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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"/><title>hump - L&Ouml;VE Helper Utilities for More Productivity</title><link rel="stylesheet" type="text/css" href="style.css" /><link rel="stylesheet" type="text/css" href="highlight.css" /><script type="text/javascript" src="highlight.pack.js"></script><script type="text/javascript">window.onload = function() {var examples = document.getElementsByTagName("code");for (i = 0; i < examples.length; ++i) {if (examples[i].className == "lua")hljs.highlightBlock(examples[i], " ");}};</script></head><body><a name="top" id="top"></a><div id="header"><h1><a href="http://github.com/vrld/hump">hump</a><span class="small"> Helper Utilities for More Productivity</span></h1><ul id="main-nav"><li><a href="#intro">Introduction</a></li><li><a href="#doc">Documentation</a></li><li><a href="#license">License</a></li><li><a href="#download">Download</a></li></ul><h2>&nbsp;</h2></div><a name="intro" id="intro"></a><div class="outer-block"><h3>Introduction<a class="top" href="#top">^ top</a></h3><div class="preamble"><p><em>Helper Utilities for a Multitude of Problems</em> is a set of lightweight helpers for the <strong>awesome</strong> <a href="http://love2d.org/">L&Ouml;VE</a> Engine.</p><p><em>hump</em> differs from other libraries in that every component is independent of the remaining ones (apart from camera.lua, which does depends on vector-light.lua). <em>hump</em>'s footprint is very small and thus should fit nicely into your projects.</p></div></div><a name="doc"></a><div class="outer-block"><h3>Documentation<a class="top" href="#top">^ top</a></h3><div class="preamble"><dl><dt><a href="#Gamestate">hump.gamestate</a></dt><dd>A gamestate system</dd><dt><a href="#Timer">hump.timer</a></dt><dd>Delayed function calls and helpers for interpolating functions.</dd><dt><a href="#vector">hump.vector</a></dt><dd>2D vector math.</dd><dt><a href="#vector-light">hump.vector-light</a></dt><dd>Lightweight 2D vector math.</dd><dt><a href="#Class">hump.class</a></dt><dd>Class-based object orientated programming for Lua</dd><dt><a href="#Signal">hump.signal</a></dt><dd>Simple Signal/Slot (aka. Observer) implementation.</dd><dt><a href="#Camera">hump.camera</a></dt><dd>A camera for L&Ouml;VE</dd><dt><a href="#Ringbuffer">hump.ringbuffer</a></dt><dd>A data structure that wraps around itself.</dd></dl></div></div><a name="Gamestate" id="Gamestate"></a><div class="outer-block"><h3>hump.gamestate<a class="top" href="#top">^ top</a></h3><div class="preamble"><pre><code class="lua">Gamestate = require "hump.gamestate"</code></pre><p>A gamestate encapsulates independent data an behaviour into a single entity.</p><p>A typical game could consist of a <em>menu-state</em>, a <em>level-state</em> and a <em>game-over-state</em>.</p></div><div class="overview"><h4>Module overview</h4><dl><dt><a href="#Gamestate-callbacks">callbacks</a></dt><dd>Gamestate Callbacks</dd><dt><a href="#Gamestate-new">new()</a></dt><dd>Create a new gamestate.</dd><dt><a href="#Gamestate-switch">switch()</a></dt><dd>Switch to gamestate.</dd><dt><a href="#Gamestate-update">update()</a></dt><dd>Update current gamestate.</dd><dt><a href="#Gamestate-draw">draw()</a></dt><dd>Draw the current gamestate.</dd><dt><a href="#Gamestate-focus">focus()</a></dt><dd>Inform current gamestate of a focus event.</dd><dt><a href="#Gamestate-keypressed">keypressed()</a></dt><dd>Inform current gamestate of a keypressed event.</dd><dt><a href="#Gamestate-keyreleased">keyreleased()</a></dt><dd>Inform current gamestate of a keyreleased event.</dd><dt><a href="#Gamestate-mousepressed">mousepressed()</a></dt><dd>Inform current gamestate of a mousepressed event.</dd><dt><a href="#Gamestate-mousereleased">mousereleased()</a></dt><dd>Inform current gamestate of a mousereleased event.</dd><dt><a href="#Gamestate-joystickpressed">joystickpressed()</a></dt><dd>Inform current gamestate of a joystickpressed event.</dd><dt><a href="#Gamestate-joystickreleased">joystickreleased()</a></dt><dd>Inform current gamestate of a joystickreleased event.</dd><dt><a href="#Gamestate-quit">quit()</a></dt><dd>Inform current gamestate of a quit event.</dd><dt><a href="#Gamestate-registerEvents">registerEvents()</a></dt><dd>Automatically do all of the above when needed.</dd></dl></div><a name="Gamestate-callbacks" id="Gamestate-callbacks"></a><div class="section-block"><h4>Gamestate Callbacks<a class="top" href="#Gamestate">^ top</a></h4><p>A gamestate can define (nearly) all callbacks that L&Ouml;VE defines. In addition, there are callbacks for entering and leaving a state.:</p><p><dl><dt><code class="lua">init()</code></dt><dd>Called once before entering the state. See <code class="lua">switch()</code>.</dd><dt><code class="lua">enter(previous, ...)</code></dt><dd>Called when entering the state. See <code class="lua">switch()</code>.</dd><dt><code class="lua">leave()</code></dt><dd>Called when leaving a state. See <code class="lua">switch()</code>.</dd><dt><code class="lua">update()</code></dt><dd>Update the game state. Called every frame.</dd><dt><code class="lua">draw()</code></dt><dd>Draw on the screen. Called every frame.</dd><dt><code class="lua">focus()</code></dt><dd>Called if the window gets or looses focus.</dd><dt><code class="lua">keypressed()</code></dt><dd>Triggered when a key is pressed.</dd><dt><code class="lua">keyreleased()</code></dt><dd>Triggered when a key is released.</dd><dt><code class="lua">mousepressed()</code></dt><dd>Triggered when a mouse button is pressed.</dd><dt><code class="lua">mousereleased()</code></dt><dd>Triggered when a mouse button is released.</dd><dt><code class="lua">joystickpressed()</code></dt><dd>Triggered when a joystick button is pressed.</dd><dt><code class="lua">joystickreleased()</code></dt><dd>Triggered when a joystick button is released.</dd><dt><code class="lua">quit()</code></dt><dd>Called on quitting the game. Only called on the active gamestate.</dd></dl></p><p>When using <code class="lua">registerEvents()</code>, all these callbacks will receive the same arguments as the <a href="http://love2d.org/wiki/love">L&Ouml;VE callbacks</a> do.</p><div class="example">Example:<pre><code class="lua">menu = Gamestate.new()
function menu:init() -- run only once
self.background = love.graphics.newImage('bg.jpg')
Buttons.initialize()
end
function menu:enter(previous) -- run every time the state is entered
Buttons.setActive(Buttons.start)
end
function menu:update(dt)
Buttons.update(dt)
end
function menu:draw()
love.graphics.draw(self.background, 0, 0)
Buttons.draw()
end
function menu:keyreleased(key)
if key == 'up' then
Buttons.selectPrevious()
elseif key == 'down' then
Buttons.selectNext()
elseif
Buttons.active:onClick()
end
end
function menu:mousereleased(x,y, mouse_btn)
local button = Buttons.hovered(x,y)
if button then
Button.select(button)
if mouse_btn == 'l' then
button:onClick()
end
end
end</code></pre></div></div><a name="Gamestate-new" id="Gamestate-new"></a><div class="ref-block"><h4>function <span class="name">new</span><span class="arglist">()</span><a class="top" href="#Gamestate">^ top</a></h4><p>Declare a new gamestate. A gamestate can define several <a href="#Gamestate-callbacks">callbacks</a>.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>Gamestate</dt><dd>The new gamestate.</dd></dl></div><div class="example">Example:<pre><code class="lua">menu = Gamestate.new()</code></pre></div></div><a name="Gamestate-switch" id="Gamestate-switch"></a><div class="ref-block"><h4>function <span class="name">switch</span><span class="arglist">(to, ...)</span><a class="top" href="#Gamestate">^ top</a></h4><p>Switch to a gamestate, with any additional arguments passed to the new state.</p><p>Switching a gamestate will call the <code class="lua">leave()</code> callback on the current gamestate, replace the current gamestate with to, call the <code class="lua">init()</code> function if the state was not yet inialized and finally call <code class="lua">enter(old_state, ...)</code> on the new gamestate.</p><div class="arguments">Parameters:<dl><dt>Gamestate <code>to</code></dt><dd>Target gamestate.</dd><dt>mixed <code>...</code></dt><dd>Additional arguments to pass to to:enter().</dd></dl></div><div class="returns">Returns:<dl><dt>mixed</dt><dd>The results of to:enter()</dd></dl></div><div class="example">Example:<pre><code class="lua">Gamestate.switch(game, level_two)</code></pre></div></div><a name="Gamestate-update" id="Gamestate-update"></a><a name="Gamestate-draw" id="Gamestate-draw"></a><a name="Gamestate-focus" id="Gamestate-focus"></a><a name="Gamestate-keypressed" id="Gamestate-keypressed"></a><a name="Gamestate-keyreleased" id="Gamestate-keyreleased"></a><a name="Gamestate-mousepressed" id="Gamestate-mousepressed"></a><a name="Gamestate-mousereleased" id="Gamestate-mousereleased"></a><a name="Gamestate-joystickpressed" id="Gamestate-joystickpressed"></a><a name="Gamestate-joystickreleased" id="Gamestate-joystickreleased"></a><a name="Gamestate-quit" id="Gamestate-quit"></a><div class="ref-block"><h4>function <span class="name">update</span><span class="arglist">(...)</span><a class="top" href="#Gamestate">^ top</a></h4><h4>function <span class="name">draw</span><span class="arglist">(...)</span><a class="top" href="#Gamestate">^ top</a></h4><h4>function <span class="name">focus</span><span class="arglist">(...)</span><a class="top" href="#Gamestate">^ top</a></h4><h4>function <span class="name">keypressed</span><span class="arglist">(...)</span><a class="top" href="#Gamestate">^ top</a></h4><h4>function <span class="name">keyreleased</span><span class="arglist">(...)</span><a class="top" href="#Gamestate">^ top</a></h4><h4>function <span class="name">mousepressed</span><span class="arglist">(...)</span><a class="top" href="#Gamestate">^ top</a></h4><h4>function <span class="name">mousereleased</span><span class="arglist">(...)</span><a class="top" href="#Gamestate">^ top</a></h4><h4>function <span class="name">joystickpressed</span><span class="arglist">(...)</span><a class="top" href="#Gamestate">^ top</a></h4><h4>function <span class="name">joystickreleased</span><span class="arglist">(...)</span><a class="top" href="#Gamestate">^ top</a></h4><h4>function <span class="name">quit</span><span class="arglist">(...)</span><a class="top" href="#Gamestate">^ top</a></h4><p>Calls the corresponding function on the current gamestate (see <a href="#Gamestate-callbacks">callbacks</a>).</p><p>Only needed when not using <code class="lua">registerEvents()</code>.</p><div class="arguments">Parameters:<dl><dt>mixed <code>...</code></dt><dd>Arguments to pass to the corresponding <a href="#Gamestate-callbacks">callback</a>.</dd></dl></div><div class="returns">Returns:<dl><dt>mixed</dt><dd>The results of the callback function.</dd></dl></div><div class="example">Example:<pre><code class="lua">function love.update(dt)
Gamestate.update(dt)
end
function love.draw()
local mx,my = love.mouse.getPosition()
Gamestate.draw(mx, my)
end
function love.keypressed(key, code)
Gamestate.keypressed(key, code)
end</code></pre></div></div><a name="Gamestate-registerEvents" id="Gamestate-registerEvents"></a><div class="ref-block"><h4>function <span class="name">registerEvents</span><span class="arglist">(callbacks)</span><a class="top" href="#Gamestate">^ top</a></h4><p>Register love callbacks to call <code class="lua">Gamestate.update()</code>, <code class="lua">Gamestate.draw()</code>, etc. automatically.</p><p>This is by done by overwriting the love callbacks, e.g.: <pre><code class="lua">local old_update = love.update
function love.update(dt)
old_update(dt)
Gamestate.current:update(dt)
end</code></pre></p><p><span class="warning">Note:</span> Only works when called in <code class="lua">love.load()</code> or any other function that is executedafter the whole file is loaded.</p><div class="arguments">Parameters:<dl><dt>table <code>callbacks</code> (optional)</dt><dd>Names of the callbacks to register. If omitted, register all callbacks.</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">function love.load()
Gamestate.registerEvents()
Gamestate.switch(menu)
end</code></pre><pre><code class="lua">function love.load()
Gamestate.registerEvents{'draw', 'update', 'quit'}
Gamestate.switch(menu)
end</code></pre></div></div></div><a name="Timer" id="Timer"></a><div class="outer-block"><h3>hump.timer<a class="top" href="#top">^ top</a></h3><div class="preamble"><pre><code class="lua">Timer = require "hump.timer"</code></pre><p>hump.timer provides a simple interface to use delayed functions, i.e. functions that will be executed after some amount time has passed. For example, you can use a timer to set the player invincible for a short amount of time.</p><p>In addition, the module offers facilities to create functions that interpolate or oscillate over time. An interpolator could fade the color or a text message, whereas an oscillator could be used for the movement of foes in a shmup.</p></div><div class="overview"><h4>Module overview</h4><dl><dt><a href="#Timer-new">new()</a></dt><dd>Create new timer instance.</dd><dt><a href="#Timer-add">add()</a></dt><dd>Schedule a function.</dd><dt><a href="#Timer-addPeriodic">addPeriodic()</a></dt><dd>Add a periodic function.</dd><dt><a href="#Timer-cancel">cancel()</a></dt><dd>Cancel a scheduled function.</dd><dt><a href="#Timer-clear">clear()</a></dt><dd>Remove all timed and periodic functions.</dd><dt><a href="#Timer-update">update()</a></dt><dd>Update scheduled functions.</dd><dt><a href="#Timer-Interpolator">Interpolator()</a></dt><dd>Create a new interpolating function.</dd><dt><a href="#Timer-Oscillator">Oscillator()</a></dt><dd>Create a new oscillating function.</dd></dl></div><a name="Timer-new" id="Timer-new"></a><div class="ref-block"><h4>function <span class="name">new</span><span class="arglist">()</span><a class="top" href="#Timer">^ top</a></h4><p><span class="warning">If you don't need multiple independent schedulers, you can use the global/default timer (see examples).</span></p><p>Creates a new timer instance that is independent of the global timer: It will manage it's own list of scheduled functions and does not in any way affect the the global timer. Likewise, the global timer does not affect the timer instance.</p><p><span class="warning">Note:</span> Timer instances use the colon-notation (e.g. <code class="lua">instance:update(dt)</code>), while the global timer uses the dot-notation (e.g. <code class="lua">Timer.update(dt)</code>).</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>Timer</dt><dd>A timer instance</dd></dl></div><div class="example">Example:<pre><code class="lua">menuTimer = Timer.new()</code></pre></div></div><a name="Timer-add" id="Timer-add"></a><a name="Timer-instance:add" id="Timer-instance:add"></a><div class="ref-block"><h4>function <span class="name">add</span><span class="arglist">(delay, func)</span><a class="top" href="#Timer">^ top</a></h4><h4>function <span class="name">instance:add</span><span class="arglist">(delay, func)</span><a class="top" href="#Timer">^ top</a></h4><p>Schedule a function. The function will be executed after <code class="lua">delay</code> seconds have elapsed, given that <code class="lua">update(dt)</code> is called every frame.</p><p>Note that there is no guarantee that the delay will not be exceeded, it is only guaranteed that the function will not be executed <em>before</em> the delay has passed.</p><p>It is an error to schedule a function again if it is not yet finished or canceled.</p><p><code class="lua">func</code> will receive itself as only parameter. This is useful to implement periodic behavior (see the example).</p><div class="arguments">Parameters:<dl><dt>number <code>delay</code></dt><dd>Number of seconds the function will be delayed.</dd><dt>function <code>func</code></dt><dd>The function to be delayed.</dd></dl></div><div class="returns">Returns:<dl><dt>function</dt><dd>The timer handle.</dd></dl></div><div class="example">Example:<pre><code class="lua">-- grant the player 5 seconds of immortality
player.isInvincible = true
Timer.add(5, function() player.isInvincible = false end)</code></pre><pre><code class="lua">-- print "foo" every second. See addPeriodic.
Timer.add(1, function(func) print("foo") Timer.add(1, func) end)</code></pre><pre><code class="lua">menuTimer:add(1, finishAnimation)</code></pre></div></div><a name="Timer-addPeriodic" id="Timer-addPeriodic"></a><a name="Timer-instance:addPeriodic" id="Timer-instance:addPeriodic"></a><div class="ref-block"><h4>function <span class="name">addPeriodic</span><span class="arglist">(delay, func, count)</span><a class="top" href="#Timer">^ top</a></h4><h4>function <span class="name">instance:addPeriodic</span><span class="arglist">(delay, func, count)</span><a class="top" href="#Timer">^ top</a></h4><p>Add a function that will be called <code class="lua">count</code> times every <code class="lua">delay</code> seconds.</p><p>If <code class="lua">count</code> is omitted, the function will be called until it returns <code class="lua">false</code> or <code class="lua">clear()</code> is called.</p><div class="arguments">Parameters:<dl><dt>number <code>delay</code></dt><dd>Number of seconds between two consecutive function calls.</dd><dt>function <code>func</code></dt><dd>The function to be called periodically.</dd><dt>number <code>count</code> (optional)</dt><dd>Number of times the function is to be called.</dd></dl></div><div class="returns">Returns:<dl><dt>function</dt><dd>The timer handle.</dd></dl></div><div class="example">Example:<pre><code class="lua">Timer.addPeriodic(1, function() lamp:toggleLight() end)</code></pre><pre><code class="lua">mothership_timer:addPeriodic(0.3, function() self:spawnFighter() end, 5)</code></pre><pre><code class="lua">-- flicker player's image as long as he is invincible
Timer.addPeriodic(0.1, function()
player:flipImage()
return player.isInvincible
end)</code></pre></div></div><a name="Timer-cancel" id="Timer-cancel"></a><a name="Timer-instance:cancel" id="Timer-instance:cancel"></a><div class="ref-block"><h4>function <span class="name">cancel</span><span class="arglist">(func)</span><a class="top" href="#Timer">^ top</a></h4><h4>function <span class="name">instance:cancel</span><span class="arglist">(func)</span><a class="top" href="#Timer">^ top</a></h4><p>Prevent a timer from being executed in the future.</p><p><em>Always</em> use the function handle returned by <code class="lua">add()</code>/<code class="lua">addPeriodic()</code> to cancel a timer.</p><p><em>Never</em> use this inside a scheduled function.</p><div class="arguments">Parameters:<dl><dt>function <code>func</code></dt><dd>The function to be canceled.</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">function tick()
print('tick... tock...')
end
handle = Timer.addPeriodic(1, tick)
-- later
Timer.cancel(handle) -- NOT: Timer.cancel(tick)</code></pre></div></div><a name="Timer-clear" id="Timer-clear"></a><a name="Timer-instance:clear" id="Timer-instance:clear"></a><div class="ref-block"><h4>function <span class="name">clear</span><span class="arglist">()</span><a class="top" href="#Timer">^ top</a></h4><h4>function <span class="name">instance:clear</span><span class="arglist">()</span><a class="top" href="#Timer">^ top</a></h4><p>Remove all timed and periodic functions. Functions that have not yet been executed will discarded. <em>Never</em> use this inside a scheduled function.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">Timer.clear()</code></pre></div></div><a name="Timer-update" id="Timer-update"></a><a name="Timer-instance:update" id="Timer-instance:update"></a><div class="ref-block"><h4>function <span class="name">update</span><span class="arglist">(dt)</span><a class="top" href="#Timer">^ top</a></h4><h4>function <span class="name">instance:update</span><span class="arglist">(dt)</span><a class="top" href="#Timer">^ top</a></h4><p>Update timers and execute functions if the deadline is reached. Use this in <code class="lua">love.update(dt)</code>.</p><div class="arguments">Parameters:<dl><dt>number <code>dt</code></dt><dd>Time that has passed since the last update().</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">function love.update(dt)
do_stuff()
Timer.update(dt)
end</code></pre></div></div><a name="Timer-Interpolator" id="Timer-Interpolator"></a><div class="ref-block"><h4>function <span class="name">Interpolator</span><span class="arglist">(length, func)</span><a class="top" href="#Timer">^ top</a></h4><p>Create a wrapper for an interpolating function, i.e. a function that acts depending on how much time has passed.</p><p>The wrapper will have the prototype: <pre><code class="lua">function wrapper(dt, ...)</code></pre> where <code class="lua">dt</code> is the time that has passed since the last call of the wrapper and <code class="lua">...</code> are arguments passed to the interpolating function. It will return whatever the interpolating functions returns if the interpolation is not yet finished or nil if the interpolation is done.</p><p>The prototype of the interpolating function is: <pre><code class="lua">function interpolator(fraction, ...)</code></pre> where <code class="lua">fraction</code> is a number between 0 and 1 depending on how much time has passed and <code class="lua">...</code> are additional arguments supplied to the wrapper.</p><div class="arguments">Parameters:<dl><dt>number <code>length</code></dt><dd>Interpolation length in seconds.</dd><dt>function <code>func</code></dt><dd>Interpolating function.</dd></dl></div><div class="returns">Returns:<dl><dt>function</dt><dd>The wrapper function.</dd></dl></div><div class="example">Example:<pre><code class="lua">fader = Timer.Interpolator(5, function(frac, r,g,b)
love.graphics.setBackgroundColor(frac*r,frac*g,frac*b)
end)
function love.update(dt)
fader(dt, 255,255,255)
end</code></pre></div></div><a name="Timer-Oscillator" id="Timer-Oscillator"></a><div class="ref-block"><h4>function <span class="name">Oscillator</span><span class="arglist">(length, func)</span><a class="top" href="#Timer">^ top</a></h4><p>Create a wrapper for an oscillating function, which is basically a looping interpolating function.</p><p>The function prototypes are the same as with <code class="lua">Interpolator()</code>: <pre><code class="lua">function wrapper(dt, ...)</code></pre> <pre><code class="lua">function oscillator(fraction, ...)</code></pre></p><p>As with <code class="lua">Interpolator</code>, the wrapper will return whatever <code class="lua">oscillator()</code> returns.</p><div class="arguments">Parameters:<dl><dt>number <code>length</code></dt><dd>Length of one interpolation period.</dd><dt>function <code>func</code></dt><dd>Oscillating function.</dd></dl></div><div class="returns">Returns:<dl><dt>function</dt><dd>The wrapper function.</dd></dl></div><div class="example">Example:<pre><code class="lua">mover = Timer.Oscillator(10, function(frac)
return 400 + 300 * math.sin(2*math.pi*frac)
end)
local xpos = 100
function love.update(dt)
xpos = mover(dt)
end
function love.draw()
love.graphics.circle('fill', xpos, 300, 80, 36)
end</code></pre></div></div></div><a name="vector" id="vector"></a><div class="outer-block"><h3>hump.vector<a class="top" href="#top">^ top</a></h3><div class="preamble"><pre><code class="lua">vector = require "hump.vector"</code></pre><p>A handy 2D vector class providing most of the things you do with vectors.</p><p>You can access the individual coordinates by using <code class="lua">vec.x</code> and <code class="lua">vec.y</code>.</p></div><div class="overview"><h4>Module overview</h4><dl><dt><a href="#vector-operators">operators</a></dt><dd>Arithmetics and relations</dd><dt><a href="#vector-new">new()</a></dt><dd>Create a new vector.</dd><dt><a href="#vector-isvector">isvector()</a></dt><dd>Test if value is a vector.</dd><dt><a href="#vector-vector:clone">vector:clone()</a></dt><dd>Copy a vector.</dd><dt><a href="#vector-vector:unpack">vector:unpack()</a></dt><dd>Extract coordinates.</dd><dt><a href="#vector-vector:permul">vector:permul()</a></dt><dd>Per element multiplication.</dd><dt><a href="#vector-vector:len">vector:len()</a></dt><dd>Get length.</dd><dt><a href="#vector-vector:len2">vector:len2()</a></dt><dd>Get squared length.</dd><dt><a href="#vector-vector:dist">vector:dist()</a></dt><dd>Distance to other vector.</dd><dt><a href="#vector-vector:normalized">vector:normalized()</a></dt><dd>Get normalized vector.</dd><dt><a href="#vector-vector:normalize_inplace">vector:normalize_inplace()</a></dt><dd>Normalize vector in-place.</dd><dt><a href="#vector-vector:rotated">vector:rotated()</a></dt><dd>Get rotated vector.</dd><dt><a href="#vector-vector:rotate_inplace">vector:rotate_inplace()</a></dt><dd>Rotate vector in-place.</dd><dt><a href="#vector-vector:perpendicular">vector:perpendicular()</a></dt><dd>Get perpendicular vector.</dd><dt><a href="#vector-vector:projectOn">vector:projectOn()</a></dt><dd>Get projection onto another vector.</dd><dt><a href="#vector-vector:mirrorOn">vector:mirrorOn()</a></dt><dd>Mirrors vector on other vector</dd><dt><a href="#vector-vector:cross">vector:cross()</a></dt><dd>Cross product of two vectors.</dd></dl></div><a name="vector-operators" id="vector-operators"></a><div class="section-block"><h4>Arithmetics and relations<a class="top" href="#vector">^ top</a></h4><p>Vector arithmetic is implemented by using <code class="lua">__add</code>, <code class="lua">__mul</code> and other metamethods:</p><p><dl><dt><code class="lua">vector + vector = vector</code></dt><dd>Component wise sum.</dd><dt><code class="lua">vector - vector = vector</code></dt><dd>Component wise difference.</dd><dt><code class="lua">vector * vector = number</code></dt><dd>Dot product.</dd><dt><code class="lua">number * vector = vector</code></dt><dd>Scalar multiplication (scaling).</dd><dt><code class="lua">vector * number = vector</code></dt><dd>Scalar multiplication.</dd><dt><code class="lua">vector / number = vector</code></dt><dd>Scalar multiplication.</dd></dl></p><p>Relational operators are defined, too:</p><p><dl><dt>a == b</dt><dd><code class="lua">true</code>, if <code class="lua">a.x == b.x</code> and <code class="lua">a.y == b.y</code>.</dd><dt>a <= b</dt><dd><code class="lua">true</code>, if <code class="lua">a.x <= b.x</code> and <code class="lua">a.y <= b.y</code>.</dd><dt>a < b</dt><dd>Lexical sort: <code class="lua">true</code>, if <code class="lua">a.x < b.x</code> or <code class="lua">a.x == b.x</code> and <code class="lua">a.y < b.y</code>.</dd></dl></p><div class="example">Example:<pre><code class="lua">-- acceleration, player.velocity and player.position are vectors
acceleration = vector(0,-9)
player.velocity = player.velocity + acceleration * dt
player.position = player.position + player.velocity * dt</code></pre></div></div><a name="vector-new" id="vector-new"></a><div class="ref-block"><h4>function <span class="name">new</span><span class="arglist">(x,y)</span><a class="top" href="#vector">^ top</a></h4><p>Create a new vector.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x,y</code></dt><dd>Coordinates.</dd></dl></div><div class="returns">Returns:<dl><dt>vector</dt><dd>The vector.</dd></dl></div><div class="example">Example:<pre><code class="lua">a = vector.new(10,10)</code></pre><pre><code class="lua">-- as a shortcut, you can call the module like a function:
vector = require "hump.vector"
a = vector(10,10)</code></pre></div></div><a name="vector-isvector" id="vector-isvector"></a><div class="ref-block"><h4>function <span class="name">isvector</span><span class="arglist">(v)</span><a class="top" href="#vector">^ top</a></h4><p>Test whether a variable is a vector.</p><div class="arguments">Parameters:<dl><dt>mixed <code>v</code></dt><dd>The variable to test.</dd></dl></div><div class="returns">Returns:<dl><dt>boolean</dt><dd><code class="lua">true</code> if <code class="lua">v</code> is a vector, <code class="lua">false</code> otherwise</dd></dl></div><div class="example">Example:<pre><code class="lua">if not vector.isvector(v) then
v = vector(v,0)
end</code></pre></div></div><a name="vector-vector:clone" id="vector-vector:clone"></a><div class="ref-block"><h4>function <span class="name">vector:clone</span><span class="arglist">()</span><a class="top" href="#vector">^ top</a></h4><p>Copy a vector. Simply assigning a vector a vector to a variable will create a reference, so when modifying the vector referenced by the new variable would also change the old one: <pre><code class="lua">a = vector(1,1) -- create vector
b = a -- b references a
c = a:clone() -- c is a copy of a
b.x = 0 -- changes a,b and c
print(a,b,c) -- prints '(1,0), (1,0), (1,1)'</code></pre></p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>vector</dt><dd>Copy of the vector</dd></dl></div><div class="example">Example:<pre><code class="lua">copy = original:clone</code></pre></div></div><a name="vector-vector:unpack" id="vector-vector:unpack"></a><div class="ref-block"><h4>function <span class="name">vector:unpack</span><span class="arglist">()</span><a class="top" href="#vector">^ top</a></h4><p>Extract coordinates.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>numbers</dt><dd>The coordinates</dd></dl></div><div class="example">Example:<pre><code class="lua">x,y = pos:unpack()</code></pre><pre><code class="lua">love.graphics.draw(self.image, self.pos:unpack())</code></pre></div></div><a name="vector-vector:permul" id="vector-vector:permul"></a><div class="ref-block"><h4>function <span class="name">vector:permul</span><span class="arglist">(other)</span><a class="top" href="#vector">^ top</a></h4><p>Multiplies vectors coordinate wise, i.e. <code class="lua">result = vector(a.x * b.x, a.y * b.y)</code>.</p><p>This does not change either argument vectors, but creates a new one.</p><div class="arguments">Parameters:<dl><dt>vector <code>other</code></dt><dd>The other vector</dd></dl></div><div class="returns">Returns:<dl><dt>vector</dt><dd>The new vector as described above</dd></dl></div><div class="example">Example:<pre><code class="lua">scaled = original:permul(vector(1,1.5))</code></pre></div></div><a name="vector-vector:len" id="vector-vector:len"></a><div class="ref-block"><h4>function <span class="name">vector:len</span><span class="arglist">()</span><a class="top" href="#vector">^ top</a></h4><p>Get length of a vector, i.e. <code class="lua">math.sqrt(vec.x * vec.x + vec.y * vec.y)</code>.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>number</dt><dd>Length of the vector.</dd></dl></div><div class="example">Example:<pre><code class="lua">distance = (a - b):len()</code></pre></div></div><a name="vector-vector:len2" id="vector-vector:len2"></a><div class="ref-block"><h4>function <span class="name">vector:len2</span><span class="arglist">()</span><a class="top" href="#vector">^ top</a></h4><p>Get squared length of a vector, i.e. <code class="lua">vec.x * vec.x + vec.y * vec.y</code>.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>number</dt><dd>Squared length of the vector.</dd></dl></div><div class="example">Example:<pre><code class="lua">-- get closest vertex to a given vector
closest, dsq = vertices[1], (pos - vertices[1]):len2()
for i = 2,#vertices do
local temp = (pos - vertices[i]):len2()
if temp < dsq then
closest, dsq = vertices[i], temp
end
end</code></pre></div></div><a name="vector-vector:dist" id="vector-vector:dist"></a><div class="ref-block"><h4>function <span class="name">vector:dist</span><span class="arglist">(other)</span><a class="top" href="#vector">^ top</a></h4><p>Get distance of two vectors. The same as <code class="lua">(a - b):len()</code>.</p><div class="arguments">Parameters:<dl><dt>vector <code>other</code></dt><dd>Other vector to measure the distance to.</dd></dl></div><div class="returns">Returns:<dl><dt>number</dt><dd>The distance of the vectors.</dd></dl></div><div class="example">Example:<pre><code class="lua">-- get closest vertex to a given vector
-- slightly slower than the example using len2()
closest, dist = vertices[1], pos:dist(vertices[1])
for i = 2,#vertices do
local temp = pos:dist(vertices[i])
if temp < dist then
closest, dist = vertices[i], temp
end
end</code></pre></div></div><a name="vector-vector:normalized" id="vector-vector:normalized"></a><div class="ref-block"><h4>function <span class="name">vector:normalized</span><span class="arglist">()</span><a class="top" href="#vector">^ top</a></h4><p>Get normalized vector, i.e. a vector with the same direction as the input vector, but with length 1.</p><p>This does not change the input vector, but creates a new vector.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>vector</dt><dd>Vector with same direction as the input vector, but length 1.</dd></dl></div><div class="example">Example:<pre><code class="lua">direction = velocity:normalized()</code></pre></div></div><a name="vector-vector:normalize_inplace" id="vector-vector:normalize_inplace"></a><div class="ref-block"><h4>function <span class="name">vector:normalize_inplace</span><span class="arglist">()</span><a class="top" href="#vector">^ top</a></h4><p>Normalize a vector, i.e. make the vector unit length. Great to use on intermediate results.</p><p><span class="warning">This modifies the vector. If in doubt, use <code class="lua">vector:normalized()</code>.</span></p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>vector</dt><dd>Itself - the normalized vector</dd></dl></div><div class="example">Example:<pre><code class="lua">normal = (b - a):perpendicular():normalize_inplace()</code></pre></div></div><a name="vector-vector:rotated" id="vector-vector:rotated"></a><div class="ref-block"><h4>function <span class="name">vector:rotated</span><span class="arglist">(phi)</span><a class="top" href="#vector">^ top</a></h4><p>Get a rotated vector.</p><p>This does not change the input vector, but creates a new vector.</p><div class="arguments">Parameters:<dl><dt>number <code>phi</code></dt><dd>Rotation angle in <a href="http://en.wikipedia.org/wiki/Radians">radians</a>.</dd></dl></div><div class="returns">Returns:<dl><dt>vector</dt><dd>The rotated vector</dd></dl></div><div class="example">Example:<pre><code class="lua">-- approximate a circle
circle = {}
for i = 1,30 do
local phi = 2 * math.pi * i / 30
circle[#circle+1] = vector(0,1):rotated(phi)
end</code></pre></div><div class="example">Sketch:<img src="vector-rotated.png" width="260" height="171" /></div></div><a name="vector-vector:rotate_inplace" id="vector-vector:rotate_inplace"></a><div class="ref-block"><h4>function <span class="name">vector:rotate_inplace</span><span class="arglist">(phi)</span><a class="top" href="#vector">^ top</a></h4><p>Rotate a vector in-place. Great to use on intermediate results.</p><p><span class="warning">This modifies the vector. If in doubt, use <code class="lua">vector:rotate()</code></span></p><div class="arguments">Parameters:<dl><dt>number <code>phi</code></dt><dd>Rotation angle in <a href="http://en.wikipedia.org/wiki/Radians">radians</a>.</dd></dl></div><div class="returns">Returns:<dl><dt>vector</dt><dd>Itself - the rotated vector</dd></dl></div><div class="example">Example:<pre><code class="lua">-- ongoing rotation
spawner.direction:rotate_inplace(dt)</code></pre></div></div><a name="vector-vector:perpendicular" id="vector-vector:perpendicular"></a><div class="ref-block"><h4>function <span class="name">vector:perpendicular</span><span class="arglist">()</span><a class="top" href="#vector">^ top</a></h4><p>Quick rotation by 90&deg;. Creates a new vector. The same (but faster) as <code class="lua">vec:rotate(math.pi/2)</code></p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>vector</dt><dd>A vector perpendicular to the input vector</dd></dl></div><div class="example">Example:<pre><code class="lua">normal = (b - a):perpendicular():normalize_inplace()</code></pre></div><div class="example">Sketch:<img src="vector-perpendicular.png" width="267" height="202" /></div></div><a name="vector-vector:projectOn" id="vector-vector:projectOn"></a><div class="ref-block"><h4>function <span class="name">vector:projectOn</span><span class="arglist">(v)</span><a class="top" href="#vector">^ top</a></h4><p>Project vector onto another vector (see sketch).</p><div class="arguments">Parameters:<dl><dt>vector <code>v</code></dt><dd>The vector to project on.</dd></dl></div><div class="returns">Returns:<dl><dt>vector</dt><dd>The projected vector.</dd></dl></div><div class="example">Example:<pre><code class="lua">velocity_component = velocity:projectOn(axis)</code></pre></div><div class="example">Sketch:<img src="vector-projectOn.png" width="605" height="178" /></div></div><a name="vector-vector:mirrorOn" id="vector-vector:mirrorOn"></a><div class="ref-block"><h4>function <span class="name">vector:mirrorOn</span><span class="arglist">(v)</span><a class="top" href="#vector">^ top</a></h4><p>Mirrors vector on the axis defined by the other vector.</p><div class="arguments">Parameters:<dl><dt>vector <code>v</code></dt><dd>The vector to mirror on.</dd></dl></div><div class="returns">Returns:<dl><dt>vector</dt><dd>The mirrored vector.</dd></dl></div><div class="example">Example:<pre><code class="lua">deflected_velocity = ball.velocity:mirrorOn(surface_normal)</code></pre></div><div class="example">Sketch:<img src="vector-mirrorOn.png" width="334" height="201" /></div></div><a name="vector-vector:cross" id="vector-vector:cross"></a><div class="ref-block"><h4>function <span class="name">vector:cross</span><span class="arglist">(other)</span><a class="top" href="#vector">^ top</a></h4><p>Get cross product of both vectors. Equals the area of the parallelogram spanned by both vectors.</p><div class="arguments">Parameters:<dl><dt>vector <code>other</code></dt><dd>Vector to compute the cross product with.</dd></dl></div><div class="returns">Returns:<dl><dt>number</dt><dd>Cross product of both vectors.</dd></dl></div><div class="example">Example:<pre><code class="lua">parallelogram_area = a:cross(b)</code></pre></div><div class="example">Sketch:<img src="vector-cross.png" width="271" height="137" /></div></div></div><a name="vector-light" id="vector-light"></a><div class="outer-block"><h3>hump.vector-light<a class="top" href="#top">^ top</a></h3><div class="preamble"><pre><code class="lua">vector = require "hump.vector-light"</code></pre><p>An table-free version of <code class="lua">hump.vector</code>. Instead of a vector class, <code class="lua">hump.vector-light</code> provides functions that operate on numbers.</p><p>Using this module instead of <code class="lua">vector</code> might result in faster code, but does so at the expense of readability. Unless you are sure that it causes a significant performance penalty, I recommend to use <code class="lua">hump.vector</code>.</p></div><div class="overview"><h4>Module overview</h4><dl><dt><a href="#vector-light-str">str()</a></dt><dd>String representation.</dd><dt><a href="#vector-light-mul">mul()</a></dt><dd>Product of a vector and a scalar.</dd><dt><a href="#vector-light-div">div()</a></dt><dd>Product of a vector and the inverse of a scalar.</dd><dt><a href="#vector-light-add">add()</a></dt><dd>Sum of two vectors.</dd><dt><a href="#vector-light-sub">sub()</a></dt><dd>Difference of two vectors.</dd><dt><a href="#vector-light-permul">permul()</a></dt><dd>Per element multiplication.</dd><dt><a href="#vector-light-dot">dot()</a></dt><dd>[^http://en.wikipedia.org/wiki/Dot_product Dot product]</dd><dt><a href="#vector-light-det">det()</a></dt><dd>Cross product</dd><dt><a href="#vector-light-cross">cross()</a></dt><dd>Cross product</dd><dt><a href="#vector-light-eq">eq()</a></dt><dd>Equality.</dd><dt><a href="#vector-light-le">le()</a></dt><dd>Partial lexical order.</dd><dt><a href="#vector-light-lt">lt()</a></dt><dd>Strict lexical order.</dd><dt><a href="#vector-light-len">len()</a></dt><dd>Get length.</dd><dt><a href="#vector-light-len2">len2()</a></dt><dd>Get squared length.</dd><dt><a href="#vector-light-dist">dist()</a></dt><dd>Distance of two points.</dd><dt><a href="#vector-light-normalize">normalize()</a></dt><dd>Normalize vector.</dd><dt><a href="#vector-light-rotate">rotate()</a></dt><dd>Rotate vector.</dd><dt><a href="#vector-light-perpendicular">perpendicular()</a></dt><dd>Get perpendicular vector.</dd><dt><a href="#vector-light-project">project()</a></dt><dd>Project projection onto another vector.</dd><dt><a href="#vector-light-mirror">mirror()</a></dt><dd>Mirrors vector on other vector.</dd></dl></div><a name="vector-light-str" id="vector-light-str"></a><div class="ref-block"><h4>function <span class="name">str</span><span class="arglist">(x,y)</span><a class="top" href="#vector-light">^ top</a></h4><p>Transforms a vector to a string of the form <code class="lua">(x,y)</code>.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x,y</code></dt><dd>The vector</dd></dl></div><div class="returns">Returns:<dl><dt>string</dt><dd>The string representation</dd></dl></div><div class="example">Example:<pre><code class="lua">print(vector.str(love.mouse.getPosition()))</code></pre></div></div><a name="vector-light-mul" id="vector-light-mul"></a><a name="vector-light-div" id="vector-light-div"></a><div class="ref-block"><h4>function <span class="name">mul</span><span class="arglist">(s, x,y)</span><a class="top" href="#vector-light">^ top</a></h4><h4>function <span class="name">div</span><span class="arglist">(s, x,y)</span><a class="top" href="#vector-light">^ top</a></h4><p>Computes <code class="lua">x*s,y*s</code> and <code class="lua">x/s,y/s</code> respectively. The order of arguments is chosen so that it's possible to chain multiple operations (see example).</p><div class="arguments">Parameters:<dl><dt>number <code>s</code></dt><dd>The scalar.</dd><dt>numbers <code>x,y</code></dt><dd>The vector.</dd></dl></div><div class="returns">Returns:<dl><dt>numbers</dt><dd>The result of the operation.</dd></dl></div><div class="example">Example:<pre><code class="lua">velx,vely = vec.mul(dt, vec.add(velx,vely, accx,accy))</code></pre><pre><code class="lua">x,y = vec.div(self.zoom, x-w/2, y-h/2)</code></pre></div></div><a name="vector-light-add" id="vector-light-add"></a><a name="vector-light-sub" id="vector-light-sub"></a><div class="ref-block"><h4>function <span class="name">add</span><span class="arglist">(x1,y1, x2,y2)</span><a class="top" href="#vector-light">^ top</a></h4><h4>function <span class="name">sub</span><span class="arglist">(x1,y1, x2,y2)</span><a class="top" href="#vector-light">^ top</a></h4><p>Computes the sum/difference of vectors. Same as <code class="lua">x1+x2,y1+y2</code> and <code class="lua">x1-x2,y1-y2</code> respectively. Meant to be used in conjunction with other functions.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x1,y1</code></dt><dd>First vector.</dd><dt>numbers <code>x2,y2</code></dt><dd>Second vector.</dd></dl></div><div class="returns">Returns:<dl><dt>numbers</dt><dd>The result of the operation.</dd></dl></div><div class="example">Example:<pre><code class="lua">player.x,player.y = vector.add(player.x,player.y, vector.mul(dt, dx,dy))</code></pre><pre><code class="lua">dx,dy = vector.sub(400,300, love.mouse.getPosition())</code></pre></div></div><a name="vector-light-permul" id="vector-light-permul"></a><div class="ref-block"><h4>function <span class="name">permul</span><span class="arglist">(x1,y1, x2,y2)</span><a class="top" href="#vector-light">^ top</a></h4><p>Multiplies vectors coordinate wise, i.e. <code class="lua">x1*x2,y1*y2</code>.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x1,y1</code></dt><dd>First vector.</dd><dt>numbers <code>x2,y2</code></dt><dd>Second vector.</dd></dl></div><div class="returns">Returns:<dl><dt>numbers</dt><dd>The result of the operation.</dd></dl></div><div class="example">Example:<pre><code class="lua">x,y = vector.permul(x,y, 1,1.5)</code></pre></div></div><a name="vector-light-dot" id="vector-light-dot"></a><div class="ref-block"><h4>function <span class="name">dot</span><span class="arglist">(x1,y1, x2,y2)</span><a class="top" href="#vector-light">^ top</a></h4><p>Computes the <a href="http://en.wikipedia.org/wiki/Dot_product">dot product</a> of two vectors, <code class="lua">x1*x2+y1*y2</code>.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x1,y1</code></dt><dd>First vector.</dd><dt>numbers <code>x2,y2</code></dt><dd>Second vector.</dd></dl></div><div class="returns">Returns:<dl><dt>number</dt><dd>The dot product.</dd></dl></div><div class="example">Example:<pre><code class="lua">cosphi = vector.dot(rx,ry, vx,vy)</code></pre></div></div><a name="vector-light-det" id="vector-light-det"></a><a name="vector-light-cross" id="vector-light-cross"></a><div class="ref-block"><h4>function <span class="name">det</span><span class="arglist">(x1,y1, x2,y2)</span><a class="top" href="#vector-light">^ top</a></h4><h4>function <span class="name">cross</span><span class="arglist">(x1,y1, x2,y2)</span><a class="top" href="#vector-light">^ top</a></h4><p>Computes the cross product/determinant of two vectors, <code class="lua">x1*y2-y1*x2</code>.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x1,y1</code></dt><dd>First vector.</dd><dt>numbers <code>x2,y2</code></dt><dd>Second vector.</dd></dl></div><div class="returns">Returns:<dl><dt>number</dt><dd>The cross product.</dd></dl></div><div class="example">Example:<pre><code class="lua">parallelogram_area = vector.det(ax,ay, bx,by)</code></pre></div></div><a name="vector-light-eq" id="vector-light-eq"></a><a name="vector-light-le" id="vector-light-le"></a><a name="vector-light-lt" id="vector-light-lt"></a><div class="ref-block"><h4>function <span class="name">eq</span><span class="arglist">(x1,y1, x2,y2)</span><a class="top" href="#vector-light">^ top</a></h4><h4>function <span class="name">le</span><span class="arglist">(x1,y1, x2,y2)</span><a class="top" href="#vector-light">^ top</a></h4><h4>function <span class="name">lt</span><span class="arglist">(x1,y1, x2,y2)</span><a class="top" href="#vector-light">^ top</a></h4><p>Compares two vectors according to <dl><dt><code class="lua">vector.eq(x1,y1, x2,y2)</code></dt><dd><code class="lua">x1 == x2 and y1 == y2</code></dd><dt><code class="lua">vector.le(x1,y1, x2,y2)</code></dt><dd><code class="lua">x1 <= x2 and y1 <= y2</code></dd><dt><code class="lua">vector.lt(x1,y1, x2,y2)</code></dt><dd><code class="lua">x1 < x2 or (x1 == x2) and y1 <= y2</code></dd></dl> </p><div class="arguments">Parameters:<dl><dt>numbers <code>x1,y1</code></dt><dd>First vector.</dd><dt>numbers <code>x2,y2</code></dt><dd>Second vector.</dd></dl></div><div class="returns">Returns:<dl><dt>boolean</dt><dd>The result of the operation.</dd></dl></div><div class="example">Example:<pre><code class="lua">...</code></pre></div></div><a name="vector-light-len" id="vector-light-len"></a><div class="ref-block"><h4>function <span class="name">len</span><span class="arglist">(x,y)</span><a class="top" href="#vector-light">^ top</a></h4><p>Get length of a vector, i.e. <code class="lua">math.sqrt(x*x + y*y)</code>.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x,y</code></dt><dd>The vector.</dd></dl></div><div class="returns">Returns:<dl><dt>number</dt><dd>Length of the vector.</dd></dl></div><div class="example">Example:<pre><code class="lua">distance = vector.len(love.mouse.getPosition())</code></pre></div></div><a name="vector-light-len2" id="vector-light-len2"></a><div class="ref-block"><h4>function <span class="name">len2</span><span class="arglist">(x,y)</span><a class="top" href="#vector-light">^ top</a></h4><p>Get squared length of a vector, i.e. <code class="lua">x*x + y*y</code>.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x,y</code></dt><dd>The vector.</dd></dl></div><div class="returns">Returns:<dl><dt>number</dt><dd>Squared length of the vector.</dd></dl></div><div class="example">Example:<pre><code class="lua">-- get closest vertex to a given vector
closest, dsq = vertices[1], vector.len2(px-vertices[1].x, py-vertices[1].y)
for i = 2,#vertices do
local temp = vector.len2(px-vertices[i].x, py-vertices[i].y)
if temp < dsq then
closest, dsq = vertices[i], temp
end
end</code></pre></div></div><a name="vector-light-dist" id="vector-light-dist"></a><div class="ref-block"><h4>function <span class="name">dist</span><span class="arglist">(x1,y1, x2,y2)</span><a class="top" href="#vector-light">^ top</a></h4><p>Get distance of two points. The same as <code class="lua">vector.len(x1-x2, y1-y2)</code>.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x1,y1</code></dt><dd>First vector.</dd><dt>numbers <code>x2,y2</code></dt><dd>Second vector.</dd></dl></div><div class="returns">Returns:<dl><dt>number</dt><dd>The distance of the points.</dd></dl></div><div class="example">Example:<pre><code class="lua">-- get closest vertex to a given vector
-- slightly slower than the example using len2()
closest, dist = vertices[1], vector.dist(px,py, vertices[1].x,vertices[1].y)
for i = 2,#vertices do
local temp = vector.dist(px,py, vertices[i].x,vertices[i].y)
if temp < dist then
closest, dist = vertices[i], temp
end
end</code></pre></div></div><a name="vector-light-normalize" id="vector-light-normalize"></a><div class="ref-block"><h4>function <span class="name">normalize</span><span class="arglist">(x,y)</span><a class="top" href="#vector-light">^ top</a></h4><p>Get normalized vector, i.e. a vector with the same direction as the input vector, but with length 1.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x,y</code></dt><dd>The vector.</dd></dl></div><div class="returns">Returns:<dl><dt>numbers</dt><dd>Vector with same direction as the input vector, but length 1.</dd></dl></div><div class="example">Example:<pre><code class="lua">dx,dy = vector.normalize(vx,vy)</code></pre></div></div><a name="vector-light-rotate" id="vector-light-rotate"></a><div class="ref-block"><h4>function <span class="name">rotate</span><span class="arglist">(phi, x,y)</span><a class="top" href="#vector-light">^ top</a></h4><p>Get a rotated vector.</p><div class="arguments">Parameters:<dl><dt>number <code>phi</code></dt><dd>Rotation angle in <a href="http://en.wikipedia.org/wiki/Radians">radians</a>.</dd><dt>numbers <code>x,y</code></dt><dd>The vector.</dd></dl></div><div class="returns">Returns:<dl><dt>numbers</dt><dd>The rotated vector</dd></dl></div><div class="example">Example:<pre><code class="lua">-- approximate a circle
circle = {}
for i = 1,30 do
local phi = 2 * math.pi * i / 30
circle[i*2-1], circle[i*2] = vector.rotate(phi, 0,1)
end</code></pre></div></div><a name="vector-light-perpendicular" id="vector-light-perpendicular"></a><div class="ref-block"><h4>function <span class="name">perpendicular</span><span class="arglist">(x,y)</span><a class="top" href="#vector-light">^ top</a></h4><p>Quick rotation by 90&deg;. The same (but faster) as <code class="lua">vector.rotate(math.pi/2, x,y)</code></p><div class="arguments">Parameters:<dl><dt>numbers <code>x,y</code></dt><dd>The vector.</dd></dl></div><div class="returns">Returns:<dl><dt>numbers</dt><dd>A vector perpendicular to the input vector</dd></dl></div><div class="example">Example:<pre><code class="lua">nx,ny = vector.normalize(vector.perpendicular(bx-ax, by-ay))</code></pre></div></div><a name="vector-light-project" id="vector-light-project"></a><div class="ref-block"><h4>function <span class="name">project</span><span class="arglist">(x,y, u,v)</span><a class="top" href="#vector-light">^ top</a></h4><p>Project vector onto another vector.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x,y</code></dt><dd>The vector to project.</dd><dt>numbers <code>u,v</code></dt><dd>The vector to project onto.</dd></dl></div><div class="returns">Returns:<dl><dt>numbers</dt><dd>The projected vector.</dd></dl></div><div class="example">Example:<pre><code class="lua">vx_p,vy_p = vector.project(vx,vy, ax,ay)</code></pre></div></div><a name="vector-light-mirror" id="vector-light-mirror"></a><div class="ref-block"><h4>function <span class="name">mirror</span><span class="arglist">(x,y, u,v)</span><a class="top" href="#vector-light">^ top</a></h4><p>Mirrors vector on the axis defined by the other vector.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x,y</code></dt><dd>The vector to mirror.</dd><dt>numbers <code>u,v</code></dt><dd>The vector defining the axis.</dd></dl></div><div class="returns">Returns:<dl><dt>numbers</dt><dd>The mirrored vector.</dd></dl></div><div class="example">Example:<pre><code class="lua">vx,vy = vector.mirror(vx,vy, surface.x,surface.y)</code></pre></div></div></div><a name="Class" id="Class"></a><div class="outer-block"><h3>hump.class<a class="top" href="#top">^ top</a></h3><div class="preamble"><pre><code class="lua">Class = require "hump.class"</code></pre><p>A small, fast class implementation with multiple inheritance support</p></div><div class="overview"><h4>Module overview</h4><dl><dt><a href="#Class-new">new()</a></dt><dd>Declare a new class.</dd><dt><a href="#Class-class.construct">class.construct()</a></dt><dd>Call class constructor.</dd><dt><a href="#Class-class:inherit">class:inherit()</a></dt><dd>Explicit class inheritance/mixin support.</dd><dt><a href="#Class-object:is_a">object:is_a()</a></dt><dd>Test object's type.</dd><dt><a href="#Class-caveats">caveats</a></dt><dd>Caveats</dd></dl></div><a name="Class-new" id="Class-new"></a><div class="ref-block"><h4>function <span class="name">new</span><span class="arglist">{constructor, name = the_name, inherits = super}</span><a class="top" href="#Class">^ top</a></h4><p>Declare a new class.</p><p>The constructor will receive the newly create object as first argument.</p><p>You can check if an object is an instance of a class using <code class="lua">object:is_a()</code>.</p><p>The name of the variable that holds the module can be used as a shortcut to <code class="lua">new()</code> (see example).</p><div class="arguments">Parameters:<dl><dt>function <code>constructor</code> (optional)</dt><dd>Class constructor. Can be accessed with <code class="lua">theclass.construct(object, ...)</code></dd><dt>string <code>the_name</code> (optional)</dt><dd>Class name (used only to make the class compliant to <code class="lua">tostring()</code>.</dd><dt>class or table of classes <code>super</code> (optional)</dt><dd>Classes to inherit from. Can either be a single class or a table of classes</dd></dl></div><div class="returns">Returns:<dl><dt>class</dt><dd>The class</dd></dl></div><div class="example">Example:<pre><code class="lua">Class = require 'hump.class' -- `Class' is now a shortcut to new()
-- define unnamed class
Feline = Class{function(self, size, weight)
self.size = size
self.weight = weight
end}
print(Feline) -- prints '<unnamed class>
-- define class method
function Feline:stats()
return string.format("size: %.02f, weight %.02f", self.size, self.weight)
end
-- create two objects
garfield = Feline(.7, 45)
felix = Feline(.8, 12)
print("Garfield: " .. garfield:stats(), "Felix: " .. felix:stats())
</code></pre><pre><code class="lua">Class = require 'hump.class'
-- define class with explicit name 'Feline'
Feline = Class{name = "Feline", function(self, size, weight)
self.size = size
self.weight = weight
end}
garfield = Feline(.7, 45)
print(Feline, garfield) -- prints '<unnamed class> <instance of <unnamed class>>'
</code></pre><pre><code class="lua">Class = require 'hump.class'
A = Class{}
function A:foo()
print('foo')
end
B = Class{}
function B:bar()
print('bar')
end
-- single inheritance
C = Class{inherits = A}
instance = C()
instance:foo() -- prints 'foo'
-- multiple inheritance
D = Class{inherits = {A,B}}
instance = D()
instance:foo() -- prints 'foo'
instance:bar() -- prints 'bar'
</code></pre></div></div><a name="Class-class.construct" id="Class-class.construct"></a><div class="ref-block"><h4>function <span class="name">class.construct</span><span class="arglist">(object, ...)</span><a class="top" href="#Class">^ top</a></h4><p>Calls class constructor of a class on an object</p><p>Derived classes use this function their constructors to initialize the parent class(es) portions of the object.</p><div class="arguments">Parameters:<dl><dt>Object <code>object</code></dt><dd>The object. Usually <code class="lua">self</code>.</dd><dt>mixed <code>...</code></dt><dd>Arguments to pass to the constructor</dd></dl></div><div class="returns">Returns:<dl><dt>mixed</dt><dd>Whatever the parent class constructor returns</dd></dl></div><div class="example">Example:<pre><code class="lua">Class = require 'hump.class'
Shape = Class{function(self, area)
self.area = area
end}
function Shape:__tostring()
return "area = " .. self.area
end
Rectangle = Class{inherits = Shape, function(self, width, height)
Shape.construct(self, width * height)
self.width = width
self.height = height
end}
function Rectangle:__tostring()
local strs = {
"width = " .. self.width,
"height = " .. self.height,
Shape.__tostring(self)
},
return table.concat(strs, ", ")
end
print( Rectangle(2,4) ) -- prints 'width = 2, height = 4, area = 8'
</code></pre><pre><code class="lua">Menu = Class{function(self)
self.entries = {}
end}
function Menu:add(title, entry)
self.entries[#self.entries + 1] = entry
end
function Menu:display()
-- ...
end
Entry = Class{function(self, title, command)
self.title = title
self.command = command
end}
function Entry:execute()
return self.command()
end
Submenu = Class{inherits = {Menu, Entry}, function(self, title)
Menu.construct(self)
-- redirect self:execute() to self:display()
Entry.construct(self, title, Menu.display)
end}
</code></pre></div></div><a name="Class-class:inherit" id="Class-class:inherit"></a><div class="ref-block"><h4>function <span class="name">class:inherit</span><span class="arglist">(...)</span><a class="top" href="#Class">^ top</a></h4><p>Inherit functions and variables of another class, if they are not already defined for the class. This is done by simply copying the functions and variables over to the subclass. The Lua rules for copying apply (i.e. tables are referenced, functions and primitive types are copied by value).</p><p><span class="warning">Be careful with changing table values in a subclass: This will change the value in the parent class too.</span></p><p>If more than one parent class is specified, inherit from all of these, in order of occurrence. That means that when two parent classes define the same method, the one from the first class will be inherited.</p><p>Note: <code class="lua">class:inherit()</code> doesn't actually care if the arguments supplied are hump classes. Just any table will work.</p><div class="arguments">Parameters:<dl><dt>tables <code>...</code></dt><dd>Parent classes to inherit from</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">Class = require 'hump.class'
Entity = Class{function(self)
GameObjects.register(self)
end}
Collidable = {
dispatch_collision = function(self, other, dx, dy)
if self.collision_handler[other.type])
return collision_handler[other.type](self, other, dx, dy)
end
return collision_handler["*"](self, other, dx, dy)
end,
collision_handler = {["*"] = function() end},
}
Spaceship = Class{function(self)
self.type = "Spaceship"
-- ...
end}
-- make Spaceship collidable
Spaceship:inherit(Collidable)
function Spaceship:collision_handler["Spaceship"](other, dx, dy)
-- ...
end
</code></pre></div></div><a name="Class-object:is_a" id="Class-object:is_a"></a><div class="ref-block"><h4>function <span class="name">object:is_a</span><span class="arglist">(cls)</span><a class="top" href="#Class">^ top</a></h4><p>Tests whether an object is an instance of a class.</p><div class="arguments">Parameters:<dl><dt>class <code>cls</code></dt><dd>Class to test. Note: this is the class itself, <em>not</em> the name of the class.</dd></dl></div><div class="returns">Returns:<dl><dt>Boolean</dt><dd><code class="lua">true</code> if the object is an instance of the class, <code class="lua">false</code> otherwise</dd></dl></div><div class="example">Example:<pre><code class="lua">Class = require 'hump.class'
A = Class{}
B = Class{inherits=A}
C = Class{inherits=B}
a, b, c = A(), B(), C()
print(a:is_a(A), a:is_a(B), a:is_a(C)) --> true false false
print(b:is_a(A), b:is_a(B), b:is_a(C)) --> true true false
print(c:is_a(A), c:is_a(B), c:is_a(C)) --> true true true
D = Class{}
E = Class{inherits={B,D}}
d, e = D(), E()
print(d:is_a(A), d:is_a(B), d:is_a(D)) --> false false true
print(e:is_a(A), e:is_a(B), e:is_a(D)) --> true true true
</code></pre></div></div><a name="Class-caveats" id="Class-caveats"></a><div class="section-block"><h4>Caveats<a class="top" href="#Class">^ top</a></h4><p>Be careful when using metamethods like <code class="lua">__add</code> or <code class="lua">__mul</code>: If subclass inherits those methods from a superclass, but does not overwrite them, the result of the operation may be of the type superclass. Consider the following: <pre><code class="lua">Class = require 'hump.class'
A = Class{function(self, x) self.x = x end}
function A:__add(other) return A(self.x + other.x) end
function A:show() print("A:", self.x) end
B = Class{inherits = A, function(self, x, y) A.construct(self, x) self.y = y end}
function B:show() print("B:", self.x, self.y) end
function B:foo() print("foo") end
one, two = B(1,2), B(3,4)
result = one + two
result:show() -- prints "A: 4"
result:foo() -- error: method does not exist</code></pre></p><p>Note that while you can define the <code class="lua">__index</code> metamethod of the class, this is not a good idea: It will break the class. To add a custom <code class="lua">__index</code> metamethod without breaking the class system, you have to use <code class="lua">rawget()</code>. But beware that this won't affect subclasses: <pre><code class="lua">Class = require 'hump.class'
A = Class{}
function A:foo() print('bar') end
function A:__index(key)
print(key)
return rawget(A, key)
end
instance = A()
instance:foo() -- prints foo <newline> bar
B = Class{inherits = A}
instance = B()
instance:foo() -- prints only foo</code></pre></p></div></div><a name="Signal" id="Signal"></a><div class="outer-block"><h3>hump.signal<a class="top" href="#top">^ top</a></h3><div class="preamble"><pre><code class="lua">Signal = require "hump.signal"</code></pre><p>A simple yet effective implementation of <a href="http://en.wikipedia.org/wiki/Signals_and_slots">Signals and Slots</a>, also known as <a href="http://en.wikipedia.org/wiki/Observer_pattern">Observer pattern</a>: Functions can be dynamically bound to <em>signals</em>. When a signal is <em>emitted</em>, all registered functions will be invoked. Simple as that.</p><p><code class="lua">hump.signal</code> makes things more interesing by allowing to emit all signals that match a <a href="http://www.lua.org/manual/5.1/manual.html#5.4.1">Lua string
pattern</a>.</p></div><div class="overview"><h4>Module overview</h4><dl><dt><a href="#Signal-new">new()</a></dt><dd>Create new signal registry.</dd><dt><a href="#Signal-register">register()</a></dt><dd>Register function with a signal.</dd><dt><a href="#Signal-emit">emit()</a></dt><dd>Call all functions bound to a signal.</dd><dt><a href="#Signal-remove">remove()</a></dt><dd>Remove functions from registry.</dd><dt><a href="#Signal-clear">clear()</a></dt><dd>Clears a signal registry.</dd><dt><a href="#Signal-emit_pattern">emit_pattern()</a></dt><dd>Emits signals matching a pattern.</dd><dt><a href="#Signal-remove_pattern">remove_pattern()</a></dt><dd>Remove functions from signals matching a pattern.</dd><dt><a href="#Signal-clear_pattern">clear_pattern()</a></dt><dd>Clears signal registry matching a pattern.</dd></dl></div><a name="Signal-new" id="Signal-new"></a><div class="ref-block"><h4>function <span class="name">new</span><span class="arglist">()</span><a class="top" href="#Signal">^ top</a></h4><p><span class="warning">If you don't need multiple independent registries, you can use the global/default registry (see examples).</span></p><p>Creates a new signal registry that is independent of the default registry: It will manage it's own list of signals and does not in any way affect the the global registry. Likewise, the global registry does not affect the instance.</p><p><span class="warning">Note:</span> Independent registries use the colon-notation (e.g. <code class="lua">instance:emit("foo")</code>), while the global registry uses the dot-notation (e.g. <code class="lua">Signal.emit("foo")</code>).</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>Registry</dt><dd>A new signal registry.</dd></dl></div><div class="example">Example:<pre><code class="lua">player.signals = Signals.new()</code></pre></div></div><a name="Signal-register" id="Signal-register"></a><a name="Signal-instance:register" id="Signal-instance:register"></a><div class="ref-block"><h4>function <span class="name">register</span><span class="arglist">(s, f)</span><a class="top" href="#Signal">^ top</a></h4><h4>function <span class="name">instance:register</span><span class="arglist">(s, f)</span><a class="top" href="#Signal">^ top</a></h4><p>Registers a function <code class="lua">f</code> to be called when signal <code class="lua">s</code> is emitted. </p><div class="arguments">Parameters:<dl><dt>string <code>s</code></dt><dd>The signal identifier.</dd><dt>function <code>f</code></dt><dd>The function to register.</dd></dl></div><div class="returns">Returns:<dl><dt>function</dt><dd>A function handle to use in <code class="lua">remove</code>.</dd></dl></div><div class="example">Example:<pre><code class="lua">Signal.register('level-complete', function() self.fanfare:play() end)</code></pre><pre><code class="lua">handle = Signal.register('level-load', function(level) level.show_help() end)</code></pre><pre><code class="lua">menu:register('key-left', select_previous_item)</code></pre></div></div><a name="Signal-emit" id="Signal-emit"></a><a name="Signal-instance:emit" id="Signal-instance:emit"></a><div class="ref-block"><h4>function <span class="name">emit</span><span class="arglist">(s, ...)</span><a class="top" href="#Signal">^ top</a></h4><h4>function <span class="name">instance:emit</span><span class="arglist">(s, ...)</span><a class="top" href="#Signal">^ top</a></h4><p>Calls all functions bound to signal <code class="lua">s</code> with the supplied arguments. </p><div class="arguments">Parameters:<dl><dt>string <code>s</code></dt><dd>The signal identifier.</dd><dt>mixed <code>...</code> (optional)</dt><dd>Arguments to pass to the bound functions.</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">function love.keypressed(key)
if key == 'left' then menu:emit('key-left') end
end</code></pre><pre><code class="lua">if level.is_finished() then
Signal.emit('level-load', level.next_level)
end</code></pre><pre><code class="lua">function on_collide(dt, a,b, dx,dy)
a.signals:emit('collide', b, dx, dy)
b.signals:emit('collide', a, -dx,-dy)
end</code></pre></div></div><a name="Signal-remove" id="Signal-remove"></a><a name="Signal-instance:remove" id="Signal-instance:remove"></a><div class="ref-block"><h4>function <span class="name">remove</span><span class="arglist">(s, ...)</span><a class="top" href="#Signal">^ top</a></h4><h4>function <span class="name">instance:remove</span><span class="arglist">(s, ...)</span><a class="top" href="#Signal">^ top</a></h4><p>Unbinds (removes) functions from signal <code class="lua">s</code>. </p><div class="arguments">Parameters:<dl><dt>string <code>s</code></dt><dd>The signal identifier.</dd><dt>functions <code>...</code></dt><dd>Functions to unbind from the signal.</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">Signal.remove('level-load', handle)</code></pre></div></div><a name="Signal-clear" id="Signal-clear"></a><a name="Signal-instance:clear" id="Signal-instance:clear"></a><div class="ref-block"><h4>function <span class="name">clear</span><span class="arglist">(s)</span><a class="top" href="#Signal">^ top</a></h4><h4>function <span class="name">instance:clear</span><span class="arglist">(s)</span><a class="top" href="#Signal">^ top</a></h4><p>Removes all functions from signal <code class="lua">s</code>. </p><div class="arguments">Parameters:<dl><dt>string <code>s</code></dt><dd>The signal identifier.</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">Signal.clear('key-left')</code></pre></div></div><a name="Signal-emit_pattern" id="Signal-emit_pattern"></a><a name="Signal-instance:emit_pattern" id="Signal-instance:emit_pattern"></a><div class="ref-block"><h4>function <span class="name">emit_pattern</span><span class="arglist">(p, ...)</span><a class="top" href="#Signal">^ top</a></h4><h4>function <span class="name">instance:emit_pattern</span><span class="arglist">(p, ...)</span><a class="top" href="#Signal">^ top</a></h4><p>Emits all signals matching a <a href="http://www.lua.org/manual/5.1/manual.html#5.4.1">string pattern</a>. </p><div class="arguments">Parameters:<dl><dt>string <code>p</code></dt><dd>The signal identifier pattern.</dd><dt>mixed <code>...</code> (optional)</dt><dd>Arguments to pass to the bound functions.</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">Signal.emit_pattern('^update%-.*', dt)</code></pre></div></div><a name="Signal-remove_pattern" id="Signal-remove_pattern"></a><a name="Signal-instance:remove_pattern" id="Signal-instance:remove_pattern"></a><div class="ref-block"><h4>function <span class="name">remove_pattern</span><span class="arglist">(p, ...)</span><a class="top" href="#Signal">^ top</a></h4><h4>function <span class="name">instance:remove_pattern</span><span class="arglist">(p, ...)</span><a class="top" href="#Signal">^ top</a></h4><p>Removes functions from all signals matching a <a href="http://www.lua.org/manual/5.1/manual.html#5.4.1">string pattern</a>. </p><div class="arguments">Parameters:<dl><dt>string <code>p</code></dt><dd>The signal identifier pattern.</dd><dt>functions <code>...</code></dt><dd>Functions to unbind from the signals.</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">Signal.remove_pattern('key%-.*', play_click_sound)</code></pre></div></div><a name="Signal-clear_pattern" id="Signal-clear_pattern"></a><a name="Signal-instance:clear_pattern" id="Signal-instance:clear_pattern"></a><div class="ref-block"><h4>function <span class="name">clear_pattern</span><span class="arglist">(p)</span><a class="top" href="#Signal">^ top</a></h4><h4>function <span class="name">instance:clear_pattern</span><span class="arglist">(p)</span><a class="top" href="#Signal">^ top</a></h4><p>Removes all functions from all signals matching a <a href="http://www.lua.org/manual/5.1/manual.html#5.4.1">string pattern</a>. </p><div class="arguments">Parameters:<dl><dt>string <code>p</code></dt><dd>The signal identifier pattern.</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">Signal.clear_pattern('sound%-.*')</code></pre><pre><code class="lua">Signal.clear_pattern('.*') -- clear all signals</code></pre></div></div></div><a name="Camera" id="Camera"></a><div class="outer-block"><h3>hump.camera<a class="top" href="#top">^ top</a></h3><div class="preamble"><pre><code class="lua">Camera = require "hump.camera"</code></pre><p><span class="warning">Depends on hump.vector-light</span></p><p>A camera utility for L&Ouml;VE. A camera can "look" at a position. It can zoom in and out and it can rotate it's view. In the background, this is done by actually moving, scaling and rotating everything in the game world. But don't worry about that.</p></div><div class="overview"><h4>Module overview</h4><dl><dt><a href="#Camera-new">new()</a></dt><dd>Create a new camera object.</dd><dt><a href="#Camera-camera:rotate">camera:rotate()</a></dt><dd>Rotate camera object.</dd><dt><a href="#Camera-camera:move">camera:move()</a></dt><dd>Move camera object.</dd><dt><a href="#Camera-camera:attach">camera:attach()</a></dt><dd>Attach camera object.</dd><dt><a href="#Camera-camera:detach">camera:detach()</a></dt><dd>Detach camera object.</dd><dt><a href="#Camera-camera:draw">camera:draw()</a></dt><dd>Attach, draw and detach.</dd><dt><a href="#Camera-camera:worldCoords">camera:worldCoords()</a></dt><dd>Convert point to world coordinates.</dd><dt><a href="#Camera-camera:cameraCoords">camera:cameraCoords()</a></dt><dd>Convert point to camera coordinates.</dd><dt><a href="#Camera-camera:mousepos">camera:mousepos()</a></dt><dd>Get mouse position in world coordinates.</dd></dl></div><a name="Camera-new" id="Camera-new"></a><div class="ref-block"><h4>function <span class="name">new</span><span class="arglist">(x,y, zoom, rot)</span><a class="top" href="#Camera">^ top</a></h4><p>Creates a new camera object. You can access the camera position using <code class="lua">camera.x, camera.y</code>, the zoom using <code class="lua">camera.zoom</code> and the rotation using <code class="lua">camera.rot</code>.</p><p>The module variable name can be used at a shortcut to <code class="lua">new()</code>.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x,y</code></dt><dd>Point for the camera to look at.</dd><dt>number <code>zoom</code></dt><dd>Camera zoom.</dd><dt>number <code>rot</code></dt><dd>Camera rotation in radians.</dd></dl></div><div class="returns">Returns:<dl><dt>camera</dt><dd>A new camera object.</dd></dl></div><div class="example">Example:<pre><code class="lua">camera = require 'hump.camera'
-- camera looking at (100,100) with zoom 2 and rotated by 45 degrees
cam = camera(100,100, 2, math.pi/2)
</code></pre></div></div><a name="Camera-camera:rotate" id="Camera-camera:rotate"></a><div class="ref-block"><h4>function <span class="name">camera:rotate</span><span class="arglist">(angle)</span><a class="top" href="#Camera">^ top</a></h4><p>Rotate the camera <em>by</em> some angle. To <em>set</em> the angle use <code class="lua">camera.rot = new_angle</code>.</p><p>This function is shortcut to <code class="lua">camera.rot = camera.rot + angle</code>.</p><div class="arguments">Parameters:<dl><dt>number <code>angle</code></dt><dd>Rotation angle in radians</dd></dl></div><div class="returns">Returns:<dl><dt>camera</dt><dd>The camera object.</dd></dl></div><div class="example">Example:<pre><code class="lua">function love.update(dt)
camera:rotate(dt)
end</code></pre><pre><code class="lua">function love.update(dt)
camera:rotate(dt):move(dt,dt)
end</code></pre></div></div><a name="Camera-camera:move" id="Camera-camera:move"></a><div class="ref-block"><h4>function <span class="name">camera:move</span><span class="arglist">(dx,dy)</span><a class="top" href="#Camera">^ top</a></h4><p><em>Move</em> the camera <em>by</em> some vector. To <em>set</em> the position, use <code class="lua">camera.x,camera.y = new_x,new_y</code>.</p><p>This function is shortcut to <code class="lua">camera.x,camera.y = camera.x+dx, camera.y+dy</code>.</p><div class="arguments">Parameters:<dl><dt>numbers <code>dx,dy</code></dt><dd>Direction to move the camera.</dd></dl></div><div class="returns">Returns:<dl><dt>camera</dt><dd>The camera object.</dd></dl></div><div class="example">Example:<pre><code class="lua">function love.update(dt)
camera:move(dt * 5, dt * 6):rotate(dt)
end</code></pre></div></div><a name="Camera-camera:attach" id="Camera-camera:attach"></a><div class="ref-block"><h4>function <span class="name">camera:attach</span><span class="arglist">()</span><a class="top" href="#Camera">^ top</a></h4><p>Start looking through the camera.</p><p>Apply camera transformations, i.e. move, scale and rotate everything until <code class="lua">camera:detach()</code> as if looking through the camera.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">function love.draw()
camera:attach()
draw_world()
cam:detach()
draw_hud()
end</code></pre></div></div><a name="Camera-camera:detach" id="Camera-camera:detach"></a><div class="ref-block"><h4>function <span class="name">camera:detach</span><span class="arglist">()</span><a class="top" href="#Camera">^ top</a></h4><p>Stop looking through the camera.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">function love.draw()
camera:attach()
draw_world()
cam:detach()
draw_hud()
end</code></pre></div></div><a name="Camera-camera:draw" id="Camera-camera:draw"></a><div class="ref-block"><h4>function <span class="name">camera:draw</span><span class="arglist">(func)</span><a class="top" href="#Camera">^ top</a></h4><p>Wrap a function between a <code class="lua">camera:attach()</code>/<code class="lua">camera:detach()</code> pair: <pre><code class="lua">cam:attach()
func()
cam:detach()</code></pre></p><div class="arguments">Parameters:<dl><dt>function <code>func</code></dt><dd>Drawing function to be wrapped.</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">function love.draw()
camera:draw(draw_world)
draw_hud()
end</code></pre></div></div><a name="Camera-camera:worldCoords" id="Camera-camera:worldCoords"></a><a name="Camera-camera:cameraCoords" id="Camera-camera:cameraCoords"></a><div class="ref-block"><h4>function <span class="name">camera:worldCoords</span><span class="arglist">(x, y)</span><a class="top" href="#Camera">^ top</a></h4><h4>function <span class="name">camera:cameraCoords</span><span class="arglist">(x, y)</span><a class="top" href="#Camera">^ top</a></h4><p>Because a camera has a point it looks at, a rotation and a zoom factor, it defines a coordinate system. A point now has two sets of coordinates: One defines where the point is to be found in the game world, and the other describes the position on the computer screen. The first set of coordinates is called <em>world coordinates</em>, the second one <em>camera coordinates</em>. Sometimes it is needed to convert between the two coordinate systems, for example to get the position of a mouse click in the game world in a strategy game, or to see if an object is visible on the screen.</p><p>These two functions convert a point between these two coordinate systems.</p><div class="arguments">Parameters:<dl><dt>numbers <code>x, y</code></dt><dd>Point to transform.</dd></dl></div><div class="returns">Returns:<dl><dt>numbers</dt><dd>Transformed point.</dd></dl></div><div class="example">Example:<pre><code class="lua">x,y = camera:worldCoords(love.mouse.getPosition())
selectedUnit:plotPath(x,y)
</code></pre><pre><code class="lua">x,y = cam:toCameraCoords(player.pos)
love.graphics.line(x, y, love.mouse.getPosition())
</code></pre></div></div><a name="Camera-camera:mousepos" id="Camera-camera:mousepos"></a><div class="ref-block"><h4>function <span class="name">camera:mousepos</span><span class="arglist">()</span><a class="top" href="#Camera">^ top</a></h4><p>Shortcut to <code class="lua">camera:worldCoords(love.mouse.getPosition())</code>.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>numbers</dt><dd>Mouse position in world coordinates.</dd></dl></div><div class="example">Example:<pre><code class="lua">x,y = camera:mousepos()
selectedUnit:plotPath(x,y)
</code></pre></div></div></div><a name="Ringbuffer" id="Ringbuffer"></a><div class="outer-block"><h3>hump.ringbuffer<a class="top" href="#top">^ top</a></h3><div class="preamble"><pre><code class="lua">Ringbuffer = require "hump.ringbuffer"</code></pre><p>A ring-buffer is a circular array: It does not have a first nor a last item, but it has a <em>selected</em> or <em>current</em> element.</p><p>A ring-buffer can be used to implement <em>Tomb Raider</em> style inventories, looping play-lists, recurring dialogs (like a unit's answers when selecting it multiple times in <em>Warcraft</em>) and generally everything that has a circular or looping structure.</p></div><div class="overview"><h4>Module overview</h4><dl><dt><a href="#Ringbuffer-new">new()</a></dt><dd>Create new ring-buffer.</dd><dt><a href="#Ringbuffer-ringbuffer:insert">ringbuffer:insert()</a></dt><dd>Insert element.</dd><dt><a href="#Ringbuffer-ringbuffer:remove">ringbuffer:remove()</a></dt><dd>Remove currently selected item.</dd><dt><a href="#Ringbuffer-ringbuffer:removeAt">ringbuffer:removeAt()</a></dt><dd>Remove an item.</dd><dt><a href="#Ringbuffer-ringbuffer:next">ringbuffer:next()</a></dt><dd>Select next item.</dd><dt><a href="#Ringbuffer-ringbuffer:prev">ringbuffer:prev()</a></dt><dd>Select previous item.</dd><dt><a href="#Ringbuffer-ringbuffer:get">ringbuffer:get()</a></dt><dd>Get currently selected item.</dd><dt><a href="#Ringbuffer-ringbuffer:size">ringbuffer:size()</a></dt><dd>Get ringbuffer size.</dd></dl></div><a name="Ringbuffer-new" id="Ringbuffer-new"></a><div class="ref-block"><h4>function <span class="name">new</span><span class="arglist">(...)</span><a class="top" href="#Ringbuffer">^ top</a></h4><p>Create new ring-buffer.</p><p>The module name is a shortcut to this function.</p><div class="arguments">Parameters:<dl><dt>mixed <code>...</code></dt><dd>Initial elements.</dd></dl></div><div class="returns">Returns:<dl><dt>Ringbuffer</dt><dd>The ring-buffer object.</dd></dl></div><div class="example">Example:<pre><code class="lua">Ringbuffer = require 'hump.ringbuffer'
rb = ringbuffer(1,2,3)
</code></pre></div></div><a name="Ringbuffer-ringbuffer:insert" id="Ringbuffer-ringbuffer:insert"></a><div class="ref-block"><h4>function <span class="name">ringbuffer:insert</span><span class="arglist">(...)</span><a class="top" href="#Ringbuffer">^ top</a></h4><p>Insert items behind current element.</p><div class="arguments">Parameters:<dl><dt>mixed <code>...</code></dt><dd>Items to insert.</dd></dl></div><div class="returns">Returns:<dl><dt>Nothing</dt></dl></div><div class="example">Example:<pre><code class="lua">rb = RingbuffeR(1,5,6) -- content: 1,5,6
rb:insert(2,3,4) -- content: 1,2,3,4,5,6
</code></pre></div></div><a name="Ringbuffer-ringbuffer:remove" id="Ringbuffer-ringbuffer:remove"></a><div class="ref-block"><h4>function <span class="name">ringbuffer:remove</span><span class="arglist">()</span><a class="top" href="#Ringbuffer">^ top</a></h4><p>Remove current item, return it and select next element.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>mixed</dt><dd>The removed item.</dd></dl></div><div class="example">Example:<pre><code class="lua">rb = Ringbuffer(1,2,3,4) -- content: 1,2,3,4
val = rb:remove() -- content: 2,3,4
print(val) -- prints `1'
</code></pre></div></div><a name="Ringbuffer-ringbuffer:removeAt" id="Ringbuffer-ringbuffer:removeAt"></a><div class="ref-block"><h4>function <span class="name">ringbuffer:removeAt</span><span class="arglist">(pos)</span><a class="top" href="#Ringbuffer">^ top</a></h4><p>Remove the item at a position relative to the current element.</p><div class="arguments">Parameters:<dl><dt>number <code>pos</code></dt><dd>Position of the item to remove.</dd></dl></div><div class="returns">Returns:<dl><dt>mixed</dt><dd>The removed item.</dd></dl></div><div class="example">Example:<pre><code class="lua">rb = Ringbuffer(1,2,3,4,5) -- content: 1,2,3,4,5
rb:removeAt(2) -- content: 1,2,4,5
rb:removeAt(-1) -- content: 1,2,4
</code></pre></div></div><a name="Ringbuffer-ringbuffer:next" id="Ringbuffer-ringbuffer:next"></a><div class="ref-block"><h4>function <span class="name">ringbuffer:next</span><span class="arglist">()</span><a class="top" href="#Ringbuffer">^ top</a></h4><p>Select and return the next element.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>mixed</dt><dd>The next item.</dd></dl></div><div class="example">Example:<pre><code class="lua">rb = Ringbuffer(1,2,3)
rb:next() -- content: 2,3,1
rb:next() -- content: 3,1,2
x = rb:next() -- content: 1,2,3
print(x) -- prints `1'
</code></pre></div></div><a name="Ringbuffer-ringbuffer:prev" id="Ringbuffer-ringbuffer:prev"></a><div class="ref-block"><h4>function <span class="name">ringbuffer:prev</span><span class="arglist">()</span><a class="top" href="#Ringbuffer">^ top</a></h4><p>Select and return the previous item.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>mixed</dt><dd>The previous item.</dd></dl></div><div class="example">Example:<pre><code class="lua">rb = Ringbuffer(1,2,3)
rb:prev()) -- content: 3,1,2
rb:prev()) -- content: 2,3,1
x = rb:prev() -- content: 1,2,3
print(x) -- prints `1'
</code></pre></div></div><a name="Ringbuffer-ringbuffer:get" id="Ringbuffer-ringbuffer:get"></a><div class="ref-block"><h4>function <span class="name">ringbuffer:get</span><span class="arglist">()</span><a class="top" href="#Ringbuffer">^ top</a></h4><p>Return the current element.</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>mixed</dt><dd>The currently selected element.</dd></dl></div><div class="example">Example:<pre><code class="lua">rb = Ringbuffer(1,2,3)
rb:next() -- content: 2,3,1
print(rb:get()) -- prints '2'
</code></pre></div></div><a name="Ringbuffer-ringbuffer:size" id="Ringbuffer-ringbuffer:size"></a><div class="ref-block"><h4>function <span class="name">ringbuffer:size</span><span class="arglist">()</span><a class="top" href="#Ringbuffer">^ top</a></h4><p>Get number of items in the buffer</p><div class="arguments">Parameters:<dl><dt>None</dt></dl></div><div class="returns">Returns:<dl><dt>number</dt><dd>Number of items in the buffer.</dd></dl></div><div class="example">Example:<pre><code class="lua">rb = Ringbuffer(1,2,3)
print(rb:size()) -- prints '3'
rb:remove()
print(rb:size()) -- prints '2'
</code></pre></div></div></div><a name="license" id="license"></a><div class="outer-block"><h3>License<a class="top" href="#top">^ top</a></h3><div class="preamble"><p>Yay, <em>free software</em>:</p><blockquote><p>Copyright (c) 2010 Matthias Richter</p><p>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:</p><p>The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.</p><p>Except as contained in this notice, the name(s) of the above copyright holders shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization.</p><p>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.</p></blockquote></div></div><a name="download" id="download"></a><div class="outer-block"><h3>Download<a class="top" href="#top">^ top</a></h3><div class="preamble"><p>You can view and download the individual modules on github: <a href="http://github.com/vrld/hump">vrld/hump</a>. You may also download the whole packed sourcecode either in <a href="http://github.com/vrld/hump/zipball/master">zip</a> or <a href="http://github.com/vrld/hump/tarball/master">tar</a> formats.</p><p>You can clone the project with <a href="http://git-scm.com">Git</a> by running: <pre>git clone git://github.com/vrld/hump</pre> Once done, you can check for updates by running <pre>git pull</pre></p></div></div></body>
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