blob: d313710e5cc2fb7f938e9e07ce3a37776ba04624 [file] [log] [blame]
--PolyPoints.lua
--[[
/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2017 William Wilgus
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
]]
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
-- decodes ascii string back to t_pts
function points_from_ascii(encstr, scale)
scale = scale or 1
local t_pts = {}
encstr = encstr or "00000008"
local chroffset = tonumber(string.sub(encstr, 1, 3)) or 0
local chrlen = tonumber(string.sub(encstr, 4, 8)) or 0
if string.len(encstr) ~= chrlen then
error("Invalid Points String" .. string.len(encstr), 2)
end
for i = 9, string.len(encstr) - 1, 2 do
local x = string.byte(encstr, i, i) - chroffset
local y = string.byte(encstr, i + 1, i + 1) - chroffset
t_pts[#t_pts + 1] = x * scale
t_pts[#t_pts + 1] = y * scale
end
return t_pts
end
--------------------------------------------------------------------------------
-- encodes t_pts as a ascii string non print chars are excluded so
-- size is limited to approx ~ 90x90
function points_to_ascii(t_pts)
if not t_pts then return "" end
local chroffset = 33
local maxoffset = 126 - 33
local t_enc = {[1] = string.format("%03d%05d", chroffset, #t_pts + 8)}
local max_n, min_n = 0, 0
for i = 1, #t_pts, 2 do
if t_pts[i] > max_n then max_n = t_pts[i] end
if t_pts[i] < min_n then min_n = t_pts[i] end
if t_pts[i+1] > max_n then max_n = t_pts[i+1] end
if t_pts[i+1] < min_n then min_n = t_pts[i+1] end
if max_n > maxoffset or min_n < 0 then break; end
t_enc[#t_enc + 1] = string.char(t_pts[i] + chroffset)
t_enc[#t_enc + 1] = string.char(t_pts[i+1] + chroffset)
end
if min_n >= 0 and (max_n - min_n) <= maxoffset then
return table.concat(t_enc)
else
return "00000008"
end
end
--------------------------------------------------------------------------------
-- scales t_pts by percentage (x/y)
function points_scale_pct(t_pts, x_pct, y_pct)
for i = 1, #t_pts, 2 do
local t_pt = {t_pts[i], t_pts[i + 1]}
t_pt = t_pt or {0, 0}
t_pts[i] = (t_pt[1] * x_pct) / 100
t_pts[i+1] = (t_pt[2] * y_pct) / 100
end
return t_pts
end
--------------------------------------------------------------------------------
-- scales t_pts by (x/y)
function points_scale(t_pts, width, height)
local max_x, max_y = 0, 0
for i = 1, #t_pts, 2 do
if t_pts[i] > max_x then max_x = t_pts[i] end
if t_pts[i+1] > max_y then max_y = t_pts[i+1] end
end
local x_pct = (width * 100) / max_x
local y_pct = (height * 100) / max_y
return points_scale_pct(t_pts, x_pct, y_pct)
end
--------------------------------------------------------------------------------
--[[
function scaleup(t_pts, scale_x, scale_y)
local t_coord
for key,value in pairs(t_pts) do
t_coord = t_pts[key]
t_coord[1] = t_coord[1] * scale_x
t_coord[2] = t_coord[2] * scale_y
t_pts[key] = t_coord
end
end
function scaledn(t_pts, scale_x, scale_y)
local t_coord
for key,value in pairs(t_pts) do
t_coord = t_pts[key]
t_coord[1] = t_coord[1] / scale_x
t_coord[2] = t_coord[2] / scale_y
t_pts[key] = t_coord
end
end
]]