my example code is down there. i want that wheel to cind of “collect” (dont know the english word) this chain and move this cind of strange crane up or down. but my joints dont: they always go around the wheel. how can i change this?
greetings, maxiking
the Main:
function setup()
displayMode(FULLSCREEN)
supportedOrientations(LANDSCAPE_ANY)
w = WIDTH
h = HEIGHT
getImages()
debugDraw = PhysicsDebugDraw()
debugDraw:init()
--manager = SceneManager()
--scenes = {}
--manager:init(scenes)
createWorld()
pc = color(125, 30, 30, 255)
npc = color(255, 0, 0, 255)
buttonC = button("closeButton",w - 70,h - 70,w - 30,h - 30,pc,npc,"rect")
buttonR = button("right",w - 70,30,w - 30,70,pc,npc,"rect")
buttonL = button("left",w - 170,30,w - 130,70,pc,npc,"rect")
buttonS = button("stop",w - 170,100,w - 30,140,pc,npc,"rect")
frame = 0
end
function draw()
background(40, 40, 50)
touched()
drawButtons()
debugDraw:draw()
frame = frame + 1
if rotatingLeft then
wheel.angle = wheel.angle + 5
elseif rotatingRight then
wheel.angle = wheel.angle - 5
end
end
function touched()
t = CurrentTouch
buttonC:touched(t)
buttonR:touched(t)
buttonL:touched(t)
buttonS:touched(t)
debugDraw:touched(t)
end
function drawButtons()
buttonC:draw()
buttonR:draw()
buttonL:draw()
buttonS:draw()
local xx = (w - 170 + w - 30) / 2
local yy = (100 + 140) / 2
font("ArialRoundedMTBold")
fill(0, 0, 0, 255)
fontSize(15)
text("stop",xx,yy)
local Cstate = buttonC:getInfo()[2]
local Rstate = buttonR:getInfo()[2]
local Lstate = buttonL:getInfo()[2]
if Cstate == 3 then
close()
end
if Rstate== 1 or Rstate == 2 or Rstate == 3 then
rotatingRight = true
else
rotatingRight = false
end
if Lstate == 1 or Lstate == 2 or Lstate == 3 then
rotatingLeft = true
else
rotatingLeft = false
end
end
function createWorld()
physics.pause()
-- Creating the crane:
crane = physics.body(POLYGON,
vec2(-5,0),
vec2(-5,-50),
vec2(-45,-50),
vec2(-45,-60),
vec2(45,-60),
vec2(45,-50),
vec2(5,-50),
vec2(5,0))
crane.x = 300
crane.y = h - 100
crane.mass = 0.5
debugDraw:addBody(crane)
-- Creating the chainpoints:
cp1 = physics.body(CIRCLE,10)
cp1.x = 315
cp1.y = h - 80
cp1.type = STATIC
debugDraw:addBody(cp1)
cp2 = physics.body(CIRCLE,10)
cp2.x = 285
cp2.y = h - 80
cp2.type = STATIC
debugDraw:addBody(cp2)
-- Creating the chain itself:
--chain = physics.body(CHAIN,
-- vec2(300,h - 100),
-- vec2(300,h - 90),
-- vec2(300,h - 80),
-- vec2(300,h - 70),
-- vec2(300,h - 60),
-- vec2(310,h - 60),
-- vec2(320,h - 60),
-- vec2(330,h - 60),
-- vec2(340,h - 60),
-- vec2(350,h - 60),
-- vec2(360,h - 60))
--debugDraw:addBody(chain)
-- hmmm... the chain seems always to be static. lets try it like this:
chain = {}
chainJoints = {}
local xx = 300
local yy = h - 100
for i = 1, 3 do
chain[i] = physics.body(POLYGON,
vec2(xx - 1,yy),
vec2(xx - 1,yy + 20),
vec2(xx + 1,yy + 20),
vec2(xx + 1,yy))
debugDraw:addBody(chain[i])
chainJoints[i] = physics.joint(REVOLUTE,chain[i - 1],chain[i],vec2(xx,yy))
debugDraw:addJoint(chainJoints[i])
yy = yy + 20
end
for i = 4,15 do
chain[i] = physics.body(POLYGON,
vec2(xx ,yy - 1),
vec2(xx + 20,yy - 1),
vec2(xx + 20,yy + 1),
vec2(xx,yy + 1))
debugDraw:addBody(chain[i])
chainJoints[i] = physics.joint(REVOLUTE,chain[i - 1],chain[i],vec2(xx,yy))
debugDraw:addJoint(chainJoints[i])
xx = xx + 20
end
for i = 16,21 do
chain[i] = physics.body(POLYGON,
vec2(xx + 1,yy),
vec2(xx - 1,yy),
vec2(xx - 1,yy - 20),
vec2(xx + 1,yy - 20))
debugDraw:addBody(chain[i])
chainJoints[i] = physics.joint(REVOLUTE,chain[i - 1],chain[i],vec2(xx,yy))
debugDraw:addJoint(chainJoints[i])
yy = yy - 20
end
for i = 22,28 do
chain[i] = physics.body(POLYGON,
vec2(xx ,yy - 1),
vec2(xx - 20,yy - 1),
vec2(xx - 20,yy + 1),
vec2(xx,yy + 1))
debugDraw:addBody(chain[i])
chainJoints[i] = physics.joint(REVOLUTE,chain[i - 1],chain[i],vec2(xx,yy))
debugDraw:addJoint(chainJoints[i])
xx = xx - 20
end
-- Creating a joint between the crane and the chain:
craneConnection = physics.joint(REVOLUTE,chain[1],crane,vec2(300,h - 100))
debugDraw:addJoint(craneConnection)
-- Creating the wheel:
wheel = physics.body(CIRCLE,30)
wheel.x = 400
wheel.y = h - 130
wheel.type = STATIC
debugDraw:addBody(wheel)
-- Creating a joint between the wheel and the chain:
wheelConnection = physics.joint(REVOLUTE,chain[#chain],wheel,vec2(400,h - 160))
debugDraw:addJoint(wheelConnection)
physics.resume()
end
my Button Class ( !UPDATED! you can take it from here.)
button = class()
-- by max tamussino
-- contact: max@visuals.at
function button:init(title,x1,y1,x2,y2,colorPressed,colorNotPressed,image1,image2)
-- this button class makes it easier to create buttons. the best thing is: it keeps
-- the touched function short ;)
-- so here is how to use it:
-- - the title the title should be a string, and should represent the function of the button,
-- like: "closeButton"
-- - x1,y1,x2,y2 are the coordinates
-- - good to know: the button can either be a rect or a sprite (in spritely or not).
-- 1) For the rect:
-- - colorPressed: the color the rect is filled with when the button is pressed.
-- - colorNotPressed: the color the rect is filled with when the button is not pressed.
-- - image1: must be set to ""rect"" (string!!).
-- - image2: must be nil.
-- - coordinates: for rectMode(CORNERS)
-- 2) For the sprite:
-- Two possibilities:
-- a) changing image:
-- - this possibility changes the normal image (image1) to image2 if
-- the button is touched.
-- - colorPressed and colorNotPressed both must be nil.
-- - image1: normal image
-- - image2: displayed instead of the normal one when touched.
-- b) changing tint:
-- - this possibility changes the fill color of the sprite if the 1
-- button is touched
-- - colorPressed: the tint() if the button is not touched
-- - colorNotPressed: the tint() if the button is touched
-- - image2: must be nil
--
--
-- the button:getInfo() function returns a table with the title ( [1] )and the state( [2] ).
-- to use this, you can can keep track of your buttonstates like this:
--
--
--
--
-- if button:getInfo()[2] == 3 then
-- if button:getInfo()[1] == "closeButton" then
-- close()
-- elseif button:getInfo()[1] == "openMenuButton" then
-- if not menuShown then
-- menuShown = true
-- else
-- menuShown = false
-- end
-- elseif button:getInfo()[1] == "showHelpScreenButton" then
-- if not helpScreenShown then
-- helpScreenShown = true
-- else
-- helpScreenShown = false
-- end
-- end
-- end
--
-- i hope it helps you guys! have fun creating buttons! :)
self.title = title
self.x1 = x1
self.y1 = y1
self.x2 = x2
self.y2 = y2
self.cp = colorPressed
self.cnp = colorNotPressed
self.image1 = image1
if not self.cp then
if not self.cnp then
self.image2 = image2
end
end
self.pressed = false
rectMode(CORNERS)
end
function button:draw()
spriteMode(CORNERS)
if self.state == 1 or self.state == 2 then
self.pressed = true
else
self.pressed = false
end
if self.image1 == "rect" then
if self.pressed then
fill(self.cp)
rect(self.x1 - 2,self.y1 - 2,self.x2 - 2,self.y2 - 2)
else
fill(self.cnp)
rect(self.x1,self.y1,self.x2,self.y2)
end
elseif self.image2 then
if self.pressed then
sprite(self.image2,self.x1 - 2,self.y1 - 2,self.x2 - 2,self.y2 - 2)
else
sprite(self.image1,self.x1,self.y1,self.x2,self.y2)
end
else
if self.pressed then
tint(self.cp)
sprite(self.image1,self.x1 - 2,self.y1 - 2,self.x2 - 2,self.y2 - 2)
else
tint(self.cnp)
sprite(self.image1,self.x1,self.y1,self.x2,self.y2)
end
end
if self.state == 3 then
if ElapsedTime > endTime + 0.01 then
self.state = 0
end
end
end
function button:touched()
t = CurrentTouch
if t.x > self.x1 and t.y > self.y1 and t.x < self.x2 and t.y < self.y2 then
if t.state == BEGAN then
self.state = 1
touching = true
elseif t.state == MOVING then
self.state = 2
elseif t.state == ENDED then
if touching then
self.state = 3
end
touching = false
endTime = ElapsedTime
end
else
self.state = 0
end
end
function button:getInfo()
return {self.title, self.state}
end
and the debug draw:
PhysicsDebugDraw = class()
function PhysicsDebugDraw:init()
self.bodies = {}
self.joints = {}
self.touchMap = {}
self.contacts = {}
end
function PhysicsDebugDraw:addBody(body)
table.insert(self.bodies,body)
end
function PhysicsDebugDraw:addJoint(joint)
table.insert(self.joints,joint)
end
function PhysicsDebugDraw:clear()
-- deactivate all bodies
for i,body in ipairs(self.bodies) do
body:destroy()
end
for i,joint in ipairs(self.joints) do
joint:destroy()
end
self.bodies = {}
self.joints = {}
self.contacts = {}
self.touchMap = {}
end
function PhysicsDebugDraw:draw()
pushStyle()
smooth()
strokeWidth(5)
stroke(128,0,128)
local gain = 2.0
local damp = 0.5
for k,v in pairs(self.touchMap) do
local worldAnchor = v.body:getWorldPoint(v.anchor)
local touchPoint = v.tp
local diff = touchPoint - worldAnchor
local vel = v.body:getLinearVelocityFromWorldPoint(worldAnchor)
v.body:applyForce( (1/1) * diff * gain - vel * damp, worldAnchor)
line(touchPoint.x, touchPoint.y, worldAnchor.x, worldAnchor.y)
end
stroke(0,255,0,255)
strokeWidth(5)
if self.joints then
for k,joint in pairs(self.joints) do
local a = joint.anchorA
local b = joint.anchorB
line(a.x,a.y,b.x,b.y)
end
end
stroke(255,255,255,255)
noFill()
if self.bodies then
for i,body in ipairs(self.bodies) do
pushMatrix()
translate(body.x, body.y)
rotate(body.angle)
if body.type == STATIC then
stroke(255,255,255,255)
elseif body.type == DYNAMIC then
stroke(150,255,150,255)
elseif body.type == KINEMATIC then
stroke(150,150,255,255)
end
if body.shapeType == POLYGON then
strokeWidth(5.0)
local points = body.points
for j = 1,#points do
a = points[j]
b = points[(j % #points)+1]
line(a.x, a.y, b.x, b.y)
end
elseif body.shapeType == CHAIN or body.shapeType == EDGE then
strokeWidth(5.0)
local points = body.points
for j = 1,#points-1 do
a = points[j]
b = points[j+1]
line(a.x, a.y, b.x, b.y)
end
elseif body.shapeType == CIRCLE then
strokeWidth(5.0)
line(0,0,body.radius-3,0)
strokeWidth(2.5)
ellipse(0,0,body.radius*2)
end
popMatrix()
end
end
stroke(255, 0, 0, 255)
fill(255, 0, 0, 255)
for k,v in pairs(self.contacts) do
for m,n in ipairs(v.points) do
ellipse(n.x, n.y, 10, 10)
end
end
popStyle()
end
function PhysicsDebugDraw:touched(touch)
local touchPoint = vec2(touch.x, touch.y)
if touch.state == BEGAN then
for i,body in ipairs(self.bodies) do
if body.type == DYNAMIC and body:testPoint(touchPoint) then
self.touchMap[touch.id] = {tp = touchPoint, body = body, anchor = body:getLocalPoint(touchPoint)}
return true
end
end
elseif touch.state == MOVING and self.touchMap[touch.id] then
self.touchMap[touch.id].tp = touchPoint
return true
elseif touch.state == ENDED and self.touchMap[touch.id] then
self.touchMap[touch.id] = nil
return true;
end
return false
end
I’ll ask @John to see if he has any suggestions — it sounds like you are trying to drive a chain with a wheel, like a bicycle?
Yes, exactly. I was trying to create a crane steerable with wheels.
I’d recommend using motors instead of trying to simulate a chain like that. The reason is that the simulation probably wont be stable enough to give you the results you want. The only other suggestion I would give is to increase the friction of the chain and wheel bodies and maybe decrease the length of the chain links to make it tighter.
motors? whats that?
well, i decreased the length, but thats quite hard because the joint between wheel and the chain dös not behave correctly, ill play around with it, but thanks!
Check out the demo code Physics Lab test 6 " motors"