bmp mode working

init.lua

@@ -1,8 +1,8 @@
-PROCESSOR = "tiff8" -- options are: "py", "gm", "magick", "imlib2", "pngLua"
+PROCESSOR = "native" -- options are: "native", "py", "gm", "magick", "imlib2"
+--imlib2 treats 16-bit as 8-bit and requires imlib2, magick requires magick wand -- magick is the most tested mode
 --gm does not work and requires graphicksmagick, py is bit slow and requires lunatic-python to be built, and the PIL,
---imlib2 treats 16-bit as 8-bit and requires imlib2, magick requires magick wand
 --convert uses commandline imagemagick "convert" or graphicsmagick "gm convert" ("convert.exe" or "gm.exe convert")
---png locks up and does not work... tiff8 is for uncompressed grayscale 8-bit tiffs only
+--native handles png, tiff, and bmp files but none currently only bmp works and only on 24 bit images with good headers
 MODPATH = minetest.get_modpath("realterrain")
 WORLDPATH = minetest.get_worldpath()
 RASTERS = MODPATH .. "/rasters/"
@@ -17,7 +17,7 @@ local imagesize = ie.require "imagesize"
 
 --[[package.path = (MODPATH.."/lib/luasocket/?.lua;"..MODPATH.."/lib/luasocket/?/init.lua;"..package.path)
 local socket = ie.require "socket"--]]
-local py, gm, magick, imlib2, convert, png
+local native, py, gm, magick, imlib2, convert
 if PROCESSOR == "py" then
 	package.loadlib("/usr/lib/x86_64-linux-gnu/libpython2.7.so", "*") --may not need to explicitly state this
 	package.path = (MODPATH.."/lib/lunatic-python-bugfix-1.1.1/?.lua;"..package.path)
@@ -37,12 +37,9 @@ elseif PROCESSOR == "gm" then
 	gm = ie.require "graphicsmagick"
 elseif PROCESSOR == "convert" then
 	convert = "convert" -- could also be convert.exe, "gm convert" or "gm.exe convert"
-elseif PROCESSOR == "png" then
-	package.path = (MODPATH.."/lib/pngLua/?.lua;"..MODPATH.."/lib/pngLua/?/init.lua;"..package.path)
-	ie.require "png"
-	png = true
-elseif PROCESSOR == "tiff8" then
-	tiff8 = true
+elseif PROCESSOR == "native" then
+	dofile(MODPATH.."/lib/iohelpers.lua")
+	dofile(MODPATH.."/lib/imageloader.lua")
 end
 local realterrain = {}
 realterrain.settings = {}
@@ -57,9 +54,9 @@ realterrain.settings.zoffset = 0
 realterrain.settings.waterlevel = 0
 realterrain.settings.alpinelevel = 1000
 
-realterrain.settings.fileelev   = 'demo/dem.tif'
+realterrain.settings.fileelev   = 'demo/dem.bmp'
 realterrain.settings.elevbits = 8 --@todo remove this setting when magick autodetects bitdepth
-realterrain.settings.filecover = 'demo/biomes.tif'
+realterrain.settings.filecover = 'demo/biomes.bmp'
 realterrain.settings.coverbits = 8 --@todo remove this setting when magick autodetects bitdepth
 
 realterrain.settings.fileinput = ''
@@ -562,9 +559,9 @@ realterrain.input3 = {}
 function realterrain.init()
 	local mode = realterrain.get_mode()
 	local imageload
-	if gm then imageload = gm.Image
-	elseif magick then imageload = magick.load_image
-	elseif imlib2 then imageload = imlib2.image.load
+	if PROCESSOR == "gm" then imageload = gm.Image
+	elseif PROCESSOR == "magick" then imageload = magick.load_image
+	elseif PROCESSOR == "imlib2" then imageload = imlib2.image.load
 	end
 	local rasternames = {}
 	table.insert(rasternames, "elev")
@@ -575,45 +572,38 @@ function realterrain.init()
 	for k,rastername in next, rasternames do
 			
 		if realterrain.settings["file"..rastername] ~= ""  then 
-			if tiff8 then
+			if PROCESSOR == "native" then
 				--use imagesize to get the dimensions and header offset
 				local width, length, format = imagesize.imgsize(RASTERS..realterrain.settings["file"..rastername])
-				
-				if format == "image/tiff" then
+				print(rastername..": format: "..format)
+				if string.sub(format, -3) == "bmp" or string.sub(format, -6) == "bitmap" then
+					dofile(MODPATH.."/lib/loader_bmp.lua")
+					local bitmap, e = imageloader.load(RASTERS..realterrain.settings["file"..rastername])
+					if e then print(e) end
+					realterrain[rastername].image = bitmap
+					realterrain[rastername].width = width
+					realterrain[rastername].length = length
+					realterrain[rastername].bits = tonumber(realterrain.settings[rastername.."bits"])
+					realterrain[rastername].format = "bmp"
+				elseif format == "image/png" then
+					dofile(MODPATH.."/lib/loader_png.lua")
+					local bitmap, e = imageloader.load(RASTERS..realterrain.settings["file"..rastername])
+					if e then print(e) end
+					realterrain[rastername].image = bitmap
+					realterrain[rastername].width = realterrain[rastername].image.width
+					realterrain[rastername].length = realterrain[rastername].image.height
+					realterrain[rastername].format = "png"
+				elseif format == "image/tiff" then
 					local file = io.open(RASTERS..realterrain.settings["file"..rastername], "rb")
 					realterrain[rastername].image = file
 					realterrain[rastername].width = width
 					realterrain[rastername].length = length
 					realterrain[rastername].bits = tonumber(realterrain.settings[rastername.."bits"])
+					realterrain[rastername].format = "tiff"
 				else
-					print("tiff8 processor requires an uncompressed 8-bit grayscale tiff file")
-					return
+					print("your file should be an uncompressed tiff, png or bmp")
 				end
-			elseif png then
-				--@todo use imagesize to determine format
-				local function get_png(filename)
-					local ok, r = pcall(pngImage, filename)
-					if not ok then return nil, r end  -- NOTE: r == error message
-					return r
-				end
-
-				local img, e = get_png(RASTERS..realterrain.settings["file"..rastername]) --@todo locks up, no error!
-				if not img then
-					print(e)
-					return nil, e
-				end
-				--@todocheck if the image is a png and if so load it
-				realterrain[rastername].image = img
-				img = nil
-				if realterrain[rastername].image then
-					realterrain[rastername].width = realterrain[rastername].image.width
-					realterrain[rastername].length = realterrain[rastername].image.height
-				else
-					print("your "..rastername.." file is missing or is not a PNG (should be: "..realterrain.settings["file"..rastername].."), maybe delete or edit world/realterrain_settings")
-					realterrain[rastername] = {}
-				end
-				
-			elseif py then
+			elseif PROCESSOR == "py" then
 				py.execute(rastername.." = Image.open('"..RASTERS..realterrain.settings["file"..rastername] .."')")
 				py.execute(rastername.."_w, "..rastername.."_l = "..rastername..".size")
 				realterrain[rastername].width = tonumber(tostring(py.eval(rastername.."_w")))
@@ -631,12 +621,12 @@ function realterrain.init()
 			else 
 				realterrain[rastername].image = imageload(RASTERS..realterrain.settings["file"..rastername])
 				if realterrain[rastername].image then
-					if gm then
+					if PROCESSOR == "gm" then
 						realterrain[rastername].width, realterrain[rastername].length = realterrain[rastername].image:size()
 					else--imagick or imlib2
 						realterrain[rastername].width = realterrain[rastername].image:get_width()
 						realterrain[rastername].length = realterrain[rastername].image:get_height()
-						if magick then
+						if PROCESSOR == "magick" then
 							realterrain[rastername].bits = realterrain.settings[rastername.."bits"]
 						end
 					end
@@ -692,6 +682,7 @@ function realterrain.generate(minp, maxp)
 	local x1 = maxp.x
 	local y1 = maxp.y
 	local z1 = maxp.z
+
 	local x0 = minp.x
 	local y0 = minp.y
 	local z0 = minp.z
@@ -1133,52 +1124,63 @@ end
 --the raw get pixel method that uses the selected method and accounts for bit depth
 function realterrain.get_raw_pixel(x,z, rastername) -- "rastername" is a string
 	local r,g,b
+	local width, length
+	width = realterrain[rastername].width
+	length = realterrain[rastername].length
 	--check to see if the image is even on the raster, otherwise skip
-	if ( x >= 0 and x < realterrain[rastername].width )
-		and ( z >= 0 and z < realterrain[rastername].length ) then
+	if ( x >= 0 and x < width ) and ( z >= 0 and z < length ) then
 		--print(rastername..": x "..x..", z "..z)
-		if tiff8 then
-			local file = realterrain[rastername].image
-			if not file then
-				print("tiff8 problem retrieving file handle")
-			end
-			--print(file)
-			local width, length
-			width = realterrain[rastername].width
-			length = realterrain[rastername].length
-			
-			
-			if realterrain[rastername].bits == 8 then
-				file:seek("set", ((z) * width) + x)
-				r = file:read(1)
-				if r then
-					r = r:byte() -- -32?
-					
-					r = tonumber(r)
-					--print(r)
-				else
-					print(rastername..": nil value encountered at x: "..x..", z: "..z)
-					r = nil
+		if PROCESSOR == "native" then
+			if realterrain[rastername].format == "bmp" then
+				local bitmap = realterrain[rastername].image
+				local c
+				if bitmap.pixels[z] and bitmap.pixels[z][x] then
+					c = bitmap.pixels[z][x]
+					r = c.r
+					g = c.g
+					b = c.b
 				end
-			else
-				file:seek("set", ((z) * width * 2) + (x*2)+1)
-				local r1 = file:read(1)
-				local r2 = file:read(1)
-				if r1 and r2 then
-					r = tonumber(r1:byte()) + tonumber(r2:byte())
-					--print(r)
+			elseif realterrain[rastername].format == "png" then
+				local bitmap = realterrain[rastername].image
+				local c
+				if bitmap.pixels[z] and bitmap.pixels[z][x] then
+					c = bitmap.pixels[z][x]
+					r = c.r
+					g = c.g
+					b = c.b
+				end
+			elseif realterrain[rastername].format == "tiff" then
+				local file = realterrain[rastername].image
+				if not file then
+					print("tiff mode problem retrieving file handle")
+				end
+				--print(file)
+				
+				if realterrain[rastername].bits == 8 then
+					file:seek("set", ((z) * width) + x)
+					r = file:read(1)
+					if r then
+						r = r:byte() -- -32?
+						
+						r = tonumber(r)
+						--print(r)
+					else
+						print(rastername..": nil value encountered at x: "..x..", z: "..z)
+						r = nil
+					end
 				else
-					print(rastername..": one of two bytes is nil")
+					file:seek("set", ((z) * width * 2) + (x*2)+1)
+					local r1 = file:read(1)
+					local r2 = file:read(1)
+					if r1 and r2 then
+						r = tonumber(r1:byte()) + tonumber(r2:byte())
+						--print(r)
+					else
+						print(rastername..": one of two bytes is nil")
+					end
 				end
 			end
-			
-			
-		elseif png then
-			local pixel = img.scanLines[y].pixels[x]
-			r=pixel.R
-			g=pixel.G
-			b=pixel.B 
-		elseif py then
+		elseif PROCESSOR == "py" then
 			if realterrain[rastername].mode == "RGB" then
 				py.execute(rastername.."_r, "..rastername.."_g,"..rastername.."_b = "..rastername.."_pixels["..x..", "..z.."]")
 				r = tonumber(tostring(py.eval(rastername.."_r")))
@@ -1190,12 +1192,12 @@ function realterrain.get_raw_pixel(x,z, rastername) -- "rastername" is a string
 			--print(r)
 		else
 			if realterrain[rastername].image then
-				if magick then
+				if PROCESSOR == "magick" then
 					r,g,b = realterrain[rastername].image:get_pixel(x, z) --@todo change when magick autodetects bit depth
 					r = math.floor(r * (2^realterrain[rastername].bits))
 					g = math.floor(g * (2^realterrain[rastername].bits))
 					b = math.floor(b * (2^realterrain[rastername].bits))
-				elseif imlib2 then
+				elseif PROCESSOR == "imlib2" then
 					r = realterrain[rastername].image:get_pixel(x, z).red
 					g = realterrain[rastername].image:get_pixel(x, z).green
 					b = realterrain[rastername].image:get_pixel(x, z).blue
@@ -1270,9 +1272,9 @@ end
 function realterrain.get_enumeration(rastername, xstart, width, zstart, length) --raster is a string so py can use it
 	local enumeration
 	
-	if gm then
+	if PROCESSOR == "gm" then
 		enumeration = realterrain[rastername].image:clone():crop(width,length,xstart,zstart):format("txt"):toString()
-	elseif magick then
+	elseif PROCESSOR == "magick" then
 		local tmpimg
 		tmpimg = realterrain[rastername].image:clone()
 		tmpimg:crop(width,length,xstart,zstart)
@@ -1304,7 +1306,7 @@ function realterrain.build_heightmap(xstart, xend, zstart, zend, get_cover, get_
 	if mode.get_input3 then	table.insert(rasternames, "input3")	end
 	for k,rastername in next, rasternames do
 			
-		if py then
+		if PROCESSOR == "py" then
 			--py.execute(rastername.."_pixels = "..rastername..".load()")
 			for z = zstart, zend, 1  do
 				if not pixels[z] then pixels[z] = {} end
@@ -1323,7 +1325,7 @@ function realterrain.build_heightmap(xstart, xend, zstart, zend, get_cover, get_
 			end
 		end
 		local enumeration
-		if gm or magick then
+		if PROCESSOR == "gm" or PROCESSOR == "magick" then
 			enumeration = realterrain.get_enumeration(rastername, xstart, width, zstart, length)
 			--print("entire enumeration: "..enumeration)
 			local entries = 0
@@ -1331,7 +1333,7 @@ function realterrain.build_heightmap(xstart, xend, zstart, zend, get_cover, get_
 			local mincol, maxcol, minrow, maxrow
 			local firstline = true
 			for k,line in next, string.split(enumeration, "\n") do                         
-				if magick and firstline then
+				if PROCESSOR == "magick" and firstline then
 					firstline = false --first line is a head in IM but not GM
 				else
 					entries = entries + 1

lib/imageloader.lua

@@ -0,0 +1,96 @@
+
+imageloader = { }
+
+local types = { }
+
+local bmp_meta = {
+	__index = bmp_methods,
+}
+
+--[[
+typedef = {
+	description = "FOO File",
+	check = func(filename), --> bool
+	load = func(filename), --> table or (nil, errormsg)
+}
+]]
+
+function imageloader.register_type(def)
+	types[#types + 1] = def
+end
+
+local function find_loader(filename)
+	for _,def in ipairs(types) do
+		local r = def.check(filename)
+		if r then
+			return def
+		end
+	end
+	return nil, "imageloader: unknown file type"
+end
+
+function imageloader.load(filename)
+	local def, e = find_loader(filename)
+	if not def then return nil, e end
+	if e then print(e) end
+	local r, e = def.load(filename)
+	if r then
+		r = setmetatable(r, bmp_meta)
+	end
+	return r, e
+end
+
+function imageloader.type(filename)
+	local def, e = find_loader(filename)
+	if not def then return nil, e end
+	return def.description
+end
+--[[
+function imageloader.to_schematic(bmp, pal)
+	local data = { }
+	local datai = 1
+	for z = 1, bmp.h do
+		for x = 1, bmp.w do
+			local c = bmp.pixels[z][bmp.w + 1 - x]
+			local i = palette.bestfit_color(pal, c)
+			if (i == 1) and ((c.r ~= 255) or (c.g ~= 0) or (c.r ~= 255)) then
+				print("WARNING: wrong color taken as transparency:"
+					..(("at (%d,%d): [R=%d,G=%d,B=%d]"):format(x, z, c.r, c.g, c.b))
+				)
+			end
+			local node = pal[i].node
+			data[datai] = { name=node }
+			datai = datai + 1
+		end
+	end
+	return {
+		size = { x=bmp.w, y=1, z=bmp.h },
+		data = data,
+	}
+end
+
+minetest.register_chatcommand("loadimage", {
+	description = "Load an image file into the world at current position",
+	params = "<filename>",
+	func = function(name, param)
+		param = param:trim()
+		if param == "" then
+			minetest.chat_send_player(name, "[imageloader] Usage: /loadimage <filename>")
+			return
+		end
+		minetest.chat_send_player(name, "[imageloader] Loading image...")
+		local bmp, e = imageloader.load(minetest.get_modpath("imageloader").."/images/"..param)
+		if not bmp then
+			minetest.chat_send_player(name, "[imageloader] Failed to load image: "..(e or "unknown error"))
+			return
+		end
+		print(("Image loaded: size: %dx%d"):format(bmp.w, bmp.h))
+		minetest.chat_send_player(name, "[imageloader] Creating schematic...")
+		local schem = imageloader.to_schematic(bmp, palette.wool_palette)
+		print(("Schematic created: size: %dx%dx%d"):format(schem.size.x, schem.size.y, schem.size.z))
+		minetest.chat_send_player(name, "[imageloader] Placing schematic...")
+		local pos = minetest.get_player_by_name(name):getpos()
+		minetest.place_schematic(pos, schem, 0)
+		minetest.chat_send_player(name, "[imageloader] DONE!")
+	end,
+})--]]

lib/iohelpers.lua

@@ -0,0 +1,49 @@
+
+ioh = { }
+
+local function read_bytes(f, c, d)
+
+	local s = (d < 0) and c or 1
+	local e = (d < 0) and 1 or c
+
+	local buf = f:read(c)
+	if (not buf) or (buf:len() ~= c) then return nil end
+
+	local r = 0
+
+	for x = s, e, d do
+		r = r * 256
+		r = r + buf:byte(x)
+	end
+
+	return r
+
+end
+
+local function write_bytes(f, n, c, d)
+
+	local s = (d < 0) and c or 1
+	local e = (d < 0) and 1 or c
+
+	local buf = ""
+
+	for x = s, e, d do
+		local ch = (n % 256)
+		buf = buf..string.char(ch)
+		n = (n - ch) / 256
+	end
+
+	f:write(buf)
+
+end
+
+
+function ioh.read_int16_le(f) return read_bytes(f, 2, -1) end
+function ioh.read_int32_le(f) return read_bytes(f, 4, -1) end
+function ioh.read_int16_be(f) return read_bytes(f, 2,  1) end
+function ioh.read_int32_be(f) return read_bytes(f, 4,  1) end
+
+function ioh.write_int16_le(f, n) write_bytes(f, n, 2, -1) end
+function ioh.write_int32_le(f, n) write_bytes(f, n, 4, -1) end
+function ioh.write_int16_be(f, n) write_bytes(f, n, 2,  1) end
+function ioh.write_int32_be(f, n) write_bytes(f, n, 4,  1) end

lib/loader_bmp.lua

@@ -0,0 +1,251 @@
+
+-- Original file is part of Allegro 4.4.
+-- BMP loader by Seymour Shlien.
+-- OS/2 BMP support and BMP save function by Jonas Petersen.
+-- Translated to Lua by Diego Martínez <lkaezadl3@gmail.com>
+
+local BI_RGB = 0
+
+local OS2INFOHEADERSIZE = 12
+local WININFOHEADERSIZE = 40
+
+local figetw = ioh.read_int16_le
+local figetl = ioh.read_int32_le
+local function fgetc(f) return (f:read(1) or " "):byte() end
+
+--[[ read_bmfileheader:
+  |  Reads a BMP file header and check that it has the BMP magic number.
+  ]]
+local function read_bmfileheader(f, fileheader)
+
+	fileheader.bfType = figetw(f)
+	fileheader.bfSize = figetl(f)
+	fileheader.bfReserved1 = figetw(f)
+	fileheader.bfReserved2 = figetw(f)
+	fileheader.bfOffBits = figetl(f)
+
+	if fileheader.bfType ~= 19778 then return false end
+
+	return true
+
+end
+
+--[[ read_win_bminfoheader:
+  |  Reads information from a BMP file header.
+  ]]
+local function read_win_bminfoheader(f, infoheader)
+
+	local win_infoheader
+
+	local win_infoheader = { }
+	win_infoheader.biWidth = figetl(f)
+	win_infoheader.biHeight = figetl(f)
+	win_infoheader.biPlanes = figetw(f)
+	win_infoheader.biBitCount = figetw(f)
+	win_infoheader.biCompression = figetl(f)
+	win_infoheader.biSizeImage = figetl(f)
+	win_infoheader.biXPelsPerMeter = figetl(f)
+	win_infoheader.biYPelsPerMeter = figetl(f)
+	win_infoheader.biClrUsed = figetl(f)
+	win_infoheader.biClrImportant = figetl(f)
+
+	infoheader.biWidth = win_infoheader.biWidth
+	infoheader.biHeight = win_infoheader.biHeight
+	infoheader.biBitCount = win_infoheader.biBitCount
+	infoheader.biCompression = win_infoheader.biCompression
+
+	return true
+
+end
+
+--[[ read_os2_bminfoheader:
+  |  Reads information from an OS/2 format BMP file header.
+  ]]
+local function read_os2_bminfoheader(f, infoheader)
+
+	local os2_infoheader = { }
+
+	os2_infoheader.biWidth = figetw(f)
+	os2_infoheader.biHeight = figetw(f)
+	os2_infoheader.biPlanes = figetw(f)
+	os2_infoheader.biBitCount = figetw(f)
+
+	infoheader.biWidth = os2_infoheader.biWidth
+	infoheader.biHeight = os2_infoheader.biHeight
+	infoheader.biBitCount = os2_infoheader.biBitCount
+	infoheader.biCompression = 0
+
+	return true
+
+end
+
+--[[ read_24bit_line:
+  |  Support function for reading the 24 bit bitmap file format, doing
+  |  our best to convert it down to a 256 color palette.
+  ]]
+local function read_24bit_line(length, f, line)
+
+	local ii = 0
+
+	for i = 1, length do
+		local c = { }
+		c.b = fgetc(f)
+		c.g = fgetc(f)
+		c.r = fgetc(f)
+		c.a = 255
+		line[i] = c
+		ii = ii + 1
+	end
+
+	-- padding
+	ii = (ii * 3) % 4
+	if ii ~= 0 then
+		while ii < 4 do
+			fgetc(f)
+			ii = ii + 1
+		end
+	end
+
+end
+
+--[[ read_32bit_line:
+  |  Support function for reading the 32 bit bitmap file format, doing
+  |  our best to convert it down to a 256 color palette.
+  ]]
+local function read_32bit_line(length, f, line)
+
+	for i = 1, length do
+		local c = { }
+		c.b = fgetc(f)
+		c.g = fgetc(f)
+		c.r = fgetc(f)
+		c.a = fgetc(f)
+		line[i] = c
+	end
+
+end
+
+--[[ read_image:
+  |  For reading the noncompressed BMP image format.
+  ]]
+local function read_image(f, bmp, infoheader)
+
+	local i, line, height, dir
+
+	height = infoheader.biHeight
+	line = (height < 0) and 1 or height
+	dir = (height < 0) and 1 or -1
+	height = math.abs(height)
+
+	print(("[imageloader.bmp] size=%dx%d bpp=%d"):format(
+		infoheader.biWidth,
+		infoheader.biHeight,
+		infoheader.biBitCount
+	))
+
+	bmp.pixels = { }
+
+	for i = 1, height do
+		local row = { }
+		bmp.pixels[line] = row
+		if infoheader.biBitCount == 24 then
+			read_24bit_line(infoheader.biWidth, f, row)
+		elseif infoheader.biBitCount == 32 then
+			read_32bit_line(infoheader.biWidth, f, row)
+		else
+			return false
+		end
+		line = line + dir
+	end
+
+	return true
+
+end
+
+local function get_bmp_infoheader(f)
+
+	local fileheader = { }
+	local infoheader = { }
+	local bmp, biSize
+	local bpp, dest_depth
+
+	if not read_bmfileheader(f, fileheader) then
+		return nil, "loader_bmp: failed to read file header"
+	end
+
+	biSize = figetl(f)
+
+	if biSize == WININFOHEADERSIZE then
+		if not read_win_bminfoheader(f, infoheader) then
+			return nil, "loader_bmp: failed to read info header"
+		end
+	elseif biSize == OS2INFOHEADERSIZE then
+		if not read_os2_bminfoheader(f, infoheader) then
+			return nil, "loader_bmp: failed to read info header"
+		end
+	else
+		return nil, "loader_bmp: unsupported file format"
+	end
+
+	if --[[(infoheader.biBitCount == 8) or (infoheader.biBitCount == 16)
+		or --]](infoheader.biBitCount == 24) or (infoheader.biBitCount == 32) then
+		bpp = infoheader.biBitCount
+	else
+		return nil, "loader_bmp: unsupported color depth "..infoheader.biBitCount
+	end
+
+	if infoheader.biCompression ~= BI_RGB then
+		return nil, "loader_bmp: unsupported compression scheme: "..infoheader.biCompression
+	end
+
+	return infoheader
+
+end
+
+--[[ load_bmp_pf:
+  |  Like load_bmp, but starts loading from the current place in the PACKFILE
+  |  specified. If successful the offset into the file will be left just after
+  |  the image data. If unsuccessful the offset into the file is unspecified,
+  |  i.e. you must either reset the offset to some known place or close the
+  |  packfile. The packfile is not closed by this function.
+  ]]
+local function load_bmp_pf(f)
+
+	local infoheader, e = get_bmp_infoheader(f)
+
+	if not infoheader then return nil, e end
+
+	local bmp = {
+		bpp = bpp,
+		w = infoheader.biWidth,
+		h = math.abs(infoheader.biHeight),
+	}
+
+	read_image(f, bmp, infoheader)
+
+	return bmp
+
+end
+
+local function check_bmp(filename)
+	local f, e = io.open(filename, "rb")
+	if not f then return nil, e end
+	local r, e = get_bmp_infoheader(f)
+	if e then print(e) end
+	f:close()
+	return r, e
+end
+
+local function load_bmp(filename)
+	local f, e = io.open(filename, "rb")
+	if not f then return nil, e end
+	local r, e = load_bmp_pf(f)
+	f:close()
+	return r, e
+end
+
+imageloader.register_type({
+	description = "Windows or OS/2 Bitmap",
+	load = load_bmp,
+	check = check_bmp,
+})

lib/loader_png.lua

@@ -0,0 +1,37 @@
+package.path = (MODPATH.."/lib/pngLua/?.lua;"
+		..MODPATH.."/lib/pngLua/?/init.lua;"
+		..package.path)
+
+require "png"
+
+local function get_png(filename)
+	local ok, r = pcall(pngImage, filename)
+	if not ok then return nil, r end  -- NOTE: r == error message
+	return r
+end
+
+local function load_png(filename)
+	local img, e = get_png(filename)
+	if not img then return nil, e end
+	local pixels = { }
+	local bmp = {
+		w = img.width, h = img.height,
+		pixels = pixels,
+	}
+	for y = 1, bmp.h do
+		local oline = { }
+		local iline = img.scanLines[y]
+		pixels[y] = oline
+		for x = 1, bmp.w do
+			local pixel = iline.pixels[x]
+			oline[x] = { r=pixel.R, g=pixel.G, b=pixel.B }
+		end
+	end
+	return bmp
+end
+
+imageloader.register_type({
+	description = "Portable Network Graphics",
+	load = load_png,
+	check = get_png,
+})

lib/pngLua/stream.lua

@@ -3,7 +3,6 @@ Stream = class()
 Stream.data = ""
 Stream.position = 1
 Stream.__name = "Stream"
-
 function Stream:bsRight(num, pow)
     return math.floor(num / 2^pow)
 end
@@ -21,7 +20,7 @@ function Stream:bytesToNum(bytes)
 	return n
 end
 
-function Stream:__init(param)
+function Stream:__init(param) --@todo realterrain note: gets this far 3 times then does nothing...
 	if (param.inputF ~= nil) then
 		self.data = io.open(param.inputF, "rb"):read("*all")
 	end