The existing update_drop_highlights system tinted PileMarker sprites
green for valid drops, but the marker is a card-sized rectangle that
sits behind the stack. Once a tableau column had any cards on it the
marker was occluded and the highlight effectively invisible — the
handoff's "drops feel guess-y because there's no preview" point.
A new update_drop_target_overlays system spawns an overlay above every
legal target during drag: a soft DROP_TARGET_FILL rectangle sized to
the pile's actual visible footprint (full fanned column for tableaux,
card-sized for foundations and empty tableaux) plus four thin
DROP_TARGET_OUTLINE edges forming a 3 px border. Z_DROP_OVERLAY = 50
sits above static cards (z ~1) but below the dragged stack (DRAG_Z =
500), so the overlay never occludes the card the player is holding.
The valid-target enumeration mirrors update_drop_highlights exactly so
the rules can't drift, and pile geometry mirrors input_plugin's
pile_drop_rect. The original marker-tint system is untouched; it still
does its job for empty-pile placeholders. The overlay layer is purely
additive — running alongside, not replacing.
Token values reuse the existing STATE_SUCCESS hue (#4ADE80) at 10%
fill / 75% outline so the overlay green matches the rest of the
success-signal palette (foundation completion, sync OK, etc.).
Three headless tests pin the contract: overlay spawns for valid
tableau drops, doesn't spawn for invalid destinations, and despawns
the moment the drag ends.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
funman300
f6c916641a