19.4.28 setVelocityFunc

self = physics.Body:setVelocityFunc(func)

Parameter

Type

Description

self

in physics.Body

The input Body

func

in function(body, grav, damping, dt)

A callback function that updates the ve- locity of the Body on each time step

self

out physics.Body

The input Body is returned as the output

Sets the velocity function of the body. The velocity function must be a function that accepts a Body, a gravity vector, a numeric damping factor, and a time step value. The function should call body:updateVelocity to adjust the velocity of the body.

Returns the Body.

Listing 19.2: Example for physics.Body:setVelocityFunc()

functionsampleVelocityFunc(body, gravity, damping, dt) 
    local pos = body:pos()
    local sqdist = pos:lengthsq()
    local g = pos:mult(-GravityStrength /
        (sqdist * math.sqrt(sqdist)))
    body:updateVelocity(g, damping, dt)
end

body:setVelocityFunc(sampleVelocityFunc)

Introduced in platform.apiLevel = '2.0'