Xurkon
134 lines
3.8 KiB
Lua
134 lines
3.8 KiB
Lua
---@class RamerDouglasPeucker
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local RamerDouglasPeucker = QuestieLoader:CreateModule("RamerDouglasPeucker")
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-- code after this point is Ramer-Douglas-Peucker algorithm implemented by Eryn Lynn
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--[[
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MIT License
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Copyright (c) 2018 Eryn Lynn
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE. ]]
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-- Implementation of the Ramer–Douglas–Peucker algorithm
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-- readme https://github.com/evaera/RobloxLuaAlgorithms#ramerdouglaspeuckerlua
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-- author: evaera
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local function getSqDist(p1, p2)
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local dx = p1[1] - p2[1]
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local dy = p1[2] - p2[2]
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return dx * dx + dy * dy
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end
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local function simplifyRadialDist(points, sqTolerance)
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local prevPoint = points[1]
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local newPoints = {prevPoint}
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local point
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for i=2, #points do
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point = points[i]
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if getSqDist(point, prevPoint) > sqTolerance then
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table.insert(newPoints, point)
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prevPoint = point
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end
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end
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if prevPoint ~= point then
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table.insert(newPoints, point)
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end
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return newPoints
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end
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local function getSqSegDist(p, p1, p2)
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local x = p1[1]
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local y = p1[2]
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local dx = p2[1] - x
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local dy = p2[2] - y
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if dx ~= 0 or dy ~= 0 then
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local t = ((p[1] - x) * dx + (p[2] - y) * dy) / (dx * dx + dy * dy)
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if t > 1 then
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x = p2[1]
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y = p2[2]
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elseif t > 0 then
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x = x + dx * t
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y = y + dy * t
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end
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end
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dx = p[1] - x
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dy = p[2] - y
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return dx * dx + dy * dy
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end
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local function simplifyDPStep(points, first, last, sqTolerance, simplified)
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local maxSqDist = sqTolerance
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local index
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for i=first+1, last do
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local sqDist = getSqSegDist(points[i], points[first], points[last])
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if sqDist > maxSqDist then
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index = i
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maxSqDist = sqDist
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end
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end
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if maxSqDist > sqTolerance then
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if index - first > 1 then
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simplifyDPStep(points, first, index, sqTolerance, simplified)
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end
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table.insert(simplified, points[index])
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if last - index > 1 then
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simplifyDPStep(points, index, last, sqTolerance, simplified)
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end
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end
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end
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local function simplifyDouglasPeucker(points, sqTolerance)
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local last = #points
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local simplified={points[1]}
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simplifyDPStep(points, 1, last, sqTolerance, simplified)
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table.insert(simplified, points[last])
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return simplified
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end
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local _RamerDouglasPeucker = function(points, tolerance, highestQuality)
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if #points <= 2 then
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return points
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end
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local sqTolerance = tolerance ~= nil and tolerance^2 or 1
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points = highestQuality and points or simplifyRadialDist(points, sqTolerance)
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points = simplifyDouglasPeucker(points, sqTolerance)
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return points
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end
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setmetatable(RamerDouglasPeucker, { __call = function(_, ...) return _RamerDouglasPeucker(...) end}) |