'print('hello world') - Execute Lua in the console by prepending a ' (single quote)
luaeval("code"); - Execute Lua code
luacall("funcName", %args...); - Call a Lua function (supports indexing tables and object methods)
luaexec("fileName"); - Execute a Lua file. Path rules are the same as when executing .cs files, relative paths are allowed.
luaget("varName"); - Read a Lua global variable (supports indexing tables)
luaset("varName", %value); - Write a Lua global variable (supports indexing tables)

From Lua

bl.eval('code') - Eval TorqueScript code
bl.funcName(args) - Call a TorqueScript function
bl.varName - Read a TorqueScript global variable
bl['varName'] - Read a TorqueScript global variable (i.e. with special characters in the name, or from an array)
bl.set('varName', value) - Write a TorqueScript global variable
bl['namespaceName::funcName'](args) - Call a namespaced TorqueScript function

Accessing Torque Objects from Lua

bl.objectName - Access a Torque object by name
bl[objectID] - Access a Torque object by ID (or name)
object.fieldOrKey - Read a field or Lua key from a Torque object
object:set('field', value) - Write a field on a Torque object
object.key = value - Associate Lua data with a Torque object
object:method(args) - Call a Torque object method
object[index] - Access a member of a Torque set or group
for child in object:members() do - Iterate objects within of a Torque set or group. Indices start at 0 like in Torque. bl.isObject(object, objectID, or 'objectName') - Check if an object exists
object:exists() - Check if an object exists

Timing/Schedules

sched = bl.schedule(timeMs, function, args...) - Schedule a Lua function to be called later, similar to schedule in Torque
sched:cancel() - Cancel a previously scheduled timer

Raycasts and Searches

hitObject, hitPos, hitNormal = bl.raycast(vector{startPosX,y,z}, vector{endPosX,y,z}, 'objtype'/{'objtypes',...}, ignoreObjects...?) - Cast a ray in the world over objects of the specified type(s) (possibly excluding some objects), and return the object hit, the position of the hit, and the normal vector to the surface hit. See the Types section for a list of valid object types.
for object in bl.boxSearch(vector{centerX,y,z}, vector{sizeX,y,z}, 'objtype'/{'objtypes',...}) do - Find all objects in the world of the specified type(s) whose bounding box overlaps with the specified box. See the Types section for a list of valid object types.
for object in bl.radiusSearch(vector{centerX,y,z}, radius, 'objtype'/{'objtypes',...}) do - Find all objects of the specified type(s) whose bounding box overlaps with the specified sphere. See the Types section for a list of valid object types.

Server-Client Communication

bl.addServerCmd('commandName', function(client, args...) ... end) - Register a /command on the server
bl.addClientCmd('commandName', function(args...) ... end) - Register a client command on the client
bl.commandToServer('commandName', args...) - Execute a server command as a client
bl.commandToClient('commandName', args...) - As the server, execute a client command on a specific client
bl.commandToAll('commandName', args...) - As the server, execute a client command on all clients

Packages/Hooks

bl.hook('packageName', 'functionName', 'before'/'after', function(args) ... end) - Hook a Torque function with a Lua function.
args is an array containing the arguments provided to the function. If the hook is before, these can be modified before being passed to the parent function.
If args._return is set to anything other than nil by a before hook, the parent function will not be called, and the function will simply return that value. Also in this case, any after hook will not be executed.
In an after hook, args._return is set to the value returned by the parent function, and can be modified.
bl.unhook('packageName', 'functionName', 'before'/'after') - Remove a previously defined hook
bl.unhook('packageName', 'functionName') - Remove any previously defined hooks on the function within the package
bl.unhook('packageName') - Remove any previously defined hooks within the package

Modules and Dependencies

dofile('Add-Ons/Path/file.lua') - Execute a Lua file. Relative paths (./file.lua) are allowed. .. is not allowed.

require('modulePath.moduleName') - Load a Lua file or external library.
require replaces . with / in the path, and then searches for files in the following order:

./modulePath/moduleName.lua
./modulePath/moduleName/init.lua
modulePath/moduleName.lua (Relative to game directory)
modulePath/moduleName/init.lua (Relative to game directory)
modules/lualib/modulePath/moduleName.lua
modules/lualib/modulePath/moduleName/init.lua
modules/lualib/modulePath/moduleName.dll - C libraries for Lua can be loaded

Like in standard Lua, modules loaded using require are only executed the first time require is called with that path (from anywhere). Subsequent calls simply return the result from the initial execution. To allow hot reloading, use dofile.

File I/O

Lua's builtin file I/O is emulated, and is confined to the same directories as TorqueScript file I/O.
Relative paths (./) are allowed. .. is not allowed.
file = io.open('./file.txt', 'r'/'w'/'a'/'rb'/'wb'/'ab') - Open a file
file:read(numberOfChars/'*a') - Read an opened file (must be opened in 'r' (read) or 'rb' (read binary) mode)
file:write(string) - Write an opened file (must be opened in 'w' (write), 'a' (append), 'wb' or 'ab' mode)
file:close() - Close an opened file
Reading files from ZIPs is supported, with caveats. Null characters are not allowed, and \r\n becomes \n. Generally, text formats work, and binary formats don't.
When reading from outside ZIPs, binary files are fully supported.

Object Creation

bl.new('className') - Create a new Torque object
bl.new('className', {fieldName = value, ...}) - Create a new Torque object with the given fields
bl.new('className objectName', fields?) - Create a new named Torque object
bl.new('className objectName:parentName', fields?) - Create a new named Torque object with inheritance
bl.datablock('datablockClassName datablockName', fields?) - Create a new datablock
bl.datablock('datablockClassName datablockName:parentDatablockName', fields?) - Create a new datablock with inheritance

Classes and Types

bl.type('varName', 'type') - Register the type of a Torque global variable, for conversion when accessing from Lua. Valid types are 'boolean', 'object', 'string' (prevents automatic conversion), and nil (default, applies automatic conversion).
bl.type('funcName', 'type') - Register the return type of a Torque function, for conversion when calling from Lua. Valid types are 'bool', 'object', and nil - all other conversion is automatic. Already done for all default functions.
bl.type('className::funcName', 'type') - Register the return type of a Torque object method.
bl.class('className') - Register an existing Torque class to be used from Lua. Already done for all built-in classes.
bl.class('className', 'parentClassName') - Same as above, with inheritance
bl.boolean(arg) - Manually convert a Torque boolean (0 or 1) into a Lua boolean.
bl.object(arg) - Manually convert a Torque object reference (object ID or name) into a Lua object.
bl.string(arg) - Manually convert any automatically-converted Torque value back into a string. This is not as reliable as using bl.type to specify the type as a string beforehand.

Vector

vec = vector{x,y,z} - Create a vector. Can have any number of elements
vec1 + vec2 - Add
vec1 - vec2 - Subtract
vec * number - Scale (x*n, y*n, z*n)
vec / number - Scale (x/n, y/n, z/n)
vec ^ number - Exponentiate (x^n, y^n, z^n)
vec1 * vec2 - Multiply elements piecewise (x1*x2, y1*y2, z1*z2)
vec1 / vec2 - Divide elements piecewise (x1/x2, y1/y2, z1/z2)
vec1 ^ vec2 - Exponentiate elements piecewise (x1^x2, y1^y2, z1^z2)
-vec - Negate/invert
vec1 == vec2 - Compare by value
vec:length() - Length
vec:normalize() - Preserve direction but scale so magnitude is 1
vec:floor() - Floor each element
vec:ceil() - Ceil each element
vec:abs() - Absolute value each element
vec1:dot(vec2) - Dot product
vec1:cross(vec2) - Cross product (Only defined for two vectors of length 3)
vec:rotateZ(radians) - Rotate counterclockwise about the Z (vertical) axis
vec:rotateByAngleId(0/1/2/3) - Rotate counterclockwise about the Z (vertical) axis in increments of 90 degrees
vec:tsString() - Convert to string usable by Torque. Done automatically when a vector is passed to Torque.
vec1:distance(vec2) - Distance between two points
vec2 = vec:copy() - Clone a vector so its elements can be modified without affecting the original. Usually not needed - the builtin vector functions never modify vectors in-place.

Matrix

WIP

Extended Standard Lua Library

string[index]
string[{start,stop}]
string.split(str, separator='' (splits into chars), noregex=false)
string.bytes(str)
string.trim(str, charsToTrim=' \t\r\n')
table.empty
table.map(func, ...)
table.mapk(func, ...)
table.map_list(func, ...)
table.mapi_list(func, ...)
table.swap(tbl)
table.reverse(list)
table.islist(list)
table.append(list, ...)
table.join(...)
table.contains(tbl, val)
table.contains_list(list, val)
table.copy(tbl)
table.copy_list(list)
table.sortcopy(tbl, sortFunction?)
table.removevalue(tbl, val)
table.removevalue_list(tbl, val)
table.tostring(tbl)
for char in string.chars(str) do
string.escape(str, escapes={['\n']='\\n', etc. (C standard)})
string.unescape(str, escapeChar='\\', unescapes={['\\n']='\n', etc.})
io.readall(filename)
io.writeall(filename, str)
math.round(num)
math.mod(divisor, modulus)
math.clamp(num, min, max)

Type Conversion

When a TorqueScript function is called from Lua or vice-versa, the arguments and return value must be converted between the two languages' type systems.
TorqueScript stores no type information; all values in TorqueScript are strings. So it's necessary to make some inferences when converting values between the two languages.

From Lua to TorqueScript

nil becomes the empty string ""
true and false become "1" and "0" respectively
A Torque object container becomes its object ID
A vector becomes a string containing three numbers separated by spaces
A table of two vectors becomes a string containing six numbers separated by spaces
(WIP) A matrix is converted into an axis-angle (a "transform"), a string containing seven numbers separated by spaces
Any string is passed directly as a string
Tables cannot be passed and will throw an error

From TorqueScript to Lua

The empty string "" becomes nil
Any numeric value becomes a Lua number, except as specified with bl.type, which may convert a value into a boolean or a Torque object container.
A string containing two or three numbers separated by single spaces becomes a vector
A string containing six numbers separated by single spaces becomes a table of two vectors, usually defining the corners a bounding box
(WIP) A string containing seven numbers separated by single spaces is treated as an axis-angle (a "transform"), and is converted into a matrix representing the translation and rotation
Any other string is passed directly as a string

For scenarios where the automatic TorqueScript->Lua conversion rules are insufficient or incorrect, use bl.type.
To convert things by hand, use bl.object, bl.boolean, or bl.string.

I/O and Safety

All Lua code is sandboxed, and file access is confined to the default directories in the same way TorqueScript is.
BlockLua also has access to any C libraries installed in the modules/lualib folder, so be careful throwing things in there.

Unsafe Mode

BlockLua can be built in Unsafe Mode by specifying the -DBLLUA_UNSAFE compiler flag. This removes the sandboxing of Lua code, allowing it to access any file and use any library, including ffi.
A more limited option is -DBLLUA_ALLOWFFI, which allows the use of the ffi library. This can still be exploited to grant all the same access as full unsafe mode.
Please do not publish add-ons that require either of these.

List of Object Types

'all' - Any object
'player' - Players or bots
'item' - Items
'vehicle' - Vehicles
'projectile' - Projectiles
'brick' - Bricks with raycasting enabled
'brickalways' - All bricks including those with raycasting disabled
Other types: 'static', 'environment', 'terrain', 'water', 'trigger', 'marker', 'gamebase', 'shapebase', 'camera', 'staticshape', 'vehicleblocker', 'explosion', 'corpse', 'debris', 'physicalzone', 'staticts', 'staticrendered', 'damagableitem'

Compiling

With any 32-bit variant of GCC installed (such as MinGW or MSYS2), run the following command in the repo directory:
g++ src/bllua4.cpp -o BlockLua.dll -m32 -shared -static-libgcc -Isrc -Iinc/tsfuncs -Iinc/lua -lpsapi -L. -llua5.1

LuaJIT (lua5.1.dll) can be obtained from https://luajit.org/