Collision Detection isTouching issue

[chester.t.gardner3]

Hi, I posted a little while back, and had a reasonably quick response, so thought I’d try again, with my latest issue. I posted this on StackOverflow too, just in case.

I have a simple project at the moment, to demonstrate my issue.

I have 4 boundaries around a player_object -> newRect. The boundaries are static, the player_object is dynamic. The following code does apply a collision detection, and prevents the player_object from moving through the boundary, but, if the user then pressed the direction key again, in the direction of the boundary that the player_object isTouching, the player_object passes through the boundary object then the collision detection reasserts, and the player_object’s movement stops. I’ve had a look at preCollision and object properties, but I think there is something inherently wrong in my approach. Ideas?

local composer = require( "composer" ) local scene = composer.newScene() local physics = require( "physics" ) physics.start() physics.setGravity( 0, 0 ) -- system.activate( "multitouch" ) -- Variables width = display.actualContentWidth height = display.actualContentHeight movementX = 0 movementY = 0 movementSpeed = 5 playerMoving = false wDown = false aDown = false sDown = false dDown = false -- / -- Map group\_map1 = display.newGroup() mapBoundary\_left = display.newRect(width \* 0.051, height \* 0.5, width \* 0.01, height) mapBoundary\_right = display.newRect(width \* 0.949, height \* 0.5, width \* 0.01, height) mapBoundary\_top = display.newRect(width \* 0.5, height \* 0.051, width, width \* 0.01) mapBoundary\_bottom = display.newRect(width \* 0.5, height \* 0.949, width, width \* 0.01) mapBoundary\_left:setFillColor(1,1,1) mapBoundary\_right:setFillColor(1,1,1) mapBoundary\_top:setFillColor(1,1,1) mapBoundary\_bottom:setFillColor(1,1,1) mapBoundary\_left.type = "leftboundary" mapBoundary\_right.type = "rightboundary" mapBoundary\_top.type = "topboundary" mapBoundary\_bottom.type = "bottomboundary" physics.addBody( mapBoundary\_left, "static", {friction=1, bounce=0} ) physics.addBody( mapBoundary\_right, "static", {friction=1, bounce=0} ) physics.addBody( mapBoundary\_top, "static", {friction=1, bounce=0} ) physics.addBody( mapBoundary\_bottom, "static", {friction=1, bounce=0} ) -- / -- Player player\_object = display.newRect(width \* 0.5,height \* 0.5,10,10) physics.addBody( player\_object, "dynamic", {friction=1, bounce=0} ) player\_object.type = "player" function func\_collision(self, event) if event.other.type == "leftboundary" then aDown = false elseif event.other.type == "rightboundary" then dDown = false elseif event.other.type == "topboundary" then wDown = false elseif event.other.type == "bottomboundary" then sDown = false end end player\_object.collision = func\_collision player\_object:addEventListener("collision") -- / function func\_movePlayer(event) if aDown == true and dDown == true then movementX = 0 elseif aDown == true and dDown == false then movementX = -movementSpeed elseif aDown == false and dDown == true then movementX = movementSpeed elseif aDown == false and dDown == false then movementX = 0 end if wDown == true and sDown == true then movementY = 0 elseif wDown == true and sDown == false then movementY = -movementSpeed elseif wDown == false and sDown == true then movementY = movementSpeed elseif wDown == false and sDown == false then movementY = 0 end player\_object.x = player\_object.x + movementX player\_object.y = player\_object.y + movementY player\_object.rotation = 0 end Runtime:addEventListener("enterFrame", func\_movePlayer) function func\_onKeyEvent( event ) local message = "Key '" .. event.keyName .. "' was pressed " .. event.phase -- print( message ) if event.keyName == "w" then if event.phase == "down" then wDown = true elseif event.phase == "up" then wDown = false end end if event.keyName == "a" then if event.phase == "down" then aDown = true elseif event.phase == "up" then aDown = false end end if event.keyName == "s" then if event.phase == "down" then sDown = true elseif event.phase == "up" then sDown = false end end if event.keyName == "d" then if event.phase == "down" then dDown = true elseif event.phase == "up" then dDown = false end end if event.keyName == "space" then -- Attack/Jump? end end Runtime:addEventListener( "key", func\_onKeyEvent )

[Alex10]

You are moving your object incrementally, rather than using physics to move it. You need to decide whether you want to use physics to control the bounds the player can move, or do it in code. I personally prefer to use physics wherever I can, since I can always switch easily if necessary.

I changed very little of your code, so to illustrate the change, modify your Runtime listener with the below:

 --player\_object.x = player\_object.x + movementX --player\_object.y = player\_object.y + movementY player\_object:setLinearVelocity((movementX),(movementY)) player\_object.rotation = 0

You don’t really need the rotation locking line there, as the isFixedRotation API will accomplish the same thing. I would also suggest increasing the  movementSpeed value to something above 100, so that the movement can take place at a faster rate.

[chester.t.gardner3]

Thank you so very kindly for this! I would not have gotten to that solution without help!

It’s strange though, because I’m fairly certain that the code I used was taken from one of the Corona Tutorials (I’ve had this code & problem sitting for a while though, and cannot find the tutorial again).

None-the-less. THANKS!

[Alex10]

You are moving your object incrementally, rather than using physics to move it. You need to decide whether you want to use physics to control the bounds the player can move, or do it in code. I personally prefer to use physics wherever I can, since I can always switch easily if necessary.

I changed very little of your code, so to illustrate the change, modify your Runtime listener with the below:

 --player\_object.x = player\_object.x + movementX --player\_object.y = player\_object.y + movementY player\_object:setLinearVelocity((movementX),(movementY)) player\_object.rotation = 0

You don’t really need the rotation locking line there, as the isFixedRotation API will accomplish the same thing. I would also suggest increasing the  movementSpeed value to something above 100, so that the movement can take place at a faster rate.

[chester.t.gardner3]

Thank you so very kindly for this! I would not have gotten to that solution without help!

It’s strange though, because I’m fairly certain that the code I used was taken from one of the Corona Tutorials (I’ve had this code & problem sitting for a while though, and cannot find the tutorial again).

None-the-less. THANKS!