xpm.lua

-- Lua XPM generating library

-- (C) 2009 Matthew Wild <mwild1@gmail.com>

-- Released under the MIT/X11 license

module("xpm", package.seeall);

_M.__index = _M;

function new(width, height, name)

	return setmetatable({

			name = name,

			width = width,

			height = height,

			colours = { [false] = true }, ncolours = 1;

		}, _M);

end

function setpixel(xpm, x, y, colour)

	if not xpm[y] then

		xpm[y] = { [x] = colour };

	else

		xpm[y][x] = colour;

	end

	if colour and not xpm.colours[colour] then

		xpm.colours[colour] = true;

		xpm.ncolours = xpm.ncolours + 1;

	end

end

function render(xpm, f)

	local err;

	if type(f) == "string" then

		f = io.open(f, "w+");

	end

	if io.type(f) ~= "file" then

		error("No valid output file", 2);

	end

	f:write("/* XPM */\n");

	f:write("static char * ", name or "xpm", "[] = {\n");

	f:write(string.format([["%d %d %d %d",]], xpm.width, xpm.height, xpm.ncolours, 1), "\n");

	local colourmap = new_colourmap(xpm.colours);

	for colour in pairs(xpm.colours) do

		f:write('"', colourmap[colour], "      c ", colour or "None", '",\n');

	end

	for y=1,xpm.height do

		if xpm[y] then

			f:write('"');

			for x=1,xpm.width do

				local pixel = xpm[y][x];

				if pixel then

					f:write(colourmap[pixel]);

				else

					f:write(" ");

				end

			end

			f:write('"', y == xpm.height and "" or ",",'\n');

		else

			f:write('"', string.rep(" ", xpm.width), '"', y == xpm.height and "" or ",", '\n');

		end

	end

	f:write("};\n");

end

function new_colourmap(colours)

	return setmetatable({ [false] = " ", curr = 35 }, { __index = 

		function (cm, colour)

			cm.curr = cm.curr + 1;

			cm[colour] = string.char(cm.curr);

			return rawget(cm, colour);

		end; });

end

return _M;