Wall hitbox and action system

src/main/kotlin/group/ouroboros/potrogue/blocks/GameBlock.kt

@@ -1,19 +1,20 @@
 package group.ouroboros.potrogue.blocks
 
-import group.ouroboros.potrogue.builders.GameTileRepository.EMPTY
 import group.ouroboros.potrogue.builders.GameTileRepository.FLOOR
 import group.ouroboros.potrogue.builders.GameTileRepository.PLAYER
 import group.ouroboros.potrogue.builders.GameTileRepository.WALL
 import group.ouroboros.potrogue.extensions.GameEntity
+import group.ouroboros.potrogue.extensions.occupiesBlock
 import group.ouroboros.potrogue.extensions.tile
 import kotlinx.collections.immutable.persistentMapOf
 import org.hexworks.amethyst.api.entity.EntityType
+import org.hexworks.cobalt.datatypes.Maybe
 import org.hexworks.zircon.api.data.BlockTileType
 import org.hexworks.zircon.api.data.Tile
 import org.hexworks.zircon.api.data.base.BaseBlock
 
 class GameBlock(
-    private var defaultTile: Tile = FLOOR,
+    private var defaultTile: Tile = WALL,
     // We added currentEntities which is just a mutable list of Entity objects which is empty by default
     private val currentEntities: MutableList<GameEntity<EntityType>> = mutableListOf(),
 ) : BaseBlock<Tile>(
@@ -21,6 +22,13 @@ class GameBlock(
     tiles = persistentMapOf(BlockTileType.CONTENT to defaultTile)
 ) {
 
+    companion object {
+
+        fun createWith(entity: GameEntity<EntityType>) = GameBlock(
+            currentEntities = mutableListOf(entity)
+        )
+    }
+
     val isFloor: Boolean
         get() = defaultTile == FLOOR
 
@@ -31,6 +39,13 @@ class GameBlock(
     val isEmptyFloor: Boolean
         get() = currentEntities.isEmpty()
 
+    // occupier will return the first entity which has the BlockOccupier flag or an empty Maybe if there is none
+    val occupier: Maybe<GameEntity<EntityType>>
+        get() = Maybe.ofNullable(currentEntities.firstOrNull { it.occupiesBlock })
+
+    val isOccupied: Boolean
+        get() = occupier.isPresent // Note how we tell whether a block is occupied by checking for the presence of an occupier
+
     // Exposed a getter for entities which takes a snapshot (defensive copy) of the current entities and returns them.
     // We do this because we don’t want to expose the internals of GameBlock which would make currentEntities mutable to the outside world
     val entities: Iterable<GameEntity<EntityType>>
@@ -60,4 +75,7 @@ class GameBlock(
             else -> defaultTile
         }
     }
+
+
+
 }

src/main/kotlin/group/ouroboros/potrogue/builders/EntityFactory.kt

@@ -2,7 +2,9 @@ package group.ouroboros.potrogue.builders
 
 import group.ouroboros.potrogue.entity.attributes.EntityPosition
 import group.ouroboros.potrogue.entity.attributes.EntityTile
+import group.ouroboros.potrogue.entity.attributes.flags.BlockOccupier
 import group.ouroboros.potrogue.entity.attributes.types.Player
+import group.ouroboros.potrogue.entity.attributes.types.Wall
 import group.ouroboros.potrogue.entity.systems.CameraMover
 import group.ouroboros.potrogue.entity.systems.InputReceiver
 import group.ouroboros.potrogue.entity.systems.Movable
@@ -20,10 +22,24 @@ fun <T : EntityType> newGameEntityOfType(
 // We define our factory as an object since we’ll only ever have a single instance of it.
 object EntityFactory {
 
+    // WALLS!
+    fun newWall() = newGameEntityOfType(Wall) {
+        attributes(
+            EntityPosition(),
+            BlockOccupier,
+            EntityTile(GameTileRepository.WALL)
+        )
+        //facets(Diggable)
+    }
+
     // We add a function for creating a newPlayer and call newGameEntityOfType with our previously created Player type.
     fun newPlayer() = newGameEntityOfType(Player) {
         // We specify our Attributes, Behaviors and Facets. We only have Attributes so far though.
-        attributes(EntityPosition(), EntityTile(GameTileRepository.PLAYER))
+        attributes(
+            EntityPosition(),
+            EntityTile(GameTileRepository.PLAYER),
+            //EntityActions(Dig::class)
+        )
         behaviors(InputReceiver)
         facets(Movable, CameraMover)
     }

src/main/kotlin/group/ouroboros/potrogue/builders/GameBlockFactory.kt

@@ -5,5 +5,5 @@ import group.ouroboros.potrogue.blocks.GameBlock
 object GameBlockFactory {
     fun floor() = GameBlock(GameTileRepository.FLOOR)
 
-    fun wall() = GameBlock(GameTileRepository.WALL)
+    fun wall() = GameBlock.createWith(EntityFactory.newWall())
 }

src/main/kotlin/group/ouroboros/potrogue/builders/GameTileRepository.kt

@@ -30,7 +30,7 @@ object GameTileRepository {
         .buildCharacterTile()
 
     //Player Tile
-    val PLAYER = Tile.newBuilder()
+    val PLAYER: CharacterTile = Tile.newBuilder()
         .withCharacter('☺')
         .withBackgroundColor(FLOOR_BACKGROUND)
         .withForegroundColor(ACCENT_COLOR)

src/main/kotlin/group/ouroboros/potrogue/entity/attributes/EntityActions.kt

@@ -0,0 +1,40 @@
+package group.ouroboros.potrogue.entity.attributes
+
+import group.ouroboros.potrogue.entity.messages.EntityAction
+import group.ouroboros.potrogue.extensions.GameEntity
+import group.ouroboros.potrogue.world.GameContext
+import org.hexworks.amethyst.api.base.BaseAttribute
+import org.hexworks.amethyst.api.entity.EntityType
+import kotlin.reflect.KClass
+
+class EntityActions (
+    // This Attribute is capable of holding classes of any kind of EntityAction.
+    // We use vararg here which is similar to how varargs work in Java:
+    // we can create the EntityActions object with any number of constructor parameters like this:
+    // EntityActions(Dig::class, Look::class).
+    // We need to use the class objects (KClass) here instead of the actual EntityAction objects because each time we perform an action
+    // a new EntityAction has to be created.
+    // So you can think about actions here as templates.
+    private vararg val actions: KClass<out EntityAction<out EntityType, out EntityType>>
+) : BaseAttribute() {
+
+    // This function can be used to create the actual EntityAction objects by using the given context, source and target
+    fun createActionsFor(
+        context: GameContext,
+        source: GameEntity<EntityType>,
+        target: GameEntity<EntityType>
+    ): Iterable<EntityAction<out EntityType, out EntityType>> {
+        return actions.map {
+            try {
+                // When we create the actions we just call the first constructor of the class and hope for the best.
+                // There is no built-in way in Kotlin (nor in Java) to make sure that a class has a specific constructor in compile time so that’s why
+                it.constructors.first().call(context, source, target)
+
+            // We catch any exceptions and rethrow them here stating that the operation failed.
+            // We just have to remember that whenever we create an EntityAction it has a constructor for the 3 mandatory fields.
+            } catch (e: Exception) {
+                throw IllegalArgumentException("Can't create EntityAction. Does it have the proper constructor?")
+            }
+        }
+    }
+}

src/main/kotlin/group/ouroboros/potrogue/entity/attributes/flags/BlockOccupier.kt

@@ -0,0 +1,5 @@
+package group.ouroboros.potrogue.entity.attributes.flags
+
+import org.hexworks.amethyst.api.base.BaseAttribute
+
+object BlockOccupier : BaseAttribute()

src/main/kotlin/group/ouroboros/potrogue/entity/attributes/types/EntityTypes.kt

@@ -4,4 +4,8 @@ import org.hexworks.amethyst.api.base.BaseEntityType
 
 object Player : BaseEntityType(
     name = "player"
+)
+
+object Wall : BaseEntityType(
+    name = "wall"
 )

src/main/kotlin/group/ouroboros/potrogue/entity/messages/EntityAction.kt

@@ -0,0 +1,27 @@
+package group.ouroboros.potrogue.entity.messages
+
+import group.ouroboros.potrogue.extensions.GameEntity
+import group.ouroboros.potrogue.extensions.GameMessage
+import org.hexworks.amethyst.api.entity.EntityType
+
+// Our EntityAction is different from a regular GameMessage in a way that it also has a target.
+// So an EntityAction represents source trying to perform an action on target.
+
+// We have two generic type parameters, S and T.
+// S is the EntityType of the source, T is the EntityType of the target.
+// This will be useful later on as we’ll see.
+interface EntityAction <S : EntityType, T : EntityType> : GameMessage {
+
+    // We save the reference to target in all EntityActions
+    val target: GameEntity<T>
+
+    // The component1, component2 … componentN methods implement destructuring in Kotlin.
+    // Since destructuring is positional as we’ve seen previously by implementing the
+    // component* functions we can control how an EntityAction can be destructured.
+    // In our case with these 3 operator functions we can destructure any EntityActions like this:
+    //
+    //val (context, source, target) = entityAction
+    operator fun component1() = context
+    operator fun component2() = source
+    operator fun component3() = target
+}

src/main/kotlin/group/ouroboros/potrogue/entity/systems/Diggable.kt

@@ -0,0 +1,9 @@
+package group.ouroboros.potrogue.entity.systems
+
+object Diggable /*: BaseFacet<GameContext, Dig>(Dig::class)*/ {
+    /*override suspend fun receive(message: Dig): Response {
+        val (context, _, target) = message
+        context.world.removeEntity(target)
+        return Consumed
+    }*/
+}

src/main/kotlin/group/ouroboros/potrogue/entity/systems/InputReceiver.kt

@@ -24,11 +24,13 @@ object InputReceiver  : BaseBehavior<GameContext>() {
             // We use when which is similar to switch in Java to check which key was pressed.
             // Zircon has a KeyCode for all keys which can be pressed. when in Kotlin is also an expression,
             // and not a statement so it returns a value. We can change it into our newPosition variable.
+
             val newPosition = when (uiEvent.code) {
                 KeyCode.KEY_W -> currentPos.withRelativeY(-1)
                 KeyCode.KEY_A -> currentPos.withRelativeX(-1)
                 KeyCode.KEY_S -> currentPos.withRelativeY(1)
                 KeyCode.KEY_D -> currentPos.withRelativeX(1)
+
                 KeyCode.ESCAPE -> exitProcess(0)
                 else -> {
                     // If some key is pressed other than WASD, then we just return the current position, so no movement will happen

src/main/kotlin/group/ouroboros/potrogue/entity/systems/Movable.kt

@@ -4,6 +4,7 @@ import group.ouroboros.potrogue.entity.attributes.types.Player
 import group.ouroboros.potrogue.entity.messages.MoveCamera
 import group.ouroboros.potrogue.entity.messages.MoveTo
 import group.ouroboros.potrogue.extensions.position
+import group.ouroboros.potrogue.extensions.tryActionsOn
 import group.ouroboros.potrogue.world.GameContext
 import org.hexworks.amethyst.api.Consumed
 import org.hexworks.amethyst.api.MessageResponse
@@ -39,6 +40,7 @@ object Movable  : BaseFacet<GameContext, MoveTo>(MoveTo::class) {
         val previousPosition = entity.position
         // Here we say that we’ll return Pass as a default
         var result: Response = Pass
+        /*
         // Then we check whether moving the entity was successful or not (remember the success return value?)
         if (world.moveEntity(entity, position)) {
             // If the move was successful and the entity we moved is the player
@@ -56,6 +58,30 @@ object Movable  : BaseFacet<GameContext, MoveTo>(MoveTo::class) {
         }
         // Finally we return the result
         return result
-    }
+    }*/
 
+        // We will only do anything if there is a block at the given position.
+        // It is possible that there are no blocks at the edge of the map for example (if we want to move off the map)
+        world.fetchBlockAtOrNull(position)?.let { block ->
+            if (block.isOccupied) {
+                // If the block is occupied we try our actions on the block
+                result = entity.tryActionsOn(context, block.occupier.get())
+            } else {
+                //Otherwise we do what we were doing before
+                if (world.moveEntity(entity, position)) {
+                    result = Consumed
+                    if (entity.type == Player) {
+                        result = MessageResponse(
+                            MoveCamera(
+                                context = context,
+                                source = entity,
+                                previousPosition = previousPosition
+                            )
+                        )
+                    }
+                }
+            }
+        }
+        return result
+    }
 }

src/main/kotlin/group/ouroboros/potrogue/extensions/EntityExtensions.kt

@@ -0,0 +1,33 @@
+package group.ouroboros.potrogue.extensions
+
+import group.ouroboros.potrogue.entity.attributes.EntityActions
+import group.ouroboros.potrogue.entity.attributes.flags.BlockOccupier
+import group.ouroboros.potrogue.world.GameContext
+import org.hexworks.amethyst.api.Consumed
+import org.hexworks.amethyst.api.Pass
+import org.hexworks.amethyst.api.Response
+
+val AnyGameEntity.occupiesBlock: Boolean
+    get() = findAttribute(BlockOccupier::class).isPresent
+
+// We define this function as an extension function on AnyGameEntity.
+// This means that from now on we can call tryActionsOn on any of our entities!
+// It is also a suspend fun because the receiveMessage function we call later is also a suspending function.
+// Suspending is part of the Kotlin Coroutines API and it is a deep topic.
+// We’re not going to cover it here as we don’t take advantage of it
+suspend fun AnyGameEntity.tryActionsOn(context: GameContext, target: AnyGameEntity): Response {
+    var result: Response = Pass
+    // We can only try the actions of an entity which has at least one, so we try to find the attribute.
+    findAttributeOrNull(EntityActions::class)?.let {
+        // if we find the attribute we just create the actions for our context/source/target combination
+        it.createActionsFor(context, this, target).forEach { action ->
+            // And we then send the message to the target for immediate processing and if the message is Consumed it means that
+            if (target.receiveMessage(action) is Consumed) {
+                result = Consumed
+                // We can break out of the forEach block.
+                return@forEach
+            }
+        }
+    }
+    return result
+}

src/main/kotlin/group/ouroboros/potrogue/world/World.kt

@@ -60,6 +60,14 @@ class World (
         }
     }
 
+    fun removeEntity(entity: Entity<EntityType, GameContext>) {
+        fetchBlockAt(entity.position).map {
+            it.removeEntity(entity)
+        }
+        engine.removeEntity(entity)
+        entity.position = Position3D.unknown()
+    }
+
     // Added a function for adding an Entity at an empty position.
     // This function needs a little explanation though.
     // What happens here is that we try to find and empty position in our World within the given bounds (offset and size).