Difference between revisions of "B2.MouseJoint"

From GiderosMobile
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=== Methods ===
 
=== Methods ===
[[b2.MouseJoint:getDampingRatio]] {{<translate>returns the damping ratio</translate>}}<br/>
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[[b2.MouseJoint:getDampingRatio]] ''<translate>returns the damping ratio</translate>''<br/>
[[b2.MouseJoint:getFrequency]] {{<translate>returns the response frequency in Hertz</translate>}}<br/>
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[[b2.MouseJoint:getFrequency]] ''<translate>returns the response frequency in Hertz</translate>''<br/>
[[b2.MouseJoint:getMaxForce]] {{<translate>returns the maximum force in N</translate>}}<br/>
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[[b2.MouseJoint:getMaxForce]] ''<translate>returns the maximum force in N</translate>''<br/>
[[b2.MouseJoint:getTarget]] {{<translate>returns the x and y coordinates of the target point</translate>}}<br/>
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[[b2.MouseJoint:getTarget]] ''<translate>returns the x and y coordinates of the target point</translate>''<br/>
[[b2.MouseJoint:setDampingRatio]] {{<translate>sets the damping ratio (0 = no damping, 1 = critical damping)</translate>}}<br/>
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[[b2.MouseJoint:setDampingRatio]] ''<translate>sets the damping ratio (0 = no damping, 1 = critical damping)</translate>''<br/>
[[b2.MouseJoint:setFrequency]] {{<translate>sets the response frequency in Hertz</translate>}}<br/>
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[[b2.MouseJoint:setFrequency]] ''<translate>sets the response frequency in Hertz</translate>''<br/>
[[b2.MouseJoint:setMaxForce]] {{<translate>sets the maximum force in N</translate>}}<br/>
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[[b2.MouseJoint:setMaxForce]] ''<translate>sets the maximum force in N</translate>''<br/>
[[b2.MouseJoint:setTarget]] {{<translate>updates the target point</translate>}}<br/>
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[[b2.MouseJoint:setTarget]] ''<translate>updates the target point</translate>''<br/>
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=== Events ===
 
=== Events ===
 
=== Constants ===
 
=== Constants ===
 
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Revision as of 14:35, 23 August 2018

Supported platforms: android, ios, mac, pc
Available since: Gideros 2011.6

Description


A mouse joint is used to make a point on a body track a specified world point. This a soft constraint with a maximum force. This allows the constraint to stretch and without applying huge forces.

Examples

Mouse joint

--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

Methods

b2.MouseJoint:getDampingRatio returns the damping ratio
b2.MouseJoint:getFrequency returns the response frequency in Hertz
b2.MouseJoint:getMaxForce returns the maximum force in N
b2.MouseJoint:getTarget returns the x and y coordinates of the target point
b2.MouseJoint:setDampingRatio sets the damping ratio (0 = no damping, 1 = critical damping)
b2.MouseJoint:setFrequency sets the response frequency in Hertz
b2.MouseJoint:setMaxForce sets the maximum force in N
b2.MouseJoint:setTarget updates the target point

Events

Constants