/*
* Copyright 2016 DiffPlug
*
* 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.diffplug.talks.rxjava_and_swt;
import org.eclipse.swt.graphics.RGB;
import org.junit.Assert;
import org.junit.Test;
public class YCbCrTest {
@Test
/** Round trip every RGB color through the YCbCr color space. */
public void roundTrip() {
for (int r = 0; r < 255; ++r) {
for (int g = 0; g < 255; ++g) {
for (int b = 0; b < 255; ++b) {
roundTripTestCase(r, g, b);
}
}
}
}
private void roundTripTestCase(int r, int g, int b) {
RGB expected = new RGB(r, g, b);
RGB yCbCr = ColorPicker.toYCbCr(expected);
RGB roundTrip = ColorPicker.fromYCbCr(yCbCr);
if (!expected.equals(roundTrip)) {
// if they don't match exactly, allow a maximum delta of 1 for rounding errors
int deltaR = Math.abs(roundTrip.red - expected.red);
int deltaG = Math.abs(roundTrip.green - expected.green);
int deltaB = Math.abs(roundTrip.blue - expected.blue);
int maxDelta = Math.max(Math.max(deltaR, deltaG), deltaB);
Assert.assertTrue(maxDelta <= 1);
}
}
}
