test: moving platform interaction

tests/test_moving_platform.py

@@ -0,0 +1,70 @@
+import pytest
+
+from tests.support import makeLevel
+from game.sim.level import PlatformSpawn
+from game.sim.world import World
+from game.sim.movingPlatform import MovingPlatform
+from game.sim.inputCommand import InputCommand
+
+
+def buildPlatformWorld(spawn):
+    level = makeLevel([
+        " p        ",
+        "          ",
+        "          ",
+        "          ",
+        "XXXXXXXXXX",
+    ])
+    level.platforms.append(spawn)
+    return World(level)
+
+
+def test_platformOscillatesBetweenEndpoints():
+    platform = MovingPlatform(16, 32, 48, 8, 80, 32, 4.0)
+    seen = []
+    for _ in range(60):
+        platform.update()
+        seen.append(platform.x)
+    assert max(seen) <= 80.0 + 1e-6
+    assert min(seen) >= 16.0 - 1e-6
+    assert platform.direction in (-1, 1)
+
+
+def seatOnPlatform(world):
+    platform = world.platforms[0]
+    world.player.x = platform.x + 6
+    world.player.y = platform.y - world.player.h
+    world.player.vx = 0.0
+    world.player.vy = 0.0
+    for _ in range(6):
+        world.step(InputCommand())
+    return platform
+
+
+def test_playerCarriedHorizontallyByPlatform():
+    world = buildPlatformWorld(PlatformSpawn(16, 48, 48, 8, 160, 48, 1.0))
+    platform = seatOnPlatform(world)
+    assert world.player.onGround
+    assert world.player.groundPlatform is not None
+    playerStart = world.player.x
+    platformStart = platform.x
+    for _ in range(10):
+        world.step(InputCommand())
+    playerDelta = world.player.x - playerStart
+    platformDelta = platform.x - platformStart
+    assert abs(platformDelta) > 4.0
+    assert playerDelta == pytest.approx(platformDelta, abs=0.6)
+
+
+def test_playerCarriedVerticallyByPlatform():
+    world = buildPlatformWorld(PlatformSpawn(16, 60, 48, 8, 16, 20, 1.0))
+    platform = seatOnPlatform(world)
+    assert world.player.groundPlatform is not None
+    playerStart = world.player.y
+    platformStart = platform.y
+    for _ in range(8):
+        world.step(InputCommand())
+    playerDelta = world.player.y - playerStart
+    platformDelta = platform.y - platformStart
+    assert abs(platformDelta) > 3.0
+    assert playerDelta == pytest.approx(platformDelta, abs=0.9)