MatrixTest.cpp revision 259fbaf7a464827bc560517988daeb5836e11e98
1
2/*
3 * Copyright 2011 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8#include "Test.h"
9#include "SkMath.h"
10#include "SkMatrix.h"
11#include "SkMatrixUtils.h"
12#include "SkRandom.h"
13
14static bool nearly_equal_scalar(SkScalar a, SkScalar b) {
15    // Note that we get more compounded error for multiple operations when
16    // SK_SCALAR_IS_FIXED.
17#ifdef SK_SCALAR_IS_FLOAT
18    const SkScalar tolerance = SK_Scalar1 / 200000;
19#else
20    const SkScalar tolerance = SK_Scalar1 / 1024;
21#endif
22
23    return SkScalarAbs(a - b) <= tolerance;
24}
25
26static bool nearly_equal(const SkMatrix& a, const SkMatrix& b) {
27    for (int i = 0; i < 9; i++) {
28        if (!nearly_equal_scalar(a[i], b[i])) {
29            printf("not equal %g %g\n", (float)a[i], (float)b[i]);
30            return false;
31        }
32    }
33    return true;
34}
35
36static bool are_equal(skiatest::Reporter* reporter,
37                      const SkMatrix& a,
38                      const SkMatrix& b) {
39    bool equal = a == b;
40    bool cheapEqual = a.cheapEqualTo(b);
41    if (equal != cheapEqual) {
42#ifdef SK_SCALAR_IS_FLOAT
43        if (equal) {
44            bool foundZeroSignDiff = false;
45            for (int i = 0; i < 9; ++i) {
46                float aVal = a.get(i);
47                float bVal = b.get(i);
48                int aValI = *SkTCast<int*>(&aVal);
49                int bValI = *SkTCast<int*>(&bVal);
50                if (0 == aVal && 0 == bVal && aValI != bValI) {
51                    foundZeroSignDiff = true;
52                } else {
53                    REPORTER_ASSERT(reporter, aVal == bVal && aValI == aValI);
54                }
55            }
56            REPORTER_ASSERT(reporter, foundZeroSignDiff);
57        } else {
58            bool foundNaN = false;
59            for (int i = 0; i < 9; ++i) {
60                float aVal = a.get(i);
61                float bVal = b.get(i);
62                int aValI = *SkTCast<int*>(&aVal);
63                int bValI = *SkTCast<int*>(&bVal);
64                if (sk_float_isnan(aVal) && aValI == bValI) {
65                    foundNaN = true;
66                } else {
67                    REPORTER_ASSERT(reporter, aVal == bVal && aValI == bValI);
68                }
69            }
70            REPORTER_ASSERT(reporter, foundNaN);
71        }
72#else
73        REPORTER_ASSERT(reporter, false);
74#endif
75    }
76    return equal;
77}
78
79static bool is_identity(const SkMatrix& m) {
80    SkMatrix identity;
81    identity.reset();
82    return nearly_equal(m, identity);
83}
84
85static void test_matrix_recttorect(skiatest::Reporter* reporter) {
86    SkRect src, dst;
87    SkMatrix matrix;
88
89    src.set(0, 0, SK_Scalar1*10, SK_Scalar1*10);
90    dst = src;
91    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
92    REPORTER_ASSERT(reporter, SkMatrix::kIdentity_Mask == matrix.getType());
93    REPORTER_ASSERT(reporter, matrix.rectStaysRect());
94
95    dst.offset(SK_Scalar1, SK_Scalar1);
96    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
97    REPORTER_ASSERT(reporter, SkMatrix::kTranslate_Mask == matrix.getType());
98    REPORTER_ASSERT(reporter, matrix.rectStaysRect());
99
100    dst.fRight += SK_Scalar1;
101    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
102    REPORTER_ASSERT(reporter,
103                    (SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask) == matrix.getType());
104    REPORTER_ASSERT(reporter, matrix.rectStaysRect());
105
106    dst = src;
107    dst.fRight = src.fRight * 2;
108    matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
109    REPORTER_ASSERT(reporter, SkMatrix::kScale_Mask == matrix.getType());
110    REPORTER_ASSERT(reporter, matrix.rectStaysRect());
111}
112
113static void test_flatten(skiatest::Reporter* reporter, const SkMatrix& m) {
114    // add 100 in case we have a bug, I don't want to kill my stack in the test
115    char buffer[SkMatrix::kMaxFlattenSize + 100];
116    uint32_t size1 = m.writeToMemory(NULL);
117    uint32_t size2 = m.writeToMemory(buffer);
118    REPORTER_ASSERT(reporter, size1 == size2);
119    REPORTER_ASSERT(reporter, size1 <= SkMatrix::kMaxFlattenSize);
120
121    SkMatrix m2;
122    uint32_t size3 = m2.readFromMemory(buffer);
123    REPORTER_ASSERT(reporter, size1 == size3);
124    REPORTER_ASSERT(reporter, are_equal(reporter, m, m2));
125
126    char buffer2[SkMatrix::kMaxFlattenSize + 100];
127    size3 = m2.writeToMemory(buffer2);
128    REPORTER_ASSERT(reporter, size1 == size3);
129    REPORTER_ASSERT(reporter, memcmp(buffer, buffer2, size1) == 0);
130}
131
132static void test_matrix_max_stretch(skiatest::Reporter* reporter) {
133    SkMatrix identity;
134    identity.reset();
135    REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMaxStretch());
136
137    SkMatrix scale;
138    scale.setScale(SK_Scalar1 * 2, SK_Scalar1 * 4);
139    REPORTER_ASSERT(reporter, SK_Scalar1 * 4 == scale.getMaxStretch());
140
141    SkMatrix rot90Scale;
142    rot90Scale.setRotate(90 * SK_Scalar1);
143    rot90Scale.postScale(SK_Scalar1 / 4, SK_Scalar1 / 2);
144    REPORTER_ASSERT(reporter, SK_Scalar1 / 2 == rot90Scale.getMaxStretch());
145
146    SkMatrix rotate;
147    rotate.setRotate(128 * SK_Scalar1);
148    REPORTER_ASSERT(reporter, SkScalarAbs(SK_Scalar1 - rotate.getMaxStretch()) <= SK_ScalarNearlyZero);
149
150    SkMatrix translate;
151    translate.setTranslate(10 * SK_Scalar1, -5 * SK_Scalar1);
152    REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMaxStretch());
153
154    SkMatrix perspX;
155    perspX.reset();
156    perspX.setPerspX(SkScalarToPersp(SK_Scalar1 / 1000));
157    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMaxStretch());
158
159    SkMatrix perspY;
160    perspY.reset();
161    perspY.setPerspX(SkScalarToPersp(-SK_Scalar1 / 500));
162    REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMaxStretch());
163
164    SkMatrix baseMats[] = {scale, rot90Scale, rotate,
165                           translate, perspX, perspY};
166    SkMatrix mats[2*SK_ARRAY_COUNT(baseMats)];
167    for (size_t i = 0; i < SK_ARRAY_COUNT(baseMats); ++i) {
168        mats[i] = baseMats[i];
169        bool invertable = mats[i].invert(&mats[i + SK_ARRAY_COUNT(baseMats)]);
170        REPORTER_ASSERT(reporter, invertable);
171    }
172    SkMWCRandom rand;
173    for (int m = 0; m < 1000; ++m) {
174        SkMatrix mat;
175        mat.reset();
176        for (int i = 0; i < 4; ++i) {
177            int x = rand.nextU() % SK_ARRAY_COUNT(mats);
178            mat.postConcat(mats[x]);
179        }
180        SkScalar stretch = mat.getMaxStretch();
181
182        if ((stretch < 0) != mat.hasPerspective()) {
183            stretch = mat.getMaxStretch();
184        }
185
186        REPORTER_ASSERT(reporter, (stretch < 0) == mat.hasPerspective());
187
188        if (mat.hasPerspective()) {
189            m -= 1; // try another non-persp matrix
190            continue;
191        }
192
193        // test a bunch of vectors. None should be scaled by more than stretch
194        // (modulo some error) and we should find a vector that is scaled by
195        // almost stretch.
196        static const SkScalar gStretchTol = (105 * SK_Scalar1) / 100;
197        static const SkScalar gMaxStretchTol = (97 * SK_Scalar1) / 100;
198        SkScalar max = 0;
199        SkVector vectors[1000];
200        for (size_t i = 0; i < SK_ARRAY_COUNT(vectors); ++i) {
201            vectors[i].fX = rand.nextSScalar1();
202            vectors[i].fY = rand.nextSScalar1();
203            if (!vectors[i].normalize()) {
204                i -= 1;
205                continue;
206            }
207        }
208        mat.mapVectors(vectors, SK_ARRAY_COUNT(vectors));
209        for (size_t i = 0; i < SK_ARRAY_COUNT(vectors); ++i) {
210            SkScalar d = vectors[i].length();
211            REPORTER_ASSERT(reporter, SkScalarDiv(d, stretch) < gStretchTol);
212            if (max < d) {
213                max = d;
214            }
215        }
216        REPORTER_ASSERT(reporter, SkScalarDiv(max, stretch) >= gMaxStretchTol);
217    }
218}
219
220static void test_matrix_is_similarity(skiatest::Reporter* reporter) {
221    SkMatrix mat;
222
223    // identity
224    mat.setIdentity();
225    REPORTER_ASSERT(reporter, mat.isSimilarity());
226
227    // translation only
228    mat.reset();
229    mat.setTranslate(SkIntToScalar(100), SkIntToScalar(100));
230    REPORTER_ASSERT(reporter, mat.isSimilarity());
231
232    // scale with same size
233    mat.reset();
234    mat.setScale(SkIntToScalar(15), SkIntToScalar(15));
235    REPORTER_ASSERT(reporter, mat.isSimilarity());
236
237    // scale with one negative
238    mat.reset();
239    mat.setScale(SkIntToScalar(-15), SkIntToScalar(15));
240    REPORTER_ASSERT(reporter, mat.isSimilarity());
241
242    // scale with different size
243    mat.reset();
244    mat.setScale(SkIntToScalar(15), SkIntToScalar(20));
245    REPORTER_ASSERT(reporter, !mat.isSimilarity());
246
247    // scale with same size at a pivot point
248    mat.reset();
249    mat.setScale(SkIntToScalar(15), SkIntToScalar(15),
250                 SkIntToScalar(2), SkIntToScalar(2));
251    REPORTER_ASSERT(reporter, mat.isSimilarity());
252
253    // scale with different size at a pivot point
254    mat.reset();
255    mat.setScale(SkIntToScalar(15), SkIntToScalar(20),
256                 SkIntToScalar(2), SkIntToScalar(2));
257    REPORTER_ASSERT(reporter, !mat.isSimilarity());
258
259    // skew with same size
260    mat.reset();
261    mat.setSkew(SkIntToScalar(15), SkIntToScalar(15));
262    REPORTER_ASSERT(reporter, !mat.isSimilarity());
263
264    // skew with different size
265    mat.reset();
266    mat.setSkew(SkIntToScalar(15), SkIntToScalar(20));
267    REPORTER_ASSERT(reporter, !mat.isSimilarity());
268
269    // skew with same size at a pivot point
270    mat.reset();
271    mat.setSkew(SkIntToScalar(15), SkIntToScalar(15),
272                SkIntToScalar(2), SkIntToScalar(2));
273    REPORTER_ASSERT(reporter, !mat.isSimilarity());
274
275    // skew with different size at a pivot point
276    mat.reset();
277    mat.setSkew(SkIntToScalar(15), SkIntToScalar(20),
278                SkIntToScalar(2), SkIntToScalar(2));
279    REPORTER_ASSERT(reporter, !mat.isSimilarity());
280
281    // perspective x
282    mat.reset();
283    mat.setPerspX(SkScalarToPersp(SK_Scalar1 / 2));
284    REPORTER_ASSERT(reporter, !mat.isSimilarity());
285
286    // perspective y
287    mat.reset();
288    mat.setPerspY(SkScalarToPersp(SK_Scalar1 / 2));
289    REPORTER_ASSERT(reporter, !mat.isSimilarity());
290
291#ifdef SK_SCALAR_IS_FLOAT
292    /* We bypass the following tests for SK_SCALAR_IS_FIXED build.
293     * The long discussion can be found in this issue:
294     *     http://codereview.appspot.com/5999050/
295     * In short, we haven't found a perfect way to fix the precision
296     * issue, i.e. the way we use tolerance in isSimilarityTransformation
297     * is incorrect. The situation becomes worse in fixed build, so
298     * we disabled rotation related tests for fixed build.
299     */
300
301    // rotate
302    for (int angle = 0; angle < 360; ++angle) {
303        mat.reset();
304        mat.setRotate(SkIntToScalar(angle));
305        REPORTER_ASSERT(reporter, mat.isSimilarity());
306    }
307
308    // see if there are any accumulated precision issues
309    mat.reset();
310    for (int i = 1; i < 360; i++) {
311        mat.postRotate(SkIntToScalar(1));
312    }
313    REPORTER_ASSERT(reporter, mat.isSimilarity());
314
315    // rotate + translate
316    mat.reset();
317    mat.setRotate(SkIntToScalar(30));
318    mat.postTranslate(SkIntToScalar(10), SkIntToScalar(20));
319    REPORTER_ASSERT(reporter, mat.isSimilarity());
320
321    // rotate + uniform scale
322    mat.reset();
323    mat.setRotate(SkIntToScalar(30));
324    mat.postScale(SkIntToScalar(2), SkIntToScalar(2));
325    REPORTER_ASSERT(reporter, mat.isSimilarity());
326
327    // rotate + non-uniform scale
328    mat.reset();
329    mat.setRotate(SkIntToScalar(30));
330    mat.postScale(SkIntToScalar(3), SkIntToScalar(2));
331    REPORTER_ASSERT(reporter, !mat.isSimilarity());
332#endif
333
334    // all zero
335    mat.setAll(0, 0, 0, 0, 0, 0, 0, 0, 0);
336    REPORTER_ASSERT(reporter, !mat.isSimilarity());
337
338    // all zero except perspective
339    mat.setAll(0, 0, 0, 0, 0, 0, 0, 0, SK_Scalar1);
340    REPORTER_ASSERT(reporter, !mat.isSimilarity());
341
342    // scales zero, only skews
343    mat.setAll(0, SK_Scalar1, 0,
344               SK_Scalar1, 0, 0,
345               0, 0, SkMatrix::I()[8]);
346    REPORTER_ASSERT(reporter, mat.isSimilarity());
347}
348
349// For test_matrix_decomposition, below.
350static bool scalar_nearly_equal_relative(SkScalar a, SkScalar b,
351                                         SkScalar tolerance = SK_ScalarNearlyZero) {
352    // from Bruce Dawson
353    SkScalar diff = SkScalarAbs(a - b);
354    if (diff < tolerance) {
355        return true;
356    }
357
358    a = SkScalarAbs(a);
359    b = SkScalarAbs(b);
360    SkScalar largest = (b > a) ? b : a;
361
362    if (diff <= largest*tolerance) {
363        return true;
364    }
365
366    return false;
367}
368
369static void test_matrix_decomposition(skiatest::Reporter* reporter) {
370    SkMatrix mat;
371    SkScalar rotation0, scaleX, scaleY, rotation1;
372
373    const float kRotation0 = 15.5f;
374    const float kRotation1 = -50.f;
375    const float kScale0 = 5000.f;
376    const float kScale1 = 0.001f;
377
378    // identity
379    mat.reset();
380    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
381    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation0));
382    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleX, SK_Scalar1));
383    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleY, SK_Scalar1));
384    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation1));
385    // make sure it doesn't crash if we pass in NULLs
386    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, NULL, NULL, NULL, NULL));
387
388    // rotation only
389    mat.setRotate(kRotation0);
390    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
391    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(rotation0, SkDegreesToRadians(kRotation0)));
392    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleX, SK_Scalar1));
393    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleY, SK_Scalar1));
394    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation1));
395
396    // uniform scale only
397    mat.setScale(kScale0, kScale0);
398    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
399    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation0));
400    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleX, kScale0));
401    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleY, kScale0));
402    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation1));
403
404    // anisotropic scale only
405    mat.setScale(kScale1, kScale0);
406    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
407    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation0));
408    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleX, kScale1));
409    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleY, kScale0));
410    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation1));
411
412    // rotation then uniform scale
413    mat.setRotate(kRotation1);
414    mat.postScale(kScale0, kScale0);
415    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
416    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(rotation0, SkDegreesToRadians(kRotation1)));
417    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleX, kScale0));
418    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleY, kScale0));
419    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation1));
420
421    // uniform scale then rotation
422    mat.setScale(kScale0, kScale0);
423    mat.postRotate(kRotation1);
424    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
425    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(rotation0, SkDegreesToRadians(kRotation1)));
426    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleX, kScale0));
427    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleY, kScale0));
428    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation1));
429
430    // rotation then uniform scale+reflection
431    mat.setRotate(kRotation0);
432    mat.postScale(kScale1, -kScale1);
433    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
434    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(rotation0, SkDegreesToRadians(kRotation0)));
435    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleX, kScale1));
436    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleY, -kScale1));
437    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation1));
438
439    // uniform scale+reflection, then rotate
440    mat.setScale(kScale0, -kScale0);
441    mat.postRotate(kRotation1);
442    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
443    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(rotation0, SkDegreesToRadians(-kRotation1)));
444    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleX, kScale0));
445    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleY, -kScale0));
446    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation1));
447
448    // rotation then anisotropic scale
449    mat.setRotate(kRotation1);
450    mat.postScale(kScale1, kScale0);
451    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
452    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(rotation0, SkDegreesToRadians(kRotation1)));
453    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleX, kScale1));
454    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleY, kScale0));
455    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation1));
456
457    // anisotropic scale then rotation
458    mat.setScale(kScale1, kScale0);
459    mat.postRotate(kRotation0);
460    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
461    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation0));
462    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleX, kScale1));
463    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleY, kScale0));
464    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(rotation1, SkDegreesToRadians(kRotation0)));
465
466    // rotation, uniform scale, then different rotation
467    mat.setRotate(kRotation1);
468    mat.postScale(kScale0, kScale0);
469    mat.postRotate(kRotation0);
470    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
471    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(rotation0,
472                                                  SkDegreesToRadians(kRotation0 + kRotation1)));
473    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleX, kScale0));
474    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(scaleY, kScale0));
475    REPORTER_ASSERT(reporter, SkScalarNearlyZero(rotation1));
476
477    // rotation, anisotropic scale, then different rotation
478    mat.setRotate(kRotation0);
479    mat.postScale(kScale1, kScale0);
480    mat.postRotate(kRotation1);
481    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
482    // Because of the shear/skew we won't get the same results, so we need to multiply it out.
483    // Generating the matrices requires doing a radian-to-degree calculation, then degree-to-radian
484    // calculation (in setRotate()), which adds error, so this just computes the matrix elements
485    // directly.
486    SkScalar c0;
487    SkScalar s0 = SkScalarSinCos(rotation0, &c0);
488    SkScalar c1;
489    SkScalar s1 = SkScalarSinCos(rotation1, &c1);
490    // We do a relative check here because large scale factors cause problems with an absolute check
491    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMScaleX],
492                                                           scaleX*c0*c1 - scaleY*s0*s1));
493    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMSkewX],
494                                                           -scaleX*s0*c1 - scaleY*c0*s1));
495    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMSkewY],
496                                                           scaleX*c0*s1 + scaleY*s0*c1));
497    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMScaleY],
498                                                           -scaleX*s0*s1 + scaleY*c0*c1));
499
500    // try some random matrices
501    SkMWCRandom rand;
502    for (int m = 0; m < 1000; ++m) {
503        SkScalar rot0 = rand.nextRangeF(-SK_ScalarPI, SK_ScalarPI);
504        SkScalar sx = rand.nextRangeF(-3000.f, 3000.f);
505        SkScalar sy = rand.nextRangeF(-3000.f, 3000.f);
506        SkScalar rot1 = rand.nextRangeF(-SK_ScalarPI, SK_ScalarPI);
507        mat.setRotate(rot0);
508        mat.postScale(sx, sy);
509        mat.postRotate(rot1);
510
511        if (SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1)) {
512            SkScalar c0;
513            SkScalar s0 = SkScalarSinCos(rotation0, &c0);
514            SkScalar c1;
515            SkScalar s1 = SkScalarSinCos(rotation1, &c1);
516            REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMScaleX],
517                                                                   scaleX*c0*c1 - scaleY*s0*s1));
518            REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMSkewX],
519                                                                   -scaleX*s0*c1 - scaleY*c0*s1));
520            REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMSkewY],
521                                                                   scaleX*c0*s1 + scaleY*s0*c1));
522            REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMScaleY],
523                                                                   -scaleX*s0*s1 + scaleY*c0*c1));
524        } else {
525            // if the matrix is degenerate, the basis vectors should be near-parallel or near-zero
526            SkScalar perpdot = mat[SkMatrix::kMScaleX]*mat[SkMatrix::kMScaleY] -
527                               mat[SkMatrix::kMSkewX]*mat[SkMatrix::kMSkewY];
528            REPORTER_ASSERT(reporter, SkScalarNearlyZero(perpdot));
529        }
530    }
531
532    // translation shouldn't affect this
533    mat.postTranslate(-1000.f, 1000.f);
534    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
535    s0 = SkScalarSinCos(rotation0, &c0);
536    s1 = SkScalarSinCos(rotation1, &c1);
537    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMScaleX],
538                                                           scaleX*c0*c1 - scaleY*s0*s1));
539    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMSkewX],
540                                                           -scaleX*s0*c1 - scaleY*c0*s1));
541    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMSkewY],
542                                                           scaleX*c0*s1 + scaleY*s0*c1));
543    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMScaleY],
544                                                           -scaleX*s0*s1 + scaleY*c0*c1));
545
546    // perspective shouldn't affect this
547    mat[SkMatrix::kMPersp0] = 12.f;
548    mat[SkMatrix::kMPersp1] = 4.f;
549    mat[SkMatrix::kMPersp2] = 1872.f;
550    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
551    s0 = SkScalarSinCos(rotation0, &c0);
552    s1 = SkScalarSinCos(rotation1, &c1);
553    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMScaleX],
554                                                           scaleX*c0*c1 - scaleY*s0*s1));
555    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMSkewX],
556                                                           -scaleX*s0*c1 - scaleY*c0*s1));
557    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMSkewY],
558                                                           scaleX*c0*s1 + scaleY*s0*c1));
559    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMScaleY],
560                                                           -scaleX*s0*s1 + scaleY*c0*c1));
561
562    // rotation, anisotropic scale + reflection, then different rotation
563    mat.setRotate(kRotation0);
564    mat.postScale(-kScale1, kScale0);
565    mat.postRotate(kRotation1);
566    REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
567    s0 = SkScalarSinCos(rotation0, &c0);
568    s1 = SkScalarSinCos(rotation1, &c1);
569    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMScaleX],
570                                                           scaleX*c0*c1 - scaleY*s0*s1));
571    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMSkewX],
572                                                           -scaleX*s0*c1 - scaleY*c0*s1));
573    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMSkewY],
574                                                           scaleX*c0*s1 + scaleY*s0*c1));
575    REPORTER_ASSERT(reporter, scalar_nearly_equal_relative(mat[SkMatrix::kMScaleY],
576                                                           -scaleX*s0*s1 + scaleY*c0*c1));
577
578    // degenerate matrices
579    // mostly zero entries
580    mat.reset();
581    mat[SkMatrix::kMScaleX] = 0.f;
582    REPORTER_ASSERT(reporter, !SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
583    mat.reset();
584    mat[SkMatrix::kMScaleY] = 0.f;
585    REPORTER_ASSERT(reporter, !SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
586    mat.reset();
587    // linearly dependent entries
588    mat[SkMatrix::kMScaleX] = 1.f;
589    mat[SkMatrix::kMSkewX] = 2.f;
590    mat[SkMatrix::kMSkewY] = 4.f;
591    mat[SkMatrix::kMScaleY] = 8.f;
592    REPORTER_ASSERT(reporter, !SkDecomposeUpper2x2(mat, &rotation0, &scaleX, &scaleY, &rotation1));
593}
594
595// For test_matrix_homogeneous, below.
596static bool scalar_array_nearly_equal_relative(const SkScalar a[], const SkScalar b[], int count) {
597    for (int i = 0; i < count; ++i) {
598        if (!scalar_nearly_equal_relative(a[i], b[i])) {
599            return false;
600        }
601    }
602    return true;
603}
604
605// For test_matrix_homogeneous, below.
606// Maps a single triple in src using m and compares results to those in dst
607static bool naive_homogeneous_mapping(const SkMatrix& m, const SkScalar src[3],
608                                      const SkScalar dst[3]) {
609    SkScalar res[3];
610    SkScalar ms[9] = {m[0], m[1], m[2],
611                      m[3], m[4], m[5],
612                      m[6], m[7], m[8]};
613    res[0] = src[0] * ms[0] + src[1] * ms[1] + src[2] * ms[2];
614    res[1] = src[0] * ms[3] + src[1] * ms[4] + src[2] * ms[5];
615    res[2] = src[0] * ms[6] + src[1] * ms[7] + src[2] * ms[8];
616    return scalar_array_nearly_equal_relative(res, dst, 3);
617}
618
619static void test_matrix_homogeneous(skiatest::Reporter* reporter) {
620    SkMatrix mat;
621
622    const float kRotation0 = 15.5f;
623    const float kRotation1 = -50.f;
624    const float kScale0 = 5000.f;
625
626    const int kTripleCount = 1000;
627    const int kMatrixCount = 1000;
628    SkRandom rand;
629
630    SkScalar randTriples[3*kTripleCount];
631    for (int i = 0; i < 3*kTripleCount; ++i) {
632        randTriples[i] = rand.nextRangeF(-3000.f, 3000.f);
633    }
634
635    SkMatrix mats[kMatrixCount];
636    for (int i = 0; i < kMatrixCount; ++i) {
637        for (int j = 0; j < 9; ++j) {
638            mats[i].set(j, rand.nextRangeF(-3000.f, 3000.f));
639        }
640    }
641
642    // identity
643    {
644    mat.reset();
645    SkScalar dst[3*kTripleCount];
646    mat.mapHomogeneousPoints(dst, randTriples, kTripleCount);
647    REPORTER_ASSERT(reporter, scalar_array_nearly_equal_relative(randTriples, dst, kTripleCount*3));
648    }
649
650    // zero matrix
651    {
652    mat.setAll(0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f);
653    SkScalar dst[3*kTripleCount];
654    mat.mapHomogeneousPoints(dst, randTriples, kTripleCount);
655    SkScalar zeros[3] = {0.f, 0.f, 0.f};
656    for (int i = 0; i < kTripleCount; ++i) {
657        REPORTER_ASSERT(reporter, scalar_array_nearly_equal_relative(&dst[i*3], zeros, 3));
658    }
659    }
660
661    // zero point
662    {
663    SkScalar zeros[3] = {0.f, 0.f, 0.f};
664    for (int i = 0; i < kMatrixCount; ++i) {
665        SkScalar dst[3];
666        mats[i].mapHomogeneousPoints(dst, zeros, 1);
667        REPORTER_ASSERT(reporter, scalar_array_nearly_equal_relative(dst, zeros, 3));
668    }
669    }
670
671    // doesn't crash with null dst, src, count == 0
672    {
673    mats[0].mapHomogeneousPoints(NULL, NULL, 0);
674    }
675
676    // uniform scale of point
677    {
678    mat.setScale(kScale0, kScale0);
679    SkScalar dst[3];
680    SkScalar src[3] = {randTriples[0], randTriples[1], 1.f};
681    SkPoint pnt;
682    pnt.set(src[0], src[1]);
683    mat.mapHomogeneousPoints(dst, src, 1);
684    mat.mapPoints(&pnt, &pnt, 1);
685    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[0], pnt.fX));
686    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[1], pnt.fY));
687    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[2], SK_Scalar1));
688    }
689
690    // rotation of point
691    {
692    mat.setRotate(kRotation0);
693    SkScalar dst[3];
694    SkScalar src[3] = {randTriples[0], randTriples[1], 1.f};
695    SkPoint pnt;
696    pnt.set(src[0], src[1]);
697    mat.mapHomogeneousPoints(dst, src, 1);
698    mat.mapPoints(&pnt, &pnt, 1);
699    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[0], pnt.fX));
700    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[1], pnt.fY));
701    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[2], SK_Scalar1));
702    }
703
704    // rotation, scale, rotation of point
705    {
706    mat.setRotate(kRotation1);
707    mat.postScale(kScale0, kScale0);
708    mat.postRotate(kRotation0);
709    SkScalar dst[3];
710    SkScalar src[3] = {randTriples[0], randTriples[1], 1.f};
711    SkPoint pnt;
712    pnt.set(src[0], src[1]);
713    mat.mapHomogeneousPoints(dst, src, 1);
714    mat.mapPoints(&pnt, &pnt, 1);
715    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[0], pnt.fX));
716    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[1], pnt.fY));
717    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[2], SK_Scalar1));
718    }
719
720    // compare with naive approach
721    {
722    for (int i = 0; i < kMatrixCount; ++i) {
723        for (int j = 0; j < kTripleCount; ++j) {
724            SkScalar dst[3];
725            mats[i].mapHomogeneousPoints(dst, &randTriples[j*3], 1);
726            REPORTER_ASSERT(reporter, naive_homogeneous_mapping(mats[i], &randTriples[j*3], dst));
727        }
728    }
729    }
730
731}
732
733static void TestMatrix(skiatest::Reporter* reporter) {
734    SkMatrix    mat, inverse, iden1, iden2;
735
736    mat.reset();
737    mat.setTranslate(SK_Scalar1, SK_Scalar1);
738    REPORTER_ASSERT(reporter, mat.invert(&inverse));
739    iden1.setConcat(mat, inverse);
740    REPORTER_ASSERT(reporter, is_identity(iden1));
741
742    mat.setScale(SkIntToScalar(2), SkIntToScalar(4));
743    REPORTER_ASSERT(reporter, mat.invert(&inverse));
744    iden1.setConcat(mat, inverse);
745    REPORTER_ASSERT(reporter, is_identity(iden1));
746    test_flatten(reporter, mat);
747
748    mat.setScale(SK_Scalar1/2, SkIntToScalar(2));
749    REPORTER_ASSERT(reporter, mat.invert(&inverse));
750    iden1.setConcat(mat, inverse);
751    REPORTER_ASSERT(reporter, is_identity(iden1));
752    test_flatten(reporter, mat);
753
754    mat.setScale(SkIntToScalar(3), SkIntToScalar(5), SkIntToScalar(20), 0);
755    mat.postRotate(SkIntToScalar(25));
756    REPORTER_ASSERT(reporter, mat.invert(NULL));
757    REPORTER_ASSERT(reporter, mat.invert(&inverse));
758    iden1.setConcat(mat, inverse);
759    REPORTER_ASSERT(reporter, is_identity(iden1));
760    iden2.setConcat(inverse, mat);
761    REPORTER_ASSERT(reporter, is_identity(iden2));
762    test_flatten(reporter, mat);
763    test_flatten(reporter, iden2);
764
765    mat.setScale(0, SK_Scalar1);
766    REPORTER_ASSERT(reporter, !mat.invert(NULL));
767    REPORTER_ASSERT(reporter, !mat.invert(&inverse));
768    mat.setScale(SK_Scalar1, 0);
769    REPORTER_ASSERT(reporter, !mat.invert(NULL));
770    REPORTER_ASSERT(reporter, !mat.invert(&inverse));
771
772    // rectStaysRect test
773    {
774        static const struct {
775            SkScalar    m00, m01, m10, m11;
776            bool        mStaysRect;
777        }
778        gRectStaysRectSamples[] = {
779            {          0,          0,          0,           0, false },
780            {          0,          0,          0,  SK_Scalar1, false },
781            {          0,          0, SK_Scalar1,           0, false },
782            {          0,          0, SK_Scalar1,  SK_Scalar1, false },
783            {          0, SK_Scalar1,          0,           0, false },
784            {          0, SK_Scalar1,          0,  SK_Scalar1, false },
785            {          0, SK_Scalar1, SK_Scalar1,           0, true },
786            {          0, SK_Scalar1, SK_Scalar1,  SK_Scalar1, false },
787            { SK_Scalar1,          0,          0,           0, false },
788            { SK_Scalar1,          0,          0,  SK_Scalar1, true },
789            { SK_Scalar1,          0, SK_Scalar1,           0, false },
790            { SK_Scalar1,          0, SK_Scalar1,  SK_Scalar1, false },
791            { SK_Scalar1, SK_Scalar1,          0,           0, false },
792            { SK_Scalar1, SK_Scalar1,          0,  SK_Scalar1, false },
793            { SK_Scalar1, SK_Scalar1, SK_Scalar1,           0, false },
794            { SK_Scalar1, SK_Scalar1, SK_Scalar1,  SK_Scalar1, false }
795        };
796
797        for (size_t i = 0; i < SK_ARRAY_COUNT(gRectStaysRectSamples); i++) {
798            SkMatrix    m;
799
800            m.reset();
801            m.set(SkMatrix::kMScaleX, gRectStaysRectSamples[i].m00);
802            m.set(SkMatrix::kMSkewX,  gRectStaysRectSamples[i].m01);
803            m.set(SkMatrix::kMSkewY,  gRectStaysRectSamples[i].m10);
804            m.set(SkMatrix::kMScaleY, gRectStaysRectSamples[i].m11);
805            REPORTER_ASSERT(reporter,
806                    m.rectStaysRect() == gRectStaysRectSamples[i].mStaysRect);
807        }
808    }
809
810    mat.reset();
811    mat.set(SkMatrix::kMScaleX, SkIntToScalar(1));
812    mat.set(SkMatrix::kMSkewX,  SkIntToScalar(2));
813    mat.set(SkMatrix::kMTransX, SkIntToScalar(3));
814    mat.set(SkMatrix::kMSkewY,  SkIntToScalar(4));
815    mat.set(SkMatrix::kMScaleY, SkIntToScalar(5));
816    mat.set(SkMatrix::kMTransY, SkIntToScalar(6));
817    SkScalar affine[6];
818    REPORTER_ASSERT(reporter, mat.asAffine(affine));
819
820    #define affineEqual(e) affine[SkMatrix::kA##e] == mat.get(SkMatrix::kM##e)
821    REPORTER_ASSERT(reporter, affineEqual(ScaleX));
822    REPORTER_ASSERT(reporter, affineEqual(SkewY));
823    REPORTER_ASSERT(reporter, affineEqual(SkewX));
824    REPORTER_ASSERT(reporter, affineEqual(ScaleY));
825    REPORTER_ASSERT(reporter, affineEqual(TransX));
826    REPORTER_ASSERT(reporter, affineEqual(TransY));
827    #undef affineEqual
828
829    mat.set(SkMatrix::kMPersp1, SkScalarToPersp(SK_Scalar1 / 2));
830    REPORTER_ASSERT(reporter, !mat.asAffine(affine));
831
832    SkMatrix mat2;
833    mat2.reset();
834    mat.reset();
835    SkScalar zero = 0;
836    mat.set(SkMatrix::kMSkewX, -zero);
837    REPORTER_ASSERT(reporter, are_equal(reporter, mat, mat2));
838
839    mat2.reset();
840    mat.reset();
841    mat.set(SkMatrix::kMSkewX, SK_ScalarNaN);
842    mat2.set(SkMatrix::kMSkewX, SK_ScalarNaN);
843    // fixed pt doesn't have the property that NaN does not equal itself.
844#ifdef SK_SCALAR_IS_FIXED
845    REPORTER_ASSERT(reporter, are_equal(reporter, mat, mat2));
846#else
847    REPORTER_ASSERT(reporter, !are_equal(reporter, mat, mat2));
848#endif
849
850    test_matrix_max_stretch(reporter);
851    test_matrix_is_similarity(reporter);
852    test_matrix_recttorect(reporter);
853    test_matrix_decomposition(reporter);
854    test_matrix_homogeneous(reporter);
855}
856
857#include "TestClassDef.h"
858DEFINE_TESTCLASS("Matrix", MatrixTestClass, TestMatrix)
859