Method canTargetUnit

src/Battlescape/TileEngine.cpp:532–619

* Checks for another unit available for targeting and what particular voxel. * @param originVoxel Voxel of trace origin (eye or gun's barrel). * @param tile The tile to check for. * @param scanVoxel is returned coordinate of hit. * @param excludeUnit is self (not to hit self). * @param potentialUnit is a hypothetical unit to draw a virtual line of fire for AI. if left blank, this function beh

 * @return True if the unit can be targetted.
 */
bool TileEngine::canTargetUnit(Position *originVoxel, Tile *tile, Position *scanVoxel, BattleUnit *excludeUnit, BattleUnit *potentialUnit)
{
	Position targetVoxel = Position((tile->getPosition().x * 16) + 7, (tile->getPosition().y * 16) + 8, tile->getPosition().z * 24);
	std::vector<Position> _trajectory;
	bool hypothetical = potentialUnit != 0;
	if (potentialUnit == 0)
	{
		potentialUnit = tile->getUnit();
		if (potentialUnit == 0) return false; //no unit in this tile, even if it elevated and appearing in it.
	}

	if (potentialUnit == excludeUnit) return false; //skip self

	int targetMinHeight = targetVoxel.z - tile->getTerrainLevel();
	targetMinHeight += potentialUnit->getFloatHeight();

	int targetMaxHeight = targetMinHeight;
	int targetCenterHeight;
	// if there is an other unit on target tile, we assume we want to check against this unit's height
	int heightRange;

	int unitRadius = potentialUnit->getLoftemps(); //width == loft in default loftemps set
	int targetSize = potentialUnit->getArmor()->getSize() - 1;
	int xOffset = potentialUnit->getPosition().x - tile->getPosition().x;
	int yOffset = potentialUnit->getPosition().y - tile->getPosition().y;
	if (targetSize > 0)
	{
		unitRadius = 3;
	}
	// vector manipulation to make scan work in view-space
	Position relPos = targetVoxel - *originVoxel;
	float normal = unitRadius/sqrt((float)(relPos.x*relPos.x + relPos.y*relPos.y));
	int relX = floor(((float)relPos.y)*normal+0.5);
	int relY = floor(((float)-relPos.x)*normal+0.5);

	int sliceTargets[10]={0,0, relX,relY, -relX,-relY, relY,-relX, -relY,relX};

	if (!potentialUnit->isOut())
	{
		heightRange = potentialUnit->getHeight();
	}
	else
	{
		heightRange = 12;
	}

	targetMaxHeight += heightRange;
	targetCenterHeight=(targetMaxHeight+targetMinHeight)/2;
	heightRange/=2;
	if (heightRange>10) heightRange=10;
	if (heightRange<=0) heightRange=0;

	// scan ray from top to bottom  plus different parts of target cylinder
	for (int i = 0; i <= heightRange; ++i)
	{
		scanVoxel->z=targetCenterHeight+heightFromCenter[i];
		for (int j = 0; j < 5; ++j)
		{