Add control via keyboard (#6)

* Correct angle documentation

* Correct body component doc

* Add a config module with px 2 meters

* Create component to map input

* Add components for mappable actions

* Add component for elastic manipulation

* Add node to modify physics

* Add controllable node

* Add dasher node

* Add control mapper system

* Add component to limit velocity

* Add node for limiting velocity

* Add systems to move and dash

* Use meters in physics systems

* Correct documentation in render system

* Add elastic manipulation system

* Update factories to use new components

* Update main app to use new systems

* Ignore dist dir

* Also ignore cache

* Ignore personal configuration files

* Add system to reduce velocity

* Add changelog

1 files changed, 70 insertions, 0 deletions

diff --git a/lib/systems/reduce_velocity.js b/lib/systems/reduce_velocity.js
new file mode 100644
index 0000000..6521014
--- /dev/null
+++ b/lib/systems/reduce_velocity.js
@@ -0,0 +1,70 @@
+import { System } from '@serpentity/serpentity';
+
+import LimitedVelocityNode from '../nodes/limited_velocity';
+
+/**
+ * Reduces velocity if it exceeds threshold
+ *
+ * @extends {external:Serpentity.System}
+ * @class ReduceVelocitySystem
+ * @param {object} config a configuration object to extend.
+ */
+export default class ReduceVelocitySystem extends System {
+
+  constructor(config = {}) {
+
+    super();
+
+    /**
+     * The node collection of entities that have external force
+     *
+     * @property {external:Serpentity.NodeCollection} limitedVelocityEntities
+     * @instance
+     * @memberof ReduceVelocitySystem
+     */
+    this.limitedVelocityEntities = null;
+  }
+
+  /**
+   * Initializes system when added. Requests limited velocity nodes
+   *
+   * @function added
+   * @memberof ReduceVelocitySystem
+   * @instance
+   * @param {external:Serpentity.Engine} engine the serpentity engine to
+   * which we are getting added
+   */
+  added(engine) {
+
+    this.limitedVelocityEntities = engine.getNodes(LimitedVelocityNode);
+  }
+
+  /**
+   * Clears system resources when removed.
+   *
+   * @function removed
+   * @instance
+   * @memberof ReduceVelocitySystem
+   */
+  removed() {
+
+    this.limitedVelocityEntities = null;
+  }
+
+  /**
+   * Runs on every update of the loop. Checks current velocity and adjusts if necessary
+   *
+   * @function update
+   * @instance
+   * @param {Number} currentFrameDuration the duration of the current
+   * frame
+   * @memberof ReduceVelocitySystem
+   */
+  update(currentFrameDuration) {
+
+    for (const limitedVelocityEntity of this.limitedVelocityEntities) {
+      console.log(limitedVelocityEntity.body.body.velocity, limitedVelocityEntity.maxVelocity.maxVelocity);
+    }
+  }
+};
+