Mix two colors. - Android Graphics

Android examples for Graphics:Color Value

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Description

Mix two colors.

Demo Code

/*/*from w  w w.j  a  v  a 2 s .c  o  m*/
 * Copyright 2014 Soichiro Kashima
 *
 * 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.
 */
import android.os.Build;
import android.view.View;
import android.view.ViewTreeObserver;

public class Main{
    /**
     * Mix two colors.
     * <p>{@code toColor} will be {@code toAlpha/1} percent,
     * and {@code fromColor} will be {@code (1-toAlpha)/1} percent.</p>
     *
     * @param fromColor First color to be mixed.
     * @param toColor   Second color to be mixed.
     * @param toAlpha   Alpha value of toColor, 0.0f to 1.0f.
     * @return Mixed color value in ARGB. Alpha is fixed value (255).
     */
    public static int mixColors(int fromColor, int toColor, float toAlpha) {
        float[] fromCmyk = ScrollUtils.cmykFromRgb(fromColor);
        float[] toCmyk = ScrollUtils.cmykFromRgb(toColor);
        float[] result = new float[4];
        for (int i = 0; i < 4; i++) {
            result[i] = Math.min(1, fromCmyk[i] * (1 - toAlpha) + toCmyk[i]
                    * toAlpha);
        }
        return 0xff000000 + (0x00ffffff & ScrollUtils.rgbFromCmyk(result));
    }
    /**
     * Convert RGB color to CMYK color.
     *
     * @param rgbColor Target color.
     * @return CMYK array.
     */
    public static float[] cmykFromRgb(int rgbColor) {
        int red = (0xff0000 & rgbColor) >> 16;
        int green = (0xff00 & rgbColor) >> 8;
        int blue = (0xff & rgbColor);
        float black = Math.min(1.0f - red / 255.0f,
                Math.min(1.0f - green / 255.0f, 1.0f - blue / 255.0f));
        float cyan = 1.0f;
        float magenta = 1.0f;
        float yellow = 1.0f;
        if (black != 1.0f) {
            // black 1.0 causes zero divide
            cyan = (1.0f - (red / 255.0f) - black) / (1.0f - black);
            magenta = (1.0f - (green / 255.0f) - black) / (1.0f - black);
            yellow = (1.0f - (blue / 255.0f) - black) / (1.0f - black);
        }
        return new float[] { cyan, magenta, yellow, black };
    }
    /**
     * Convert CYMK color to RGB color.
     * This method doesn't check if cmyk is not null or have 4 elements in array.
     *
     * @param cmyk Target CYMK color. Each value should be between 0.0f to 1.0f,
     *             and should be set in this order: cyan, magenta, yellow, black.
     * @return ARGB color. Alpha is fixed value (255).
     */
    public static int rgbFromCmyk(float[] cmyk) {
        float cyan = cmyk[0];
        float magenta = cmyk[1];
        float yellow = cmyk[2];
        float black = cmyk[3];
        int red = (int) ((1.0f - Math.min(1.0f, cyan * (1.0f - black)
                + black)) * 255);
        int green = (int) ((1.0f - Math.min(1.0f, magenta * (1.0f - black)
                + black)) * 255);
        int blue = (int) ((1.0f - Math.min(1.0f, yellow * (1.0f - black)
                + black)) * 255);
        return ((0xff & red) << 16) + ((0xff & green) << 8) + (0xff & blue);
    }
}

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