Gideros Forum

AxlFlame

Ok, i'll do my best to explain my problem, i'd really apreciate any help!

I'm trying to create a shape at class X using a gestures module. The idea is: I have this game class and by using some values given by another class (Gestures) i wanted to create a shape at my game when the user draws a line.

Here is my code so far (this is written at the init function on the game class):

--Shape for gestures scope
local areaGestures = Shape.new()
areaGestures:setFillStyle(Shape.SOLID, 0xC0C0C0, 0.5)
areaGestures:beginPath(Shape.NON_ZERO)
areaGestures:moveTo(0, 190)
areaGestures:lineTo(application:getContentWidth(), 190)
areaGestures:lineTo(application:getContentWidth(), 220)
areaGestures:lineTo(0, 220)
areaGestures:lineTo(0, 190)
areaGestures:endPath()
self:addChild(areaGestures)

local font = TTFont.new("Fontes/tahoma.ttf", 20)

local myText = TextField.new(font, "Result: ")
myText:setPosition(50,50)
self:addChild(myText)

local function callback(name)
myText:setText(name)
end

local gest = Gestures.new({
debug = true,
draw = true,
drawColor = 0xff0000,
drawWidth = 5,
autoTrack = true,
scope = areaGestos,
allowRotation = true,
inverseShape = true,
points = 33
})

gest:addGesture("Line", {
{x = 0, y = 0},
{x = 0, y = 100}
}, callback)

gest:addGesture("ZigZag", {
{x = 0, y = 0},
{x = 50, y = 87},
{x = 100, y = 0},
{x = 150, y = 87},
}, callback)

local x = 0
local y = -100
local circle = {}
local totalPoints = 72
local step = (math.pi*2)/totalPoints

for angle = 1, totalPoints do
local newX = x*math.cos(angle*step)-y*math.sin(angle*step)
local newY = y*math.cos(angle*step)+x*math.sin(angle*step)
local point = {x = newX, y = newY}
table.insert(circle, point)
end

gest:addGesture("Circle", circle, callback)
--------------

In the Gestures class the values i need are the first and last points from the drawing made by the user that are stored in the self.points table.
The Gestures class i'm using is the one found at AppcodingEasy.com with some modifications that follows:

--Update
if match.name == "Line" then
local xIni = points[1].x;
local xFim = points[#points].x;
local yIni, yFim = 191, 220;
--local width = xFim - xIni;
--local height = yFim - yIni;
as = {}
as[i] = Shape.new()
as[i]:setFillStyle(Shape.SOLID, 00000000, 0.5)
as[i]:beginPath(Shape.NON_ZERO)
as[i]:moveTo(points[1].x, yIni)
as[i]:lineTo(points[#points].x, yIni)
as[i]:lineTo(points[#points].x, yFim)
as[i]:lineTo(points[1].x, yFim)
as[i]:lineTo(points[1].x, yIni)
as[i]:endPath()
stage:addChild(as[i])
i = i +1
floorcnt = floorcnt +1
print (floorcnt)
print (i)
if floorcnt > 1 then
stage:removeChild(as[i-1])
floorcnt = 0;
end
end

As you can see, i couldn't find a better way so i created the shape inside the Gestures class. But it just feels wrong.. The right thing would be to create the shape inside the game class, right?

So my question is, how can i access those values from another class and create shape using them? Also, would it be possible to limit the number of shapes on screen? Like, you can only have one at a time and if you draw another one the last one vanishes.

I'm sorry for the long post, i'm new to Gideros and i'm currently having a lot of problems to learn it.

Thank you for the attention!

Yuri

ar2rsawseen

Hello,

glad you found your way into the forum. ;)

It will be much easier to communicate this way.

So first you have a shape, where user can draw gestures. Right?

What does the second shape do, which is created inside Gestures class?

AxlFlame

Thanks. Hope I can count on you guys and the other way around too.

About the code, the second shape actually is gonna be a Physical body, the idea is to create a bridge where the player's character can walk.

I'm trying to use eventDispatcher to "transfer" the points[1].x and points[#points].x from the Gestures.lua to my game class, so i can create the shape inside my game class but it isn't working...

ar2rsawseen

Well outside the Gesture class it should look like (put it inside function as callback for drawing Line):

function lineCallback()
	--Update
	local xIni = gest.points[1].x;
	local xFim = gest.points[#gest.points].x;
	local yIni, yFim = 191, 220;
	--local width = xFim - xIni;
	--local height = yFim - yIni;
	as = {}
	as[i] = Shape.new()
	as[i]:setFillStyle(Shape.SOLID, 00000000, 0.5) 
	as[i]:beginPath(Shape.NON_ZERO)
	as[i]:moveTo(gest.points[1].x, yIni)
	as[i]:lineTo(gest.points[#gest.points].x, yIni)
	as[i]:lineTo(gest.points[#gest.points].x, yFim)
	as[i]:lineTo(gest.points[1].x, yFim)
	as[i]:lineTo(gest.points[1].x, yIni)
	as[i]:endPath()
	stage:addChild(as[i])
	i = i +1
	floorcnt = floorcnt +1
	print (floorcnt)
	print (i)
	if floorcnt > 1 then
		stage:removeChild(as[i-1])
		floorcnt = 0;
	end 
end

AxlFlame

You mean placing that code inside the callback function for the Line?
I tried that and this happens: "attempt to index global 'gest' (a nil value)"

Why he can't find the gest?

local gest = Gestures.new({
debug = true,
draw = true,
drawColor = 0xff0000,
drawWidth = 5,
autoTrack = true,
scope = areaGestos,
allowRotation = true,
inverseShape = true,
points = 33
})

gest:addGesture("Line", {
{x = 0, y = 0},
{x = 0, y = 100}
}, callback)

And the callback function:

local function callback(name)
myText:setText(name)
--Update
local xIni = gest.points[1].x;
local xFim = gest.points[#gest.points].x;
local yIni, yFim = 191, 220;
--local width = xFim - xIni;
--local height = yFim - yIni;
as = {}
as[i] = Shape.new()
as[i]:setFillStyle(Shape.SOLID, 00000000, 0.5)
as[i]:beginPath(Shape.NON_ZERO)
as[i]:moveTo(gest.points[1].x, yIni)
as[i]:lineTo(gest.points[#gest.points].x, yIni)
as[i]:lineTo(gest.points[#gest.points].x, yFim)
as[i]:lineTo(gest.points[1].x, yFim)
as[i]:lineTo(gest.points[1].x, yIni)
as[i]:endPath()
stage:addChild(as[i])
i = i +1
floorcnt = floorcnt +1
print (floorcnt)
print (i)
if floorcnt > 1 then
stage:removeChild(as[i-1])
floorcnt = 0;
end
end

Btw, how can i post my code like you do? Mine is so ugly and unorganized.

Thanks.

ar2rsawseen

About code posting:
http://www.giderosmobile.com/DevCenter/index.php/Forum_FAQ#How_can_I_highlight_my_Lua_code_in_the_forum_post.3F

About undefined gest, well it all depends on your code structure. The should be in the same upper scope. And gest definition should be before callback function. And probably some other circumstances I'm not aware of to make it happen. :)

Solution:
If you are using it inside the class, then make gest a class property:

self.gest = Gestures.new({
 debug = true,
 draw = true,
 drawColor = 0xff0000,
 drawWidth = 5,
 autoTrack = true,
 scope = areaGestos,
 allowRotation = true,
 inverseShape = true,
 points = 33
})

and then access it anywhere else inside the class by using self.gest

If you are not inside any class, then try removing local before definition of gest, to make it global (I know, a dirty hack).

AxlFlame

Nice, it worked, at least no more sintax erros... The problem now is that apparently the callback function isn't being called at all. I tried moving it and placing the () but still it won't work...

Here is what looks like so far:

Relevant stuff inside the game class (this is all inside the init function on the game class)
The area for drawing:

local areaGestos = Shape.new()
		areaGestos:setFillStyle(Shape.SOLID, 0xC0C0C0, 0.5)   
		areaGestos:beginPath(Shape.NON_ZERO)
		areaGestos:moveTo(0, 190)
		areaGestos:lineTo(application:getContentWidth(), 190)
		areaGestos:lineTo(application:getContentWidth(), 220)
		areaGestos:lineTo(0, 220)
		areaGestos:lineTo(0, 190)
		areaGestos:endPath()
		self:addChild(areaGestos)

Declaration for gest and adding the line:

self.gest = Gestures.new({
	debug = true,
	draw = true,
	drawColor = 0xff0000,
	drawWidth = 5,
	autoTrack = true,
	scope = areaGestos,
	allowRotation = true,
	inverseShape = true,
	points = 33
})
 
self.gest:addGesture("Line", {
	{x = 0, y = 0},
	{x = 0, y = 100}
}, callback)

The callback function, inside the game class. I tried to print those 2 values just to see if it was at least being called:

local function callback(name)
	myText:setText(name)
	print (floorcnt)
	print (i)
	--Update
	local xIni = self.gest.points[1].x;
	local xFim = self.gest.points[#self.gest.points].x;
	local yIni, yFim = 191, 220;
	--local width = xFim - xIni;
	--local height = yFim - yIni;
	as = {}
	as[i] = Shape.new()
	as[i]:setFillStyle(Shape.SOLID, 00000000, 0.5) 
	as[i]:beginPath(Shape.NON_ZERO)
	as[i]:moveTo(self.gest.points[1].x, yIni)
	as[i]:lineTo(self.gest.points[#self.gest.points].x, yIni)
	as[i]:lineTo(self.gest.points[#self.gest.points].x, yFim)
	as[i]:lineTo(self.gest.points[1].x, yFim)
	as[i]:lineTo(self.gest.points[1].x, yIni)
	as[i]:endPath()
	stage:addChild(as[i])
 
end

ar2rsawseen

callback function should be declared before using it when adding line. And you can try making same approach, by turning callback function to class property:

--self or whatever your class name is
self.callback = function(name)
	--all contents here
end
 
self.gest:addGesture("Line", {
	{x = 0, y = 0},
	{x = 0, y = 100}
}, self.callback)

AxlFlame

It is now declared right affer the gestures.new() and before the addGesture.
But this is happening:

"attempt to index field '?' (a nil value)"

This is reffering to this line:

local xIni = self.gest.points[1].x;

So that means it is not fiding the points table? Why?

ar2rsawseen

hard to tell what it can't find

try putting this before accessing points:

print(self)
print(self.gest)
print(self.gest.points)
print(self.gest.points[1])
print(self.gest.points[1].x)

And you'll see which is nil, which can not be found

AxlFlame

I did that and turns out its .x that cannot be found.

self.gest.points[1].x

All the others returned a table value: self
self.gest
self.gest.points

I don't understand, that x value should exist, why is it going like nil to the game class?

ar2rsawseen

Yes, checked the Gestures code and it is because internal points are reset when proper gesture is found, so it would be empty when there is an attempt for another gesture.

You can see it at:

function Gestures:resolve(points)
	if(#points>1) then
		self:reset()

If you remove self:reset(), then points won't be removed, but you would have to manually reset them inside callback function using gest:reset(), or you can simply move self:reset() to the end of resolve function.

AxlFlame

It worked! The problem was indeed with the self:reset on the Gestures class. I was starting to think i would have to appeal to black magic to get this done... Thanks a lot Arturs!
About the second part of this post... limiting the number of shapes on screen.

I'm trying to only allow 1 shape per time drawn on screen. Meaning if the player draws another shape, the first one should be removed or anything like that.

For this i thought the solution would be creating an array of shapes and a counter, so i can control how much is on screen.

I declared these 2 before the init function to serve as controllers.

local floorcnt = 0
local i = 0

Then inside the callback function its like this:

self.callback = function(name)
	myText:setText(name)
	print (floorcnt)
	print (i)
	--Update
	local xIni = self.gest.points[1].x;
	local xFim = self.gest.points[#self.gest.points].x;
	local yIni, yFim = 191, 220;
	--local width = xFim - xIni;
	--local height = yFim - yIni;
	as = {}
	as[i] = Shape.new()
	as[i]:setFillStyle(Shape.SOLID, 00000000, 0.5) 
	as[i]:beginPath(Shape.NON_ZERO)
	as[i]:moveTo(self.gest.points[1].x, yIni)
	as[i]:lineTo(self.gest.points[#self.gest.points].x, yIni)
	as[i]:lineTo(self.gest.points[#self.gest.points].x, yFim)
	as[i]:lineTo(self.gest.points[1].x, yFim)
	as[i]:lineTo(self.gest.points[1].x, yIni)
	as[i]:endPath()
	if floorcnt >= 1 then
		self:removeChild(as[i-1])
		self:addChild(as[i])
	else
		self:addChild(as[i])
	end
	i = i + 1
	floorcnt = floorcnt + 1	
end

But, for some reason i keep getting this error:
"bad argument #1 to 'removeChild' (Sprite expected, got nil)"

What is bugging me is that i can add the child but can't remove it... what is going on?

Thanks!

ar2rsawseen

If you need to limit only to one shape, then it's easy, you simply have one property to store shape in it and that's all:

local someShape = Shape.new()
self.callback = function(name)
	myText:setText(name)
	--Update
	local xIni = self.gest.points[1].x;
	local xFim = self.gest.points[#self.gest.points].x;
	local yIni, yFim = 191, 220;
	--local width = xFim - xIni;
	--local height = yFim - yIni;
	--clear previous shape
	someShape:clear()
	--draw new shape
	:setFillStyle(Shape.SOLID, 00000000, 0.5) 
	someShape:beginPath(Shape.NON_ZERO)
	someShape:moveTo(self.gest.points[1].x, yIni)
	someShape:lineTo(self.gest.points[#self.gest.points].x, yIni)
	someShape:lineTo(self.gest.points[#self.gest.points].x, yFim)
	someShape:lineTo(self.gest.points[1].x, yFim)
	someShape:lineTo(self.gest.points[1].x, yIni)
	someShape:endPath()	
end

That would be the best way to do it, because you are reusing existing shape.

As to why your code is not working I really can't tell from the first sight, without deeper debugging :)

AxlFlame

Ok, but what if you were to add an physical body to that shape? Something for the player's character to walk above it. Would something like this work?

My idea was to create a physical body just the size of the bridge shape i currently have.
Still... it isn't creating the body, the fixture at least, as the character just passes through the shape and fall.

Up there, before the init function i declared a b2World to use:

local b2World

My callback function:

self.callback = function(name)
	myText:setText(name)
	--Update
	local xIni = self.gest.points[1].x;
	local xFim = self.gest.points[#self.gest.points].x;
	local yIni, yFim = 196, 225;
	--Clear all
	bridge:clear()
	if bridge.body then
		b2World:destroyBody(bridge.body)
	end
	--Creating new shape
	bridge:setFillStyle(Shape.SOLID, 00000000, 0.5) 
	bridge:beginPath(Shape.NON_ZERO)
	bridge:moveTo(self.gest.points[1].x, yIni)
	bridge:lineTo(self.gest.points[#self.gest.points].x, yIni)
	bridge:lineTo(self.gest.points[#self.gest.points].x, yFim)
	bridge:lineTo(self.gest.points[1].x, yFim)
	bridge:lineTo(self.gest.points[1].x, yIni)
	bridge:endPath()
 
	areaGestos:addChild(bridge)
 
	--Physical body
	bridge.body = b2World:createBody{type = b2STATIC_BODY, 
				position = {x = bridge:getX(), y = bridge:getY()},
				};
	bridge.body.name = "bridge";	
	local bridgeShape = b2.PolygonShape.new()
	local bridgeWidth = bridge:getWidth()
	local bridgeHeight = bridge:getHeight()
	bridgeShape:set(-bridgeWidth, -bridgeHeight,
			-bridgeWidth+bridgeWidth*currentPathLen, -bridgeHeight,
			-bridgeWidth+bridgeWidth*currentPathLen, bridgeHeight,
			-bridgeWidth, bridgeHeight);	
	bridge.body:createFixture{shape = bridgeShape,
						friction = 0,
						restitution = 0,
						density = 10,
						isSensor = false
						};	
end

EDIT:

Ok, i actually got it, just switched the 'bridge:getX()' and 'bridge:getY()' for 'self.gest.points[1].x' and 'yFim' respectively. That way it gets the right position for the body!

AxlFlame

So, I got myself a new problem... It's regarding the bridge shape/physical body, thus i thought it would be ok to use this topic again.

Here's the deal: I created the shape/physical body for the bridge and both are working fine, but the game class has an parallax effect so it feels like an 2d side-scroller, moving the background always to the left.

How can i create the same effect for my bridge so it goes left with my background?

This is my callback function:

self.callback = function(name)
	myText:setText(name)
	--Update
	local xIni = self.gest.points[1].x;
	local xFim = self.gest.points[#self.gest.points].x;
	local yIni, yFim = 196, 225;
	--Erase
	bridge:clear()
	if bridge.body then
		b2World:destroyBody(bridge.body)
	end
	--New shape
	bridge:setFillStyle(Shape.SOLID, 00000000, 0.5) 
	bridge:beginPath(Shape.NON_ZERO)
	bridge:moveTo(self.gest.points[1].x, yIni)
	bridge:lineTo(self.gest.points[#self.gest.points].x, yIni)
	bridge:lineTo(self.gest.points[#self.gest.points].x, yFim)
	bridge:lineTo(self.gest.points[1].x, yFim)
	bridge:lineTo(self.gest.points[1].x, yIni)
	bridge:endPath()
	areaGestos:addChild(bridge)
 
	--Physical body for the bridge
	bridge.body = b2World:createBody{type = b2STATIC_BODY, 
							position = {x = self.gest.points[1].x, y = yFim-4},
							};
	bridge.body.name = "bridge";	
	local bridgeShape = b2.PolygonShape.new()
	local bridgeWidth = bridge:getWidth()
	local bridgeHeight = bridge:getHeight()
	bridgeShape:set(-bridgeWidth, -bridgeHeight,
					-bridgeWidth+bridgeWidth*currentPathLen, -bridgeHeight,
					-bridgeWidth+bridgeWidth*currentPathLen, bridgeHeight,
					-bridgeWidth, bridgeHeight);	
	bridge.body:createFixture{shape = bridgeShape,
						friction = 0,
						restitution = 0,
						density = 10,
						isSensor = false
						};	
	print (bridge.x)

And here i tried to make it move using the layer1Speed, already declared:

	function bridge:onEnterFrame()
		self:setX(self:getX()-layer1Speed);
		if self:getX() < screenWidth then
			bridge:clear()
			bridge:removeListeners()
		end
	end	
	function bridge:removeListeners()
		bridge:removeEventListener(Event.ENTER_FRAME, bridge.onEnterFrame, bridge);
	end
	function bridge:addListeners()
	  bridge:addEventListener(Event.ENTER_FRAME, bridge.onEnterFrame, bridge);
	end	
	bridge:addEventListener(Event.ENTER_FRAME, bridge.onEnterFrame, bridge);

With this code 2 things happened:

1- The shape did move to the left, but its body stayed still.

2- The shape sometimes isn't even drawn, but the body is there.

And one last thing: I tried printing the X for the bridge but somehow it returns a nil to me, even though the shape/body are created on scene, what could be causing it?

ar2rsawseen

Well, the problem is, that you are moving Shape object, which is attached to box2d physical object, which is not moving, because it should not move by definition of box2d world :)

Basically solution should be to move box2d object, which you have referenced inside bridge.body

function bridge:onEnterFrame()
	self.body:setPosition(self:getX()-layer1Speed, self:getY());
	if self:getX() < screenWidth then
		self:clear()
		self:removeListeners()
	end
end

And the Shape will folow ;)

AxlFlame

Well, i think i understand, but now the problem is inverse. The shape is being drawn but the physical body isn't there.
And when i try to print the bridge x up there, it still returns a nil to me.

Is it related, somehow?

ar2rsawseen

Then it means that body is moving and shape is not? :)

Inside on enter frame do you have something like:

-- edit the step values if required. These are good defaults!
	self.world:step(1/60, 8, 3)
	--iterate through all child sprites
	for i = 1, self:getNumChildren() do
		--get specific sprite
		local sprite = self:getChildAt(i)
		-- check if sprite HAS a body (ie, physical object reference we added)
		if sprite.body then
			--update position to match box2d world object's position
			--get physical body reference
			local body = sprite.body
			--get body coordinates
			local bodyX, bodyY = body:getPosition()
			--apply coordinates to sprite
			sprite:setPosition(bodyX, bodyY)
			--apply rotation to sprite
			sprite:setRotation(body:getAngle() * 180 / math.pi)
		end
	end

to move visual objects along with physical bodies?

AxlFlame

Actually no it's not. Something weird is happening and i can't tell why.
Using this code on the bridge on enter frame:

function bridge:onEnterFrame()
	self.body:setPosition(self:getX()-layer1Speed, self:getY());
	if self:getX() < screenWidth then
		self:clear()
		self:removeListeners()
	end
end

I tried to debugdraw and i saw that the shape is not being drawn and the position of the physical body is on the top of the screen, it's like its not getting the bridge X at all.
But the shape should have an X and Y, right?
It would be best if i just used an bitmap to create the bridge instead of the shape?
When i try to print the bridge X it just returns nil to me...

I'm still using the exact callback function that i pasted here before.

You mean inside the bridge:onEnterFrame or the game class enter frame?
I have that code inside my gameclass on enter frame, inside the bridge one i just have that portion of the code i pasted on the last post.

This is my game class onEnterFrame:

function gameClass:onEnterFrame() 
	--get screen dimensions
	local screenW = application:getContentWidth()
	local screenH = application:getContentHeight()
 
	--Scores
	currentScore = currentScore+layer1Speed;
	objScore:setScore(currentScore);
 
	--define offsets
	local offsetX = 0;
	local offsetY = 0;
 
	--here we need to update the physics world, and the score.
	b2World:step(worldStep, 8, 3);
	--currentScore = currentScore+layer1Speed;
	--objScore:setScore(currentScore);
	--iterate through all child sprites
	for i = 1, self:getNumChildren() do
		--get specific sprite
		local sprite = self:getChildAt(i)
		-- check if sprite HAS a body (ie, physical object reference we added)
		if sprite.body then
			--update position to match box2d world object's position
			--get physical body reference
			local body = sprite.body
			--get body coordinates
			local bodyX, bodyY = body:getPosition()
			--apply coordinates to sprite
			sprite:setPosition(bodyX, bodyY)
			--apply rotation to sprite
			sprite:setRotation(body:getAngle() * 180 / math.pi)
		end
	end
end

ar2rsawseen

Yes, the code in your post is what moves physical bodies and the sprites along them.

And there are two things to keep in mind, for a shape to properly position with physical body, it need to have 0,0 coordinates in center, so it should be drawn like:

--just example values
local width, height = 20, 100
bridge:beginPath(Shape.NON_ZERO)
bridge:moveTo(-width, -height)
bridge:lineTo(width, -height)
bridge:lineTo(width, height)
bridge:lineTo(-width, height)
bridge:lineTo(-width, -height)
bridge:endPath()

and then position bridge at according positions where you want it to be

And second thing, is a bridge (Which is a Shape object) a direct child of game class?

AxlFlame

I see, but my bridge code creates the shape based on the player's drawing. Meaning its width would be always different as it gets the first and last points from the line drawn by the player. How could i solve that?

	bridge:setFillStyle(Shape.SOLID, 00000000, 0.5) 
	bridge:beginPath(Shape.NON_ZERO)
	bridge:moveTo(self.gest.points[1].x, yIni)
	bridge:lineTo(self.gest.points[#self.gest.points].x, yIni)
	bridge:lineTo(self.gest.points[#self.gest.points].x, yFim)
	bridge:lineTo(self.gest.points[1].x, yFim)
	bridge:lineTo(self.gest.points[1].x, yIni)
	bridge:endPath()
	areaGestos:addChild(bridge)

And the bridge is not a child of the game class, i was creating it as a child of my drawable area so it doesn't get in front of other objects on screen. For that reason, i created that onEnterFrame function just for the bridge, which is created/called inside the callback function. Is it a problem?

My callback function so far:

self.callback = function(name)
	myText:setText(name)
	--Update
	local xIni = self.gest.points[1].x;
	local xFim = self.gest.points[#self.gest.points].x;
	local yIni, yFim = 196, 225;
	--Erase
	bridge:clear()
	if bridge.body then
		b2World:destroyBody(bridge.body)
	end
	--New shape
	bridge:setFillStyle(Shape.SOLID, 00000000, 0.5) 
	bridge:beginPath(Shape.NON_ZERO)
	bridge:moveTo(self.gest.points[1].x, yIni)
	bridge:lineTo(self.gest.points[#self.gest.points].x, yIni)
	bridge:lineTo(self.gest.points[#self.gest.points].x, yFim)
	bridge:lineTo(self.gest.points[1].x, yFim)
	bridge:lineTo(self.gest.points[1].x, yIni)
	bridge:endPath()
	areaGestos:addChild(bridge)
 
	--Physical body
	bridge.body = b2World:createBody{type = b2STATIC_BODY, 
					position = {x = self.gest.points[1].x, y = yFim-4},
					};
	bridge.body.name = "bridge";	
	local bridgeShape = b2.PolygonShape.new()
	local bridgeWidth = bridge:getWidth()
	local bridgeHeight = bridge:getHeight()
	bridgeShape:set(-bridgeWidth, -bridgeHeight,
					-bridgeWidth+bridgeWidth*currentPathLen, -bridgeHeight,
					-bridgeWidth+bridgeWidth*currentPathLen, bridgeHeight,
					-bridgeWidth, bridgeHeight);	
	bridge.body:createFixture{shape = bridgeShape,
						friction = 0,
						restitution = 0,
						density = 10,
						isSensor = false
						};	
	print (bridge.x)
	--Trying to move the bridge with the background
	function bridge:onEnterFrame()
		self.body:setPosition(self:getX()-layer1Speed, self:getY());
		if self:getX() < screenWidth then
			self:clear()
			self:removeListeners()
		end
	end
	function bridge:removeListeners()
		bridge:removeEventListener(Event.ENTER_FRAME, bridge.onEnterFrame, bridge);
	end
	function bridge:addListeners()
	  bridge:addEventListener(Event.ENTER_FRAME, bridge.onEnterFrame, bridge);
	end	
	bridge:addEventListener(Event.ENTER_FRAME, bridge.onEnterFrame, bridge);
end

One last thing, when i try to print bridge:getX() it returns me an 0....
That wasn't supposed to happen, right?

ar2rsawseen

Oh ok, so I probably misunderstood where you were going with this.

So about the shape it's easy, you simple get difference between first point and last point to get height and width and divide by 2 to take half width, like:

local width = math.abs(self.gest.points[1].x - self.gest.points[#self.gest.points].x)/2
local height = math.abs(yIni - yFim)/2

Why it returns 0 or nil, maybe it's a scope problem, can't tell.

But I tell you, it's hard to get my head around on this :D Maybe if you want you can share simple project where you are now, so I could experiment and make it work. Or if you don't want to share it here, you can email it to me to my username at gmail.com

AxlFlame

Ok, your email is ar2rsawseen@gmail.com right?
I just sent you my project, hope you can give it some light. I'm sorry for all the trouble!
I managed to make the bridge body have the right size, but still only the shape moves...
Hope you can help me with that! Thanks!

ar2rsawseen

Sure, will look at it today on the lunch break ;)

AxlFlame

So, i'm trying some new things here but not with a lot of success... did you received the email with the project? Turns out the project was a little bigger than i expected so i'm not sure that it was sent as it should.

ar2rsawseen

@AxlFlame yes, sorry, I've received your project, it was just so large, with so many features, that it was too hard to navigate at first and is taking me definitely more than a lunch break to figure it out. But I'll get there eventually and will notify you via email asap ;)

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