CODEWITHSUNDEEP
luacoronasdk
Dips
Dips

Reputation: 145

Spawn 3 objects but no duplicates in a row - Corona SDK

Im looking to spawn 3 objects (Red,Green,Blue) in seperate columns but should not duplicate. So somehow Im looking for it to check the colours in the other columns and place the one thats left over.

So if Blue and Red are already spawned, the last column will be a Green etc.

Should I need to specify specific orders inside a table and then everytime I spawn I just choose a random order from within that table, or is there a better way?

Cheers

Upvotes: 0

Views: 120

Answers (2)

Maicon Feldhaus
Maicon Feldhaus

Reputation: 226

You can create a list of colors and shuffle it. Something like that:

math.randomseed( os.time() )

local colors = { 
    { 1,0,0 }, -- red
    { 0,1,0 }, -- green
    { 0,0,1 }, -- blue
}

local function shuffleTable( t )
    local rand = math.random 
    assert( t, "shuffleTable() expected a table, got nil" )
    local iterations = #t
    local j

    for i = iterations, 2, -1 do
        j = rand(i)
        t[i], t[j] = t[j], t[i]
    end
end

shuffleTable( colors )

local px = display.contentCenterX
local py = display.contentCenterY - 200
for i = 1, #colors do
    local rect = display.newRect( px, py + 100 * i, 200, 100 )
    rect.fill = colors[i]
end

Upvotes: 0

Piglet
Piglet

Reputation: 28954

You will always have to make sure you use the colour only once. How and when you do that is completely irrelevant.

Of course creating objects randomly is not very efficient as you would risk to create some you cannot use.

So best would be to create 3 different objects and remove one of them randomly every time or to spawn an object using a random colour, removed from a colour list.

Upvotes: 1

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