Function squaredDistance

Squared Euclidean distance between two points.

MetricScalar!T squaredDistance(T)(
  Point2!T a,
  Point2!T b
) pure nothrow @nogc @safe
if (isGeoScalar!T);

Returns

The squared distance in MetricScalar!T.

Integer coordinate geometry is converted to floating-point metric arithmetic after each component difference has been obtained without signed overflow.

This operation does not promise exact integral arithmetic. In particular, long-coordinate results may lose precision after conversion to double.

Floating-point NaN and infinity are not rejected. Results follow normal floating-point arithmetic. Very large finite results may overflow to infinity.

This function is a metric computation, not a robust exact distance comparison predicate.

No allocation is performed.

Complexity

O(1) time and O(1) auxiliary space.

Example

Example computing squared distance without taking a square root. 

import geo;

const a = Point2!int(0, 0);
const b = Point2!int(3, 4);

static assert(
    is(typeof(squaredDistance(a, b)) == double)
);

assert(
    squaredDistance(a, b) == 25.0
);