mirror of
https://github.com/appgurueu/modlib.git
synced 2024-08-20 13:24:11 +02:00
139 lines
4.9 KiB
Lua
139 lines
4.9 KiB
Lua
-- Localize globals
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local assert, math, minetest, modlib, pairs, setmetatable, vector = assert, math, minetest, modlib, pairs, setmetatable, vector
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-- Set environment
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local _ENV = ...
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setfenv(1, _ENV)
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--+ Raycast wrapper with proper flowingliquid intersections
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function raycast(_pos1, _pos2, objects, liquids)
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local raycast = minetest.raycast(_pos1, _pos2, objects, liquids)
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if not liquids then
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return raycast
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end
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local pos1 = modlib.vector.from_minetest(_pos1)
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local _direction = vector.direction(_pos1, _pos2)
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local direction = modlib.vector.from_minetest(_direction)
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local length = vector.distance(_pos1, _pos2)
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local function next()
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for pointed_thing in raycast do
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if pointed_thing.type ~= "node" then
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return pointed_thing
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end
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local _pos = pointed_thing.under
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local pos = modlib.vector.from_minetest(_pos)
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local node = minetest.get_node(_pos)
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local def = minetest.registered_nodes[node.name]
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if not (def and def.drawtype == "flowingliquid") then return pointed_thing end
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local corner_levels = get_liquid_corner_levels(_pos)
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local full_corner_levels = true
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for _, corner_level in pairs(corner_levels) do
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if corner_level[2] < 0.5 then
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full_corner_levels = false
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break
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end
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end
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if full_corner_levels then
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return pointed_thing
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end
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local relative = pos1 - pos
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local inside = true
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for _, prop in pairs(relative) do
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if prop <= -0.5 or prop >= 0.5 then
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inside = false
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break
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end
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end
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local function level(x, z)
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local function distance_squared(corner)
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return (x - corner[1]) ^ 2 + (z - corner[3]) ^ 2
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end
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local irrelevant_corner, distance = 1, distance_squared(corner_levels[1])
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for index = 2, 4 do
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local other_distance = distance_squared(corner_levels[index])
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if other_distance > distance then
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irrelevant_corner, distance = index, other_distance
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end
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end
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local function corner(off)
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return corner_levels[((irrelevant_corner + off) % 4) + 1]
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end
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local base = corner(2)
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local edge_1, edge_2 = corner(1) - base, corner(3) - base
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-- Properly selected edges will have a total length of 2
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assert(math.abs(edge_1[1] + edge_1[3]) + math.abs(edge_2[1] + edge_2[3]) == 2)
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if edge_1[1] == 0 then
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edge_1, edge_2 = edge_2, edge_1
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end
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local level = base[2] + (edge_1[2] * ((x - base[1]) / edge_1[1])) + (edge_2[2] * ((z - base[3]) / edge_2[3]))
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assert(level >= -0.5 and level <= 0.5)
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return level
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end
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inside = inside and (relative[2] < level(relative[1], relative[3]))
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if inside then
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-- pos1 is inside the liquid node
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pointed_thing.intersection_point = _pos1
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pointed_thing.intersection_normal = vector.new(0, 0, 0)
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return pointed_thing
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end
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local function intersection_normal(axis, dir)
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return {x = 0, y = 0, z = 0, [axis] = dir}
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end
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local function plane(axis, dir)
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local offset = dir * 0.5
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local diff_axis = (relative[axis] - offset) / -direction[axis]
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local intersection_point = {}
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for plane_axis = 1, 3 do
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if plane_axis ~= axis then
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local value = direction[plane_axis] * diff_axis + relative[plane_axis]
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if value < -0.5 or value > 0.5 then
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return
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end
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intersection_point[plane_axis] = value
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end
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end
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intersection_point[axis] = offset
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return intersection_point
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end
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if direction[2] > 0 then
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local intersection_point = plane(2, -1)
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if intersection_point then
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pointed_thing.intersection_point = (intersection_point + pos):to_minetest()
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pointed_thing.intersection_normal = intersection_normal("y", -1)
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return pointed_thing
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end
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end
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for coord, other in pairs{[1] = 3, [3] = 1} do
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if direction[coord] ~= 0 then
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local dir = direction[coord] > 0 and -1 or 1
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local intersection_point = plane(coord, dir)
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if intersection_point then
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local height = 0
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for _, corner in pairs(corner_levels) do
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if corner[coord] == dir * 0.5 then
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height = height + (math.abs(intersection_point[other] + corner[other])) * corner[2]
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end
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end
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if intersection_point[2] <= height then
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pointed_thing.intersection_point = (intersection_point + pos):to_minetest()
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pointed_thing.intersection_normal = intersection_normal(modlib.vector.index_aliases[coord], dir)
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return pointed_thing
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end
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end
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end
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end
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for _, triangle in pairs{
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{corner_levels[3], corner_levels[2], corner_levels[1]},
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{corner_levels[4], corner_levels[3], corner_levels[1]}
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} do
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local pos_on_ray = modlib.vector.ray_triangle_intersection(relative, direction, triangle)
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if pos_on_ray and pos_on_ray <= length then
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pointed_thing.intersection_point = (pos1 + modlib.vector.multiply_scalar(direction, pos_on_ray)):to_minetest()
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pointed_thing.intersection_normal = modlib.vector.triangle_normal(triangle):to_minetest()
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return pointed_thing
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end
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end
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end
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end
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return setmetatable({next = next}, {__call = next})
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end |