1 files changed, 55 insertions, 0 deletions
diff --git a/engine/systems/Render.ts b/engine/systems/Render.ts
new file mode 100644
index 0000000..b5479e1
--- /dev/null
+++ b/engine/systems/Render.ts
@@ -0,0 +1,55 @@
+import { System, SystemNames } from ".";
+import { BoundingBox, ComponentNames, Sprite } from "../components";
+import type { Entity } from "../entities";
+import { Game } from "../Game";
+import type { DrawArgs } from "../interfaces";
+import { clamp } from "../utils";
+
+export class Render extends System {
+  private ctx: CanvasRenderingContext2D;
+
+  constructor(ctx: CanvasRenderingContext2D) {
+    super(SystemNames.Render);
+    this.ctx = ctx;
+  }
+
+  public update(dt: number, game: Game) {
+    this.ctx.clearRect(0, 0, this.ctx.canvas.width, this.ctx.canvas.height);
+
+    game.componentEntities.get(ComponentNames.Sprite)?.forEach((entityId) => {
+      const entity = game.entities.get(entityId);
+      const sprite = entity.getComponent<Sprite>(ComponentNames.Sprite);
+      sprite.update(dt);
+
+      let drawArgs: DrawArgs;
+      if (entity.hasComponent(ComponentNames.BoundingBox)) {
+        const boundingBox = entity.getComponent<BoundingBox>(
+          ComponentNames.BoundingBox
+        );
+
+        // don't render if we're outside the screen
+        if (
+          clamp(
+            boundingBox.center.y,
+            -boundingBox.dimension.height / 2,
+            this.ctx.canvas.height + boundingBox.dimension.height / 2
+          ) != boundingBox.center.y ||
+          clamp(
+            boundingBox.center.x,
+            -boundingBox.dimension.width / 2,
+            this.ctx.canvas.width + boundingBox.dimension.width / 2
+          ) != boundingBox.center.x
+        ) {
+          return;
+        }
+
+        drawArgs = {
+          center: boundingBox.center,
+          dimension: boundingBox.dimension,
+          rotation: boundingBox.rotation,
+        };
+      }
+      sprite.draw(this.ctx, drawArgs);
+    });
+  }
+}