Create a series of image use to test TFT screen.

TFT.lua

-- command line arg:
-- TFT.lua WxH
function check(arg)
	if not arg[1] then
		error('WxH arg not given!')
	end
	local w, h = arg[1]:match('(%d+)x(%d+)')
	if not w or not h then
		error('W or H not number!')
	end
	return tonumber(w), tonumber(h)
end



local function draw_line(cmd, x0, y0, x1, y1)
	cmd[#cmd+1] = '-draw'
	cmd[#cmd+1] = string.format("line %d,%d %d,%d", x0, y0, x1, y1)
end

local function draw_text(cmd, x, y, text)
	local f = "text %d,%d '%s'"

	cmd[#cmd+1] = '-draw'
	cmd[#cmd+1] = f:format(x, y, text)
end

local function set_out_filename(cmd, filename)
	cmd[#cmd+1] = filename
end

local function init_cmd(w, h)
	return {'convert', '-size', w..'x'..h, 'xc:black', '-background', 'black', '-fill', 'white', '-font', 'Consolas'}	
end

require('ex')

local function warp(i, N)
	return i <= N and i or N-(i%N)
end

function make_cmd()

	local W, H = check(arg)
	local MAX = math.max(W, H)
	local LEN = 20
	
	for i=1,MAX do
		local cmd = init_cmd(W, H)
		if i <= W then draw_line(cmd, i-1, 0, i-1, H) end
		if i <= H then draw_line(cmd, 0, i-1, W, i-1) end

		draw_text(cmd, 8, H-8, string.format('%03d', i))
		set_out_filename(cmd, string.format('%03d.jpg', i))
		ex.spawn(cmd)
	end
end

make_cmd()