love.draw() seems to ignore if statements

[yabobay]

In love.load(), I have (along with some other stuff, check main.lua):

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mode = line

And later on, in love.draw(), I have:

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function love.draw()
   if mode == point then
      -- draw all four corners of the first square
      love.graphics.points( square1[1] )
      love.graphics.points( square1[2] )
      love.graphics.points( square1[3] )
      love.graphics.points( square1[4] )
   end
end

Which runs just fine when mode is set to point. The problem is that it also runs when it's set to ANYTHING else. Did I mess up the if statement? Am I stupid? Is Lua stupid? Is LÖVE stupid?

[MrFariator]

Because you've never defined what the variables "line" and "point" are, this is effectively what's happening:

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function love.load()
  mode = nil
  -- ...
end

function love.draw()
  if mode == nil then
    -- because mode IS nil, this will be run every time love.draw is called
  end
end

Lua treats undeclared variables as globals with the value of nil (signifying the absence of a value), so you need to assign said "line" and "point" variables an actual value prior assigning them to "mode". As such, I believe maybe you intended was something like this?

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function love.load()
  line = "line" -- note the quotes; this makes it so we're assigning a string of value "line" to the variable
  	        -- we could assign anything else, like a number, so long the variables line and point do not share the same value
  point = "point"
  mode = line 
  -- ...
end

function love.draw()
  if mode == point then
    -- because mode's value is "line" and not "point", this code is not run
  end
end

You can read more about lua's types and values from lua pil.

[zorg]

Otherwise, you can just put single or double quotes around point and line in love.draw, if you, you know, don't want to treat those as variables, but literal strings; this goes for love.load as well, since you're setting mode to the undefined variable line:

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function love.load()
  mode = 'line'
end

function love.draw()
  if mode == 'point' then
    -- runs if mode is the string 'point'
  elseif mode == "line" then
    -- runs if mode is the string "line"
  end
end

[yabobay]

I ended up putting the quotations at

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mode = "point" -- which is only for the start, then there's a toggle

and there at the if statement. Problem solved. Thanks!

P.S.: Y'know, the worst part of that is that I always keep making that mistake.