A3D_FindNearestByRoute

Find which of several points the best route from a point reaches first, such as the nearest hospital by road rather than in a straight line.

Every point is weighed in one search, which takes about as long as a few routes.

native A3D_FindNearestByRoute(
    Float:x,
    Float:y,
    Float:z,
    const Float:targetX[],
    const Float:targetY[],
    const Float:targetZ[],
    count = sizeof (targetX),
    A3D_ROUTE:type = A3D_ROUTE_FASTEST,
    Float:heading = -1.0,
    Float:reach = 300.0
);

Parameters

Parameter	Description	Default
Float:x	Start on the X axis.
Float:y	Start on the Y axis.
Float:z	Start on the Z axis.
const Float:targetX[]	Points on the X axis.
const Float:targetY[]	Points on the Y axis.
const Float:targetZ[]	Points on the Z axis.
count	Number of points.	sizeof (targetX)
A3D_ROUTE:type	How the routes weigh the paths.	A3D_ROUTE_FASTEST
Float:heading	Direction the vehicle faces at the start, or -1.0 for none.	-1.0
Float:reach	How far from each point to look for a path, in metres.	300.0

Returns

• The index of the point reached first.
• -1 when none can be reached.

Remarks

The nearest place in a straight line is often not the nearest by road. Across a river, a highway or a hill, the road may go far around. One search weighs every place at once, in about the time of a few routes, much less than measuring each place.

Each place goes to the nearest road within reach. A place with no road within reach is left out.

Example

Finds the hospital nearest to a point by road.

static const Float:gHospitals[][3] = {
    { 1172.0, -1323.0, 15.4 },
    { 2034.0, -1405.0, 17.2 },
    { -2655.0, 639.0, 14.5 },
    { 1607.0, 1818.0, 10.8 }
};

stock NearestHospital(Float:x, Float:y, Float:z) {
    new
        Float:hospitalX[sizeof (gHospitals)],
        Float:hospitalY[sizeof (gHospitals)],
        Float:hospitalZ[sizeof (gHospitals)]
    ;

    for (new index; index != sizeof (gHospitals); ++index) {
        hospitalX[index] = gHospitals[index][0];
        hospitalY[index] = gHospitals[index][1];
        hospitalZ[index] = gHospitals[index][2];
    }

    return A3D_FindNearestByRoute(x, y, z, hospitalX, hospitalY, hospitalZ);
}

Related

• A3D_MeasureRoute: Measure the best route between two points without keeping it, which is faster than finding it.
• A3D_FindRoute: Find the best route between two points along the paths of the game.