Physics Engine (#4)

* Add matter-js as a dependency

* Add body component

* Fix renderable node doc

* Add the physics node type

* Correct typo in physics enabled node types

* Update docs on render system

* Add physics system

* Update changelog

* Add physics engine to main app

* Tweak the gravity of the world

* Add body to sumo factory

* Add angle component

* Add angle to entity

* Add angle to the nodes

* Pass angle between systems

* Set default angle to 0

* Split systems and nodes

* Fix indentaion in physics world control

* Add third sumo entity

* Adjust values for constriants and physics

* Correct docs in new nodes

* Update built-in docs

5 files changed, 118 insertions, 6 deletions

diff --git a/lib/nodes/physical.js b/lib/nodes/physical.js
new file mode 100644
index 0000000..77139ec
--- /dev/null
+++ b/lib/nodes/physical.js
@@ -0,0 +1,26 @@
+import { Node } from '@serpentity/serpentity';
+
+import BodyComponent from '../components/body';
+
+/**
+ * Node identifying an entity that can interact with physics
+ *
+ * @extends {external:Serpentity.Node}
+ * @class PhysicalNode
+ */
+export default class PhysicalNode extends Node {
+
+};
+
+/**
+ * Holds the types that are used to identify an entity with a physical
+ * body
+ *
+ * @property {object} types
+ * @name types
+ * @memberof PhysicalNode
+ */
+PhysicalNode.types = {
+  body: BodyComponent
+};
+
diff --git a/lib/nodes/physical_with_attributes.js b/lib/nodes/physical_with_attributes.js
new file mode 100644
index 0000000..96ba79d
--- /dev/null
+++ b/lib/nodes/physical_with_attributes.js
@@ -0,0 +1,31 @@
+import { Node } from '@serpentity/serpentity';
+
+import AngleComponent from '../components/angle';
+import BodyComponent from '../components/body';
+import PositionComponent from '@serpentity/components.position';
+
+/**
+ * Node identifying an entity that can interact with physics and has
+ * components updated from its values
+ *
+ * @extends {external:Serpentity.Node}
+ * @class PhysicalWithAttributesNode
+ */
+export default class PhysicalWithAttributesNode extends Node {
+
+};
+
+/**
+ * Holds the types that are used to identify an entity with a physics
+ * object and external attributes
+ *
+ * @property {object} types
+ * @name types
+ * @memberof PhysicalWithAttributesNode
+ */
+PhysicalWithAttributesNode.types = {
+  angle: AngleComponent,
+  position: PositionComponent,
+  body: BodyComponent
+};
+
diff --git a/lib/nodes/renderable.js b/lib/nodes/renderable.js
index 0a3a111..12227a3 100644
--- a/lib/nodes/renderable.js
+++ b/lib/nodes/renderable.js
@@ -1,11 +1,9 @@
 import { Node } from '@serpentity/serpentity';
 
 import PixiContainerComponent from '../components/pixi_container';
-import PositionComponent from '@serpentity/components.position';
 
 /**
- * Node identifying a renderable entity, should have position and a
- * symbol to render
+ * Node identifying a renderable entity, should have a pixi renderable
  *
  * @extends {external:Serpentity.Node}
  * @class RenderableNode
@@ -15,13 +13,12 @@ export default class RenderableNode extends Node {
 };
 
 /**
- * Holds the types that are used to identify a wave entity
+ * Holds the types that are used to identify a renderable entity
  *
  * @property {object} types
  * @name types
- * @memberof WaveNode
+ * @memberof RenderableNode
  */
 RenderableNode.types = {
-  position: PositionComponent,
   container: PixiContainerComponent
 };
diff --git a/lib/nodes/renderable_couple.js b/lib/nodes/renderable_couple.js
new file mode 100644
index 0000000..39ab886
--- /dev/null
+++ b/lib/nodes/renderable_couple.js
@@ -0,0 +1,28 @@
+import { Node } from '@serpentity/serpentity';
+
+import CoupledEntitiesComponent from '../components/coupled_entities';
+import PixiContainerComponent from '../components/pixi_container';
+
+/**
+ * Node identifying an entity that has coupled entities and can be
+ * rendered
+ *
+ * @extends {external:Serpentity.Node}
+ * @class RenderableCoupleNode
+ */
+export default class RenderableCoupleNode extends Node {
+
+};
+
+/**
+ * Holds the types that are used to identify a renderable couple
+ *
+ * @property {object} types
+ * @name types
+ * @memberof RenderableCoupleNode
+ */
+RenderableCoupleNode.types = {
+  coupledEntities: CoupledEntitiesComponent,
+  container: PixiContainerComponent
+};
+
diff --git a/lib/nodes/renderable_with_attributes.js b/lib/nodes/renderable_with_attributes.js
new file mode 100644
index 0000000..817036c
--- /dev/null
+++ b/lib/nodes/renderable_with_attributes.js
@@ -0,0 +1,30 @@
+import { Node } from '@serpentity/serpentity';
+
+import AngleComponent from '../components/angle';
+import PixiContainerComponent from '../components/pixi_container';
+import PositionComponent from '@serpentity/components.position';
+
+/**
+ * Node identifying a renderable entity, should have position and a
+ * symbol to render
+ *
+ * @extends {external:Serpentity.Node}
+ * @class RenderableWithAttributesNode
+ */
+export default class RenderableWithAttributesNode extends Node {
+
+};
+
+/**
+ * Holds the types that are used to identify a renderable with external
+ * attributes
+ *
+ * @property {object} types
+ * @name types
+ * @memberof RenderableWithAttributesNode
+ */
+RenderableWithAttributesNode.types = {
+  angle: AngleComponent,
+  position: PositionComponent,
+  container: PixiContainerComponent
+};