forked from VoxeLibre/VoxeLibre
Add mcl_explosions for ray traced explosions
Code has been adapted from the Minetest explosions API mod to have Minecraft-like explosion mechanics and work with MineClone 2.
This commit is contained in:
parent
063595ac3c
commit
1d5c11f683
|
|
@ -0,0 +1 @@
|
|||
This mod adds a common API to create explosions.
|
||||
|
|
@ -0,0 +1,266 @@
|
|||
--[[ .__ .__
|
||||
____ ___ _________ | | ____ _____|__| ____ ____ ______
|
||||
_/ __ \\ \/ /\____ \| | / _ \/ ___/ |/ _ \ / \ / ___/
|
||||
\ ___/ > < | |_> > |_( <_> )___ \| ( <_> ) | \\___ \
|
||||
\___ >__/\_ \| __/|____/\____/____ >__|\____/|___| /____ >
|
||||
\/ \/|__| \/ \/ \/
|
||||
|
||||
Explosion API mod for Minetest (adapted to MineClone 2)
|
||||
|
||||
This mod is based on the Minetest explosion API mod, but has been changed
|
||||
to have the same explosion mechanics as Minecraft and work with MineClone.
|
||||
The computation-intensive parts of the mod has been optimized to allow for
|
||||
larger explosions and faster world updating.
|
||||
|
||||
This mod was created by Elias Astrom <ryvnf@riseup.net> and is released
|
||||
under the LGPLv2.1 license.
|
||||
--]]
|
||||
|
||||
|
||||
mcl_explosions = {}
|
||||
|
||||
-- Saved sphere explosion shapes for various radiuses
|
||||
local sphere_shapes = {}
|
||||
|
||||
-- Saved node definitions in table using cid-keys for faster look-up.
|
||||
local node_br = {}
|
||||
|
||||
local AIR_CID = minetest.get_content_id('air')
|
||||
|
||||
-- The step length for the rays (Minecraft uses 0.3)
|
||||
local STEP_LENGTH = 0.3
|
||||
|
||||
minetest.after(0, function()
|
||||
-- Store blast resistance values by content ids to improve performance.
|
||||
for name, def in pairs(minetest.registered_nodes) do
|
||||
node_br[minetest.get_content_id(name)] = def._mcl_blast_resistance or 0
|
||||
end
|
||||
end)
|
||||
|
||||
-- Compute the rays which make up a sphere with radius. Returns a list of rays
|
||||
-- which can be used to trace explosions. This function is not efficient
|
||||
-- (especially for larger radiuses), so the generated rays for various radiuses
|
||||
-- should be cached and reused.
|
||||
--
|
||||
-- Should be possible to improve by using a midpoint circle algorithm multiple
|
||||
-- times to create the sphere, currently uses more of a brute-force approach.
|
||||
local function compute_sphere_rays(radius)
|
||||
local rays = {}
|
||||
local sphere = {}
|
||||
|
||||
for y = -radius, radius do
|
||||
for z = -radius, radius do
|
||||
for x = -radius, 0, 1 do
|
||||
local d = x * x + y * y + z * z
|
||||
if d <= radius * radius then
|
||||
local pos = { x = x, y = y, z = z }
|
||||
sphere[minetest.hash_node_position(pos)] = pos
|
||||
break
|
||||
end
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
for y = -radius, radius do
|
||||
for z = -radius, radius do
|
||||
for x = radius, 0, -1 do
|
||||
local d = x * x + y * y + z * z
|
||||
if d <= radius * radius then
|
||||
local pos = { x = x, y = y, z = z }
|
||||
sphere[minetest.hash_node_position(pos)] = pos
|
||||
break
|
||||
end
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
for x = -radius, radius do
|
||||
for z = -radius, radius do
|
||||
for y = -radius, 0, 1 do
|
||||
local d = x * x + y * y + z * z
|
||||
if d <= radius * radius then
|
||||
local pos = { x = x, y = y, z = z }
|
||||
sphere[minetest.hash_node_position(pos)] = pos
|
||||
break
|
||||
end
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
for x = -radius, radius do
|
||||
for z = -radius, radius do
|
||||
for y = radius, 0, -1 do
|
||||
local d = x * x + y * y + z * z
|
||||
if d <= radius * radius then
|
||||
local pos = { x = x, y = y, z = z }
|
||||
sphere[minetest.hash_node_position(pos)] = pos
|
||||
break
|
||||
end
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
for x = -radius, radius do
|
||||
for y = -radius, radius do
|
||||
for z = -radius, 0, 1 do
|
||||
local d = x * x + y * y + z * z
|
||||
if d <= radius * radius then
|
||||
local pos = { x = x, y = y, z = z }
|
||||
sphere[minetest.hash_node_position(pos)] = pos
|
||||
break
|
||||
end
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
for x = -radius, radius do
|
||||
for y = -radius, radius do
|
||||
for z = radius, 0, -1 do
|
||||
local d = x * x + y * y + z * z
|
||||
if d <= radius * radius then
|
||||
local pos = { x = x, y = y, z = z }
|
||||
sphere[minetest.hash_node_position(pos)] = pos
|
||||
break
|
||||
end
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
for _, pos in pairs(sphere) do
|
||||
rays[#rays + 1] = vector.normalize(pos)
|
||||
end
|
||||
|
||||
return rays
|
||||
end
|
||||
|
||||
-- Get position from hash. This should be identical to
|
||||
-- 'minetest.get_position_from_hash' but is used in case the hashing function
|
||||
-- would change.
|
||||
local function get_position_from_hash(hash)
|
||||
local pos = {}
|
||||
pos.x = (hash % 65536) - 32768
|
||||
hash = math.floor(hash / 65536)
|
||||
pos.y = (hash % 65536) - 32768
|
||||
hash = math.floor(hash / 65536)
|
||||
pos.z = (hash % 65536) - 32768
|
||||
return pos
|
||||
end
|
||||
|
||||
-- Traces the rays of an explosion, and updates the environment.
|
||||
--
|
||||
-- Parameters:
|
||||
-- pos - Where the rays in the explosion should start from
|
||||
-- strength - The strength of each ray
|
||||
-- raydirs - The directions for each ray
|
||||
-- radius - The maximum distance each ray will go
|
||||
-- drop_chance - Chance that destroy nodes drop their items
|
||||
-- (becomes '1.0 / strength' if unspecified)
|
||||
--
|
||||
-- Note that this function has been optimized, it contains code which has been
|
||||
-- inlined to avoid function calls and unnecessary table creation. This was
|
||||
-- measured to give a significant performance increase.
|
||||
local function trace_explode(pos, strength, raydirs, radius, drop_chance)
|
||||
local vm = minetest.get_voxel_manip()
|
||||
|
||||
local emin, emax = vm:read_from_map(vector.subtract(pos, radius),
|
||||
vector.add(pos, radius))
|
||||
local emin_x = emin.x
|
||||
local emin_y = emin.y
|
||||
local emin_z = emin.z
|
||||
|
||||
local ystride = (emax.x - emin_x + 1)
|
||||
local zstride = ystride * (emax.y - emin_y + 1)
|
||||
local pos_x = pos.x
|
||||
local pos_y = pos.y
|
||||
local pos_z = pos.z
|
||||
|
||||
local area = VoxelArea:new {
|
||||
MinEdge = emin,
|
||||
MaxEdge = emax
|
||||
}
|
||||
local data = vm:get_data()
|
||||
local destroy = {}
|
||||
|
||||
-- Trace rays
|
||||
for i = 1, #raydirs do
|
||||
local rpos_x = pos.x
|
||||
local rpos_y = pos.y
|
||||
local rpos_z = pos.z
|
||||
local rdir_x = raydirs[i].x
|
||||
local rdir_y = raydirs[i].y
|
||||
local rdir_z = raydirs[i].z
|
||||
local rstr = (0.7 + math.random() * 0.6) * strength
|
||||
|
||||
for r = 0, math.ceil(radius * (1.0 / STEP_LENGTH)) do
|
||||
local npos_x = math.floor(rpos_x + 0.5)
|
||||
local npos_y = math.floor(rpos_y + 0.5)
|
||||
local npos_z = math.floor(rpos_z + 0.5)
|
||||
local idx = (npos_z - emin_z) * zstride + (npos_y - emin_y) * ystride +
|
||||
npos_x - emin_x + 1
|
||||
|
||||
local cid = data[idx]
|
||||
local br = node_br[cid]
|
||||
local hash = (npos_z + 32768) * 65536 * 65536 +
|
||||
(npos_y + 32768) * 65536 +
|
||||
npos_x + 32768
|
||||
|
||||
rpos_x = rpos_x + STEP_LENGTH * rdir_x
|
||||
rpos_y = rpos_y + STEP_LENGTH * rdir_y
|
||||
rpos_z = rpos_z + STEP_LENGTH * rdir_z
|
||||
|
||||
rstr = rstr - 0.75 * STEP_LENGTH - (br + 0.3) * STEP_LENGTH
|
||||
|
||||
if rstr <= 0 then
|
||||
break
|
||||
end
|
||||
|
||||
if cid ~= AIR_CID then
|
||||
destroy[hash] = idx
|
||||
end
|
||||
end
|
||||
end
|
||||
|
||||
if drop_chance == nil then
|
||||
drop_chance = 1 / strength
|
||||
end
|
||||
|
||||
-- Remove destroyed blocks and drop items
|
||||
for hash, idx in pairs(destroy) do
|
||||
if math.random() <= drop_chance then
|
||||
local name = minetest.get_name_from_content_id(data[idx])
|
||||
local drop = minetest.get_node_drops(name, "")
|
||||
for _, item in ipairs(drop) do
|
||||
if type(item) == "string" then
|
||||
minetest.add_item(get_position_from_hash(hash), item)
|
||||
end
|
||||
end
|
||||
end
|
||||
data[idx] = AIR_CID
|
||||
end
|
||||
|
||||
-- Log explosion
|
||||
minetest.log('action', 'Explosion at ' .. minetest.pos_to_string(pos) ..
|
||||
' with strength ' .. strength .. ' and radius ' .. radius)
|
||||
|
||||
-- Update environment
|
||||
vm:set_data(data)
|
||||
vm:write_to_map(data)
|
||||
vm:update_liquids()
|
||||
end
|
||||
|
||||
-- Create an explosion with strength at pos.
|
||||
--
|
||||
-- Parameters:
|
||||
-- pos - The position where the explosion originates from
|
||||
-- strength - The blast strength of the explosion (a TNT explosion uses 4)
|
||||
function mcl_explosions.explode(pos, strength)
|
||||
-- The maximum blast radius (in the air)
|
||||
local radius = math.ceil(1.3 * strength / (0.3 * 0.75) * 0.3)
|
||||
|
||||
if not sphere_shapes[radius] then
|
||||
sphere_shapes[radius] = compute_sphere_rays(radius)
|
||||
end
|
||||
shape = sphere_shapes[radius]
|
||||
|
||||
trace_explode(pos, strength, shape, radius)
|
||||
end
|
||||
Loading…
Reference in New Issue