Hey everyone.
I’m coding a physics based highscore game and need to apply;
myObj:setLinearVelocity(x,y)
to my player object, based on his current angle of rotation. I’ve researched the Maths and tried putting it together, but it doesn’t perform as I’d like.
The code is drag and drop except for the arrow.png, which is simply an arrow pointing to the right on the screen.
here is my code. I’m stuck around line 139.
physics = require("physics")
physics.start()
physics.setGravity(0,0)
--physics.setDrawMode( "hybrid" ) -- uncomment to see physics interactions.
\_H = display.contentHeight;
\_W = display.contentWidth;
function player()
player1 = display.newImage ("arrow.png")
player1.x = \_W / 2
player1.y = \_H / 2
physics.addBody(player1, "dynamic", {density = 0, friction = 0, bounce = 0})
player1.myName = "player1"
function setplayerRot()
playerRot = 0
local playerRotText = display.newText( "playerRot: " .. playerRot, 10, 0, nil, 15)
playerRotText.x = \_W / 4
playerRotText.y = \_H / \_H + 50
playerRotText:setTextColor(255,255,255)
function getplayerRot()
playerRot = player1.rotation
playerRotText.text = "playerRot: " .. playerRot
end
Timer1 = timer.performWithDelay(10,getplayerRot, 0)
end
end
function radians()
p1Radians = player1.rotation \* math.pi / 180
--print (p1Radians)
end
function velocity()
velx, vely = player1:getLinearVelocity()
vx = math.cos (p1Radians) \* velx
print (vx)
end
function buttons()
function lArrow()
leftArrow = display.newRect(0,0,50,50)
leftArrow.x = \_W / \_W + 50
leftArrow.y = \_H - 50
leftArrow:setFillColor(0,255,0)
leftArrow.alpha = .75
ltouched = false
local function ltouch(event)
if event.phase == "began" then
ltouched = true
elseif event.phase == "ended" then
ltouched = false
end
end
local function lrot(event)
if ltouched == true then
player1.rotation = player1.rotation - 10
elseif ltouched == false then return false
end
end
leftArrow:addEventListener ("touch", ltouch)
Runtime:addEventListener("enterFrame", lrot)
end
function rArrow()
local rightArrow = display.newRect(0,0,50,50)
rightArrow.x = \_W - 50
rightArrow.y = \_H - 50
rightArrow:setFillColor(0,255,0)
rightArrow.alpha = .75
rtouched = false
local function rtouch(event)
if event.phase == "began" then
rtouched = true
elseif event.phase == "ended" then
rtouched = false
end
end
local function rrot(event)
if rtouched == true then
player1.rotation = player1.rotation + 10
elseif rtouched == false then return false
end
end
rightArrow:addEventListener ("touch", rtouch)
Runtime:addEventListener("enterFrame", rrot)
end
function thrustButton()
local thrustb = display.newRect(0,0,100,50)
thrustb.x = \_W/2
thrustb.y = \_H - 50
thrustb:setFillColor(0, 0, 255)
thrustb.aplha = .75
ttouched = false
local function ttouch(event)
if event.phase == "began" then
ttouched = true
elseif event.phase == "ended" then
ttouched = false
cando = true
end
end
local function ttap(event)
if ttouched == true then
if cando == true then
vel = 10 -- this is the arbitrary amount of velocity to increase player motion by.
vely = -500
p1Rads = player1.rotation \* math.pi / 180 -- step 1
velX = math.cos (p1Rads) \* vel -- upper case (velX/velx) to feed into obj:setLinearVelocity(X,Y)
velY = math.sin (-p1Rads) \* vel
print(velX,velY,player1.rotation)
player1:setLinearVelocity(velX,velY)
local function stopMovement()
player1:setLinearVelocity(0,0)
end
Timer1 = timer.performWithDelay(2000,stopMovement, 1)
cando =false
end
elseif ttouched == false then return false
end
end
thrustb:addEventListener ("touch", ttouch)
Runtime:addEventListener("enterFrame", ttap)
end
lArrow()
rArrow()
thrustButton()
end
function startGame()
player()
buttons()
setplayerRot()
end
startGame() Thanks in advance. [import]uid: 67933 topic_id: 16610 reply_id: 316610[/import]
[import]uid: 52491 topic_id: 16610 reply_id: 62517[/import]