initial take on wire auto-rotation

src/js/game/buildings/wire.js

@@ -1,10 +1,11 @@
+import { Loader } from "../../core/loader";
+import { rotateDirectionalObject } from "../../core/utils";
 import { Vector } from "../../core/vector";
 import { SOUNDS } from "../../platform/sound";
 import { enumWireType, WireComponent } from "../components/wire";
 import { Entity } from "../entity";
 import { MetaBuilding } from "../meta_building";
 import { enumLayer, GameRoot } from "../root";
-import { beltOverlayMatrices } from "./belt_base";
 
 export const arrayWireRotationVariantToType = [enumWireType.regular, enumWireType.turn, enumWireType.split];
 
@@ -108,4 +109,157 @@ export class MetaWireBuilding extends MetaBuilding {
     getSpecialOverlayRenderMatrix(rotation, rotationVariant, variant, entity) {
         return wireOverlayMatrices[entity.components.Wire.type][rotation];
     }
+
+    getPreviewSprite(rotationVariant) {
+        switch (arrayWireRotationVariantToType[rotationVariant]) {
+            case enumWireType.regular: {
+                return Loader.getSprite("sprites/buildings/wire.png");
+            }
+            case enumWireType.turn: {
+                return Loader.getSprite("sprites/buildings/wire-turn.png");
+            }
+            case enumWireType.split: {
+                return Loader.getSprite("sprites/buildings/wire-split.png");
+            }
+            default: {
+                assertAlways(false, "Invalid belt rotation variant");
+            }
+        }
+    }
+
+    getBlueprintSprite(rotationVariant) {
+        switch (arrayWireRotationVariantToType[rotationVariant]) {
+            case enumWireType.regular: {
+                return Loader.getSprite("sprites/blueprints/wire.png");
+            }
+            case enumWireType.turn: {
+                return Loader.getSprite("sprites/blueprints/wire-turn.png");
+            }
+            case enumWireType.split: {
+                return Loader.getSprite("sprites/blueprints/wire-split.png");
+            }
+            default: {
+                assertAlways(false, "Invalid belt rotation variant");
+            }
+        }
+    }
+
+    /**
+     * Should compute the optimal rotation variant on the given tile
+     * @param {object} param0
+     * @param {GameRoot} param0.root
+     * @param {Vector} param0.tile
+     * @param {number} param0.rotation
+     * @param {string} param0.variant
+     * @param {string} param0.layer
+     * @return {{ rotation: number, rotationVariant: number, connectedEntities?: Array<Entity> }}
+     */
+    computeOptimalDirectionAndRotationVariantAtTile({ root, tile, rotation, variant, layer }) {
+        const connections = root.logic.getLocalWireConnectionsAtTile(tile);
+
+        const d = rotateDirectionalObject(connections, rotation);
+
+        // "Sticky" bottom
+        connections.bottom = true;
+
+        let flag = 0;
+        flag |= d.top ? 0x1000 : 0;
+        flag |= d.right ? 0x100 : 0;
+        flag |= d.bottom ? 0x10 : 0;
+        flag |= d.left ? 0x1 : 0;
+
+        let targetType = enumWireType.regular;
+
+        switch (flag) {
+            case 0x0000:
+                // Nothing
+                break;
+
+            case 0x0001:
+                // Left
+                targetType = enumWireType.turn;
+                rotation += 90;
+                break;
+
+            case 0x0010:
+                // Bottom
+                break;
+
+            case 0x0011:
+                // Bottom | Left
+                targetType = enumWireType.turn;
+                rotation += 90;
+                break;
+
+            case 0x0100:
+                // Right
+                targetType = enumWireType.turn;
+                break;
+
+            case 0x0101:
+                // Right | Left
+                // @todo: Might want to do rotation += 90 here
+                rotation += 90;
+                break;
+
+            case 0x0110:
+                // Right | Bottom
+                targetType = enumWireType.turn;
+                break;
+
+            case 0x0111:
+                // Right | Bottom | Left
+                targetType = enumWireType.split;
+                break;
+
+            case 0x1000:
+                // Top
+                break;
+
+            case 0x1001:
+                // Top | Left
+                targetType = enumWireType.turn;
+                rotation += 180;
+                break;
+
+            case 0x1010:
+                // Top | Bottom
+                break;
+
+            case 0x1011:
+                // Top | Bottom | Left
+                targetType = enumWireType.split;
+                rotation += 90;
+                break;
+
+            case 0x1100:
+                // Top | Right
+                targetType = enumWireType.turn;
+                rotation -= 90;
+                break;
+
+            case 0x1101:
+                // Top | Right | Left
+                targetType = enumWireType.split;
+                rotation += 180;
+                break;
+
+            case 0x1110:
+                // Top | Right | Bottom
+                targetType = enumWireType.split;
+                rotation -= 90;
+                break;
+
+            case 0x1111:
+                // Top | Right | Bottom | Left
+                // @todo: Crossing
+                break;
+        }
+
+        return {
+            // Clamp rotation
+            rotation: (rotation + 360 * 10) % 360,
+            rotationVariant: arrayWireRotationVariantToType.indexOf(targetType),
+        };
+    }
 }