struct DrawData {
	int32 level;                 ///< Slice of this sprite (vertical row).
	uint16 z_height;             ///< Height of the voxel being drawn.
	SpriteOrder order;           ///< Selection when to draw this sprite (sorts sprites within a voxel). @see SpriteOrder
	const ImageData *sprite;     ///< Mouse cursor to draw.
	Point32 base;                ///< Base coordinate of the image, relative to top-left of the window.
	const Recolouring *recolour; ///< Recolouring of the sprite.
};

/**
 * Sort predicate of the draw data.
 * @param dd1 First value to compare.
 * @param dd2 Second value to compare.
 * @return \c true if \a dd1 should be drawn before \a dd2.
 */
inline bool operator<(const DrawData &dd1, const DrawData &dd2)
{
	if (dd1.level != dd2.level) return dd1.level < dd2.level; // Order on slice first.
	if (dd1.z_height != dd2.z_height) return dd1.z_height < dd2.z_height; // Lower in the same slice first.
	if (dd1.order != dd2.order) return dd1.order < dd2.order; // Type of sprite.
	return dd1.base.y < dd2.base.y;
}