Space images in an array out evenly, taking into account different image widths

Question

local xOffset = 0

for i = 1, levelPacks[prevCurrentLevelPack][prevCurrentLevel].ammount do

    if i == 1 then --setup first one

        shapesPrevArray[i].x = 30
        shapesPrevArray[i].y = 41
        shapesPrevArray[i].isVisible = true

    end

    if i > 1 then --setup the rest

        --width of previous one plus the x value of the previous one to make them next to eachother.
        xOffset = shapesPrevArray[i - 1].width + shapesPrevArray[i - 1].x
        print("offset: " .. xOffset)
        shapesPrevArray[i].x = xOffset    
        shapesPrevArray[i].y = 41
        shapesPrevArray[i].isVisible = true
        xOffset = 0

    end

    i = i + 1

end


i:2 width:60 x value:30 xoffset:90
i:3 width:40 x value:90 xoffset:130
i:4 width:50 x value:130 xoffset:180
i:5 width:70 x value:180 xoffset:250

Can anyone help me out please? I can't work out why this bit isn't spacing them out.

xOffset = shapesPrevArray[i - 1].width + shapesPrevArray[i - 1].x

If someone could explain why it isn't and point me in the right direction I would be grateful.

Thanks.

Answer 1

You should remove i = i + 1

A numeric for has the following syntax:

for var=exp1,exp2,exp3 do
  something
end

That loop will execute something for each value of var from exp1 to exp2, using exp3 as the step to increment var. This third expression is optional; when absent, Lua assumes one as the step value.

http://www.lua.org/pil/4.3.4.html