJoint function for more information about all the information needed to create a mouse joint).

(table) = b2.createMouseJointDef(bodyA,bodyB,targetx,targety,maxForce,frequencyHz,dampingRatio)

Parameters

bodyA: (b2.Body) the first attached body
bodyB: (b2.Body) the second attached body
targetx: (number) the x coordinate of the world target point
targety: (number) the y coordinate of the world target point
maxForce: (number) the maximum constraint force that can be exerted to move the candidate body
frequencyHz: (number, default = 5) the response speed
dampingRatio: (number, default = 0.7) the damping ratio. 0 = no damping, 1 = critical damping

Return values

Returns (table) A new mouse joint definition table

Examples

--create empty box2d body for joint
local ground = world:createBody({})

--joint with dummy body
local mouseJoint = nil

-- create a mouse joint on mouse down
function self:onMouseDown(event)
	local jointDef = b2.createMouseJointDef(ground, body, event.x, event.y, 100000)
	mouseJoint = world:createJoint(jointDef)
end

-- update the target of mouse joint on mouse move
function self:onMouseMove(event)
	if mouseJoint ~= nil then
		mouseJoint:setTarget(event.x, event.y)
	end
end

-- destroy the mouse joint on mouse up
function self:onMouseUp(event)
	if mouseJoint ~= nil then
		world:destroyJoint(mouseJoint)
		mouseJoint = nil
	end
end





LiquidFun