aboutsummaryrefslogtreecommitdiffhomepage
path: root/tests/MatrixTest.cpp
blob: efbd02d2c626a80ec1bf187bf8fbaa697b500367 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493

/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "Test.h"
#include "SkMath.h"
#include "SkMatrix.h"
#include "SkRandom.h"

static bool nearly_equal_scalar(SkScalar a, SkScalar b) {
    // Note that we get more compounded error for multiple operations when
    // SK_SCALAR_IS_FIXED.
#ifdef SK_SCALAR_IS_FLOAT
    const SkScalar tolerance = SK_Scalar1 / 200000;
#else
    const SkScalar tolerance = SK_Scalar1 / 1024;
#endif

    return SkScalarAbs(a - b) <= tolerance;
}

static bool nearly_equal(const SkMatrix& a, const SkMatrix& b) {
    for (int i = 0; i < 9; i++) {
        if (!nearly_equal_scalar(a[i], b[i])) {
            printf("not equal %g %g\n", (float)a[i], (float)b[i]);
            return false;
        }
    }
    return true;
}

static bool are_equal(skiatest::Reporter* reporter,
                      const SkMatrix& a,
                      const SkMatrix& b) {
    bool equal = a == b;
    bool cheapEqual = a.cheapEqualTo(b);
    if (equal != cheapEqual) {
#if SK_SCALAR_IS_FLOAT
        if (equal) {
            bool foundZeroSignDiff = false;
            for (int i = 0; i < 9; ++i) {
                float aVal = a.get(i);
                float bVal = b.get(i);
                int aValI = *SkTCast<int*>(&aVal);
                int bValI = *SkTCast<int*>(&bVal);
                if (0 == aVal && 0 == bVal && aValI != bValI) {
                    foundZeroSignDiff = true;
                } else {
                    REPORTER_ASSERT(reporter, aVal == bVal && aValI == aValI);
                }
            }
            REPORTER_ASSERT(reporter, foundZeroSignDiff);
        } else {
            bool foundNaN = false;
            for (int i = 0; i < 9; ++i) {
                float aVal = a.get(i);
                float bVal = b.get(i);
                int aValI = *SkTCast<int*>(&aVal);
                int bValI = *SkTCast<int*>(&bVal);
                if (sk_float_isnan(aVal) && aValI == bValI) {
                    foundNaN = true;
                } else {
                    REPORTER_ASSERT(reporter, aVal == bVal && aValI == bValI);
                }
            }
            REPORTER_ASSERT(reporter, foundNaN);
        }
#else
        REPORTER_ASSERT(reporter, false);
#endif
    }
    return equal;
}

static bool is_identity(const SkMatrix& m) {
    SkMatrix identity;
    identity.reset();
    return nearly_equal(m, identity);
}

static void test_matrix_recttorect(skiatest::Reporter* reporter) {
    SkRect src, dst;
    SkMatrix matrix;

    src.set(0, 0, SK_Scalar1*10, SK_Scalar1*10);
    dst = src;
    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
    REPORTER_ASSERT(reporter, SkMatrix::kIdentity_Mask == matrix.getType());
    REPORTER_ASSERT(reporter, matrix.rectStaysRect());

    dst.offset(SK_Scalar1, SK_Scalar1);
    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
    REPORTER_ASSERT(reporter, SkMatrix::kTranslate_Mask == matrix.getType());
    REPORTER_ASSERT(reporter, matrix.rectStaysRect());

    dst.fRight += SK_Scalar1;
    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
    REPORTER_ASSERT(reporter, SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask == matrix.getType());
    REPORTER_ASSERT(reporter, matrix.rectStaysRect());

    dst = src;
    dst.fRight = src.fRight * 2;
    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
    REPORTER_ASSERT(reporter, SkMatrix::kScale_Mask == matrix.getType());
    REPORTER_ASSERT(reporter, matrix.rectStaysRect());
}

static void test_flatten(skiatest::Reporter* reporter, const SkMatrix& m) {
    // add 100 in case we have a bug, I don't want to kill my stack in the test
    char buffer[SkMatrix::kMaxFlattenSize + 100];
    uint32_t size1 = m.writeToMemory(NULL);
    uint32_t size2 = m.writeToMemory(buffer);
    REPORTER_ASSERT(reporter, size1 == size2);
    REPORTER_ASSERT(reporter, size1 <= SkMatrix::kMaxFlattenSize);

    SkMatrix m2;
    uint32_t size3 = m2.readFromMemory(buffer);
    REPORTER_ASSERT(reporter, size1 == size3);
    REPORTER_ASSERT(reporter, are_equal(reporter, m, m2));

    char buffer2[SkMatrix::kMaxFlattenSize + 100];
    size3 = m2.writeToMemory(buffer2);
    REPORTER_ASSERT(reporter, size1 == size3);
    REPORTER_ASSERT(reporter, memcmp(buffer, buffer2, size1) == 0);
}

static void test_matrix_max_stretch(skiatest::Reporter* reporter) {
    SkMatrix identity;
    identity.reset();
    REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMaxStretch());

    SkMatrix scale;
    scale.setScale(SK_Scalar1 * 2, SK_Scalar1 * 4);
    REPORTER_ASSERT(reporter, SK_Scalar1 * 4 == scale.getMaxStretch());

    SkMatrix rot90Scale;
    rot90Scale.setRotate(90 * SK_Scalar1);
    rot90Scale.postScale(SK_Scalar1 / 4, SK_Scalar1 / 2);
    REPORTER_ASSERT(reporter, SK_Scalar1 / 2 == rot90Scale.getMaxStretch());

    SkMatrix rotate;
    rotate.setRotate(128 * SK_Scalar1);
    REPORTER_ASSERT(reporter, SkScalarAbs(SK_Scalar1 - rotate.getMaxStretch()) <= SK_ScalarNearlyZero);

    SkMatrix translate;
    translate.setTranslate(10 * SK_Scalar1, -5 * SK_Scalar1);
    REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMaxStretch());

    SkMatrix perspX;
    perspX.reset();
    perspX.setPerspX(SkScalarToPersp(SK_Scalar1 / 1000));
    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMaxStretch());

    SkMatrix perspY;
    perspY.reset();
    perspY.setPerspX(SkScalarToPersp(-SK_Scalar1 / 500));
    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMaxStretch());

    SkMatrix baseMats[] = {scale, rot90Scale, rotate,
                           translate, perspX, perspY};
    SkMatrix mats[2*SK_ARRAY_COUNT(baseMats)];
    for (size_t i = 0; i < SK_ARRAY_COUNT(baseMats); ++i) {
        mats[i] = baseMats[i];
        bool invertable = mats[i].invert(&mats[i + SK_ARRAY_COUNT(baseMats)]);
        REPORTER_ASSERT(reporter, invertable);
    }
    SkRandom rand;
    for (int m = 0; m < 1000; ++m) {
        SkMatrix mat;
        mat.reset();
        for (int i = 0; i < 4; ++i) {
            int x = rand.nextU() % SK_ARRAY_COUNT(mats);
            mat.postConcat(mats[x]);
        }
        SkScalar stretch = mat.getMaxStretch();

        if ((stretch < 0) != mat.hasPerspective()) {
            stretch = mat.getMaxStretch();
        }

        REPORTER_ASSERT(reporter, (stretch < 0) == mat.hasPerspective());

        if (mat.hasPerspective()) {
            m -= 1; // try another non-persp matrix
            continue;
        }

        // test a bunch of vectors. None should be scaled by more than stretch
        // (modulo some error) and we should find a vector that is scaled by
        // almost stretch.
        static const SkScalar gStretchTol = (105 * SK_Scalar1) / 100;
        static const SkScalar gMaxStretchTol = (97 * SK_Scalar1) / 100;
        SkScalar max = 0;
        SkVector vectors[1000];
        for (size_t i = 0; i < SK_ARRAY_COUNT(vectors); ++i) {
            vectors[i].fX = rand.nextSScalar1();
            vectors[i].fY = rand.nextSScalar1();
            if (!vectors[i].normalize()) {
                i -= 1;
                continue;
            }
        }
        mat.mapVectors(vectors, SK_ARRAY_COUNT(vectors));
        for (size_t i = 0; i < SK_ARRAY_COUNT(vectors); ++i) {
            SkScalar d = vectors[i].length();
            REPORTER_ASSERT(reporter, SkScalarDiv(d, stretch) < gStretchTol);
            if (max < d) {
                max = d;
            }
        }
        REPORTER_ASSERT(reporter, SkScalarDiv(max, stretch) >= gMaxStretchTol);
    }
}

// This function is extracted from src/gpu/SkGpuDevice.cpp,
// in order to make sure this function works correctly.
static bool isSimilarityTransformation(const SkMatrix& matrix,
                                       SkScalar tol = SK_ScalarNearlyZero) {
    if (matrix.isIdentity() || matrix.getType() == SkMatrix::kTranslate_Mask) {
        return true;
    }
    if (matrix.hasPerspective()) {
        return false;
    }

    SkScalar mx = matrix.get(SkMatrix::kMScaleX);
    SkScalar sx = matrix.get(SkMatrix::kMSkewX);
    SkScalar my = matrix.get(SkMatrix::kMScaleY);
    SkScalar sy = matrix.get(SkMatrix::kMSkewY);

    if (mx == 0 && sx == 0 && my == 0 && sy == 0) {
        return false;
    }

    // it has scales or skews, but it could also be rotation, check it out.
    SkVector vec[2];
    vec[0].set(mx, sx);
    vec[1].set(sy, my);

    return SkScalarNearlyZero(vec[0].dot(vec[1]), SkScalarSquare(tol)) &&
           SkScalarNearlyEqual(vec[0].lengthSqd(), vec[1].lengthSqd(),
                SkScalarSquare(tol));
}

static void test_matrix_is_similarity_transform(skiatest::Reporter* reporter) {
    SkMatrix mat;

    // identity
    mat.setIdentity();
    REPORTER_ASSERT(reporter, isSimilarityTransformation(mat));

    // translation only
    mat.reset();
    mat.setTranslate(SkIntToScalar(100), SkIntToScalar(100));
    REPORTER_ASSERT(reporter, isSimilarityTransformation(mat));

    // scale with same size
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, isSimilarityTransformation(mat));

    // scale with one negative
    mat.reset();
    mat.setScale(SkIntToScalar(-15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, isSimilarityTransformation(mat));

    // scale with different size
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, !isSimilarityTransformation(mat));

    // scale with same size at a pivot point
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(15),
                 SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, isSimilarityTransformation(mat));

    // scale with different size at a pivot point
    mat.reset();
    mat.setScale(SkIntToScalar(15), SkIntToScalar(20),
                 SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !isSimilarityTransformation(mat));

    // skew with same size
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(15));
    REPORTER_ASSERT(reporter, !isSimilarityTransformation(mat));

    // skew with different size
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, !isSimilarityTransformation(mat));

    // skew with same size at a pivot point
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(15),
                SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !isSimilarityTransformation(mat));

    // skew with different size at a pivot point
    mat.reset();
    mat.setSkew(SkIntToScalar(15), SkIntToScalar(20),
                SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !isSimilarityTransformation(mat));

    // perspective x
    mat.reset();
    mat.setPerspX(SkScalarToPersp(SK_Scalar1 / 2));
    REPORTER_ASSERT(reporter, !isSimilarityTransformation(mat));

    // perspective y
    mat.reset();
    mat.setPerspY(SkScalarToPersp(SK_Scalar1 / 2));
    REPORTER_ASSERT(reporter, !isSimilarityTransformation(mat));

#if SK_SCALAR_IS_FLOAT
    /* We bypass the following tests for SK_SCALAR_IS_FIXED build.
     * The long discussion can be found in this issue:
     *     http://codereview.appspot.com/5999050/
     * In short, we haven't found a perfect way to fix the precision
     * issue, i.e. the way we use tolerance in isSimilarityTransformation
     * is incorrect. The situation becomes worse in fixed build, so
     * we disabled rotation related tests for fixed build.
     */

    // rotate
    for (int angle = 0; angle < 360; ++angle) {
        mat.reset();
        mat.setRotate(SkIntToScalar(angle));
        REPORTER_ASSERT(reporter, isSimilarityTransformation(mat));
    }

    // see if there are any accumulated precision issues
    mat.reset();
    for (int i = 1; i < 360; i++) {
        mat.postRotate(SkIntToScalar(1));
    }
    REPORTER_ASSERT(reporter, isSimilarityTransformation(mat));

    // rotate + translate
    mat.reset();
    mat.setRotate(SkIntToScalar(30));
    mat.postTranslate(SkIntToScalar(10), SkIntToScalar(20));
    REPORTER_ASSERT(reporter, isSimilarityTransformation(mat));

    // rotate + uniform scale
    mat.reset();
    mat.setRotate(SkIntToScalar(30));
    mat.postScale(SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, isSimilarityTransformation(mat));

    // rotate + non-uniform scale
    mat.reset();
    mat.setRotate(SkIntToScalar(30));
    mat.postScale(SkIntToScalar(3), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, !isSimilarityTransformation(mat));
#endif

    // all zero
    mat.setAll(0, 0, 0, 0, 0, 0, 0, 0, 0);
    REPORTER_ASSERT(reporter, !isSimilarityTransformation(mat));

    // all zero except perspective
    mat.setAll(0, 0, 0, 0, 0, 0, 0, 0, SK_Scalar1);
    REPORTER_ASSERT(reporter, !isSimilarityTransformation(mat));

    // scales zero, only skews
    mat.setAll(0, SK_Scalar1, 0,
               SK_Scalar1, 0, 0,
               0, 0, SkMatrix::I()[8]);
    REPORTER_ASSERT(reporter, isSimilarityTransformation(mat));
}

static void TestMatrix(skiatest::Reporter* reporter) {
    SkMatrix    mat, inverse, iden1, iden2;

    mat.reset();
    mat.setTranslate(SK_Scalar1, SK_Scalar1);
    REPORTER_ASSERT(reporter, mat.invert(&inverse));
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));

    mat.setScale(SkIntToScalar(2), SkIntToScalar(2));
    REPORTER_ASSERT(reporter, mat.invert(&inverse));
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));
    test_flatten(reporter, mat);

    mat.setScale(SK_Scalar1/2, SK_Scalar1/2);
    REPORTER_ASSERT(reporter, mat.invert(&inverse));
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));
    test_flatten(reporter, mat);

    mat.setScale(SkIntToScalar(3), SkIntToScalar(5), SkIntToScalar(20), 0);
    mat.postRotate(SkIntToScalar(25));
    REPORTER_ASSERT(reporter, mat.invert(NULL));
    REPORTER_ASSERT(reporter, mat.invert(&inverse));
    iden1.setConcat(mat, inverse);
    REPORTER_ASSERT(reporter, is_identity(iden1));
    iden2.setConcat(inverse, mat);
    REPORTER_ASSERT(reporter, is_identity(iden2));
    test_flatten(reporter, mat);
    test_flatten(reporter, iden2);

    // rectStaysRect test
    {
        static const struct {
            SkScalar    m00, m01, m10, m11;
            bool        mStaysRect;
        }
        gRectStaysRectSamples[] = {
            {          0,          0,          0,           0, false },
            {          0,          0,          0,  SK_Scalar1, false },
            {          0,          0, SK_Scalar1,           0, false },
            {          0,          0, SK_Scalar1,  SK_Scalar1, false },
            {          0, SK_Scalar1,          0,           0, false },
            {          0, SK_Scalar1,          0,  SK_Scalar1, false },
            {          0, SK_Scalar1, SK_Scalar1,           0, true },
            {          0, SK_Scalar1, SK_Scalar1,  SK_Scalar1, false },
            { SK_Scalar1,          0,          0,           0, false },
            { SK_Scalar1,          0,          0,  SK_Scalar1, true },
            { SK_Scalar1,          0, SK_Scalar1,           0, false },
            { SK_Scalar1,          0, SK_Scalar1,  SK_Scalar1, false },
            { SK_Scalar1, SK_Scalar1,          0,           0, false },
            { SK_Scalar1, SK_Scalar1,          0,  SK_Scalar1, false },
            { SK_Scalar1, SK_Scalar1, SK_Scalar1,           0, false },
            { SK_Scalar1, SK_Scalar1, SK_Scalar1,  SK_Scalar1, false }
        };

        for (size_t i = 0; i < SK_ARRAY_COUNT(gRectStaysRectSamples); i++) {
            SkMatrix    m;

            m.reset();
            m.set(SkMatrix::kMScaleX, gRectStaysRectSamples[i].m00);
            m.set(SkMatrix::kMSkewX,  gRectStaysRectSamples[i].m01);
            m.set(SkMatrix::kMSkewY,  gRectStaysRectSamples[i].m10);
            m.set(SkMatrix::kMScaleY, gRectStaysRectSamples[i].m11);
            REPORTER_ASSERT(reporter,
                    m.rectStaysRect() == gRectStaysRectSamples[i].mStaysRect);
        }
    }

    mat.reset();
    mat.set(SkMatrix::kMScaleX, SkIntToScalar(1));
    mat.set(SkMatrix::kMSkewX,  SkIntToScalar(2));
    mat.set(SkMatrix::kMTransX, SkIntToScalar(3));
    mat.set(SkMatrix::kMSkewY,  SkIntToScalar(4));
    mat.set(SkMatrix::kMScaleY, SkIntToScalar(5));
    mat.set(SkMatrix::kMTransY, SkIntToScalar(6));
    SkScalar affine[6];
    REPORTER_ASSERT(reporter, mat.asAffine(affine));

    #define affineEqual(e) affine[SkMatrix::kA##e] == mat.get(SkMatrix::kM##e)
    REPORTER_ASSERT(reporter, affineEqual(ScaleX));
    REPORTER_ASSERT(reporter, affineEqual(SkewY));
    REPORTER_ASSERT(reporter, affineEqual(SkewX));
    REPORTER_ASSERT(reporter, affineEqual(ScaleY));
    REPORTER_ASSERT(reporter, affineEqual(TransX));
    REPORTER_ASSERT(reporter, affineEqual(TransY));
    #undef affineEqual

    mat.set(SkMatrix::kMPersp1, SkScalarToPersp(SK_Scalar1 / 2));
    REPORTER_ASSERT(reporter, !mat.asAffine(affine));

    SkMatrix mat2;
    mat2.reset();
    mat.reset();
    SkScalar zero = 0;
    mat.set(SkMatrix::kMSkewX, -zero);
    REPORTER_ASSERT(reporter, are_equal(reporter, mat, mat2));

    mat2.reset();
    mat.reset();
    mat.set(SkMatrix::kMSkewX, SK_ScalarNaN);
    mat2.set(SkMatrix::kMSkewX, SK_ScalarNaN);
    // fixed pt doesn't have the property that NaN does not equal itself.
#ifdef SK_SCALAR_IS_FIXED
    REPORTER_ASSERT(reporter, are_equal(reporter, mat, mat2));
#else
    REPORTER_ASSERT(reporter, !are_equal(reporter, mat, mat2));
#endif

    test_matrix_max_stretch(reporter);
    test_matrix_is_similarity_transform(reporter);
    test_matrix_recttorect(reporter);
}

#include "TestClassDef.h"
DEFINE_TESTCLASS("Matrix", MatrixTestClass, TestMatrix)