map_calculations.lua

--[[

MAP CO-ORDINATE CALCULATOR

If you update the maps (eg. different resolution, crop, etc.) you need to recalculate

1. Find two points on the map which are clearly identifiable in-game (eg. small islands).
   Preferably a fair distance from each other to reduce measurement or rounding errors.

    Eastern Kingdoms:

      I used:
        a. Brightwater Lake (the small island to the south)
        b. The entrance to the Sunken Temple.

    Kalimdor:

      I used:
        a. Darnassus, on the bridge facing the bank (or where it eventually is) at the bank end
        b. Outside Theramore, at the guard tower where the Sentry Point Guards are, on the road, next to the sign

2. Travel there in-game and find out their in-game coordinates (with the .gps command).

   Note that Y is east-west and X is north-south in the game.
   However in GIMP the X coordinate is given first and Y second, so you have to swap them around.
   So, in GIMP, if you mouse-over the spot to get the coordinates, you put them in as Y, X
   (Y being the first one as it is east/west, that is left/right)


--]]



function calc_coordinates (name, gameX1, gameY1, imageX1, imageY1,
                                 gameX2, gameY2, imageX2, imageY2,
                                 imageWidth, imageHeight)

  local gameDeltaX = math.abs (gameX2 - gameX1)
  local gameDeltaY = math.abs (gameY2 - gameY1)
  local imageDeltaX  = math.abs (imageX2 - imageX1)
  local imageDeltaY  = math.abs (imageY2 - imageY1)

  print ("**", name, "**")
  print ("Game Delta X =", gameDeltaX)
  print ("Game Delta Y =", gameDeltaY)
  print ()
  print ("Map  Delta X =", imageDeltaX)
  print ("Map  Delta Y =", imageDeltaY)
  print ()

  local Xratio = gameDeltaX / imageDeltaX
  local Yratio = gameDeltaY / imageDeltaY

  print ("X ratio =", Xratio)
  print ("Y ratio =", Yratio)

  print ()
  print (string.rep ("-", 40))
  print ("You need this stuff:")
  print ()

  -- left edge is how many pixel our reference point was from the left
  -- multiplied by the ratio factor, and adding in the reference point Y
  -- (either reference point will give the same result)

  local leftEdge = (imageY1 * Yratio) + gameY1
  local topEdge  = (imageX2 * Xratio) + gameX2
  print ("Left edge =", leftEdge, "(yards)")
  print ("Top  edge =", topEdge,  "(yards)")

  -- now calculate the width and height of the image in game units

  local mapWidth = imageWidth * Yratio
  local mapHeight = imageHeight * Xratio
  print ("Map width  =",  mapWidth, "(yards)")
  print ("Map height =", mapHeight, "(yards)")

  print ()
  print ("For PHP:")
  print ()

  print ("    //" .. string.rep ('-', 10) .. " " .. name .. " " .. string.rep ('-', 10))
  print ("    $mapLeftPoint = " .. leftEdge  .. ';  // game units (yards)')
  print ("    $mapTopPoint  = " .. topEdge   .. ';  //      "')
  print ("    $mapWidth     = " .. mapWidth  .. ';  //      "')
  print ("    $mapHeight    = " .. mapHeight .. ';  //      "')


end -- calc_coordinates

calc_coordinates ("Eastern Kingdoms",

                  -- Brightwater Lake (small island below larger one)
                  2484.981,   -- X (in-game)
                  24.705,     -- Y (in-game)
                  410,        -- map X (pixels)
                  803,        -- map Y (pixels)

                  -- Sunken Temple entrance (south)
                  -10473.484, -- X (in-game)
                  -3816.771,  -- Y (in-game)
                  2855,       -- map X (pixels)
                  1530,       -- map Y (pixels)

                  2000,       -- map width  (pixels)
                  3770)       -- map height (pixels)

print ()
print (string.rep ("*", 70))
print ()
calc_coordinates ("Kalimdor",

                  -- Darnassus on edge of bridge looking at bank
                  9945.852,     -- X (in-game)
                  2474.220,     -- Y (in-game)
                  278.4,        -- map X (pixels)
                  392.1,        -- map Y (pixels)

                  -- Theramore outside guard tower just up road (next to sign)
                  -3418.184,    -- X (in-game)
                  -4172.095,    -- Y (in-game)
                  2325.5,       -- map X (pixels)
                  1406.8,       -- map Y (pixels)

                  2000,         -- map width  (pixels)
                  3770)         -- map height (pixels)