feat: 添加敌机射击策略

app/src/main/java/net/imshit/aircraftwar/element/shoot/enemy/EnemyDirectShootStrategy.kt

@@ -0,0 +1,15 @@
+package net.imshit.aircraftwar.element.shoot.enemy
+
+import net.imshit.aircraftwar.element.bullet.EnemyBullet
+import net.imshit.aircraftwar.logic.Games
+
+class EnemyDirectShootStrategy : EnemyShootStrategy {
+    override fun shoot(
+        game: Games, x: Float, y: Float, speedY: Float, power: Int
+    ): List<EnemyBullet> {
+        val direction = 1
+        val bulletY = y + direction * 2
+        val bulletSpeedY = speedY + direction * 0.1f
+        return listOf(EnemyBullet(game, x, bulletY, 0f, bulletSpeedY, power))
+    }
+}

app/src/main/java/net/imshit/aircraftwar/element/shoot/enemy/EnemyNoShootStrategy.kt

@@ -0,0 +1,12 @@
+package net.imshit.aircraftwar.element.shoot.enemy
+
+import net.imshit.aircraftwar.element.bullet.EnemyBullet
+import net.imshit.aircraftwar.logic.Games
+
+class EnemyNoShootStrategy : EnemyShootStrategy {
+    override fun shoot(
+        game: Games, x: Float, y: Float, speedY: Float, power: Int
+    ): List<EnemyBullet> {
+        return listOf()
+    }
+}

app/src/main/java/net/imshit/aircraftwar/element/shoot/enemy/EnemyScatterShootStrategy.kt

@@ -0,0 +1,30 @@
+package net.imshit.aircraftwar.element.shoot.enemy
+
+import net.imshit.aircraftwar.element.bullet.EnemyBullet
+import net.imshit.aircraftwar.logic.Games
+
+class EnemyScatterShootStrategy : EnemyShootStrategy {
+    override fun shoot(
+        game: Games, x: Float, y: Float, speedY: Float, power: Int
+    ): List<EnemyBullet> {
+        val direction = 1
+        val shootNum = 3
+        val bulletY = y + direction * 2
+        val bulletCenterSpeedX = 0f
+        val bulletCenterSpeedY = speedY + direction * 0.1f
+        return mutableListOf<EnemyBullet>().apply {
+            for (i in 0 until shootNum) {
+                add(
+                    EnemyBullet(
+                        game,
+                        x + (i * 2 - shootNum + 1) * 10,
+                        bulletY,
+                        bulletCenterSpeedX + (i * 2 - shootNum + 1) * 0.01f,
+                        bulletCenterSpeedY,
+                        power
+                    )
+                )
+            }
+        }.toList()
+    }
+}

app/src/main/java/net/imshit/aircraftwar/element/shoot/enemy/EnemyShootStrategy.kt

@@ -0,0 +1,15 @@
+package net.imshit.aircraftwar.element.shoot.enemy
+
+import net.imshit.aircraftwar.element.bullet.EnemyBullet
+import net.imshit.aircraftwar.element.shoot.ShootStrategy
+import net.imshit.aircraftwar.logic.Games
+
+interface EnemyShootStrategy : ShootStrategy {
+    override fun shoot(
+        game: Games,
+        x: Float,
+        y: Float,
+        speedY: Float,
+        power: Int
+    ): List<EnemyBullet>
+}

app/src/main/java/net/imshit/aircraftwar/element/shoot/enemy/EnemyShootStrategyFactory.kt

@@ -0,0 +1,14 @@
+package net.imshit.aircraftwar.element.shoot.enemy
+
+import net.imshit.aircraftwar.element.shoot.AbstractShootStrategyFactory
+
+class EnemyShootStrategyFactory : AbstractShootStrategyFactory() {
+    override fun getStrategy(shootNum: Int): EnemyShootStrategy {
+        return when (shootNum) {
+            0 -> EnemyNoShootStrategy()
+            1 -> EnemyDirectShootStrategy()
+            3 -> EnemyScatterShootStrategy()
+            else -> EnemyNoShootStrategy()
+        }
+    }
+}