| /* |
| * Copyright (C) 2014 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.internal.view.animation; |
| |
| import android.animation.TimeInterpolator; |
| import android.util.TimeUtils; |
| import android.view.Choreographer; |
| |
| /** |
| * Interpolator that builds a lookup table to use. This is a fallback for |
| * building a native interpolator from a TimeInterpolator that is not marked |
| * with {@link HasNativeInterpolator} |
| * |
| * This implements TimeInterpolator to allow for easier interop with Animators |
| */ |
| @HasNativeInterpolator |
| public class FallbackLUTInterpolator implements NativeInterpolatorFactory, TimeInterpolator { |
| |
| private TimeInterpolator mSourceInterpolator; |
| private final float mLut[]; |
| |
| /** |
| * Used to cache the float[] LUT for use across multiple native |
| * interpolator creation |
| */ |
| public FallbackLUTInterpolator(TimeInterpolator interpolator, long duration) { |
| mSourceInterpolator = interpolator; |
| mLut = createLUT(interpolator, duration); |
| } |
| |
| private static float[] createLUT(TimeInterpolator interpolator, long duration) { |
| long frameIntervalNanos = Choreographer.getInstance().getFrameIntervalNanos(); |
| int animIntervalMs = (int) (frameIntervalNanos / TimeUtils.NANOS_PER_MS); |
| int numAnimFrames = (int) Math.ceil(((double) duration) / animIntervalMs); |
| float values[] = new float[numAnimFrames]; |
| float lastFrame = numAnimFrames - 1; |
| for (int i = 0; i < numAnimFrames; i++) { |
| float inValue = i / lastFrame; |
| values[i] = interpolator.getInterpolation(inValue); |
| } |
| return values; |
| } |
| |
| @Override |
| public long createNativeInterpolator() { |
| return NativeInterpolatorFactoryHelper.createLutInterpolator(mLut); |
| } |
| |
| /** |
| * Used to create a one-shot float[] LUT & native interpolator |
| */ |
| public static long createNativeInterpolator(TimeInterpolator interpolator, long duration) { |
| float[] lut = createLUT(interpolator, duration); |
| return NativeInterpolatorFactoryHelper.createLutInterpolator(lut); |
| } |
| |
| @Override |
| public float getInterpolation(float input) { |
| return mSourceInterpolator.getInterpolation(input); |
| } |
| } |