Method tryGo

MicropolisCore/src/MicropolisEngine/src/traffic.cpp:344–383

* Try to drive one tile in a random direction. * @param pos Current position. * @param dirLast Forbidden direction for movement (to prevent reversing). * @return Direction of movement, \c #DIR2_INVALID is returned if not moved. */

 * @return Direction of movement, \c #DIR2_INVALID is returned if not moved.
 */
Direction2 Micropolis::tryGo(const Position &pos, Direction2 dirLast)
{
    Direction2 directions[4];

    // Find connections from current position.
    Direction2 dir = DIR2_NORTH;
    int count = 0;
    for (int i = 0; i < 4; i++) {
        if (dir != dirLast && roadTest(getTileFromMap(pos, dir, DIRT))) {
            // found a road in an allowed direction
            directions[i] = dir;
            count++;
        } else {
            directions[i] = DIR2_INVALID;
        }

        dir = rotate90(dir);
    }

    if (count == 0) { // dead end
        return DIR2_INVALID;
    }

    // We have at least one way to go.

    if (count == 1) { // only one solution
        for (int i = 0; i < 4; i++) {
            if (directions[i] != DIR2_INVALID) {
                return directions[i];
            }
        }
    }

    // more than one choice, draw a random number.
    int i = getRandom16() & 3;
    while (directions[i] == DIR2_INVALID) {
        i = (i + 1) & 3;
    }
    return directions[i];
}


/**