tests/tests/transition/src/android/transition/cts/ArcMotionTest.java

/*
 * Copyright (C) 2016 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.transition.cts;

import android.graphics.Path;
import android.graphics.PathMeasure;
import android.transition.ArcMotion;

import junit.framework.TestCase;

public class ArcMotionTest extends PathMotionTest {

    public void test90Quadrants() throws Throwable {
        ArcMotion arcMotion = new ArcMotion();
        arcMotion.setMaximumAngle(90);

        Path expected = arcWithPoint(0, 100, 100, 0, 100, 100);
        Path path = arcMotion.getPath(0, 100, 100, 0);
        assertPathMatches(expected, path);

        expected = arcWithPoint(100, 0, 0, -100, 100, -100);
        path = arcMotion.getPath(100, 0, 0, -100);
        assertPathMatches(expected, path);

        expected = arcWithPoint(0, -100, -100, 0, -100, -100);
        path = arcMotion.getPath(0, -100, -100, 0);
        assertPathMatches(expected, path);

        expected = arcWithPoint(-100, 0, 0, 100, -100, 100);
        path = arcMotion.getPath(-100, 0, 0, 100);
        assertPathMatches(expected, path);
    }

    public void test345Triangles() throws Throwable {
        // 3-4-5 triangles are easy to calculate the control points
        ArcMotion arcMotion = new ArcMotion();
        arcMotion.setMaximumAngle(90);
        Path expected;
        Path path;

        expected = arcWithPoint(0, 120, 160, 0, 125, 120);
        path = arcMotion.getPath(0, 120, 160, 0);
        assertPathMatches(expected, path);

        expected = arcWithPoint(0, 160, 120, 0, 120, 125);
        path = arcMotion.getPath(0, 160, 120, 0);
        assertPathMatches(expected, path);

        expected = arcWithPoint(-120, 0, 0, 160, -120, 125);
        path = arcMotion.getPath(-120, 0, 0, 160);
        assertPathMatches(expected, path);

        expected = arcWithPoint(-160, 0, 0, 120, -125, 120);
        path = arcMotion.getPath(-160, 0, 0, 120);
        assertPathMatches(expected, path);

        expected = arcWithPoint(0, -120, -160, 0, -125, -120);
        path = arcMotion.getPath(0, -120, -160, 0);
        assertPathMatches(expected, path);

        expected = arcWithPoint(0, -160, -120, 0, -120, -125);
        path = arcMotion.getPath(0, -160, -120, 0);
        assertPathMatches(expected, path);

        expected = arcWithPoint(120, 0, 0, -160, 120, -125);
        path = arcMotion.getPath(120, 0, 0, -160);
        assertPathMatches(expected, path);

        expected = arcWithPoint(160, 0, 0, -120, 125, -120);
        path = arcMotion.getPath(160, 0, 0, -120);
        assertPathMatches(expected, path);
    }

    private Path arcWithPoint(float startX, float startY, float endX, float endY,
            float eX, float eY) {
        float c1x = (eX + startX)/2;
        float c1y = (eY + startY)/2;
        float c2x = (eX + endX)/2;
        float c2y = (eY + endY)/2;
        Path path = new Path();
        path.moveTo(startX, startY);
        path.cubicTo(c1x, c1y, c2x, c2y, endX, endY);
        return path;
    }

    public void testMaximumAngle() throws Throwable {
        ArcMotion arcMotion = new ArcMotion();
        arcMotion.setMaximumAngle(45f);
        assertEquals(45f, arcMotion.getMaximumAngle());

        float ratio = (float) Math.tan(Math.PI/8);
        float ex = 50 + (50 * ratio);
        float ey = ex;

        Path expected = arcWithPoint(0, 100, 100, 0, ex, ey);
        Path path = arcMotion.getPath(0, 100, 100, 0);
        assertPathMatches(expected, path);
    }

    public void testMinimumHorizontalAngle() throws Throwable {
        ArcMotion arcMotion = new ArcMotion();
        arcMotion.setMinimumHorizontalAngle(45);
        assertEquals(45f, arcMotion.getMinimumHorizontalAngle());

        float ey = (float)(Math.tan(Math.PI/8) * 50);
        float ex = 50;
        Path expected = arcWithPoint(0, 0, 100, 0, ex, ey);
        Path path = arcMotion.getPath(0, 0, 100, 0);
        assertPathMatches(expected, path);

        // Pretty much the same, but follows a different path.
        expected = arcWithPoint(0, 0, 100.001f, 0, ex, ey);
        path = arcMotion.getPath(0, 0, 100.001f, 0);
        assertPathMatches(expected, path);
    }

    public void testMinimumVerticalAngle() throws Throwable {
        ArcMotion arcMotion = new ArcMotion();
        arcMotion.setMinimumVerticalAngle(45);
        assertEquals(45f, arcMotion.getMinimumVerticalAngle());

        float ex = (float)(Math.tan(Math.PI/8) * 50);
        float ey = 50;
        Path expected = arcWithPoint(0, 0, 0, 100, ex, ey);
        Path path = arcMotion.getPath(0, 0, 0, 100);
        assertPathMatches(expected, path);

        // Pretty much the same, but follows a different path.
        expected = arcWithPoint(0, 0, 0, 100.001f, ex, ey);
        path = arcMotion.getPath(0, 0, 0, 100.001f);
        assertPathMatches(expected, path);
    }
}