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