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-rw-r--r--builtin/builtin.lua32
-rw-r--r--builtin/misc.lua10
-rw-r--r--builtin/vector.lua136
-rw-r--r--doc/lua_api.txt29
4 files changed, 192 insertions, 15 deletions
diff --git a/builtin/builtin.lua b/builtin/builtin.lua
index d573cba90..34477e6aa 100644
--- a/builtin/builtin.lua
+++ b/builtin/builtin.lua
@@ -11,18 +11,20 @@ math.randomseed(os.time())
os.setlocale("C", "numeric")
-- Load other files
-dofile(minetest.get_modpath("__builtin").."/serialize.lua")
-dofile(minetest.get_modpath("__builtin").."/misc_helpers.lua")
-dofile(minetest.get_modpath("__builtin").."/item.lua")
-dofile(minetest.get_modpath("__builtin").."/misc_register.lua")
-dofile(minetest.get_modpath("__builtin").."/item_entity.lua")
-dofile(minetest.get_modpath("__builtin").."/deprecated.lua")
-dofile(minetest.get_modpath("__builtin").."/misc.lua")
-dofile(minetest.get_modpath("__builtin").."/privileges.lua")
-dofile(minetest.get_modpath("__builtin").."/auth.lua")
-dofile(minetest.get_modpath("__builtin").."/chatcommands.lua")
-dofile(minetest.get_modpath("__builtin").."/static_spawn.lua")
-dofile(minetest.get_modpath("__builtin").."/detached_inventory.lua")
-dofile(minetest.get_modpath("__builtin").."/falling.lua")
-dofile(minetest.get_modpath("__builtin").."/features.lua")
-dofile(minetest.get_modpath("__builtin").."/voxelarea.lua")
+local modpath = minetest.get_modpath("__builtin")
+dofile(modpath.."/serialize.lua")
+dofile(modpath.."/misc_helpers.lua")
+dofile(modpath.."/item.lua")
+dofile(modpath.."/misc_register.lua")
+dofile(modpath.."/item_entity.lua")
+dofile(modpath.."/deprecated.lua")
+dofile(modpath.."/misc.lua")
+dofile(modpath.."/privileges.lua")
+dofile(modpath.."/auth.lua")
+dofile(modpath.."/chatcommands.lua")
+dofile(modpath.."/static_spawn.lua")
+dofile(modpath.."/detached_inventory.lua")
+dofile(modpath.."/falling.lua")
+dofile(modpath.."/features.lua")
+dofile(modpath.."/voxelarea.lua")
+dofile(modpath.."/vector.lua")
diff --git a/builtin/misc.lua b/builtin/misc.lua
index f4e7dbca6..4be03c38a 100644
--- a/builtin/misc.lua
+++ b/builtin/misc.lua
@@ -106,3 +106,13 @@ function minetest.formspec_escape(str)
return str
end
+function math.hypot(x, y)
+ local t
+ x = math.abs(x)
+ y = math.abs(y)
+ t = math.min(x, y)
+ x = math.max(x, y)
+ t = t / x
+ return x * math.sqrt(1 + t * t)
+end
+
diff --git a/builtin/vector.lua b/builtin/vector.lua
new file mode 100644
index 000000000..f534471c2
--- /dev/null
+++ b/builtin/vector.lua
@@ -0,0 +1,136 @@
+
+vector = {}
+
+function vector.new(a, b, c)
+ v = {x=0, y=0, z=0}
+ if type(a) == "table" then
+ v = {x=a.x, y=a.y, z=a.z}
+ elseif a and b and c then
+ v = {x=a, y=b, z=c}
+ end
+ setmetatable(v, {
+ __add = vector.add,
+ __sub = vector.subtract,
+ __mul = vector.multiply,
+ __div = vector.divide,
+ __umn = function(v) return vector.multiply(v, -1) end,
+ __len = vector.length,
+ __eq = vector.equals,
+ })
+ return v
+end
+
+function vector.equals(a, b)
+ return a.x == b.x and
+ a.y == b.y and
+ a.z == b.z
+end
+
+function vector.length(v)
+ return math.hypot(v.x, math.hypot(v.y, v.z))
+end
+
+function vector.normalize(v)
+ return vector.divide(v, vector.length(v))
+end
+
+function vector.round(v)
+ return {
+ x = math.floor(v.x + 0.5),
+ y = math.floor(v.y + 0.5),
+ z = math.floor(v.z + 0.5)
+ }
+end
+
+function vector.distance(a, b)
+ local x = a.x - b.x
+ local y = a.y - b.y
+ local z = a.z - b.z
+ return math.hypot(x, math.hypot(y, z))
+end
+
+function vector.direction(pos1, pos2)
+ local x_raw = pos2.x - pos1.x
+ local y_raw = pos2.y - pos1.y
+ local z_raw = pos2.z - pos1.z
+ local x_abs = math.abs(x_raw)
+ local y_abs = math.abs(y_raw)
+ local z_abs = math.abs(z_raw)
+ if x_abs >= y_abs and
+ x_abs >= z_abs then
+ y_raw = y_raw * (1 / x_abs)
+ z_raw = z_raw * (1 / x_abs)
+ x_raw = x_raw / x_abs
+ end
+ if y_abs >= x_abs and
+ y_abs >= z_abs then
+ x_raw = x_raw * (1 / y_abs)
+ z_raw = z_raw * (1 / y_abs)
+ y_raw = y_raw / y_abs
+ end
+ if z_abs >= y_abs and
+ z_abs >= x_abs then
+ x_raw = x_raw * (1 / z_abs)
+ y_raw = y_raw * (1 / z_abs)
+ z_raw = z_raw / z_abs
+ end
+ return {x=x_raw, y=y_raw, z=z_raw}
+end
+
+
+function vector.add(a, b)
+ if type(b) == "table" then
+ return vector.new(
+ a.x + b.x,
+ a.y + b.y,
+ a.z + b.z)
+ else
+ return vector.new(
+ a.x + b,
+ a.y + b,
+ a.z + b)
+ end
+end
+
+function vector.subtract(a, b)
+ if type(b) == "table" then
+ return vector.new(
+ a.x - b.x,
+ a.y - b.y,
+ a.z - b.z)
+ else
+ return vector.new(
+ a.x - b,
+ a.y - b,
+ a.z - b)
+ end
+end
+
+function vector.multiply(a, b)
+ if type(b) == "table" then
+ return vector.new(
+ a.x * b.x,
+ a.y * b.y,
+ a.z * b.z)
+ else
+ return vector.new(
+ a.x * b,
+ a.y * b,
+ a.z * b)
+ end
+end
+
+function vector.divide(a, b)
+ if type(b) == "table" then
+ return vector.new(
+ a.x / b.x,
+ a.y / b.y,
+ a.z / b.z)
+ else
+ return vector.new(
+ a.x / b,
+ a.y / b,
+ a.z / b)
+ end
+end
+
diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index a9f2d0d46..5a2fdf102 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -988,12 +988,41 @@ Inventory location:
- "nodemeta:<X>,<Y>,<Z>": Any node metadata
- "detached:<name>": A detached inventory
+Vector helpers
+---------------
+vector.new([x[, y, z]]) -> vector
+ ^ x is a table or the x position.
+vector.direction(p1, p2) -> vector
+vector.distance(p1, p2) -> number
+vector.length(v) -> number
+vector.normalize(v) -> vector
+vector.round(v) -> vector
+vector.equal(v1, v2) -> bool
+vector.add(v, x) -> vector
+ ^ x can be annother vector or a number
+vector.subtract(v, x) -> vector
+vector.multiply(v, x) -> vector
+vector.divide(v, x) -> vector
+
+You can also use Lua operators on vectors.
+For example:
+ v1 = vector.new()
+ v1 = v1 + 5
+ v2 = vector.new(v1)
+ v1 = v1 * v2
+ if v1 == v2 then
+ error("Math broke")
+ end
+
Helper functions
-----------------
dump2(obj, name="_", dumped={})
^ Return object serialized as a string, handles reference loops
dump(obj, dumped={})
^ Return object serialized as a string
+math.hypot(x, y)
+^ Get the hypotenuse of a triangle with legs x and y.
+ Usefull for distance calculation.
string:split(separator)
^ eg. string:split("a,b", ",") == {"a","b"}
string:trim()