Movement Problem in Corona

Solar2D Lua Language
#1

Hi, I’m trying to make a game where you swipe up, down, left or right to move a block in that direction, I’ve got all the code right, except for one small problem: In the swipe function, this line of code:  timer.performWithDelay(200, eventAdd), gives the user the ability to swipe the block in a different direction while it is still moving, which is something that I don’t want. However, if I comment out this line of code, it causes this problem: If I, for example, swipe up and allow the block to collide with “ceiling” and then try to swipe up again, the block sticks to “ceiling” and I am unable to make any more moves. Please help, any will be greatly appreciated :slight_smile:

local composer = require( “composer” )

local scene = composer.newScene()

local physics = require “physics”

physics.start()

physics.setGravity(0,0)

physics.setDrawMode(“normal”)

physics.setVelocityIterations( 100)

physics.setPositionIterations( 100)

local beginX 

local beginY  

local endX  

local endY 

local xDistance  

local yDistance  

local rect = display.newRect(10,10,10,10)

physics.addBody(rect,“dynamic”, {bounce = 0.000})

rect.linearDamping = 0

rect.isBullet = false

rect.isFixedRotation = true

rect.x = 200

rect.y = 210

rect.isAwake = false

rect.isBodyActive = true

rect:setFillColor(0,0,1)

local ceiling = display.newLine(0,0,500,0)

ceiling.y = -45

physics.addBody(ceiling, “static”, {density = 1000, bounce = 0, friction = -100})

local ground = display.newLine(0,0,500,0)

ground.y = 525

physics.addBody(ground, “static”, {density = 1000,bounce = 0, friction = -100})

local leftWall = display.newLine(-1,600,-1,-2000)

physics.addBody(leftWall, “static”, {density = 1000,bounce = 0, friction = -100})

local rightWall = display.newLine(321,600,321,-2000)

physics.addBody(rightWall, “static”, {density = 1000,bounce = 0})

function checkSwipeDirection()

        xDistance =  math.abs(endX - beginX) 

        yDistance =  math.abs(endY - beginY)

        

        if xDistance > yDistance then

                if beginX > endX then

                        print(“swipe left”)

                        rect:setLinearVelocity(-600,0)

                        

                else 

                        print(“swipe right”)

                        rect:setLinearVelocity(600,0)

                        

                end

        else 

                if beginY > endY then

                        print(“swipe up”)

                        rect:setLinearVelocity(0,-600)

                        

                else 

                        print(“swipe down”)

                        rect:setLinearVelocity(0,600)

                end

        end

        

end

function eventAdd()

    Runtime:addEventListener(“touch”, swipe)

end

function eventRemove()

    Runtime:removeEventListener(“touch”, swipe)

end

function swipe(event)

        if event.phase == “began” then

                beginX = event.x

                beginY = event.y

                

        end

        

        if event.phase == “ended”  then

                endX = event.x

                endY = event.y

                checkSwipeDirection();

                Runtime:removeEventListener(“touch”, swipe)

                timer.performWithDelay(200, eventAdd)  – this removes the problem of

                                                       – stick, however it allows                              

                                                       – the blocks to move at any point

                                                       – in time

        end

end

function onCollision( event )

if ( event.phase == “began” ) then

           timer.performWithDelay(200, eventAdd)

end

end

if rect.isAwake == false then

Runtime:addEventListener(“touch”, swipe)

end

Runtime:addEventListener(“collision”, onCollision)

#2

I figured out the problem, when you swipe left and then left again (or do the same for any other direction) it records the first collision as a collision, however, the second swipe in the same direction obviously makes it go nowhere, however, it is not recorded as a collision, but it is recorded as a swipe movement, therefore the event listener is removed and thus you can’t move. I don’t have any idea how to fix this and would really like some help. PLEASE! Any ideas on how to solve this will be appreciated, it’s been driving me crazy

#3

You should set some (probably global in the unit not on an object since you probably don’0t want want anything to move while another object is moving) variable that will tell you if there is an object already moving and in that situation ignore swipe. When the transition (movement) completes then unset the flag.

#4

I figured out the problem, when you swipe left and then left again (or do the same for any other direction) it records the first collision as a collision, however, the second swipe in the same direction obviously makes it go nowhere, however, it is not recorded as a collision, but it is recorded as a swipe movement, therefore the event listener is removed and thus you can’t move. I don’t have any idea how to fix this and would really like some help. PLEASE! Any ideas on how to solve this will be appreciated, it’s been driving me crazy

#5

You should set some (probably global in the unit not on an object since you probably don’0t want want anything to move while another object is moving) variable that will tell you if there is an object already moving and in that situation ignore swipe. When the transition (movement) completes then unset the flag.