/*
* Java port of Bullet (c) 2008 Martin Dvorak <jezek2@advel.cz>
*
* Bullet Continuous Collision Detection and Physics Library
* Copyright (c) 2003-2008 Erwin Coumans http://www.bulletphysics.com/
*
* This software is provided 'as-is', without any express or implied warranty.
* In no event will the authors be held liable for any damages arising from
* the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
package com.bulletphysics.linearmath;
import com.bulletphysics.BulletGlobals;
/**
* Utility functions for scalars (floats).
*
* @author jezek2
*/
public class ScalarUtil {
public static float fsel(float a, float b, float c) {
return a >= 0 ? b : c;
}
public static boolean fuzzyZero(float x) {
return Math.abs(x) < BulletGlobals.FLT_EPSILON;
}
public static float atan2Fast(float y, float x) {
float coeff_1 = BulletGlobals.SIMD_PI / 4.0f;
float coeff_2 = 3.0f * coeff_1;
float abs_y = Math.abs(y);
float angle;
if (x >= 0.0f) {
float r = (x - abs_y) / (x + abs_y);
angle = coeff_1 - coeff_1 * r;
}
else {
float r = (x + abs_y) / (abs_y - x);
angle = coeff_2 - coeff_1 * r;
}
return (y < 0.0f) ? -angle : angle;
}
}