OK, so I'm programming my first game in Nspire Lua, and I have a lot of questions, but first let me deal with problems I've had so far.
The game is a simple pong clone. Here is the code so far:
function on.paint(gc)
    local screen = platform.window
    local h=screen:height()
    local w=screen:width()
    gc:setFont("sansserif", "b", 24)
    gc:setColorRGB(255,193,37)
    local sw = gc:getStringWidth("Pong")
    local sh = gc:getStringHeight("Pong")
    gc:drawString("Pong",w/2-sw/2,h/16+sh/16)
    gc:setFont("sansserif", "r", 12)
    gc:setColorRGB(255,255,255)
    local s2w = gc:getStringWidth("Simple Pong clone by njaddison")
    local s2h = gc:getStringHeight("Simple Pong clone by njaddison")
    gc:drawString("Simple Pong clone by njaddison",w/2-s2w/2,h/2+s2h/2)
end

function on.enterKey()
    screen:invalidate()
endSo far I've finished the title screen (subject to change) and that's pretty much it. I'm trying to make it so once you press the escape key after the game starts (game starts by pressing enter key), it will restart the code, or at least recall the title screen function. I think this is possible with while true do loop, but I kept running into errors, and I don't even know if I can recall a function that is in a loop with a function that is outside of one.
Also, how would I go about making the title screen background black? I want it to look a bit like the original pong, and also, you can't see the "Simple pong clone by njaddison" if the screen is white because the text is white.

EDIT:
Also, an animation of pong in the background of the title screen would be nice, like with the lua clone of Cubefield.

Hi, I wanted to know how to go about mirroring an image locally in lua. I have a bunch of images for character animations and I need copies of them mirrored horizontally but instead of inserting them in as seperate mirrored images I'd like to make mirrored copies of them within my code.

The first thing I tried was using image:copy() to copy them and make the width negative, however that gave an error since lua requires the width value to be >0.

Next I studied the way the image strings are made and figured out how I could potentially switch certain parts of an image's string to mirror it. However, I tried to make a function that would manipulate parts of an image's string and got errors, because the foreward slash that is used in the strings doesn't function like a normal string value, and it overally screws up everything you try to do with it (I tried using "\\" too, but then it didn't think that "\" in the image string = "\\").

So before I go crazy searching further for a really complex way to manipulate image strings, is there a simpler way to mirror images in lua?
Please help! 

I'm not so sure about mirroring images within the Lua code itself, but if you have the original image (.gif, .png etc) you could mirror it and convert it to image code.

I'm hoping that I won't have to do that. I have quite a few images because they are for animations, and duplicating every one of those images to have a mirrored version of it would almost double the current file size. I know it has to be possible to do it locally since nspaint can modify and output image code, I'm just not quite sure how.

Thanks so much!

I actually had spent some time studying the lua image string format by loading in a 2x2 pattern as well as a mirrored copy of the image and I found what parts of it
I needed to move around, my problem was the implementation of it. I was trying to split the image string into table values, separated by each "\". Then I was going
to move around the table values and concatenate the table for the final mirrored image. However since forward slashes act as some kind of weird special character
in lua, it overall just didn't work. I guess I was over complicating it.


Thanks again, now I can continue to make progress on my project!


For your help, here's a teaser of my project which so far is turning out really awesome if I do say so myself! 

Please could someone help me ?

Here's my code :


------------------------------------------------
----------- LUA FALLDOWN, BY ANTOX98 -----------
------------------------------------------------


platform.apilevel = "2.0"


require "physics"


----------------------
----- BALL CLASS -----
----------------------


Ball = class()
Seg = class()


function Ball:init(x, y, w, mass)   
    self.width = w
    self.body = physics.Body(mass, physics.misc.momentForCircle(mass, 0, 10, ZERO))
    self.body:setPos(physics.Vect(x, y))
    self.body:setMass(mass)
    self.shape = physics.CircleShape(self.body, w, ZERO)
    self.shape:setRestitution(0.6)
    self.shape:setFriction(0.6)
end


function Seg:init(x1, y1, x2, y2)
    local a, b = physics.Vect(x1, y1), physics.Vect(x2, y2)
       
    local mass = physics.misc.INFINITY()
    self.coor = {x1,y1,x2,y2}
    self.body = physics.Body(mass, physics.misc.momentForSegment(mass, a, b))
    --self.body:setPos(physics.Vect(x1, y1))
    self.body:setMass(mass)
    self.shape = physics.SegmentShape(self.body, a, b, 10)
    self.shape:setRestitution(0.6)
    self.shape:setFriction(0.6)
end


function Ball:paint(gc)
    local p = self.body:pos()
    local x, y = p:x(), p:y()
    local r = self.width / 2
   
    gc:setColorRGB(255,0,0)
    gc:fillArc(x+r, y+r , self.width, self.width, 0, 360)
end


function Seg:paint(gc)
   
    local a = self.shape:a()
    local b = self.shape:b()
   
    gc:setColorRGB(0,0,0)
    gc:drawLine(a:x(), a:y(), b:x(), b:y())
end


function initGame()
    w = 318
    h = 212
   
    ZERO = physics.Vect(0,0)
    LARGE = physics.misc.INFINITY()
   
    space = physics.Space()
    space:setGravity(physics.Vect(0,9.)
   
    sol = Seg(0,200,w,200)
    --space:addBody(sol.body)
    space:addShape(sol.shape)
   
    ball = Ball(w/2-10, 30, 20, 1000)
   
    space:addBody(ball.body)
    space:addShape(ball.shape)
   
    sol.body:setPos(physics.Vect(0,-30))
   
    timer.start(0.01)
end
initGame()


function on.timer()
    space:step(0.1)
    platform.window:invalidate()
end


function on.paint(gc)
    ball:paint(gc) 
    sol:paint(gc)
end
sol.body:setPos(physics.Vect(0,-30))
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[/size][size=78%]Strangely, the body moves but not the shape....[/size][/code]