*
* @return
*/
public static List<WalkStep> generateWalkSteps(Graph graph, State[] states, WalkStep previous) {
List<WalkStep> steps = new ArrayList<WalkStep>();
WalkStep step = null;
double lastAngle = 0, distance = 0; // distance used for appending elevation profiles
int roundaboutExit = 0; // track whether we are in a roundabout, and if so the exit number
String roundaboutPreviousStreet = null;
for (int i = 0; i < states.length - 1; i++) {
State backState = states[i];
State forwardState = states[i + 1];
Edge edge = forwardState.getBackEdge();
boolean createdNewStep = false, disableZagRemovalForThisStep = false;
if (edge instanceof FreeEdge) {
continue;
}
if (forwardState.getBackMode() == null || !forwardState.getBackMode().isOnStreetNonTransit()) {
continue; // ignore STLs and the like
}
Geometry geom = edge.getGeometry();
if (geom == null) {
continue;
}
// generate a step for getting off an elevator (all
// elevator narrative generation occurs when alighting). We don't need to know what came
// before or will come after
if (edge instanceof ElevatorAlightEdge) {
// don't care what came before or comes after
step = createWalkStep(graph, forwardState);
createdNewStep = true;
disableZagRemovalForThisStep = true;
// tell the user where to get off the elevator using the exit notation, so the
// i18n interface will say 'Elevator to <exit>'
// what happens is that the webapp sees name == null and ignores that, and it sees
// exit != null and uses to <exit>
// the floor name is the AlightEdge name
// reset to avoid confusion with 'Elevator on floor 1 to floor 1'
step.streetName = ((ElevatorAlightEdge) edge).getName();
step.relativeDirection = RelativeDirection.ELEVATOR;
steps.add(step);
continue;
}
String streetName = edge.getName();
int idx = streetName.indexOf('(');
String streetNameNoParens;
if (idx > 0)
streetNameNoParens = streetName.substring(0, idx - 1);
else
streetNameNoParens = streetName;
if (step == null) {
// first step
step = createWalkStep(graph, forwardState);
createdNewStep = true;
steps.add(step);
double thisAngle = DirectionUtils.getFirstAngle(geom);
if (previous == null) {
step.setAbsoluteDirection(thisAngle);
step.relativeDirection = RelativeDirection.DEPART;
} else {
step.setDirections(previous.angle, thisAngle, false);
}
// new step, set distance to length of first edge
distance = edge.getDistance();
} else if (((step.streetName != null && !step.streetNameNoParens().equals(streetNameNoParens))
&& (!step.bogusName || !edge.hasBogusName())) ||
// if we are on a roundabout now and weren't before, start a new step
edge.isRoundabout() != (roundaboutExit > 0) ||
isLink(edge) && !isLink(backState.getBackEdge())
) {
/* street name has changed, or we've changed state from a roundabout to a street */
if (roundaboutExit > 0) {
// if we were just on a roundabout,
// make note of which exit was taken in the existing step
step.exit = Integer.toString(roundaboutExit); // ordinal numbers from
if (streetNameNoParens.equals(roundaboutPreviousStreet)) {
step.stayOn = true;
}
// localization
roundaboutExit = 0;
}
/* start a new step */
step = createWalkStep(graph, forwardState);
createdNewStep = true;
steps.add(step);
if (edge.isRoundabout()) {
// indicate that we are now on a roundabout
// and use one-based exit numbering
roundaboutExit = 1;
roundaboutPreviousStreet = backState.getBackEdge().getName();
idx = roundaboutPreviousStreet.indexOf('(');
if (idx > 0)
roundaboutPreviousStreet = roundaboutPreviousStreet.substring(0, idx - 1);
}
double thisAngle = DirectionUtils.getFirstAngle(geom);
step.setDirections(lastAngle, thisAngle, edge.isRoundabout());
// new step, set distance to length of first edge
distance = edge.getDistance();
} else {
/* street name has not changed */
double thisAngle = DirectionUtils.getFirstAngle(geom);
RelativeDirection direction = WalkStep.getRelativeDirection(lastAngle, thisAngle,
edge.isRoundabout());
boolean optionsBefore = backState.multipleOptionsBefore();
if (edge.isRoundabout()) {
// we are on a roundabout, and have already traversed at least one edge of it.
if (optionsBefore) {
// increment exit count if we passed one.
roundaboutExit += 1;
}
}
if (edge.isRoundabout() || direction == RelativeDirection.CONTINUE) {
// we are continuing almost straight, or continuing along a roundabout.
// just append elevation info onto the existing step.
} else {
// we are not on a roundabout, and not continuing straight through.
// figure out if there were other plausible turn options at the last
// intersection
// to see if we should generate a "left to continue" instruction.
boolean shouldGenerateContinue = false;
if (edge instanceof StreetEdge) {
// the next edges will be PlainStreetEdges, we hope
double angleDiff = getAbsoluteAngleDiff(thisAngle, lastAngle);
for (Edge alternative : backState.getVertex().getOutgoingStreetEdges()) {
if (alternative.getName().equals(streetName)) {
// alternatives that have the same name
// are usually caused by street splits
continue;
}
double altAngle = DirectionUtils.getFirstAngle(alternative
.getGeometry());
double altAngleDiff = getAbsoluteAngleDiff(altAngle, lastAngle);
if (angleDiff > Math.PI / 4 || altAngleDiff - angleDiff < Math.PI / 16) {
shouldGenerateContinue = true;
break;
}
}
} else {
double angleDiff = getAbsoluteAngleDiff(lastAngle, thisAngle);
// FIXME: this code might be wrong with the removal of the edge-based graph
State twoStatesBack = backState.getBackState();
Vertex backVertex = twoStatesBack.getVertex();
for (Edge alternative : backVertex.getOutgoingStreetEdges()) {
List<Edge> alternatives = alternative.getToVertex()
.getOutgoingStreetEdges();
if (alternatives.size() == 0) {
continue; // this is not an alternative
}
alternative = alternatives.get(0);
if (alternative.getName().equals(streetName)) {
// alternatives that have the same name
// are usually caused by street splits
continue;
}
double altAngle = DirectionUtils.getFirstAngle(alternative
.getGeometry());
double altAngleDiff = getAbsoluteAngleDiff(altAngle, lastAngle);
if (angleDiff > Math.PI / 4 || altAngleDiff - angleDiff < Math.PI / 16) {
shouldGenerateContinue = true;
break;
}
}
}
if (shouldGenerateContinue) {
// turn to stay on same-named street
step = createWalkStep(graph, forwardState);
createdNewStep = true;
steps.add(step);
step.setDirections(lastAngle, thisAngle, false);
step.stayOn = true;
// new step, set distance to length of first edge
distance = edge.getDistance();
}
}
}
State exitState = backState;
Edge exitEdge = exitState.getBackEdge();
while (exitEdge instanceof FreeEdge) {
exitState = exitState.getBackState();
exitEdge = exitState.getBackEdge();
}
if (exitState.getVertex() instanceof ExitVertex) {
step.exit = ((ExitVertex) exitState.getVertex()).getExitName();
}
if (createdNewStep && !disableZagRemovalForThisStep && forwardState.getBackMode() == backState.getBackMode()) {
//check last three steps for zag
int last = steps.size() - 1;
if (last >= 2) {
WalkStep threeBack = steps.get(last - 2);
WalkStep twoBack = steps.get(last - 1);
WalkStep lastStep = steps.get(last);
if (twoBack.distance < MAX_ZAG_DISTANCE
&& lastStep.streetNameNoParens().equals(threeBack.streetNameNoParens())) {
if (((lastStep.relativeDirection == RelativeDirection.RIGHT ||
lastStep.relativeDirection == RelativeDirection.HARD_RIGHT) &&
(twoBack.relativeDirection == RelativeDirection.RIGHT ||
twoBack.relativeDirection == RelativeDirection.HARD_RIGHT)) ||