feat(sim): moving platforms and particle effects

game/sim/movingPlatform.py

@@ -0,0 +1,53 @@
+from .geometry import Aabb
+
+
+class MovingPlatform:
+    def __init__(self, x, y, w, h, toX, toY, speed, oneWay=False):
+        self.x = float(x)
+        self.y = float(y)
+        self.w = float(w)
+        self.h = float(h)
+        self.fromX = float(x)
+        self.fromY = float(y)
+        self.toX = float(toX)
+        self.toY = float(toY)
+        self.speed = float(speed)
+        self.oneWay = bool(oneWay)
+        self.progress = 0.0
+        self.direction = 1
+        self.deltaX = 0.0
+        self.deltaY = 0.0
+
+    @property
+    def aabb(self):
+        return Aabb(self.x, self.y, self.w, self.h)
+
+    def spanLength(self):
+        dx = self.toX - self.fromX
+        dy = self.toY - self.fromY
+        return (dx * dx + dy * dy) ** 0.5
+
+    def update(self):
+        span = self.spanLength()
+        prevX = self.x
+        prevY = self.y
+        if span == 0.0:
+            self.deltaX = 0.0
+            self.deltaY = 0.0
+            return
+        step = self.speed / span
+        self.progress += step * self.direction
+        if self.progress >= 1.0:
+            self.progress = 1.0
+            self.direction = -1
+        elif self.progress <= 0.0:
+            self.progress = 0.0
+            self.direction = 1
+        self.x = self.fromX + (self.toX - self.fromX) * self.progress
+        self.y = self.fromY + (self.toY - self.fromY) * self.progress
+        self.deltaX = self.x - prevX
+        self.deltaY = self.y - prevY
+
+    @classmethod
+    def fromSpawn(cls, spawn):
+        return cls(spawn.x, spawn.y, spawn.w, spawn.h, spawn.toX, spawn.toY, spawn.speed, spawn.oneWay)