Adhere to new class commons specs.

class.lua

@@ -83,7 +83,7 @@ local function new(args)
 end
 
 -- interface for cross class-system compatibility (see https://github.com/bartbes/Class-Commons).
-if class_commons ~= false and not common then
+if common_class ~= false and not common then
 	common = {}
 	function common.class(name, prototype, parent)
 		local init = prototype.init or (parent or {}).init
@@ -94,7 +94,6 @@ if class_commons ~= false and not common then
 	end
 end
 
-
 -- the module
 return setmetatable({new = new, inherit = inherit},
 	{__call = function(_,...) return new(...) end})

init.lua

@@ -24,14 +24,19 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ]]--
 
-local _NAME = (...)
-if not (common and common.class and common.instance) then
-	class_commons = true
+local _NAME, common_local = ..., common
+if not (type(common) == 'table' and common.class and common.instance) then
+	assert(common_class ~= false, 'No class commons specification available.')
 	require(_NAME .. '.class')
 end
 local Shapes      = require(_NAME .. '.shapes')
 local Spatialhash = require(_NAME .. '.spatialhash')
 
+-- reset global table `common' (required by class commons)
+if common_local ~= common then
+	common_local, common = common, common_local
+end
+
 local newPolygonShape = Shapes.newPolygonShape
 local newCircleShape  = Shapes.newCircleShape
 local newPointShape   = Shapes.newPointShape
@@ -48,7 +53,7 @@ function HC:init(cell_size, callback_collide, callback_stop)
 
 	self.on_collide = callback_collide or __NULL__
 	self.on_stop    = callback_stop    or __NULL__
-	self._hash      = common.instance(Spatialhash, cell_size)
+	self._hash      = common_local.instance(Spatialhash, cell_size)
 end
 
 function HC:clear()
@@ -57,7 +62,7 @@ function HC:clear()
 	self._ghost_shapes   = {}
 	self.groups          = {}
 	self._colliding_only_last_frame = {}
-	self._hash           = common.instance(Spatialhash, self._hash.cell_size)
+	self._hash           = common_local.instance(Spatialhash, self._hash.cell_size)
 	return self
 end
 
@@ -296,9 +301,9 @@ function HC:setSolid(shape, ...)
 end
 
 -- the module
-HC = common.class("HardonCollider", HC)
+HC = common_local.class("HardonCollider", HC)
 local function new(...)
-	return common.instance(HC, ...)
+	return common_local.instance(HC, ...)
 end
 
 return setmetatable({HardonCollider = HC, new = new},

polygon.lua

@@ -24,10 +24,11 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ]]--
 
-local _PACKAGE = (...):match("^(.+)%.[^%.]+")
-if not (common and common.class and common.instance) then
-	class_commons = true
+local _PACKAGE, common_local = (...):match("^(.+)%.[^%.]+"), common
+if not (type(common) == 'table' and common.class and common.instance) then
+	assert(common_class ~= false, 'No class commons specification available.')
 	require(_PACKAGE .. '.class')
+	common_local, common = common, common_local
 end
 local vector = require(_PACKAGE .. '.vector-light')
 
@@ -454,6 +455,6 @@ function Polygon:intersectsRay(x,y, dx,dy)
 	return tmin ~= math.huge, tmin
 end
 
-Polygon = common.class('Polygon', Polygon)
-newPolygon = function(...) return common.instance(Polygon, ...) end
+Polygon = common_local.class('Polygon', Polygon)
+newPolygon = function(...) return common_local.instance(Polygon, ...) end
 return Polygon

shapes.lua

@@ -26,15 +26,20 @@ THE SOFTWARE.
 
 local math_min, math_sqrt, math_huge = math.min, math.sqrt, math.huge
 
-local _PACKAGE = (...):match("^(.+)%.[^%.]+")
-if not (common and common.class and common.instance) then
-	class_commons = true
+local _PACKAGE, common_local = (...):match("^(.+)%.[^%.]+"), common
+if not (type(common) == 'table' and common.class and common.instance) then
+	assert(common_class ~= false, 'No class commons specification available.')
 	require(_PACKAGE .. '.class')
 end
 local vector  = require(_PACKAGE .. '.vector-light')
 local Polygon = require(_PACKAGE .. '.polygon')
 local GJK     = require(_PACKAGE .. '.gjk') -- actual collision detection
 
+-- reset global table `common' (required by class commons)
+if common_local ~= common then
+	common_local, common = common, common_local
+end
+
 --
 -- base class
 --
@@ -77,7 +82,7 @@ function ConcavePolygonShape:init(poly)
 	self._polygon = poly
 	self._shapes = poly:splitConvex()
 	for i,s in ipairs(self._shapes) do
-		self._shapes[i] = common.instance(ConvexPolygonShape, s)
+		self._shapes[i] = common_local.instance(ConvexPolygonShape, s)
 	end
 end
 
@@ -402,33 +407,33 @@ function PointShape:draw()
 end
 
 
-Shape = common.class('Shape', Shape)
-ConvexPolygonShape  = common.class('ConvexPolygonShape',  ConvexPolygonShape,  Shape)
-ConcavePolygonShape = common.class('ConcavePolygonShape', ConcavePolygonShape, Shape)
-CircleShape         = common.class('CircleShape',         CircleShape,         Shape)
-PointShape          = common.class('PointShape',          PointShape,          Shape)
+Shape = common_local.class('Shape', Shape)
+ConvexPolygonShape  = common_local.class('ConvexPolygonShape',  ConvexPolygonShape,  Shape)
+ConcavePolygonShape = common_local.class('ConcavePolygonShape', ConcavePolygonShape, Shape)
+CircleShape         = common_local.class('CircleShape',         CircleShape,         Shape)
+PointShape          = common_local.class('PointShape',          PointShape,          Shape)
 
 local function newPolygonShape(polygon, ...)
 	-- create from coordinates if needed
 	if type(polygon) == "number" then
-		polygon = common.instance(Polygon, polygon, ...)
+		polygon = common_local.instance(Polygon, polygon, ...)
 	else
 		polygon = polygon:clone()
 	end
 
 	if polygon:isConvex() then
-		return common.instance(ConvexPolygonShape, polygon)
+		return common_local.instance(ConvexPolygonShape, polygon)
 	end
 
-	return common.instance(ConcavePolygonShape, polygon)
+	return common_local.instance(ConcavePolygonShape, polygon)
 end
 
 local function newCircleShape(...)
-	return common.instance(CircleShape, ...)
+	return common_local.instance(CircleShape, ...)
 end
 
 local function newPointShape(...)
-	return common.instance(PointShape, ...)
+	return common_local.instance(PointShape, ...)
 end
 
 return {

spatialhash.lua

@@ -27,10 +27,11 @@ THE SOFTWARE.
 local floor = math.floor
 local min, max = math.min, math.max
 
-local _PACKAGE = (...):match("^(.+)%.[^%.]+")
-if not (common and common.class and common.instance) then
-	class_commons = true
+local _PACKAGE, common_local = (...):match("^(.+)%.[^%.]+"), common
+if not (type(common) == 'table' and common.class and common.instance) then
+	assert(common_class ~= false, 'No class commons specification available.')
 	require(_PACKAGE .. '.class')
+	common_local, common = common, common_local
 end
 
 local Spatialhash = {}
@@ -155,4 +156,4 @@ function Spatialhash:draw(how, show_empty, print_key)
 	end
 end
 
-return common.class('Spatialhash', Spatialhash)
+return common_local.class('Spatialhash', Spatialhash)