sjamble/feature-query-msg

cardinal/component/movement.go

@@ -18,9 +18,9 @@ type Location struct {
 }
 
 type Movement struct {
-	Direction Direction
-	Velocity  float32
-	Location  Location
+	CurrentDirection Direction
+	Velocity         float32
+	CurrentLocation  Location
 }
 
 func (Movement) Name() string {

cardinal/msg/movement_player.go

@@ -0,0 +1 @@
+package msg

cardinal/system/movement_system.go

@@ -0,0 +1,49 @@
+package system
+
+import (
+	"fmt"
+	"pkg.world.dev/world-engine/cardinal"
+	"pkg.world.dev/world-engine/cardinal/search/filter"
+	"pkg.world.dev/world-engine/cardinal/types"
+	comp "shantanu-starter-game/component"
+	"shantanu-starter-game/msg"
+)
+
+// MovementSystem updates the player's location based on its velocity and direction.
+func MovementSystem(world cardinal.WorldContext) error {
+	return cardinal.NewSearch().Entity(
+		filter.Exact(filter.Component[comp.Player](), filter.Component[comp.Movement]())).
+		Each(world, func(id types.EntityID) bool {
+			movement, err := cardinal.GetComponent[comp.Movement](world, id)
+			if err != nil {
+				return true
+			}
+
+			// TODO: How to get delta time?
+			movement.CurrentLocation.X += movement.Velocity * float32(movement.CurrentDirection.X)
+			movement.CurrentLocation.Y += movement.Velocity * float32(movement.CurrentDirection.Y)
+
+			if err := cardinal.SetComponent[comp.Movement](world, id, movement); err != nil {
+				return true
+			}
+			return true
+		})
+}
+
+func MovementValidationSystem(world cardinal.WorldContext) error {
+	return cardinal.EachMessage[msg.AttackPlayerMsg, msg.AttackPlayerMsgReply](
+		world,
+		func(attack cardinal.TxData[msg.AttackPlayerMsg]) (msg.AttackPlayerMsgReply, error) {
+			playerID, playerHealth, err := queryTargetPlayer(world, attack.Msg.TargetNickname)
+			if err != nil {
+				return msg.AttackPlayerMsgReply{}, fmt.Errorf("failed to inflict damage: %w", err)
+			}
+
+			playerHealth.HP -= AttackDamage
+			if err := cardinal.SetComponent[comp.Health](world, playerID, playerHealth); err != nil {
+				return msg.AttackPlayerMsgReply{}, fmt.Errorf("failed to inflict damage: %w", err)
+			}
+
+			return msg.AttackPlayerMsgReply{Damage: AttackDamage}, nil
+		})
+}