Replaces plain cam.setZoom() with zoom-to-mouse: after each zoom step
the scroll is corrected by (mouseOffset from center) * (1/zBefore - 1/zAfter),
keeping the world point under the cursor fixed. Also fixes getCenterWorld()
which previously divided by zoom incorrectly. Added JSDoc to all methods.
Implements scroll correction after cam.setZoom() so the world point
under the mouse stays fixed. Formula accounts for Phaser's
center-based zoom: scrollX += (mouseX - cw/2) * (1/zBefore - 1/zAfter).
Tab switches between the two test scenes in both directions.
Also fixes centerWorld formula in ZoomTestScene overlay and logs.
Text overlay now uses a dedicated HUD camera (zoom=1, fixed scroll)
so it's never scaled by the world zoom. World objects and HUD objects
are separated via camera ignore lists. Added red screen-center
crosshair to HUD layer as a precise alignment reference.
Vite dev server gets a /api/log middleware (POST appends to
game-test.log, DELETE clears it). ZoomTestScene writes a zoom event
with before/after state on every scroll, plus a full snapshot every
2 seconds. Log entries are newline-delimited JSON.
Separate test environment at /test.html (own Vite entry, own Phaser
instance). ZoomTestScene renders a 50×50 tile grid with crosshair
markers and a live HUD overlay showing zoom, scroll, viewport in px
and tiles, mouse world/screen/tile coords, and renderer info.
Zoom uses plain cam.setZoom() — no mouse tracking — to observe
Phaser's default center-anchor behavior.
- Scroll wheel now zooms toward the mouse cursor instead of screen center
- Middle mouse button held: pan camera by dragging
- Both actions respect current zoom level
