step 6: add stable overlays and live update stress tests

tests/test_renderer.py

@@ -1,10 +1,50 @@
 from __future__ import annotations
 
+from typing import Any
+
+import dpg_map as dpgm
 from dpg_map.commands import CommandKind, MapCommand
-from dpg_map.renderer import drain_renderer_commands
+from dpg_map.renderer import MapRenderer, drain_renderer_commands
 from dpg_map.state import DirtyFlags, create_map_state
 
 
+class FakeDpg:
+    def __init__(self) -> None:
+        self.items: set[str | int] = set()
+        self.deleted: list[tuple[str | int, bool]] = []
+        self.drawn: list[tuple[str, str | int]] = []
+
+    def does_item_exist(self, tag: str | int) -> bool:
+        return tag in self.items
+
+    def add_draw_layer(self, *, parent: str | int, tag: str | int) -> None:
+        _ = parent
+        self.items.add(tag)
+
+    def delete_item(self, tag: str | int, *, children_only: bool = False) -> None:
+        self.deleted.append((tag, children_only))
+
+    def draw_rectangle(self, *args: Any, parent: str | int, **kwargs: Any) -> None:
+        _ = (args, kwargs)
+        self.drawn.append(("rectangle", parent))
+
+    def draw_image(self, *args: Any, parent: str | int, **kwargs: Any) -> None:
+        _ = (args, kwargs)
+        self.drawn.append(("image", parent))
+
+    def draw_text(self, *args: Any, parent: str | int, **kwargs: Any) -> None:
+        _ = (args, kwargs)
+        self.drawn.append(("text", parent))
+
+    def draw_circle(self, *args: Any, parent: str | int, **kwargs: Any) -> None:
+        _ = (args, kwargs)
+        self.drawn.append(("circle", parent))
+
+    def draw_polyline(self, *args: Any, parent: str | int, **kwargs: Any) -> None:
+        _ = (args, kwargs)
+        self.drawn.append(("polyline", parent))
+
+
 def test_renderer_command_drain_preserves_structural_order_and_coalesces() -> None:
     state = create_map_state(tag="renderer-drain")
     state.dirty = DirtyFlags.NONE
@@ -28,3 +68,50 @@ def test_renderer_command_drain_preserves_structural_order_and_coalesces() -> No
     assert commands[2].payload == {"tag": "a", "v": 2}
     assert state.dirty & DirtyFlags.VIEW
     assert state.dirty & DirtyFlags.OVERLAYS
+
+
+def test_overlay_draw_clears_only_overlay_layer() -> None:
+    state = create_map_state(tag="overlay-draw", center=(47.0, 2.0), zoom=8)
+    dpgm.add_marker(
+        "vehicle",
+        lat=47.0,
+        lon=2.0,
+        show_label=True,
+        label="Vehicle",
+        map_tag="overlay-draw",
+    )
+    fake = FakeDpg()
+    fake.items.add(state.drawlist_tag)
+    renderer = MapRenderer(state, fake)
+
+    renderer._draw_tile_layer(
+        visible_tiles=[], width=400, height=300, attribution="Tiles", tile_size=256
+    )
+    fake.deleted.clear()
+    with state.lock:
+        overlays = tuple(state.overlays.values())
+        layers = {name: (layer.show, layer.z_index) for name, layer in state.layers.items()}
+
+    renderer._draw_overlay_layer(
+        overlays=overlays,
+        layers=layers,
+        center=state.center,
+        zoom=state.zoom,
+        width=400,
+        height=300,
+        tile_size=256,
+    )
+
+    assert fake.deleted == [("overlay-draw##layer-overlays", True)]
+    assert ("circle", "overlay-draw##layer-overlays") in fake.drawn
+    assert ("text", "overlay-draw##layer-overlays") in fake.drawn
+
+
+def test_overlay_update_drain_sets_only_overlay_dirty() -> None:
+    state = create_map_state(tag="overlay-dirty")
+    state.dirty = DirtyFlags.NONE
+    state.command_queue.put(MapCommand(CommandKind.UPDATE_OVERLAY, state.tag, {"tag": "a"}))
+
+    drain_renderer_commands(state)
+
+    assert state.dirty == DirtyFlags.OVERLAYS