function colcheck(plr,flag,aim)

 -- player is a table

 -- player must have x,y in it's table

 -- flag must be an integer, in our case "0" symbolizes a solid wall

 -- aim: 0=left,1=right,2=up,3=down

 -- I don't need width or height in my player table because I know (in my case) it will always be 8 on both sides

 if pl.iscol==false then -- if the player can't collide, then return "false"

  return false 

  -- In our case, true = yes, there is something blocking you from moving in that direction
  -- whereas false = no, there is nothing in that direction

 end

 local x=plr.x local y=plr.y -- Make referring to the current x/y simple

 local x1=0 local x2=0 -- Declare our x1/x2/y1/y2 variables for further modification

 local y1=0 local y2=0

 if aim == 0 then -- What we do here is create a 1 pixel wide and imaginary rectangle using 2 coordinates so we can 
                  -- check for collisions, we then use our already defined 2 coords. to find the other coordinates
                  -- in the rectangle to form it completely. This is pretty complicated to be explained in text,
                  -- so I recommend you watch, read the tutorial for a visual explanation!

  x1=x x2=x-1
  y1=y y2=y+7 

 elseif aim == 1 then

  x1=x+7 x2=x+8
  y1=y y2=y+7

 elseif aim == 2 then

  x1=x x2=x+7
  y1=y y2=y-1

 elseif aim == 3 then

  x1=x x2=x+7
  y1=y+7 y2=y+8

 end
 x1/=8 x2/=8 y1/=8 y2/=8 -- Divide our imaginary box coordinates by 8, for tile conversion

 if fget(mget(x1,y1),flag) -- Check if any of our coordinates have a sprite on the same tile coord.
 or fget(mget(x2,y2),flag) -- "Or" for simplicity, if ANY of our values are colliding we return true
 or fget(mget(x2,y1),flag)
 or fget(mget(x1,y2),flag)

 then

  return true -- Yep, we found a collision

 else -- If we haven't found a collision, then

  return false -- Nope, you are good to move further

 end -- End our check
end -- End the function