initial chasms mod

chasms/LICENSE

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+MIT License
+
+Copyright (c) 2021 FaceDeer
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

chasms/init.lua

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+local data = {}
+
+local maxy = tonumber(minetest.settings:get("chasms_maxy")) or -50
+local miny = tonumber(minetest.settings:get("chasms_miny")) or -3000
+local falloff = tonumber(minetest.settings:get("chasms_falloff")) or 100
+
+local chasms_threshold = tonumber(minetest.settings:get("chasms_threshold")) or 1.0
+local np_chasms_default = {
+	offset = 0,
+	scale = 1,
+	spread = {x = 75, y = 500, z = 2000},
+	seed = 94586,
+	octaves = 2,
+	persist = 0.63,
+	lacunarity = 2.0,
+}
+local np_chasms = minetest.settings:get_np_group("chasms_params") or np_chasms_default
+-- For some reason, these numbers are returned as strings by get_np_group.
+local tonumberize_params = function(params)
+	params.scale = tonumber(params.scale)
+	params.lacunarity = tonumber(params.lacunarity)
+	params.spread.x = tonumber(params.spread.x)
+	params.spread.y = tonumber(params.spread.y)
+	params.spread.z = tonumber(params.spread.z)
+	params.offset = tonumber(params.offset)
+	params.persistence = tonumber(params.persistence)
+end
+tonumberize_params(np_chasms)
+local nobj_chasm
+local chasm_data = {}
+
+local waver_strength = 8
+local waver_vector = {x=waver_strength, y=0, z=0}
+local np_waver = {
+	offset = 0,
+	scale = waver_strength,
+	spread = {x = 50, y = 50, z = 50},
+	seed = 49585,
+	octaves = 2,
+	persist = 0.63,
+	lacunarity = 2.0,
+}
+local nobj_waver
+local waver_data = {}
+
+local minfalloff = miny + falloff
+local maxfalloff = maxy - falloff
+local get_intensity = function(y)
+	if y < miny or y > maxy then
+		return 0
+	end
+	if y <= maxfalloff and y >= minfalloff then
+		return 1
+	end
+	if y < minfalloff then
+		return (y-miny)/falloff
+	end
+--	if y > maxfalloff then
+		return (maxy-y)/falloff
+--	end
+end
+
+local c_air = minetest.get_content_id("air")
+
+minetest.register_on_generated(function(minp, maxp, seed)
+	if minp.y >= maxy or maxp.y <= miny then
+		return
+	end
+	
+	local vm, emin, emax = minetest.get_mapgen_object("voxelmanip")
+	vm:get_data(data)
+
+	nobj_chasm = nobj_chasm or minetest.get_perlin_map(np_chasms, {x = emax.x - emin.x + 1 + waver_strength*2, y = emax.y - emin.y + 1, z = emax.z - emin.z + 1})
+	nobj_chasm:get_3d_map_flat(vector.subtract(emin, waver_vector), chasm_data)
+
+	nobj_waver = nobj_waver or minetest.get_perlin_map(np_waver, {x = emax.x - emin.x + 1, y = emax.y - emin.y + 1, z = emax.z - emin.z + 1})
+	nobj_waver:get_3d_map_flat(emin, waver_data)
+
+	local chasm_area = VoxelArea:new{MinEdge = vector.subtract(emin, waver_vector), MaxEdge = vector.add(emax, waver_vector)}
+	local data_area = VoxelArea:new{MinEdge = emin, MaxEdge = emax}
+
+--	local count = {}
+
+	for i, x, y, z in data_area:iterp_xyz(minp, maxp) do
+		local waver = math.min(math.max(math.floor(waver_data[i]+0.5), -waver_strength), waver_strength)
+--		count[waver] = (count[waver] or 0) + 1
+		local intensity = get_intensity(y)
+		if chasm_data[chasm_area:index(x+waver, y, z)]*intensity > chasms_threshold then
+			data[i] = c_air
+		end
+	end
+	vm:set_data(data)
+	vm:calc_lighting()
+	vm:write_to_map()
+	
+--	minetest.debug(dump(count))
+end)

chasms/mod.conf

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+name=chasms
+depends=mapgen_helper

chasms/settingtypes.txt

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+chasms_params (Noise params for chasms) noise_params_3d 0, 1, (75, 500, 2000), 94586, 2, 0.63, 2.0
+chasms_threshold (Noise threshold for chasms) float 1.0
+chasms_maxy (Maximum Y) int -50
+chasms_miny (Minimum Y) int -3000
+chasms_falloff (Taper distance) int 100