local physics = require "physics"
physics.start()
physics.setGravity(0, 20)
physics.setDrawMode( "hybrid" )
 
-- create player with "complex body"
local player = display.newImage( "player.png",100,100 )
local playerBodyShape = { -4,-10 , 4,-10 , 4,10 , -4,10 } -- index 1
local groundSensor = { -4,12 , 4,12 , 4,20 , -4,20 } -- index 2
 
physics.addBody( player, "dynamic", 
        { density=3, friction=0, bounce=0, shape=playerBodyShape },
        { density=0, friction=0, bounce=0, shape=groundSensor, isSensor = true }
)
player.isFixedRotation = true
 
-- create ground
local ground = display.newRect(0, 300, 480, 20); ground:setFillColor(0,0,200)
physics.addBody( ground, "static", { density=3.0, friction=0.5, bounce=0 } )
 
-- jump button
local function touchMyRectangle(event) 
        local phase = event.phase
                        
        if phase == "began" then
                player:applyLinearImpulse( 0, -5, player.x, player.y )
        end
end
 
local myRectangle = display.newRect(0, 0, 480, 320); myRectangle:setFillColor(0,0,0,0)
myRectangle:addEventListener( "touch", touchMyRectangle )
 
-- player collision
local function OnPlayerCollision(self, event)
        
        if event.phase == "began" then
                print (event.selfElement) -- selfElement index # is correct
                
        elseif event.phase == "ended" then
                print (event.selfElement) -- selfElement index # is not correct
        end
end
 
player.collision = OnPlayerCollision
player:addEventListener("collision", player)