1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.inputmethod.keyboard.internal;
18
19import com.android.inputmethod.keyboard.internal.MatrixUtils.MatrixOperationFailedException;
20
21import android.test.AndroidTestCase;
22import android.test.suitebuilder.annotation.SmallTest;
23
24@SmallTest
25public class MatrixUtilsTests extends AndroidTestCase {
26    // "run tests" -c com.android.inputmethod.keyboard.internal.MatrixUtilsTests
27    private static final boolean DEBUG = false;
28    private static final float EPSILON = 0.00001f;
29
30    private static void assertEqualsFloat(float f0, float f1) {
31        assertEqualsFloat(f0, f1, EPSILON);
32    }
33
34    /* package */ static void assertEqualsFloat(float f0, float f1, float error) {
35        assertTrue(Math.abs(f0 - f1) < error);
36    }
37
38    public void testMulti() {
39        final float[][] matrixA = {{1, 2}, {3, 4}};
40        final float[][] matrixB = {{5, 6}, {7, 8}};
41        final float[][] retval = new float[2][2];
42        try {
43            MatrixUtils.multiply(matrixA, matrixB, retval);
44        } catch (MatrixOperationFailedException e) {
45            assertTrue(false);
46        }
47        if (DEBUG) {
48            MatrixUtils.dump("multi", retval);
49        }
50        assertEqualsFloat(retval[0][0], 19);
51        assertEqualsFloat(retval[0][1], 22);
52        assertEqualsFloat(retval[1][0], 43);
53        assertEqualsFloat(retval[1][1], 50);
54    }
55
56    public void testInverse() {
57        final int N = 4;
58        final float[][] matrix =
59                {{1, 2, 3, 4}, {4, 0, 5, 6}, {6, 4, 2, 0}, {6, 4, 2, 1}};
60        final float[][] inverse = new float[N][N];
61        final float[][] tempMatrix = new float[N][N];
62        for (int i = 0; i < N; ++i) {
63            for (int j = 0; j < N; ++j) {
64                tempMatrix[i][j] = matrix[i][j];
65            }
66        }
67        final float[][] retval = new float[N][N];
68        try {
69            MatrixUtils.inverse(tempMatrix, inverse);
70        } catch (MatrixOperationFailedException e) {
71            assertTrue(false);
72        }
73        try {
74            MatrixUtils.multiply(matrix, inverse, retval);
75        } catch (MatrixOperationFailedException e) {
76            assertTrue(false);
77        }
78        for (int i = 0; i < N; ++i) {
79            for (int j = 0; j < N; ++j) {
80                assertEqualsFloat(((i == j) ? 1.0f : 0.0f), retval[i][j]);
81            }
82        }
83    }
84}
85