tests/tests/systemui/src/com/android/cts/systemui/ColorUtils.java

/*
 * Copyright (C) 2015 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.cts.systemui;

/**
 * Copies of non-public {@link android.graphics.Color} APIs
 */
public class ColorUtils {

    public static float brightness(int argb) {
        int r = (argb >> 16) & 0xFF;
        int g = (argb >> 8) & 0xFF;
        int b = argb & 0xFF;

        int V = Math.max(b, Math.max(r, g));

        return (V / 255.f);
    }

    public static float hue(int argb) {
        int r = (argb >> 16) & 0xFF;
        int g = (argb >> 8) & 0xFF;
        int b = argb & 0xFF;

        int V = Math.max(b, Math.max(r, g));
        int temp = Math.min(b, Math.min(r, g));

        float H;

        if (V == temp) {
            H = 0;
        } else {
            final float vtemp = (float) (V - temp);
            final float cr = (V - r) / vtemp;
            final float cg = (V - g) / vtemp;
            final float cb = (V - b) / vtemp;

            if (r == V) {
                H = cb - cg;
            } else if (g == V) {
                H = 2 + cr - cb;
            } else {
                H = 4 + cg - cr;
            }

            H /= 6.f;
            if (H < 0) {
                H++;
            }
        }

        return H;
    }
}