@Override
public void run() {
LOS los1 = new LOS(BRESENHAM);
LOS los2 = new LOS(BRESENHAM);
// if a non-solid midpoint on the path can see both the start and end, consider the two ends
// to be able to see each other
if (resistanceMap[testx][testy] < 1
&& radiusStrategy.radius(startx, starty, testx, testy)
<= radiusStrategy.radius(startx, starty, targetx, targety)
&& los1.isReachable(resistanceMap, testx, testy, targetx, targety, radiusStrategy)
&& los2.isReachable(resistanceMap, startx, starty, testx, testy, radiusStrategy)) {
// record actual sight path used
path = new LinkedList<>(los2.lastPath);
path.addAll(los1.lastPath);
succeeded = true;
}
}
private boolean bresenhamReachable(Radius radiusStrategy) {
Queue<Coord> path = Bresenham.line2D(startx, starty, targetx, targety);
lastPath = new LinkedList<>();
lastPath.add(Coord.get(startx, starty));
double force = 1;
double decay = 1 / radiusStrategy.radius(startx, starty, targetx, targety);
double currentForce = force;
for (Coord p : path) {
lastPath.offer(p);
if (p.x == targetx && p.y == targety) {
return true; // reached the end
}
if (p.x != startx
|| p.y != starty) { // don't discount the start location even if on resistant cell
currentForce -= resistanceMap[p.x][p.y];
}
double r = radiusStrategy.radius(startx, starty, p.x, p.y);
if (currentForce - (r * decay) <= 0) {
return false; // too much resistance
}
}
return false; // never got to the target point
}
private boolean rayReachable(Radius radiusStrategy) {
lastPath = new LinkedList<>(); // save path for later retreival
lastPath.add(Coord.get(startx, starty));
if (startx == targetx && starty == targety) { // already there!
return true;
}
int width = resistanceMap.length;
int height = resistanceMap[0].length;
CoordDouble start = new CoordDouble(startx, starty);
CoordDouble end = new CoordDouble(targetx, targety);
// find out which direction to step, on each axis
int stepX = (int) Math.signum(end.x - start.x);
int stepY = (int) Math.signum(end.y - start.y);
double deltaY = end.x - start.x;
double deltaX = end.y - start.y;
deltaX = Math.abs(deltaX);
deltaY = Math.abs(deltaY);
int testX = (int) start.x;
int testY = (int) start.y;
double maxX = (float) (start.x % 1);
double maxY = (float) (start.y % 1);
int endTileX = (int) end.x;
int endTileY = (int) end.y;
CoordDouble collisionPoint = new CoordDouble();
while (testX >= 0
&& testX < width
&& testY >= 0
&& testY < height
&& (testX != endTileX || testY != endTileY)) {
lastPath.add(Coord.get(testX, testY));
if (maxX < maxY) {
maxX += deltaX;
testX += stepX;
if (resistanceMap[testX][testY] >= 1f) {
collisionPoint.y = testY;
collisionPoint.x = testX;
end = collisionPoint;
break;
}
} else if (maxY < maxX) {
maxY += deltaY;
testY += stepY;
if (resistanceMap[testX][testY] >= 1f) {
collisionPoint.y = testY;
collisionPoint.x = testX;
end = collisionPoint;
break;
}
} else { // directly on diagonal, move both full step
maxY += deltaY;
testY += stepY;
maxX += deltaX;
testX += stepX;
if (resistanceMap[testX][testY] >= 1f) {
collisionPoint.y = testY;
collisionPoint.x = testX;
end = collisionPoint;
break;
}
}
if (radiusStrategy.radius(testX, testY, start.x, start.y)
> radiusStrategy.radius(startx, starty, targetx, targety)) { // went too far
break;
}
}
if (end.x >= 0 && end.x < width && end.y >= 0 && end.y < height) {
lastPath.add(Coord.get((int) end.x, (int) end.y));
}
return (int) end.x == targetx && (int) end.y == targety;
}