FloatMath.java revision e2c279e8a1abc2cc7bc87b94a514a563b814cdc1
19066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project/* 29066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Copyright (C) 2007 The Android Open Source Project 39066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 49066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Licensed under the Apache License, Version 2.0 (the "License"); 59066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * you may not use this file except in compliance with the License. 69066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * You may obtain a copy of the License at 79066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 89066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 99066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 109066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Unless required by applicable law or agreed to in writing, software 119066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 129066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 139066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * See the License for the specific language governing permissions and 149066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * limitations under the License. 159066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 169066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 179066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectpackage android.util; 189066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 199066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project/** 209066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Math routines similar to those found in {@link java.lang.Math}. Performs 219066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * computations on {@code float} values directly without incurring the overhead 229066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * of conversions to and from {@code double}. 239066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 249066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * <p>On one platform, {@code FloatMath.sqrt(100)} executes in one third of the 259066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * time required by {@code java.lang.Math.sqrt(100)}.</p> 269066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 279066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectpublic class FloatMath { 289066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 299066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** Prevents instantiation. */ 309066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project private FloatMath() {} 319066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 329066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 339066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Returns the float conversion of the most positive (i.e. closest to 349066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * positive infinity) integer value which is less than the argument. 359066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 369066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param value to be converted 379066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @return the floor of value 389066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 399066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static native float floor(float value); 409066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 419066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 429066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Returns the float conversion of the most negative (i.e. closest to 439066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * negative infinity) integer value which is greater than the argument. 449066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 459066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param value to be converted 469066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @return the ceiling of value 479066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 489066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static native float ceil(float value); 499066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 509066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 519066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Returns the closest float approximation of the sine of the argument. 529066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 539066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param angle to compute the cosine of, in radians 549066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @return the sine of angle 559066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 569066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static native float sin(float angle); 579066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 589066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 599066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Returns the closest float approximation of the cosine of the argument. 609066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 619066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param angle to compute the cosine of, in radians 629066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @return the cosine of angle 639066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 649066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static native float cos(float angle); 659066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 669066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project /** 679066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Returns the closest float approximation of the square root of the 689066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * argument. 699066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 709066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @param value to compute sqrt of 719066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * @return the square root of value 729066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 739066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public static native float sqrt(float value); 745d728bb9ff8c6ad89d5a1b88b2804f954d45d763Jeff Brown 755d728bb9ff8c6ad89d5a1b88b2804f954d45d763Jeff Brown /** 765d728bb9ff8c6ad89d5a1b88b2804f954d45d763Jeff Brown * Returns the closest float approximation of the raising "e" to the power 775d728bb9ff8c6ad89d5a1b88b2804f954d45d763Jeff Brown * of the argument. 785d728bb9ff8c6ad89d5a1b88b2804f954d45d763Jeff Brown * 795d728bb9ff8c6ad89d5a1b88b2804f954d45d763Jeff Brown * @param value to compute the exponential of 805d728bb9ff8c6ad89d5a1b88b2804f954d45d763Jeff Brown * @return the exponential of value 815d728bb9ff8c6ad89d5a1b88b2804f954d45d763Jeff Brown */ 825d728bb9ff8c6ad89d5a1b88b2804f954d45d763Jeff Brown public static native float exp(float value); 83270e3381e7053c3b15aa8f508c9df9d98032cd62Jeff Brown 84270e3381e7053c3b15aa8f508c9df9d98032cd62Jeff Brown /** 85e2c279e8a1abc2cc7bc87b94a514a563b814cdc1Jeff Brown * Returns the closest float approximation of the result of raising {@code 86e2c279e8a1abc2cc7bc87b94a514a563b814cdc1Jeff Brown * x} to the power of {@code y}. 87e2c279e8a1abc2cc7bc87b94a514a563b814cdc1Jeff Brown * 88e2c279e8a1abc2cc7bc87b94a514a563b814cdc1Jeff Brown * @param x the base of the operation. 89e2c279e8a1abc2cc7bc87b94a514a563b814cdc1Jeff Brown * @param y the exponent of the operation. 90e2c279e8a1abc2cc7bc87b94a514a563b814cdc1Jeff Brown * @return {@code x} to the power of {@code y}. 91e2c279e8a1abc2cc7bc87b94a514a563b814cdc1Jeff Brown */ 92e2c279e8a1abc2cc7bc87b94a514a563b814cdc1Jeff Brown public static native float pow(float x, float y); 93e2c279e8a1abc2cc7bc87b94a514a563b814cdc1Jeff Brown 94e2c279e8a1abc2cc7bc87b94a514a563b814cdc1Jeff Brown /** 95270e3381e7053c3b15aa8f508c9df9d98032cd62Jeff Brown * Returns {@code sqrt(}<i>{@code x}</i><sup>{@code 2}</sup>{@code +} <i> 96270e3381e7053c3b15aa8f508c9df9d98032cd62Jeff Brown * {@code y}</i><sup>{@code 2}</sup>{@code )}. 97270e3381e7053c3b15aa8f508c9df9d98032cd62Jeff Brown * 98270e3381e7053c3b15aa8f508c9df9d98032cd62Jeff Brown * @param x a float number 99270e3381e7053c3b15aa8f508c9df9d98032cd62Jeff Brown * @param y a float number 100270e3381e7053c3b15aa8f508c9df9d98032cd62Jeff Brown * @return the hypotenuse 101270e3381e7053c3b15aa8f508c9df9d98032cd62Jeff Brown */ 102270e3381e7053c3b15aa8f508c9df9d98032cd62Jeff Brown public static native float hypot(float x, float y); 1039066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project} 104