feat(extract): Koordinaten, Kachel-Download und Mosaik

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tools/extract/leonida/coords.py

@@ -0,0 +1,28 @@
+"""Umrechnung zwischen gtadb-Weltkoordinaten, Kacheln und Mosaikpixeln.
+
+Spiegelt src/world/coords.js. Beide Seiten müssen dieselben Werte liefern.
+"""
+TILE_PX = 256
+WORLD_HALF = 16384
+CHUNK_SIZE = 250
+SLICE = {"x0": -1000, "x1": 2000, "y0": -500, "y1": 2500}
+
+
+def tile_for_world(x: float, y: float) -> tuple[int, int]:
+    return (int((WORLD_HALF - y) // TILE_PX), int((x + WORLD_HALF) // TILE_PX))
+
+
+def slice_tiles() -> list[tuple[int, int]]:
+    r0, c0 = tile_for_world(SLICE["x0"], SLICE["y1"])
+    r1, c1 = tile_for_world(SLICE["x1"] - 1, SLICE["y0"] + 1)
+    return [(r, c) for r in range(r0, r1 + 1) for c in range(c0, c1 + 1)]
+
+
+def mosaic_origin_px() -> tuple[int, int]:
+    """Pixelversatz der Ausschnittsecke innerhalb des ungeschnittenen Kachelrasters."""
+    r0, c0 = tile_for_world(SLICE["x0"], SLICE["y1"])
+    return (SLICE["x0"] + WORLD_HALF - c0 * TILE_PX, (WORLD_HALF - SLICE["y1"]) - r0 * TILE_PX)
+
+
+def pixel_to_world(px: int, py: int) -> tuple[float, float]:
+    return (SLICE["x0"] + px, SLICE["y1"] - py)