--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

function widget:GetInfo()
  return {
    name      = "Export Heightmap",
    desc      = "Usage: /luaui exportheightmap",
    author    = "user finished it, again",
    date      = "Feb ??, 2008",
    license   = "GNU GPL, v2 or later",
    layer     = -5,
    enabled   = true  --  loaded by default?
  }
end

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

local heightMapX = (Game.mapX * 64)
local heightMapY = (Game.mapY * 64)

local GetGroundHeight = Spring.GetGroundHeight

local le = {}

local mod = math.mod
local max = math.max
local floor = math.floor

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

do
  function le.uint32(n)
    return string.char( mod(n,256), mod(n,65536)/256, mod(n, 16777216)/65536,n/16777216 )
  end

  function le.uint16(n)
    return string.char( mod(n,256), mod(n,65536)/256 )
  end

  function le.uint8(n)
    return string.char( mod(n,256) )
  end
end

local function bmptxt(data, filename)
   local file = assert(io.open(filename,'w'), "Unable to save to "..filename)
   for row = heightMapX, 0, -1 do
      for col = 0, heightMapY, 1 do  
         file:write(tostring(data[row][col] or 0))
         file:write('\n')
      end 
   end

   file:close()
   Spring.Echo("Created temporary file " .. filename)
end

local function writeTGA(data, filename)
   local file = assert(io.open(filename,'w'), "Unable to save to "..filename)
--------------tga file header------------------------------
   file:write(le.uint8(1)) -- id length
   file:write(le.uint8(0)) -- c map type
   file:write(le.uint8(3)) -- image type
 --/-color map specification-------------------------------
     file:write(le.uint16(0)) -- first entry index
     file:write(le.uint16(16777216)) -- color map length
     file:write(le.uint8(8)) 
 --/-image specification-----------------------------------
     file:write(le.uint16(0)) --x-start
     file:write(le.uint16(0)) --y-start  
     file:write(le.uint16(heightMapX + 1)) --image x
     file:write(le.uint16(heightMapY + 1)) --image y
     file:write(le.uint8(32)) --bits per pixel
     file:write(le.uint8(0)) --image descriptor
-------------end tga file header--------------------------- 
-------------image/color map data--------------------------
   file:write(le.uint8(0)) -- image id --var
 --/-------color map data----------------------------------
   file:write(le.uint8(24)) -- c map data
 --/-------image data(pixels)------------------------------
    for row = heightMapX, 0, -1 do
       for col = 0, heightMapY, 1 do
          file:write(le.uint16(data[row][col] or 0):rep(4))
       end
    end
------------end image/color map data-----------------------
------------developer area---------------------------------  
   file:write(le.uint8(0)) -- dev fields
   file:write(le.uint8(0)) -- dev dir
------------end developer area-----------------------------

   --extension area 
   file:write(le.uint16(0)) -- ext size 2*8
   file:write("here be the author name") -- author --ascII 41
   file:write("tga file format") -- coment --ascII 324
   -- date/time stamp
     file:write(le.uint16(1)) 
     file:write(le.uint16(0))     
     file:write(le.uint16(2008)) 
     file:write(le.uint16(0)) 

   file:write("") -- job name -- ascII
   file:write(le.uint16(0)) -- job time --3*16 
   file:write("spring engine") -- soft id -- ascII
   file:write(le.uint8(0.76)) -- version --3*8

   file:write(le.uint32(0)) -- keycolor
   file:write(le.uint16(0)) -- pixel aspect ratio 2*16
   file:write(le.uint16(0)) -- gamma 2*16
   file:write(le.uint32(0)) -- c correction offset
   file:write(le.uint32(0)) -- postage stamp offset
   file:write(le.uint32(0)) -- scan line offset
   file:write(le.uint8(0)) -- attrib type

   file:write(le.uint8(0)) -- scan line table
   file:write(le.uint8(0)) -- postage stamp image 
   file:write(le.uint8(0)) -- color correction table --1k shorts 8*1000

   file:write(le.uint32(0)) -- extension area offset 
   file:write(le.uint32(0)) -- dev dir offset 
   file:write("TRUEVISION-XFILE") -- signature 

   --file:write(le.uint8(8)) -- size of image data (only necessary if compressed)
   --file:write(le.uint8(0)) -- horizontal pixels per meter
   

   file:close()
end

local function writeBmp(data, filename)
   local file = assert(io.open(filename,'w'), "Unable to save to "..filename)
   --bmptxt(data,"tmp.txt")
   file:write("B") -- windows bitmap header
   file:write("M") -- windows bitmap header
   file:write(le.uint32(0)) -- filesize, only useful for compressed bitmaps
   file:write(le.uint16(0)) -- reserved1, always 0
   file:write(le.uint16(0)) -- reserved2, always 0
   file:write(le.uint32(54)) -- offset into file of data
   -- bitmap info header
   file:write(le.uint32(40)) -- size of bitmap info header
   file:write(le.uint32(heightMapX+1)) -- width (colums)
   file:write(le.uint32(heightMapY+1)) -- height (rows)
   file:write(le.uint16(0)) -- number of planes
   file:write(le.uint16(32)) -- bits per pixel
   file:write(le.uint32(0)) -- compression type
   file:write(le.uint32(0)) -- size of image data (only necessary if compressed)
   file:write(le.uint32(3100)) -- horizontal pixels per meter
   file:write(le.uint32(3100)) -- vertical pixels per meter
   file:write(le.uint32(0)) -- number of colours used
   file:write(le.uint32(0)) -- important colours
   
   --local temp = io.open("tmp.txt",'r')
   --for line in temp:lines() do 
   --   file:write(le.uint8(line):rep(4)) 
   --end

   -- bmps are upside down
   for row = heightMapX, 0, -1 do
      for col = 0, heightMapY, 1 do
         file:write(le.uint8(data[row][col] or 0):rep(4)) 
      end    
   end

   file:close()
   Spring.Echo("Exported to " .. filename)
end

local function writeppm(data, filename)
   local file = assert(io.open(filename,'w'), "Unable to save to "..filename)

   file:write("P2")
   file:write("\n")
   file:write("# CREATOR: heightmap_exporter.lua")
   file:write("\n")
   file:write("# i know this format is bad.")
   file:write("\n")
   file:write(heightMapX+1)  
   file:write(" ") 
   file:write(heightMapY+1)  
   file:write("\n")  
   file:write("255")
   file:write("\n")  
   for row = heightMapX, 0, -1 do
      for col = 0, heightMapY, 1 do   
         file:write(tostring(data[row][col] or 0).."\n")
      end 
   end

   file:close()
   Spring.Echo("Exported to " .. filename)
end

local function writetxt(data, filename)
   local file = assert(io.open(filename,'w'), "Unable to save to "..filename)
   for row = heightMapX, 0, -1 do
      for col = 0, heightMapY, 1 do  
         if (tonumber(data[row][col]) < 100)and(tonumber(data[row][col]) > 9)then  
           data[row][col] = "0"..tostring(data[row][col])   
         end    
         if (tonumber(data[row][col]) < 10)then  
           data[row][col] = "00"..tostring(data[row][col])   
         end  
         file:write(tostring(data[row][col] or 0).."-")
      end 
      file:write('\n')
   end

   file:close()
   Spring.Echo("Exported to " .. filename)
end

function widget:TextCommand(command)
   if (string.find(command, 'exportheightmapbmp') == 1) then
      local minHeight, maxHeight = Spring.GetGroundExtremes()
      local heightDif = (maxHeight - minHeight)
      local imageData = {}

      print("min height: " .. tostring(minHeight) .. ", max height: " .. tostring(maxHeight))

      -- save the image data
      for row = 0, heightMapY, 1 do
         imageData[row] = {}

         for col = 0, heightMapX, 1 do
            local pixelHeight = GetGroundHeight(col * 8, row * 8)
            local pixelColor = floor(((pixelHeight - minHeight) / heightDif) * 255)
            imageData[row][col] = pixelColor
         end
      end

      local filename = ("LuaUI\\Widgets\\output".. string.lower(string.gsub(Game.mapName, ".smf", "_")) .. "heightmap.bmp")

      writeBmp(imageData, filename)
      Spring.Echo("Map Height - Min: " .. floor(minHeight) .. ", Max: " .. floor(maxHeight))
  
   elseif (string.find(command, 'exportheightmaptga') == 1) then
      local minHeight, maxHeight = Spring.GetGroundExtremes()
      local heightDif = (maxHeight - minHeight)
      local imageData = {}

      print("min height: " .. tostring(minHeight) .. ", max height: " .. tostring(maxHeight))

      for row = 0, heightMapY, 1 do
         imageData[row] = {}

         for col = 0, heightMapX, 1 do
            local pixelHeight = GetGroundHeight(col * 8, row * 8)
            local pixelColor = floor(((pixelHeight - minHeight) / heightDif) * 255)
            imageData[row][col] = pixelColor
         end
      end

      local filename = ("LuaUI\\Widgets\\output".. string.lower(string.gsub(Game.mapName, ".smf", "_")) .. "heightmap.tga")

      writeTGA(imageData, filename)
      Spring.Echo("Map Height - Min: " .. floor(minHeight) .. ", Max: " .. floor(maxHeight))
   end
   if (string.find(command, 'exportheightmaptxt') == 1) then
      local minHeight, maxHeight = Spring.GetGroundExtremes()
      local heightDif = (maxHeight - minHeight)
      local imageData = {}

      print("min height: " .. tostring(minHeight) .. ", max height: " .. tostring(maxHeight))

      -- save the image data
      for row = 0, heightMapY, 1 do
         imageData[row] = {}

         for col = 0, heightMapX, 1 do
            local pixelHeight = GetGroundHeight(col * 8, row * 8)
            local pixelColor = floor(((pixelHeight - minHeight) / heightDif) * 255)
            imageData[row][col] = pixelColor
         end
      end

      local filename = ("LuaUI\\Widgets\\output".. string.lower(string.gsub(Game.mapName, ".smf", "_")) .. "heightmap.txt")

      writetxt(imageData, filename)
      Spring.Echo("Map Height - Min: " .. floor(minHeight) .. ", Max: " .. floor(maxHeight))
   end
  if (string.find(command, 'exportslopemaptxt') == 1) then
      local imageData = {}

      for row = 0, heightMapY, 1 do
         imageData[row] = {}

         for col = 0, heightMapX, 1 do
            local sx,sy,sz = Spring.GetGroundNormal(col * 8, row * 8)
            local slopelevel = sx + sz
            slopelevel = slopelevel *  1000
            slopelevel = math.floor(slopelevel)     
            imageData[row][col] = slopelevel
         end
      end

      local filename = ("LuaUI\\Widgets\\output".. string.lower(string.gsub(Game.mapName, ".smf", "_")) .. "slopemap.txt")

      writetxt(imageData, filename)
   elseif (string.find(command, 'exportheightmapppm') == 1) then
      local minHeight, maxHeight = Spring.GetGroundExtremes()
      local heightDif = (maxHeight - minHeight)
      local imageData = {}

      print("min height: " .. tostring(minHeight) .. ", max height: " .. tostring(maxHeight))

      -- save the image data
      for row = 0, heightMapY, 1 do
         imageData[row] = {}

         for col = 0, heightMapX, 1 do
            local pixelHeight = GetGroundHeight(col * 8, row * 8)
            local pixelColor = floor(((pixelHeight - minHeight) / heightDif) * 255)
            imageData[row][col] = pixelColor
         end
      end

      local filename = ("LuaUI\\Widgets\\output\\" .. string.lower(string.gsub(Game.mapName, ".smf", "_")) .. "heightmap.pgm")

      writeppm(imageData, filename)
      Spring.Echo("Map Height - Min: " .. floor(minHeight) .. ", Max: " .. floor(maxHeight))
  
   end

end




--------------------------------------------------------------------------------
--------------------------------------------------------------------------------