Difference between revisions of "B2.World:step"
From GiderosMobile
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'''<translate>Available since</translate>:''' Gideros 2011.6<br/> | '''<translate>Available since</translate>:''' Gideros 2011.6<br/> | ||
'''<translate>Class</translate>:''' [[Special:MyLanguage/b2.World|b2.World]]<br/> | '''<translate>Class</translate>:''' [[Special:MyLanguage/b2.World|b2.World]]<br/> | ||
| + | |||
=== <translate>Description</translate> === | === <translate>Description</translate> === | ||
| − | + | Takes a time step. This performs collision detection, integration, and constraint solution. | |
| − | |||
| − | |||
<source lang="lua"> | <source lang="lua"> | ||
| − | + | b2.World:step(timeStep,velocityIterations,positionIterations) | |
</source> | </source> | ||
| − | + | ||
=== <translate>Parameters</translate> === | === <translate>Parameters</translate> === | ||
'''timeStep''': (number) <translate>the amount of time to simulate, this should not vary</translate> <br/> | '''timeStep''': (number) <translate>the amount of time to simulate, this should not vary</translate> <br/> | ||
'''velocityIterations''': (number) <translate>for the velocity constraint solver</translate> <br/> | '''velocityIterations''': (number) <translate>for the velocity constraint solver</translate> <br/> | ||
'''positionIterations''': (number) <translate>for the position constraint solver</translate> <br/> | '''positionIterations''': (number) <translate>for the position constraint solver</translate> <br/> | ||
| − | + | ||
=== <translate>Examples</translate> === | === <translate>Examples</translate> === | ||
| − | '''Creating Box2d body and moving Bitmap along the body''' | + | '''Creating Box2d body and moving Bitmap along the body''' |
| − | <source lang="lua">require "box2d" | + | <source lang="lua"> |
| + | require "box2d" | ||
local world = b2.World.new(0, 10, true) | local world = b2.World.new(0, 10, true) | ||
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ball:setPosition(ball.body:getPosition()) | ball:setPosition(ball.body:getPosition()) | ||
ball:setRotation(math.rad(ball.body:getAngle())) | ball:setRotation(math.rad(ball.body:getAngle())) | ||
| − | end)</source> | + | end) |
| + | </source> | ||
| + | |||
| + | {{B2.World}} | ||
Revision as of 17:29, 18 February 2020
Available since: Gideros 2011.6
Class: b2.World
Description
Takes a time step. This performs collision detection, integration, and constraint solution.
b2.World:step(timeStep,velocityIterations,positionIterations)
Parameters
timeStep: (number) the amount of time to simulate, this should not vary
velocityIterations: (number) for the velocity constraint solver
positionIterations: (number) for the position constraint solver
Examples
Creating Box2d body and moving Bitmap along the body
require "box2d"
local world = b2.World.new(0, 10, true)
--create ball bitmap object from ball graphic
local ball = Bitmap.new(Texture.new("ball.png"))
--reference center of the ball for positioning
ball:setAnchorPoint(0.5,0.5)
ball:setPosition(100,100)
--get radius
local radius = ball:getWidth()/2
--create box2d physical object
local body = world:createBody{type = b2.DYNAMIC_BODY}
local circle = b2.CircleShape.new(0, 0, radius)
local fixture = body:createFixture{shape = circle, density = 1.0,
friction = 0.1, restitution = 0.2}
ball.body = body
--add to scene
stage:addChild(ball)
stage:addEventListener(Event.ENTER_FRAME, function()
-- edit the step values if required. These are good defaults!
world:step(1/60, 8, 3)
ball:setPosition(ball.body:getPosition())
ball:setRotation(math.rad(ball.body:getAngle()))
end)
