1 files changed, 116 insertions, 0 deletions
diff --git a/lib/systems/dash.js b/lib/systems/dash.js
new file mode 100644
index 0000000..d05e9ea
--- /dev/null
+++ b/lib/systems/dash.js
@@ -0,0 +1,116 @@
+import { System } from '@serpentity/serpentity';
+
+const internals = {
+  kForce: 10
+};
+
+import DasherNode from '../nodes/dasher';
+
+/**
+ * Applies a dash as a force on an entity. Locks it until the button is released
+ * and a cooldown period has passed
+ *
+ * @extends {external:Serpentity.System}
+ * @class DashSystem
+ * @param {object} config a configuration object to extend.
+ */
+export default class DashSystem extends System {
+
+  constructor(config = {}) {
+
+    super();
+
+    /**
+     * The node collection of dashers
+     *
+     * @property {external:Serpentity.NodeCollection} dashers
+     * @instance
+     * @memberof DashSystem
+     */
+    this.dashers = null;
+  }
+
+  /**
+   * Initializes system when added. Requests dasher nodes
+   *
+   * @function added
+   * @memberof DashSystem
+   * @instance
+   * @param {external:Serpentity.Engine} engine the serpentity engine to
+   * which we are getting added
+   */
+  added(engine) {
+
+    this.dashers = engine.getNodes(DasherNode);
+  }
+
+  /**
+   * Clears system resources when removed.
+   *
+   * @function removed
+   * @instance
+   * @memberof DashSystem
+   */
+  removed() {
+
+    this.dashers = null;
+  }
+
+  /**
+   * Runs on every update of the loop. Triggers dash and manages cooldown
+   *
+   * @function update
+   * @instance
+   * @param {Number} currentFrameDuration the duration of the current
+   * frame
+   * @memberof DashSystem
+   */
+  update(currentFrameDuration) {
+
+    for (const dasher of this.dashers) {
+
+      const dash = dasher.dash;
+
+      if (dash.dashing && !dash.locked) {
+        this._dash(dasher);
+      }
+
+      if (!dash.dashing && dash.locked && dash.currentCooldown >= dash.cooldown) {
+        this._unlock(dasher);
+      }
+
+      if (dash.locked) {
+        dash.currentCooldown += currentFrameDuration;
+      }
+
+      dash.dashing = 0;
+    }
+  }
+
+  // Executes the dash action
+
+  _dash(dasher) {
+
+    const dash = dasher.dash;
+    const force = dasher.force;
+
+    const angle = force.lastAngle || 0;
+    dash.locked = true;
+    dash.currentCooldown = 0;
+
+    const xComponent = internals.kForce * Math.cos(angle);
+    const yComponent = internals.kForce * Math.sin(angle);
+
+    force.x += xComponent;
+    force.y += yComponent;
+  }
+
+  // Executes the unlock action
+
+  _unlock(dasher) {
+
+    dasher.dash.locked = false;
+  }
+};
+
+