tests/tests/graphics/src/android/graphics/cts/ColorMatrixColorFilterTest.java

/*
 * Copyright (C) 2009 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 android.graphics.cts;

import dalvik.annotation.TestLevel;
import dalvik.annotation.TestTargetClass;
import dalvik.annotation.TestTargetNew;
import dalvik.annotation.TestTargets;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.Paint;
import android.graphics.Bitmap.Config;

import junit.framework.TestCase;

@TestTargetClass(ColorMatrixColorFilter.class)
public class ColorMatrixColorFilterTest extends TestCase {

    private static final int TOLERANCE = 1;

    @TestTargets({
        @TestTargetNew(
            level = TestLevel.COMPLETE,
            method = "ColorMatrixColorFilter",
            args = {ColorMatrix.class}
        ),
        @TestTargetNew(
            level = TestLevel.COMPLETE,
            method = "ColorMatrixColorFilter",
            args = {float[].class}
        )
    })
    public void testColorMatrixColorFilter() {
        ColorMatrixColorFilter filter;

        ColorMatrix cm = new ColorMatrix();
        float[] blueToCyan = new float[] {
                1f, 0f, 0f, 0f, 0f,
                0f, 1f, 1f, 0f, 0f,
                0f, 0f, 1f, 0f, 0f,
                0f, 0f, 0f, 1f, 0f };
        cm.set(blueToCyan);
        filter = new ColorMatrixColorFilter(cm);
        Bitmap bitmap = Bitmap.createBitmap(1, 1, Config.ARGB_8888);
        Canvas canvas = new Canvas(bitmap);
        Paint paint = new Paint();
        paint.setColor(Color.BLUE);
        paint.setColorFilter(filter);
        canvas.drawPoint(0, 0, paint);
        assertColor(Color.CYAN, bitmap.getPixel(0, 0));
        paint.setColor(Color.GREEN);
        canvas.drawPoint(0, 0, paint);
        assertColor(Color.GREEN, bitmap.getPixel(0, 0));
        paint.setColor(Color.RED);
        canvas.drawPoint(0, 0, paint);
        assertColor(Color.RED, bitmap.getPixel(0, 0));
        // color components are clipped, not scaled
        paint.setColor(Color.MAGENTA);
        canvas.drawPoint(0, 0, paint);
        assertColor(Color.WHITE, bitmap.getPixel(0, 0));

        float[] transparentRedAddBlue = new float[] {
                1f, 0f, 0f, 0f, 0f,
                0f, 1f, 0f, 0f, 0f,
                0f, 0f, 1f, 0f, 64f,
                -0.5f, 0f, 0f, 1f, 0f
        };
        filter = new ColorMatrixColorFilter(transparentRedAddBlue);
        paint.setColorFilter(filter);
        paint.setColor(Color.RED);
        bitmap.eraseColor(Color.TRANSPARENT);
        canvas.drawPoint(0, 0, paint);
        assertColor(Color.argb(128, 255, 0, 64), bitmap.getPixel(0, 0));
        paint.setColor(Color.CYAN);
        canvas.drawPoint(0, 0, paint);
        // blue gets clipped
        assertColor(Color.CYAN, bitmap.getPixel(0, 0));

        // change array to filter out green
        assertEquals(1f, transparentRedAddBlue[6]);
        transparentRedAddBlue[6] = 0f;
        // changing the array has no effect
        canvas.drawPoint(0, 0, paint);
        assertColor(Color.CYAN, bitmap.getPixel(0, 0));
        // create a new filter with the changed matrix
        paint.setColorFilter(new ColorMatrixColorFilter(transparentRedAddBlue));
        canvas.drawPoint(0, 0, paint);
        assertColor(Color.BLUE, bitmap.getPixel(0, 0));
    }

    private void assertColor(int expected, int actual) {
        assertEquals(Color.red(expected), Color.red(actual), TOLERANCE);
        assertEquals(Color.green(expected), Color.green(actual), TOLERANCE);
        assertEquals(Color.blue(expected), Color.blue(actual), TOLERANCE);
        assertEquals(Color.alpha(expected), Color.alpha(actual), TOLERANCE);
    }
}