add tower builing game

public/tower_game-master/src/hook.js

@@ -0,0 +1,54 @@
+import { getSwingBlockVelocity } from './utils'
+import * as constant from './constant'
+
+export const hookAction = (instance, engine, time) => {
+  const ropeHeight = engine.getVariable(constant.ropeHeight)
+  if (!instance.ready) {
+    instance.x = engine.width / 2
+    instance.y = ropeHeight * -1.5
+    instance.ready = true
+  }
+  engine.getTimeMovement(
+    constant.hookUpMovement,
+    [[instance.y, instance.y - ropeHeight]],
+    (value) => {
+      instance.y = value
+    },
+    {
+      after: () => {
+        instance.y = ropeHeight * -1.5
+      }
+    }
+  )
+  engine.getTimeMovement(
+    constant.hookDownMovement,
+    [[instance.y, instance.y + ropeHeight]],
+    (value) => {
+      instance.y = value
+    },
+    {
+      name: 'hook'
+    }
+  )
+  const initialAngle = engine.getVariable(constant.initialAngle)
+  instance.angle = initialAngle *
+    getSwingBlockVelocity(engine, time)
+  instance.weightX = instance.x +
+    (Math.sin(instance.angle) * ropeHeight)
+  instance.weightY = instance.y +
+    (Math.cos(instance.angle) * ropeHeight)
+}
+
+export const hookPainter = (instance, engine) => {
+  const { ctx } = engine
+  const ropeHeight = engine.getVariable(constant.ropeHeight)
+  const ropeWidth = ropeHeight * 0.1
+  const hook = engine.getImg('hook')
+  ctx.save()
+  ctx.translate(instance.x, instance.y)
+  ctx.rotate((Math.PI * 2) - instance.angle)
+  ctx.translate(-instance.x, -instance.y)
+  engine.ctx.drawImage(hook, instance.x - (ropeWidth / 2), instance.y, ropeWidth, ropeHeight + 5)
+  ctx.restore()
+}
+