Function OffsetGroundSprite

src/viewport.cpp:591–610

* Called when a foundation has been drawn for the current tile. * Successive ground sprites for the current tile will be drawn as child sprites of the "foundation"-ParentSprite, not as TileSprites. * * @param x sprite x-offset (screen coordinates) of ground sprites relative to the "foundation"-ParentSprite. * @param y sprite y-offset (screen coordinates) of ground sprites relative to the "foun

 * @param y sprite y-offset (screen coordinates) of ground sprites relative to the "foundation"-ParentSprite.
 */
void OffsetGroundSprite(int x, int y)
{
	/* Switch to next foundation part */
	switch (_vd.foundation_part) {
		case FOUNDATION_PART_NONE:
			_vd.foundation_part = FOUNDATION_PART_NORMAL;
			break;
		case FOUNDATION_PART_NORMAL:
			_vd.foundation_part = FOUNDATION_PART_HALFTILE;
			break;
		default: NOT_REACHED();
	}

	/* _vd.last_child is LAST_CHILD_NONE if foundation sprite was clipped by the viewport bounds */
	if (_vd.last_child != LAST_CHILD_NONE) _vd.foundation[_vd.foundation_part] = static_cast<uint>(_vd.parent_sprites_to_draw.size()) - 1;

	_vd.foundation_offset[_vd.foundation_part].x = x * ZOOM_BASE;
	_vd.foundation_offset[_vd.foundation_part].y = y * ZOOM_BASE;
	_vd.last_foundation_child[_vd.foundation_part] = _vd.last_child;
}

/**
 * Adds a child sprite to a parent sprite.