57 lines
2.0 KiB
Lua
57 lines
2.0 KiB
Lua
local wea_c = worldeditadditions_core
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--- Interpolates between the 2 given points
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-- @param a Vector3|number The starting point.
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-- @param b Vector3|number The ending point.
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-- @param time number The percentage between 0 and 1 to interpolate to.
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-- @returns Vector3|number The interpolated point.
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local function linear_interpolate(a, b, time)
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return ((b - a) * time) + a
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end
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--- Chaikin curve smoothing implementation.
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-- This algorithm works by taking a list of points that define a segmented line,
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-- and then interpolating between them to smooth the line.
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-- @source Ported from https://git.starbeamrainbowlabs.com/sbrl-GitLab/Chaikin-Generator/src/branch/master/ChaikinGenerator/ChaikinCurve.cs
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-- @param arr_pos Vector3[] A list of points to interpolate.
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-- @param steps number The number of interpolatioon passes to do.
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-- @returns Vector3[] A (longer) list of interpolated points.
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local function chaikin(arr_pos, steps)
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-- print("DEBUG:chaikin START", wea_c.inspect(arr_pos))
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local result = wea_c.table.shallowcopy(arr_pos)
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local pos_start = result[1]
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local pos_end = result[#result]
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for pass = 1, steps do
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local result_nextpass = {}
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-- local offset = 0
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for i = 1,#result-1,1 do
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local pos_cur = result[i]
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local pos_next = result[i+1]
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-- print("DEBUG:chaikin SUBSTEP i", i, "pos_cur", pos_cur, "pos_next", pos_next)
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table.insert(result_nextpass, linear_interpolate(pos_cur, pos_next, 0.25))
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table.insert(result_nextpass, linear_interpolate(pos_cur, pos_next, 0.75))
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-- result[i+offset] = linear_interpolate(pos_cur, pos_next, 0.25)
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-- table.insert(result, i+1+offset, linear_interpolate(pos_cur, pos_next, 0.75))
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-- offset = offset + 1
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end
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-- table.remove(result, #result-1) -- In the original, but I don't know why
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result = result_nextpass
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-- Keep the starting & ending positions the same
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result[1] = pos_start
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result[#result] = pos_end
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-- print("DEBUG:chakin STEP", wea_c.inspect(result))
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end
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return result
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end
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return {
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chaikin = chaikin,
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linear_interpolate = linear_interpolate
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} |