MyMath: add 2 circle() methods

src/main/java/jme3utilities/math/MyMath.java

@@ -1,5 +1,5 @@
 /*
- Copyright (c) 2013-2024, Stephen Gold
+ Copyright (c) 2013-2024 Stephen Gold
  All rights reserved.
 
  Redistribution and use in source and binary forms, with or without
@@ -73,6 +73,44 @@ private MyMath() {
     // *************************************************************************
     // new methods exposed
 
+    /**
+     * Return the circle function {@code sqrt(1 - x^2)} for a double-precision
+     * value.
+     *
+     * @param abscissa input (≤1, ≥-1)
+     * @return positive ordinate of the unit circle at the abscissa (≤1,
+     * ≥0)
+     */
+    public static double circle(double abscissa) {
+        assert Validate.inRange(abscissa, "abscissa", -1.0, 1.0);
+
+        double y = Math.sqrt(1.0 - abscissa * abscissa);
+
+        assert y >= 0.0 : y;
+        assert y <= 1.0 : y;
+        return y;
+    }
+
+    /**
+     * Return the circle function {@code sqrt(1 - x^2)} for a single-precision
+     * value. Double-precision arithmetic is used to reduce the risk of
+     * overflow.
+     *
+     * @param abscissa input (&le;1, &ge;-1)
+     * @return positive ordinate of the unit circle at the abscissa (&le;1,
+     * &ge;0)
+     */
+    public static float circle(float abscissa) {
+        assert Validate.inRange(abscissa, "abscissa", -1f, 1f);
+
+        double x = abscissa;
+        float y = (float) circle(x);
+
+        assert y >= 0f : y;
+        assert y <= 1f : y;
+        return y;
+    }
+
     /**
      * Clamp a double-precision value between 2 limits.
      *