Can I use physics to do this?

Solar2D General Questions/Discussion
#1

Hello,

I was wondering if it is possible to make a door handle like object and be able to use physics to push it down. Like this:

luxurious-office-door-handles-ZnqVk.jpg

So when you tap the handle, it goes down, and when you lift up your finger, it goes back up.

#2

I’m pretty sure this is possible, but potentially not needed. A sprite animation or a transition.to() transitioning rotation would probably take care of it.

#3

A simple example:

 local physics = require "physics" physics.setDrawMode( "hybrid" ) physics.start() physics.setGravity(0, 0) local ball = display.newCircle(100, 240, 5) local base = display.newCircle(200, 200, 50) local handle = display.newRect(base.x, 200, 200, 40) handle:setFillColor(0.5) handle.anchorX = 0.9 physics.addBody(ball, "dynamic") physics.addBody(handle, "dynamic") physics.addBody(base, "static" ) base.isSensor = true local joint = physics.newJoint( "pivot", handle, base, base.x, base.y) joint:setRotationLimits( 0, 90 ) joint.isLimitEnabled = true local function handleTouch(event) if event.phase == "began" then display.getCurrentStage():setFocus(handle) handle:applyAngularImpulse( -40 ) elseif event.phase == "ended" then transition.to(handle, {rotation = 0, time = 1000}) handle:applyAngularImpulse( 40 ) end end handle:addEventListener("touch", handleTouch)

But as Rob says, physics might not be needed, in which case it becomes simpler. To turn the above into a physics-less version, all you have to do is remove all the physics-related bits and use transition.to instead of applying an angular impulse.

#4

Thanks Rob and hasty. I got it working now.

#5

I’m pretty sure this is possible, but potentially not needed. A sprite animation or a transition.to() transitioning rotation would probably take care of it.

#6

A simple example:

 local physics = require "physics" physics.setDrawMode( "hybrid" ) physics.start() physics.setGravity(0, 0) local ball = display.newCircle(100, 240, 5) local base = display.newCircle(200, 200, 50) local handle = display.newRect(base.x, 200, 200, 40) handle:setFillColor(0.5) handle.anchorX = 0.9 physics.addBody(ball, "dynamic") physics.addBody(handle, "dynamic") physics.addBody(base, "static" ) base.isSensor = true local joint = physics.newJoint( "pivot", handle, base, base.x, base.y) joint:setRotationLimits( 0, 90 ) joint.isLimitEnabled = true local function handleTouch(event) if event.phase == "began" then display.getCurrentStage():setFocus(handle) handle:applyAngularImpulse( -40 ) elseif event.phase == "ended" then transition.to(handle, {rotation = 0, time = 1000}) handle:applyAngularImpulse( 40 ) end end handle:addEventListener("touch", handleTouch)

But as Rob says, physics might not be needed, in which case it becomes simpler. To turn the above into a physics-less version, all you have to do is remove all the physics-related bits and use transition.to instead of applying an angular impulse.

#7

Thanks Rob and hasty. I got it working now.