Nexus Game Studio – Independent Game Developer

12 comments

1. 

   J. A. Whye

   August 30, 2011 at 7:30 pm

   Here’s a modification to your tap function:

   function button:tap(event)
   light.isVisible = (power ~= false)
   power = not power
   end

   It’s shorter, although I’ll admit it *is* more complex. But by doing it this way you can do away with the “IF” logic and make it more concise.

   Thanks for posting this, toggling something on/off comes up in quite a few situations.

   Jay
2. 

   Steve Boyce

   August 30, 2011 at 9:03 pm

   Thanks for the alternative!
3. Shooting for Genericity | Game Dev Nation

   August 31, 2011 at 1:37 am

   [...] http://www.nexusgamestudio.com/2011/08/30/lua-switch-function-code-example/ Sidebar: When writing sample code I don’t always write generically myself, so I’m not picking on the guys at Nexus Game Studio — they created a cool sample and with their permission I’m using it as a starting point for this example. [...]
4. 

   kingsley

   March 23, 2012 at 9:35 am

   here is my code

   unction gforce ()
   gravity = physics.setGravity( .0, .10)
   gravity = false
   end

   on = true

   local function dot3 ()

   local pdot = display.newImage( “assets/graphics/purpleDot.png”)
   pdot:setReferencePoint(display.centerReferencePoint)
   pdot.x = _W/2
   pdot.y = 500
   physics.addBody( pdot,”static”, { density = -0.0, friction = 0.3, bounce = 0.0, radius = 32 } );

   pdot:addEventListener(“touch”, slow_pop)
   pdot:addEventListener(“touch”, pdot )

   function pdot:touch(event)
   if (on == false) then
   gforce = false
   on = true
   else
   gforce = true
   on = false

   end
   end
   end
   timer.performWithDelay(3000, pdot, 1)

   function slow_pop (event)
   if(event.phase == “ended”) then
   audio.play(pop)
   end
   end

   tmr = timer.performWithDelay(0,dot3, 1);

   what am I going wrong here

   and second what do you call the art style of your new space game
5. 

   kingsley

   March 23, 2012 at 12:41 pm

   I’m sorry i didnt put any detail in the comment but what im trying to do is use your switch to turn on and off physics.setGravity( .0, .10) to give it a slow motion effect
6. 

   NexusBrian

   March 23, 2012 at 1:37 pm

   Hey Kingsley,

   I’ll be happy to help you out.

   What are you exactly trying to accomplish. Change the gravity after you touch ‘pdot’, and then change back to normal gravity when you touch ‘pdot’ again?

   And for the art style, it’s abstract style set in space. Although what you see here on our site is old art concepts and Stephen has been working hard on new ideas for abstract syles.

   Brian P.
7. 

   kingsley

   March 23, 2012 at 2:25 pm

   hey Brian

   Thanks for writing back and what I’m trying to accomplish is when you touch/tap pdot physics.setGravity( .0, .10) turns on and and then when you touch/ tap pdot again it goes back to normal so yes what you said was right.

   But in the long run what I really want to do is make a accelerometer I hope thats the word so when you touch a amount of dots on the screen with out touching anything else it will activate the switch which will run for 3 or 4 seconds.

   it’s like rewarding the player with an extra bonus for playing so well

   I know thats a lot

   I’m new to corona and lua and kinda to programing and scripting so I’m learning while trying to make a little game. hopping one day I could become a indie style game developer.

   I like the art especially how it give off a glow/ illuminate
8. 

   NexusBrian

   March 23, 2012 at 2:26 pm

   I just whipped this up quickly for you to check out (plug and play)

   W = display.contentWidth
   H = display.contentHeight

   –Require physics library
   physics = require”physics”

   –Initiate physics engine
   physics.start()

   –Set initial gravity
   physics.setGravity(0, 1)

   –set draw mode (optional)
   physics.setDrawMode(“hybrid”)

   –Create white circle and place at top of screen
   local pdot = display.newCircle( 0,0,20,20)
   pdot:setReferencePoint(display.centerReferencePoint)
   pdot.x = W/2
   physics.addBody( pdot,”dynamic”, { density = 1, friction = 0.3, bounce = 0, radius = 20 } );

   –Create ground for circle to bounce and react with
   local ground = display.newRect( 0,0,W, 20)
   ground.y = H
   physics.addBody( ground,”static”, { density = 1, friction = 0.3, bounce = 0.5 } );

   –Boolean for switch function
   slow = false

   –Switch function for slow motion
   local function slowMode()
   if slow == false then
   slow = true
   pdot.linearDamping = 1.5 — Set linearDamping to 1.5 (slows object linear velocity)
   print(“on”) — Print “on” in terminal to show that this is functioning
   elseif slow == true then
   slow = false
   pdot.linearDamping = 0 — Set linearDamping to 0 (resume original linear velocity)
   print(“off”) — Print “on” in terminal to show that this is functioning
   end
   end

   pdot:addEventListener(“tap”, slowMode)

   I don’t advise changing the gravity to simulate a slow motion effect on an object, since the objects linear velocity wont slow down if gravity is decreased. You need to effect the linear velocity either by adding applyForce or setLinearVelocity. I used linearDamping because I found it provided the best ‘slow motion’ effect, however use what works for your application.

   Hope this helps.

   Brian P.
9. 

   NexusBrian

   March 23, 2012 at 2:28 pm

   P.S. , You’ll have to reset all the quotations in your script editor if you copy paste from this page, something to do with formatting I think.
10. 

    kingsley

    March 23, 2012 at 2:47 pm

    oh nice that was fast lol it toke me 3 or 4 days to get where im at this is my code as of now I guess when i get back home i’ll put see whats what and see how to put it in my code.

    please tell me if in going in the right way oh and you can see how i was trying to use your on and off switch

    —————————————————————————————-
    –
    – main.lua
    –
    —————————————————————————————–

    – Your code here

    _H = display.contentHeight;
    _W = display.contentWidth;
    mR = math.random;
    numberOfBule = 45;
    numberOfRed = 15;
    local physics = require(“physics”);
    physics.start();

    –physics.setDrawMode( “hybrid” )

    –sounds and soundtrack
    local pop = audio.loadSound(“assets/media/pop01.wav”);
    local fart = audio.loadSound(“assets/media/fart.wav”);
    ————————————————————————

    function removeDot(obj)
    obj:removeSelf()
    end

    local function dots()
    local dot = display.newImage( “assets/graphics/blueDot2.png”,45, 45)
    dot:setReferencePoint(display.centerReferencePoint);
    dot.x = mR(60, _W – 50);
    dot.y = mR(70, _H – 50);
    physics.addBody( dot, { density = -1.0, friction = 4.3, bounce = 0.2, radius = 32 } );

    function dot:touch(event)
    if (event.phase == “ended”) then
    audio.play(pop);
    removeDot(self)
    return true
    end
    end

    dot:addEventListener(“touch”, dot)
    end

    tmr = timer.performWithDelay(1000,dots, numberOfBule);

    local function dots2()
    local dot2 = display.newImage( “assets/graphics/redDot.png”,14, 14)
    dot2:setReferencePoint(display.centerReferencePoint);
    dot2.x = mR(60, _W – 50);
    dot2.y = mR(70, _H – 50);
    physics.addBody( dot2, { density = 1.0, friction = 0.3, bounce = 1.5, radius = 14 } );

    dot2:addEventListener(“touch”, fart_n)

    end
    function fart_n(event)
    if(event.phase == “ended”) then
    audio.play(fart)
    end
    end
    tmr = timer.performWithDelay(3000,dots2, numberOfRed);

    local floor = display.newRect(0,0, _W,20);
    floor:setReferencePoint(display.centerReferencePoint);
    floor.x = _W/2
    floor.y = 500

    function gforce ()
    gravity = physics.setGravity( .0, .10)
    gforce.isVisible = false
    end

    on = true

    local function dot3 ()

    local pdot = display.newImage( “assets/graphics/purpleDot.png”)
    pdot:setReferencePoint(display.centerReferencePoint)
    pdot.x = _W/2
    pdot.y = 500
    physics.addBody( pdot,”static”, { density = -0.0, friction = 0.3, bounce = 0.0, radius = 32 } );

    pdot:addEventListener(“touch”, slow_pop)
    pdot:addEventListener(“touch”, pdot )

    function pdot:touch(event)
    if (on == false) then
    gforce.isVisible = false
    on = true
    else
    gforce.isVisible = true
    on = false

    end
    end
    end
    timer.performWithDelay(3000, pdot, 1)

    function slow_pop (event)
    if(event.phase == “ended”) then
    audio.play(pop)
    end
    end

    tmr = timer.performWithDelay(0,dot3, 1);

    local roof = display.newRect(0,0, _W,20);
    roof:setReferencePoint(display.centerReferencePoint);
    roof.x = _W/2
    roof.y = -38

    local left_wall = display.newRect(0,0,1, _H);
    left_wall:setReferencePoint(display.centerReferencePoint);
    left_wall.x = 0-left_wall.width/2
    left_wall.y = _H/2

    local right_wall = display.newRect(0,0,5, _H);
    right_wall:setReferencePoint(display.centerReferencePoint);
    right_wall.x = _W+right_wall.width/2
    right_wall.y = _H/2

    physics.addBody(floor, “static”, {friction = 0.3, bounce = 0.2} );

    physics.addBody(roof, “static”, {friction = 0.3, bounce = 0.2} );

    physics.addBody(left_wall, “static”, {friction = 0.3, bounce = 0.2} );

    physics.addBody(right_wall, “static”, {friction = 0.3, bounce = 0.2} );
11. 

    kingsley

    March 23, 2012 at 3:01 pm

    I was reading about applyForce, setLinearVelocity and linearDamping on a forum I think it was stackfollow or something like that but it seemed a little confusing and then someone said why don’t you just use physics.setGravity I plugged it in to my code and played with the x and y and saw that all my dots moved slow but I see what your saying about linear velocity

    I was hoping i could set my function gforce to isVisible to make it work and i was looking to see what was equivalent to isVisible for functions if there is a such thing

    and when I get back from work i’ll read up on linear velocity and then look at your code so that I can get a full understanding

    thank you I appreciate you helping me
12. 

    NexusBrian

    March 23, 2012 at 3:03 pm

    Here, E-mail me at ‘brian-nexus@live.com’ and I’ll help you further via email so we don’t have to clutter up this comment section.

    Brian P.