Add example how to add custom drawings

mod_examples/custom_drawing.js

@@ -0,0 +1,62 @@
+/**
+ * Shows how to draw overlays by visualizing which item processors are working
+ */
+
+const METADATA = {
+    website: "https://tobspr.io",
+    author: "tobspr",
+    name: "Mod Example: custom drawing",
+    version: "1",
+    id: "base",
+    description: "Displays an indicator on every item processing building when its working",
+};
+
+class ItemProcessorStatusGameSystem extends shapez.GameSystem {
+    drawChunk(parameters, chunk) {
+        const contents = chunk.containedEntitiesByLayer.regular;
+        for (let i = 0; i < contents.length; ++i) {
+            const entity = contents[i];
+            const processorComp = entity.components.ItemProcessor;
+            if (!processorComp) {
+                continue;
+            }
+
+            const staticComp = entity.components.StaticMapEntity;
+
+            const context = parameters.context;
+            const center = staticComp.getTileSpaceBounds().getCenter().toWorldSpace();
+
+            // Culling for better performance
+            if (parameters.visibleRect.containsCircle(center.x, center.y, 40)) {
+                // Circle
+                context.fillStyle = processorComp.ongoingCharges.length === 0 ? "#aaa" : "#53cf47";
+                context.strokeStyle = "#000";
+                context.lineWidth = 1;
+
+                const timeFactor = 15.23 * this.root.time.now();
+                context.beginCircle(center.x + 5, center.y + 5, 4);
+                context.fill();
+                context.stroke();
+            }
+        }
+    }
+}
+
+class Mod extends shapez.Mod {
+    init() {
+        // Register our game system
+        this.modInterface.registerGameSystem({
+            id: "item_processor_status",
+            systemClass: ItemProcessorStatusGameSystem,
+
+            // Specify at which point the update method will be called,
+            // in this case directly before the belt system. You can use
+            // before: "end" to make it the last system
+            before: "belt",
+
+            // Specify where our drawChunk method should be called, check out
+            // map_chunk_view
+            drawHooks: ["staticAfter"],
+        });
+    }
+}