Merge pull request #25 from yangruihan/master

fix README.md example error

.travis.yml

@@ -1,8 +1,8 @@
-language: erlang
+language: c
 
 env:
   global:
-    - LUAROCKS_BASE=luarocks-2.2.2
+    - LUAROCKS_BASE=luarocks-3.2.1
   matrix:
     - LUA=lua5.1 LUA_DEV=liblua5.1-dev LUA_VER=5.1 LUA_SFX=5.1 LUA_INCDIR=/usr/include/lua5.1
     - LUA=lua5.2 LUA_DEV=liblua5.2-dev LUA_VER=5.2 LUA_SFX=5.2 LUA_INCDIR=/usr/include/lua5.2

README.md

@@ -1,5 +1,12 @@
 # tiny-ecs #
 
+## NOTE
+
+Although there have been almost no commits in several years, this
+project is not abandoned. tiny-ecs is, for most intents and
+purposes, finished, and no bugs have been brought to my attention in a while.
+New issues on GitHub will be addressed.
+
 [![Build Status](https://travis-ci.org/bakpakin/tiny-ecs.png?branch=master)](https://travis-ci.org/bakpakin/tiny-ecs)[![License](http://img.shields.io/badge/Licence-MIT-brightgreen.svg)](LICENSE)
 
 Tiny-ecs is an Entity Component System for Lua that's simple, flexible, and useful.
@@ -8,11 +15,11 @@ for simulating large and complex systems. For more explanation on Entity
 Component Systems, here is some
 [basic info](http://en.wikipedia.org/wiki/Entity_component_system "Wikipedia").
 
-Tiny-ecs also works well with objected oriented programming in Lua because
+Tiny-ecs also works well with object-oriented programming in Lua because
 Systems and Entities do not use metatables. This means you can subclass your
-Systems and Entities, and use existing Lua class frameworks with tiny-ecs, no problem.
+Systems and Entities and use existing Lua class frameworks with tiny-ecs, no problem.
 For an example on how to use tiny-ecs with object-oriented Lua, take a look at the
-demo branch, specifically the systems and entities sub-directories.
+demo branch, specifically the systems and entities subdirectories.
 
 ## Overview ##
 Tiny-ecs has four important types: Worlds, Filters, Systems, and Entities.
@@ -21,7 +28,7 @@ take an Entity as a parameter.
 
 ### Entities ###
 Entities are simply Lua tables of data that gets processed by Systems. Entities
-should contain primarily data rather than code, as it is the Systems's job to
+should contain primarily data rather than code, as it is the System's job to
 do logic on data. Henceforth, a key-value pair in an Entity will
 be referred to as a Component.
 
@@ -49,7 +56,7 @@ local talkingSystem = tiny.processingSystem()
 talkingSystem.filter = tiny.requireAll("name", "mass", "phrase")
 function talkingSystem:process(e, dt)
     e.mass = e.mass + dt * 3
-    print(("%s who weighs %d pounds, says %q."):format(e.name, e.mass, e.phrase)
+    print(("%s who weighs %d pounds, says %q."):format(e.name, e.mass, e.phrase))
 end
 
 local joe = {
@@ -68,10 +75,10 @@ end
 
 ## Use It ##
 Copy paste tiny.lua into your source folder. For stability and consistent API,
-please use a tagged release or use luarocks.
+please use a tagged release or use LuaRocks.
 
 ## Luarocks ##
-Tiny-ecs is also on [Luarocks](https://luarocks.org/) and can be installed with
+Tiny-ecs is also on [LuaRocks](https://luarocks.org/) and can be installed with
 `luarocks install tiny-ecs`.
 
 ## Demo ##

init.lua

@@ -1,5 +1,6 @@
 -- Helper Lua file for easy require if tiny-ecs is used as a git submodule or
 -- folder. Not needed in many cases, including luarocks distribution.
 
-local directory = (...):match("(.-)[^%.]+$")
-return require(directory .. 'tiny')
+local args = {...}
+local directory = args[1]
+return require(directory .. '.tiny')

rockspecs/tiny-ecs-1.3-3.rockspec

@@ -0,0 +1,24 @@
+package = "tiny-ecs"
+version = "1.3-3"
+source = {
+   url = "git://github.com/bakpakin/tiny-ecs",
+   tag = version
+}
+description = {
+   summary = "Entity Component System for Lua.",
+   detailed = [[
+        Pure Lua implementation of an easy to use, compact, fast, and flexible
+        Entity Component System. Works well with Object Orientation.
+    ]],
+   homepage = "https://github.com/bakpakin/tiny-ecs",
+   license = "MIT"
+}
+dependencies = {
+   "lua >= 5.1"
+}
+build = {
+   type = "builtin",
+   modules = {
+      tiny = "tiny.lua"
+   }
+}

spec/tiny_spec.lua

@@ -310,4 +310,14 @@ describe('tiny-ecs:', function()
         assert.are.same(_G, GLOBALS)
     end)
 
+    it("Can set system indices", function()
+        local world = tiny.world()
+        local systemA = tiny.system()
+        local systemB = tiny.system()
+        world:addSystem(systemA)
+        world:addSystem(systemB)
+        world:setSystemIndex(systemA, 1)
+        assert(true)
+    end)
+
 end)

test.lua

@@ -0,0 +1,8 @@
+local tiny = require('tiny')
+
+local world = tiny.world()
+local systemA = tiny.system()
+local systemB = tiny.system()
+world:addSystem(systemA)
+world:addSystem(systemB)
+world:setSystemIndex(systemA, 1)

tiny.lua

@@ -41,12 +41,13 @@ local tiny_addSystem
 local tiny_add
 local tiny_removeEntity
 local tiny_removeSystem
-local tiny_remove
 
 --- Filter functions.
 -- A Filter is a function that selects which Entities apply to a System.
 -- Filters take two parameters, the System and the Entity, and return a boolean
--- value indicating if the Entity should be processed by the System.
+-- value indicating if the Entity should be processed by the System. A truthy
+-- value includes the entity, while a falsey (nil or false) value excludes the
+-- entity.
 --
 -- Filters must be added to Systems by setting the `filter` field of the System.
 -- Filter's returned by tiny-ecs's Filter functions are immutable and can be
@@ -229,7 +230,7 @@ end
 -- removed from the world, after all Entities are removed from the System.
 --   * `function system:preWrap(dt)` - Called on each system before update is
 -- called on any system.
---   * `function system:postWrap(dt) - Called on each system in reverse order
+--   * `function system:postWrap(dt)` - Called on each system in reverse order
 -- after update is called on each system. The idea behind `preWrap` and
 -- `postWrap` is to allow for systems that modify the behavior of other systems.
 -- Say there is a DrawingSystem, which draws sprites to the screen, and a
@@ -277,11 +278,13 @@ end
 --
 -- There is another option to (hopefully) increase performance in systems that
 -- have items added to or removed from them often, and have lots of entities in
--- them.  Setting the `nocache' field of the system might improve performance.
+-- them.  Setting the `nocache` field of the system might improve performance.
 -- It is still experimental. There are some restriction to systems without
--- caching, however.  * There is no `entities` table.  * Callbacks such onAdd,
--- onRemove, and onModify will never be called * Noncached systems cannot be
--- sorted (There is no entities list to sort).
+-- caching, however.
+--
+--   * There is no `entities` table.
+--   * Callbacks such onAdd, onRemove, and onModify will never be called
+--   * Noncached systems cannot be sorted (There is no entities list to sort).
 --
 -- @section System
 
@@ -306,7 +309,7 @@ local function processingSystemUpdate(system, dt)
 
     if process then
         if system.nocache then
-            local entities = system.world.entityList
+            local entities = system.world.entities
             local filter = system.filter
             if filter then
                 for i = 1, #entities do
@@ -330,7 +333,7 @@ local function processingSystemUpdate(system, dt)
 end
 
 -- Sorts Systems by a function system.sortDelegate(entity1, entity2) on modify.
-local function sortedSystemOnModify(system, dt)
+local function sortedSystemOnModify(system)
     local entities = system.entities
     local indices = system.indices
     local sortDelegate = system.sortDelegate
@@ -420,9 +423,6 @@ local worldMetaTable
 function tiny.world(...)
     local ret = setmetatable({
 
-        -- List of Entities to add
-        entitiesToAdd = {},
-
         -- List of Entities to remove
         entitiesToRemove = {},
 
@@ -438,14 +438,9 @@ function tiny.world(...)
         -- Set of Entities
         entities = {},
 
-        -- List of Entities
-        entityList = {},
-
-        -- Number of Entities in World
-        entityCount = 0,
-
         -- List of Systems
         systems = {}
+
     }, worldMetaTable)
 
     tiny_add(ret, ...)
@@ -459,13 +454,8 @@ end
 -- Also call this on Entities that have changed Components such that they
 -- match different Filters. Returns the Entity.
 function tiny.addEntity(world, entity)
-    if world.entities[entity] then
-        local e2c = world.entitiesToChange
-        e2c[#e2c + 1] = entity
-    else
-        local e2a = world.entitiesToAdd
-        e2a[#e2a + 1] = entity
-    end
+    local e2c = world.entitiesToChange
+    e2c[#e2c + 1] = entity
     return entity
 end
 tiny_addEntity = tiny.addEntity
@@ -497,7 +487,7 @@ function tiny.add(world, ...)
 end
 tiny_add = tiny.add
 
---- Removes an Entity to the World. Returns the Entity.
+--- Removes an Entity from the World. Returns the Entity.
 function tiny.removeEntity(world, entity)
     local e2r = world.entitiesToRemove
     e2r[#e2r + 1] = entity
@@ -529,7 +519,6 @@ function tiny.remove(world, ...)
     end
     return ...
 end
-tiny_remove = tiny.remove
 
 -- Adds and removes Systems that have been marked from the World.
 function tiny_manageSystems(world)
@@ -543,7 +532,7 @@ function tiny_manageSystems(world)
     world.systemsToAdd = {}
     world.systemsToRemove = {}
 
-    local worldEntityList = world.entityList
+    local worldEntityList = world.entities
     local systems = world.systems
 
     -- Remove Systems
@@ -623,58 +612,58 @@ end
 -- Adds, removes, and changes Entities that have been marked.
 function tiny_manageEntities(world)
 
-    local e2a = world.entitiesToAdd
     local e2r = world.entitiesToRemove
     local e2c = world.entitiesToChange
 
     -- Early exit
-    if #e2a == 0 and #e2r == 0 and #e2c == 0 then
+    if #e2r == 0 and #e2c == 0 then
         return
     end
 
     world.entitiesToChange = {}
-    world.entitiesToAdd = {}
     world.entitiesToRemove = {}
 
     local entities = world.entities
-    local entityList = world.entityList
     local systems = world.systems
-    local entityCount = world.entityCount
 
     -- Change Entities
     for i = 1, #e2c do
         local entity = e2c[i]
-        if entities[entity] then
-            for j = 1, #systems do
-                local system = systems[j]
-                if not system.nocache then
-                    local ses = system.entities
-                    local seis = system.indices
-                    local index = seis[entity]
-                    local filter = system.filter
-                    if filter and filter(system, entity) then
-                        if not index then
-                            system.modified = true
-                            index = #ses + 1
-                            ses[index] = entity
-                            seis[entity] = index
-                            local onAdd = system.onAdd
-                            if onAdd then
-                                onAdd(system, entity)
-                            end
-                        end
-                    elseif index then
+        -- Add if needed
+        if not entities[entity] then
+            local index = #entities + 1
+            entities[entity] = index
+            entities[index] = entity
+        end
+        for j = 1, #systems do
+            local system = systems[j]
+            if not system.nocache then
+                local ses = system.entities
+                local seis = system.indices
+                local index = seis[entity]
+                local filter = system.filter
+                if filter and filter(system, entity) then
+                    if not index then
                         system.modified = true
-                        local tmpEntity = ses[#ses]
-                        ses[index] = tmpEntity
-                        seis[tmpEntity] = index
-                        seis[entity] = nil
-                        ses[#ses] = nil
-                        local onRemove = system.onRemove
-                        if onRemove then
-                            onRemove(system, entity)
+                        index = #ses + 1
+                        ses[index] = entity
+                        seis[entity] = index
+                        local onAdd = system.onAdd
+                        if onAdd then
+                            onAdd(system, entity)
                         end
                     end
+                elseif index then
+                    system.modified = true
+                    local tmpEntity = ses[#ses]
+                    ses[index] = tmpEntity
+                    seis[tmpEntity] = index
+                    seis[entity] = nil
+                    ses[#ses] = nil
+                    local onRemove = system.onRemove
+                    if onRemove then
+                        onRemove(system, entity)
+                    end
                 end
             end
         end
@@ -688,12 +677,11 @@ function tiny_manageEntities(world)
         local listIndex = entities[entity]
         if listIndex then
             -- Remove Entity from world state
-            local lastEntity = entityList[#entityList]
+            local lastEntity = entities[#entities]
             entities[lastEntity] = listIndex
             entities[entity] = nil
-            entityList[listIndex] = lastEntity
-            entityList[#entityList] = nil
-            entityCount = entityCount - 1
+            entities[listIndex] = lastEntity
+            entities[#entities] = nil
             -- Remove from cached systems
             for j = 1, #systems do
                 local system = systems[j]
@@ -717,39 +705,6 @@ function tiny_manageEntities(world)
             end
         end
     end
-
-    -- Add Entities
-    for i = 1, #e2a do
-        local entity = e2a[i]
-        if not entities[entity] then
-            local listIndex = #entityList + 1
-            entities[entity] = listIndex
-            entityList[listIndex] = entity
-            entityCount = entityCount + 1
-            for j = 1, #systems do
-                local system = systems[j]
-                if not system.nocache then
-                    local ses = system.entities
-                    local seis = system.indices
-                    local filter = system.filter
-                    if filter and filter(system, entity) then
-                        system.modified = true
-                        local index = #ses + 1
-                        ses[index] = entity
-                        seis[entity] = index
-                        local onAdd = system.onAdd
-                        if onAdd then
-                            onAdd(system, entity)
-                        end
-                    end
-                end
-            end
-        end
-        e2a[i] = nil
-    end
-
-    -- Update Entity count
-    world.entityCount = entityCount
 end
 
 --- Manages Entities and Systems marked for deletion or addition. Call this
@@ -759,7 +714,7 @@ function tiny.refresh(world)
     tiny_manageSystems(world)
     tiny_manageEntities(world)
     local systems = world.systems
-    for i = 1, #systems do
+    for i = #systems, 1, -1 do
         local system = systems[i]
         if system.active then
             local onModify = system.onModify
@@ -785,10 +740,17 @@ function tiny.update(world, dt, filter)
     -- Iterate through Systems IN REVERSE ORDER
     for i = #systems, 1, -1 do
         local system = systems[i]
-        local preWrap = system.preWrap
-        if preWrap and system.active and
-            ((not filter) or filter(world, system)) then
-            preWrap(system, dt)
+        if system.active then
+            -- Call the modify callback on Systems that have been modified.
+            local onModify = system.onModify
+            if onModify and system.modified then
+                onModify(system, dt)
+            end
+            local preWrap = system.preWrap
+            if preWrap and
+                ((not filter) or filter(world, system)) then
+                preWrap(system, dt)
+            end
         end
     end
 
@@ -797,12 +759,6 @@ function tiny.update(world, dt, filter)
         local system = systems[i]
         if system.active and ((not filter) or filter(world, system)) then
 
-            -- Call the modify callback on Systems that have been modified.
-            local onModify = system.onModify
-            if onModify and system.modified then
-                onModify(system, dt)
-            end
-
             -- Update Systems that have an update method (most Systems)
             local update = system.update
             if update then
@@ -811,9 +767,7 @@ function tiny.update(world, dt, filter)
                     local bufferedTime = (system.bufferedTime or 0) + dt
                     while bufferedTime >= interval do
                         bufferedTime = bufferedTime - interval
-                        if update then
-                            update(system, interval)
-                        end
+                        update(system, interval)
                     end
                     system.bufferedTime = bufferedTime
                 else
@@ -839,7 +793,7 @@ end
 
 --- Removes all Entities from the World.
 function tiny.clearEntities(world)
-    local el = world.entityList
+    local el = world.entities
     for i = 1, #el do
         tiny_removeEntity(world, el[i])
     end
@@ -855,24 +809,19 @@ end
 
 --- Gets number of Entities in the World.
 function tiny.getEntityCount(world)
-    return world.entityCount
+    return #world.entities
 end
 
 --- Gets number of Systems in World.
 function tiny.getSystemCount(world)
-    return #(world.systems)
-end
-
---- Gets the index of the System in the World.
--- A simpler alternative is `system.index`.
-function tiny.getSystemIndex(world, system)
-    return system.index
+    return #world.systems
 end
 
 --- Sets the index of a System in the World, and returns the old index. Changes
 -- the order in which they Systems processed, because lower indexed Systems are
 -- processed first. Returns the old system.index.
 function tiny.setSystemIndex(world, system, index)
+    tiny_manageSystems(world)
     local oldIndex = system.index
     local systems = world.systems
 
@@ -905,10 +854,9 @@ worldMetaTable = {
         clearSystems = tiny.clearSystems,
         getEntityCount = tiny.getEntityCount,
         getSystemCount = tiny.getSystemCount,
-        getSystemIndex = tiny.getSystemIndex,
         setSystemIndex = tiny.setSystemIndex
     },
-    __tostring = function(self)
+    __tostring = function()
         return "<tiny-ecs_World>"
     end
 }