double GatewayPathfindingStateSpaceMP::shortestDistanceToGate(Tile tile, Gateway gateway)
{
Tile gateStart = gateway.getStart();
Tile gateEnd = gateway.getEnd();
int deltaX = 0;
int deltaY = 0;
if(gateStart.x == gateEnd.x) { //Vertical gate
int higherY, lowerY;
if(gateStart.y > gateEnd.y) {
higherY = gateStart.y;
lowerY = gateEnd.y;
}
else {
higherY = gateEnd.y;
lowerY = gateStart.y;
}
if(tile.y > higherY) {
deltaY = tile.y - higherY;
}
else if(tile.y < lowerY) {
deltaY = lowerY - tile.y;
}
deltaX = tile.x - gateStart.x;
}
else if(gateStart.y == gateEnd.y) { //Horizontal gate
int higherX, lowerX;
if(gateStart.x > gateEnd.x) {
higherX = gateStart.x;
lowerX = gateEnd.x;
}
else {
higherX = gateEnd.x;
lowerX = gateStart.x;
}
if(tile.x > higherX) {
deltaX = tile.x - higherX;
}
else if(tile.x < lowerX) {
deltaX = lowerX - tile.x;
}
deltaY = tile.y - gateStart.y;
}
else { //Diagonal gate (always 45 degrees)
int higherX, lowerX;
int higherY, lowerY;
bool backslashGate = false;
if(gateStart.y > gateEnd.y) {
higherY = gateStart.y;
lowerY = gateEnd.y;
if(gateStart.x > gateEnd.x) {
higherX = gateStart.x;
lowerX = gateEnd.x;
backslashGate = false;
}
else {
higherX = gateEnd.x;
lowerX = gateStart.x;
backslashGate = true;
}
}
else {
higherY = gateEnd.y;
lowerY = gateStart.y;
if(gateStart.x > gateEnd.x) {
higherX = gateStart.x;
lowerX = gateEnd.x;
backslashGate = true;
}
else {
higherX = gateEnd.x;
lowerX = gateStart.x;
backslashGate = false;
}
}
if(backslashGate) {
if(tile.y > (higherY - (lowerX - tile.x))) {
deltaX = tile.x - lowerX;
deltaY = tile.y - higherY;
}
else if(tile.y < (lowerY - (higherX - tile.x))) {
deltaX = higherX - tile.x;
deltaY = lowerY - tile.y;
}
else {
deltaX = deltaY =
( (tile.x - lowerX)
+ (tile.x - higherX)
+ (tile.y - lowerY)
+ (tile.y - higherY) )
/ 4;
}
}
else {
if(tile.y > (higherY - (tile.x - higherX))) {
deltaX = tile.x - higherX;
deltaY = tile.y - higherY;
}
else if(tile.y < (lowerY - (tile.x - lowerX))) {
deltaX = lowerX - tile.x;
deltaY = lowerY - tile.y;
}
else {
deltaX = deltaY =
( (tile.x - lowerX)
+ (tile.x - higherX)
+ (lowerY - tile.y)
+ (higherY - tile.y) )
/ 4;
}
}
}
return octileDistance(deltaX, deltaY);
}
