Main.java Source code

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Here is the source code for Main.java

Source

//package com.java2s;
/*******************************************************************************
 * Copyright 2015 NEGU Soft
 * 
 * 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.graphics.Bitmap;

import android.graphics.Color;

public class Main {
    /**
     * Create a bitmap that contains the transformation to make to create the final 
     * bitmap with a new tint color. You can then call processTintTransformationMap() 
     * to get a bitmap with the desired tint.
     * @param bitmap The original bitmap.
     * @param tintColor Tint color in the original bitmap.
     * @return A transformation map to be used with processTintTransformationMap(). The 
     * transformation values are stored in the red and green values. The alpha value is 
     * significant and the blue value can be ignored.
     */
    public static Bitmap createTintTransformationMap(Bitmap bitmap, int tintColor) {
        // tint color
        int[] t = new int[] { Color.red(tintColor), Color.green(tintColor), Color.blue(tintColor) };

        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        int[] pixels = new int[width * height];
        bitmap.getPixels(pixels, 0, width, 0, 0, width, height);

        int maxIndex = getMaxIndex(t);
        int mintIndex = getMinIndex(t);

        for (int i = 0; i < pixels.length; i++) {
            int color = pixels[i];
            // pixel color
            int[] p = new int[] { Color.red(color), Color.green(color), Color.blue(color) };
            int alpha = Color.alpha(color);

            float[] transformation = calculateTransformation(t[maxIndex], t[mintIndex], p[maxIndex], p[mintIndex]);
            pixels[i] = Color.argb(alpha, (int) (transformation[0] * 255), (int) (transformation[1] * 255), 0);
        }
        return Bitmap.createBitmap(pixels, width, height, Bitmap.Config.ARGB_8888);
    }

    private static int getMaxIndex(int[] values) {
        int result = 0;
        for (int i = 1; i < values.length; i++) {
            if (values[result] < values[i])
                result = i;
        }
        return result;
    }

    private static int getMinIndex(int[] values) {
        int result = 0;
        for (int i = 1; i < values.length; i++) {
            if (values[result] > values[i])
                result = i;
        }
        return result;
    }

    private static float[] calculateTransformation(int tintA, int tintB, int colorA, int colorB) {
        float a = tintA / 255f;
        float aP = tintB / 255f;
        float b = colorA / 255f;
        float bP = colorB / 255f;

        float[] result = new float[2];
        result[0] = (b - bP) / ((b * aP) + a - (bP * a) - aP);
        result[1] = (bP - (aP * result[0])) / (1f - (aP * result[0]));

        return result;
    }
}