collect_location.lua

   1 QuestHelper_File["collect_location.lua"] = "Development Version"
   2 QuestHelper_Loadtime["collect_location.lua"] = GetTime()
   3
   4 -- little endian two's complement
   5 local function signed(c)
   6   QuestHelper: Assert(not c or c >= -127 and c < 127)
   7   if not c then c = -128 end
   8   if c < 0 then c = c + 256 end
   9   return strchar(c)
  10 end
  11
  12 local function float(c)
  13   if c then
  14     c = math.floor(c * 16777216 + 0.5)  -- 24 bits of fraction baby
  15     QuestHelper: Assert(c >= -2147483647 and c < 2147483647)
  16   else
  17     c = -2147483648
  18   end
  19   if c < 0 then c = c + 4294967296 end
  20   return strchar(bit.band(c, 0xff), bit.band(c, 0xff00) / 256, bit.band(c, 0xff0000) / 65536, bit.band(c, 0xff000000) / 16777216)
  21 end
  22
  23 local function BolusizeLocation(delayed, c, z, x, y)
  24   -- c and z are *signed* integers that fit within an 8-bit int.
  25   -- x and y are floating-point values, generally between 0 and 1. We'll dedicate 24 bits to the fractional part, largely because we can.
  26   -- Overall we're using a weird 11 bytes on this. Meh.
  27   -- Also, any nil values are being turned into MIN_WHATEVER.
  28   return signed(delayed and 1 or 0) .. signed(c) .. signed(z) .. float(x) .. float(y)
  29 end
  30
  31 -- This merely provides another API function
  32 function QH_Collect_Location_Init(_, API)
  33   API.Callback_LocationBolus = BolusizeLocation  -- Yeah. *Bolusize*. You heard me.
  34   API.Callback_LocationBolusCurrent = function () return BolusizeLocation(API.Callback_Location_Raw()) end  -- This is just a convenience function, really
  35 end