The user wants:
- Natural order arrangement (canvasX = perp + ...): east (1102)
on left, west (1098) on right
- X-mirrored image (NS-mirror): within each tile, the image east
appears on the left of the tile (natural map orientation)
Combined state:
- canvasX = (perp + halfPerp + 0.5) * 256: natural order
- drawImage with negative width: X-flip (NS-mirror)
- All labels in normal orientation (no mirrorLabel)
This matches the user's description: 'die anordnung passt' (arrangement
correct) and 'der x-flip ist immer noch falsch' (image was still
mirrored, now correctly mirrored).