feat(sim): projectiles, items and inventory

game/sim/inventory.py

@@ -0,0 +1,31 @@
+class Inventory:
+    def __init__(self):
+        self.counts = {}
+        self.keys = 0
+
+    def add(self, kind, amount=1):
+        self.counts[kind] = self.counts.get(kind, 0) + amount
+        if kind == "key":
+            self.keys += amount
+        return self.counts[kind]
+
+    def count(self, kind):
+        return self.counts.get(kind, 0)
+
+    def has(self, kind, amount=1):
+        return self.count(kind) >= amount
+
+    def consume(self, kind, amount=1):
+        if self.count(kind) < amount:
+            return False
+        self.counts[kind] -= amount
+        if kind == "key":
+            self.keys -= amount
+        return True
+
+    def asDict(self):
+        return {"counts": dict(self.counts), "keys": self.keys}
+
+    def loadDict(self, record):
+        self.counts = dict(record.get("counts", {}))
+        self.keys = record.get("keys", 0)

game/sim/items.py

@@ -0,0 +1,51 @@
+from ..constants import tileSize
+from .geometry import Aabb
+
+itemDefs = {
+    "coin": {"score": 100, "size": 12, "bob": True},
+    "gem": {"score": 500, "size": 12, "bob": True},
+    "key": {"score": 50, "size": 12, "bob": False},
+    "heart": {"score": 0, "size": 14, "bob": True, "heal": 2},
+}
+
+
+class Collectible:
+    def __init__(self, kind, x, y):
+        self.kind = kind
+        self.x = float(x)
+        self.y = float(y)
+        self.collected = False
+        definition = itemDefs.get(kind, itemDefs["coin"])
+        self.size = definition["size"]
+        self.score = definition["score"]
+        self.heal = definition.get("heal", 0)
+        self.bob = definition.get("bob", False)
+        self.bobPhase = 0.0
+
+    @property
+    def aabb(self):
+        pad = (tileSize - self.size) * 0.5
+        return Aabb(self.x + pad, self.y + pad, self.size, self.size)
+
+    def update(self):
+        if self.bob:
+            self.bobPhase = (self.bobPhase + 0.15) % 6.2831853
+
+    def collect(self, player, world):
+        if self.collected:
+            return
+        self.collected = True
+        player.score += self.score
+        world.score += self.score
+        if self.kind == "coin":
+            player.coins += 1
+            world.coins += 1
+        elif self.heal:
+            player.heal(self.heal)
+        player.inventory.add(self.kind)
+        world.playSound("pickup", self.x)
+        world.spawnBurst("pickup", self.x + tileSize * 0.5, self.y + tileSize * 0.5, 5)
+
+    @classmethod
+    def fromSpawn(cls, spawn):
+        return cls(spawn.kind, spawn.x, spawn.y)

game/sim/projectile.py

@@ -0,0 +1,32 @@
+from .. import constants
+from .entity import Actor
+from . import physics
+
+
+class Projectile(Actor):
+    def __init__(self, x, y, vx, vy, owner="enemy", damage=1):
+        super().__init__(x, y, 6, 6)
+        self.vx = vx
+        self.vy = vy
+        self.owner = owner
+        self.damage = damage
+        self.life = constants.projectileLife
+        self.gravityScale = 0.0
+
+    def update(self, world):
+        self.life -= 1
+        if self.life <= 0:
+            self.alive = False
+            return
+        if self.gravityScale:
+            self.vy += constants.gravity * self.gravityScale
+        self.x += self.vx
+        self.y += self.vy
+        box = self.aabb
+        for tileBox in physics.solidTilesOverlapping(world.level, box):
+            if box.intersects(tileBox):
+                self.alive = False
+                world.spawnBurst("spark", self.centerX, self.centerY, 4)
+                return
+        if self.centerX < -32 or self.centerX > world.level.pixelWidth() + 32:
+            self.alive = False