Detonate rifle grenades on impact with original Half-Life fireball

tools/shot_grenade.gd

@@ -0,0 +1,34 @@
+extends SceneTree
+## Capture the real impact effect in the Compatibility renderer, no remote score calls.
+func _initialize() -> void:
+	call_deferred("run_test")
+
+func run_test() -> void:
+	root.size = Vector2i(1280, 720)
+	var world = load("res://scenes/main.tscn").instantiate()
+	root.add_child(world)
+	world.spawning = true
+	world.start_screen.hide()
+	world.player.set_physics_process(false)
+	world.player.position = Vector3(0, 0.1, 4)
+	world.player.camera.look_at(Vector3(0, 1, -1))
+	Input.mouse_mode = Input.MOUSE_MODE_VISIBLE
+	await create_timer(0.3).timeout
+	var grenade = load("res://scripts/grenade.gd").new()
+	grenade.position = Vector3(0, 0.6, -1)
+	world.add_child(grenade)
+	grenade.linear_velocity = Vector3(0, -4, 0)
+	await grenade.detonated
+	await process_frame
+	var effect = world.get_node("GrenadeExplosion")
+	effect.set_process(false)
+	for index in [0, 3, 7, 11, 14]:
+		effect.fireball.show()
+		effect._set_frame(index)
+		await process_frame
+		await RenderingServer.frame_post_draw
+		root.get_texture().get_image().save_png("/tmp/zombie-grenade-frame-%02d.png" % index)
+	print("SHOT: original sprite frames 0/3/7/11/14 at real floor impact")
+	world.queue_free()
+	await process_frame
+	quit()