Method SpiralTileIterator

src/tilearea.cpp:302–326

* See SpiralTileSequence constructor for description. */

 * See SpiralTileSequence constructor for description.
 */
SpiralTileIterator::SpiralTileIterator(TileIndex center, uint diameter) :
	max_radius(diameter / 2),
	cur_radius(0),
	dir(DIAGDIR_BEGIN)
{
	assert(diameter > 0);

	if (diameter % 2 == 1) {
		this->extent.fill(1);
		this->dir = INVALID_DIAGDIR; // special case for odd diameters, see Increment()
		this->position = 0;

		this->x = TileX(center);
		this->y = TileY(center);
	} else {
		this->extent.fill(0);
		this->dir = DIAGDIR_BEGIN;
		this->InitPosition();

		/* Start with the west corner of the center 2x2 rect */
		this->x = TileX(center) + 1;
		this->y = TileY(center);
	}
	this->SkipOutsideMap();
}

/**
 * See SpiralTileSequence constructor for description.