1 /*
2  * Copyright 2011 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "SkMath.h"
9 #include "SkMatrix.h"
10 #include "SkMatrixUtils.h"
11 #include "SkRandom.h"
12 #include "Test.h"
13 
nearly_equal_scalar(SkScalar a,SkScalar b)14 static bool nearly_equal_scalar(SkScalar a, SkScalar b) {
15     const SkScalar tolerance = SK_Scalar1 / 200000;
16     return SkScalarAbs(a - b) <= tolerance;
17 }
18 
nearly_equal(const SkMatrix & a,const SkMatrix & b)19 static bool nearly_equal(const SkMatrix& a, const SkMatrix& b) {
20     for (int i = 0; i < 9; i++) {
21         if (!nearly_equal_scalar(a[i], b[i])) {
22             SkDebugf("not equal %g %g\n", (float)a[i], (float)b[i]);
23             return false;
24         }
25     }
26     return true;
27 }
28 
are_equal(skiatest::Reporter * reporter,const SkMatrix & a,const SkMatrix & b)29 static bool are_equal(skiatest::Reporter* reporter,
30                       const SkMatrix& a,
31                       const SkMatrix& b) {
32     bool equal = a == b;
33     bool cheapEqual = a.cheapEqualTo(b);
34     if (equal != cheapEqual) {
35         if (equal) {
36             bool foundZeroSignDiff = false;
37             for (int i = 0; i < 9; ++i) {
38                 float aVal = a.get(i);
39                 float bVal = b.get(i);
40                 int aValI = *SkTCast<int*>(&aVal);
41                 int bValI = *SkTCast<int*>(&bVal);
42                 if (0 == aVal && 0 == bVal && aValI != bValI) {
43                     foundZeroSignDiff = true;
44                 } else {
45                     REPORTER_ASSERT(reporter, aVal == bVal && aValI == aValI);
46                 }
47             }
48             REPORTER_ASSERT(reporter, foundZeroSignDiff);
49         } else {
50             bool foundNaN = false;
51             for (int i = 0; i < 9; ++i) {
52                 float aVal = a.get(i);
53                 float bVal = b.get(i);
54                 int aValI = *SkTCast<int*>(&aVal);
55                 int bValI = *SkTCast<int*>(&bVal);
56                 if (sk_float_isnan(aVal) && aValI == bValI) {
57                     foundNaN = true;
58                 } else {
59                     REPORTER_ASSERT(reporter, aVal == bVal && aValI == bValI);
60                 }
61             }
62             REPORTER_ASSERT(reporter, foundNaN);
63         }
64     }
65     return equal;
66 }
67 
is_identity(const SkMatrix & m)68 static bool is_identity(const SkMatrix& m) {
69     SkMatrix identity;
70     identity.reset();
71     return nearly_equal(m, identity);
72 }
73 
assert9(skiatest::Reporter * reporter,const SkMatrix & m,SkScalar a,SkScalar b,SkScalar c,SkScalar d,SkScalar e,SkScalar f,SkScalar g,SkScalar h,SkScalar i)74 static void assert9(skiatest::Reporter* reporter, const SkMatrix& m,
75                     SkScalar a, SkScalar b, SkScalar c,
76                     SkScalar d, SkScalar e, SkScalar f,
77                     SkScalar g, SkScalar h, SkScalar i) {
78     SkScalar buffer[9];
79     m.get9(buffer);
80     REPORTER_ASSERT(reporter, buffer[0] == a);
81     REPORTER_ASSERT(reporter, buffer[1] == b);
82     REPORTER_ASSERT(reporter, buffer[2] == c);
83     REPORTER_ASSERT(reporter, buffer[3] == d);
84     REPORTER_ASSERT(reporter, buffer[4] == e);
85     REPORTER_ASSERT(reporter, buffer[5] == f);
86     REPORTER_ASSERT(reporter, buffer[6] == g);
87     REPORTER_ASSERT(reporter, buffer[7] == h);
88     REPORTER_ASSERT(reporter, buffer[8] == i);
89 }
90 
test_set9(skiatest::Reporter * reporter)91 static void test_set9(skiatest::Reporter* reporter) {
92 
93     SkMatrix m;
94     m.reset();
95     assert9(reporter, m, 1, 0, 0, 0, 1, 0, 0, 0, 1);
96 
97     m.setScale(2, 3);
98     assert9(reporter, m, 2, 0, 0, 0, 3, 0, 0, 0, 1);
99 
100     m.postTranslate(4, 5);
101     assert9(reporter, m, 2, 0, 4, 0, 3, 5, 0, 0, 1);
102 
103     SkScalar buffer[9];
104     sk_bzero(buffer, sizeof(buffer));
105     buffer[SkMatrix::kMScaleX] = 1;
106     buffer[SkMatrix::kMScaleY] = 1;
107     buffer[SkMatrix::kMPersp2] = 1;
108     REPORTER_ASSERT(reporter, !m.isIdentity());
109     m.set9(buffer);
110     REPORTER_ASSERT(reporter, m.isIdentity());
111 }
112 
test_matrix_recttorect(skiatest::Reporter * reporter)113 static void test_matrix_recttorect(skiatest::Reporter* reporter) {
114     SkRect src, dst;
115     SkMatrix matrix;
116 
117     src.set(0, 0, SK_Scalar1*10, SK_Scalar1*10);
118     dst = src;
119     matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
120     REPORTER_ASSERT(reporter, SkMatrix::kIdentity_Mask == matrix.getType());
121     REPORTER_ASSERT(reporter, matrix.rectStaysRect());
122 
123     dst.offset(SK_Scalar1, SK_Scalar1);
124     matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
125     REPORTER_ASSERT(reporter, SkMatrix::kTranslate_Mask == matrix.getType());
126     REPORTER_ASSERT(reporter, matrix.rectStaysRect());
127 
128     dst.fRight += SK_Scalar1;
129     matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
130     REPORTER_ASSERT(reporter,
131                     (SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask) == matrix.getType());
132     REPORTER_ASSERT(reporter, matrix.rectStaysRect());
133 
134     dst = src;
135     dst.fRight = src.fRight * 2;
136     matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
137     REPORTER_ASSERT(reporter, SkMatrix::kScale_Mask == matrix.getType());
138     REPORTER_ASSERT(reporter, matrix.rectStaysRect());
139 }
140 
test_flatten(skiatest::Reporter * reporter,const SkMatrix & m)141 static void test_flatten(skiatest::Reporter* reporter, const SkMatrix& m) {
142     // add 100 in case we have a bug, I don't want to kill my stack in the test
143     static const size_t kBufferSize = SkMatrix::kMaxFlattenSize + 100;
144     char buffer[kBufferSize];
145     size_t size1 = m.writeToMemory(nullptr);
146     size_t size2 = m.writeToMemory(buffer);
147     REPORTER_ASSERT(reporter, size1 == size2);
148     REPORTER_ASSERT(reporter, size1 <= SkMatrix::kMaxFlattenSize);
149 
150     SkMatrix m2;
151     size_t size3 = m2.readFromMemory(buffer, kBufferSize);
152     REPORTER_ASSERT(reporter, size1 == size3);
153     REPORTER_ASSERT(reporter, are_equal(reporter, m, m2));
154 
155     char buffer2[kBufferSize];
156     size3 = m2.writeToMemory(buffer2);
157     REPORTER_ASSERT(reporter, size1 == size3);
158     REPORTER_ASSERT(reporter, memcmp(buffer, buffer2, size1) == 0);
159 }
160 
test_matrix_min_max_scale(skiatest::Reporter * reporter)161 static void test_matrix_min_max_scale(skiatest::Reporter* reporter) {
162     SkScalar scales[2];
163     bool success;
164 
165     SkMatrix identity;
166     identity.reset();
167     REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMinScale());
168     REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMaxScale());
169     success = identity.getMinMaxScales(scales);
170     REPORTER_ASSERT(reporter, success && SK_Scalar1 == scales[0] && SK_Scalar1 == scales[1]);
171 
172     SkMatrix scale;
173     scale.setScale(SK_Scalar1 * 2, SK_Scalar1 * 4);
174     REPORTER_ASSERT(reporter, SK_Scalar1 * 2 == scale.getMinScale());
175     REPORTER_ASSERT(reporter, SK_Scalar1 * 4 == scale.getMaxScale());
176     success = scale.getMinMaxScales(scales);
177     REPORTER_ASSERT(reporter, success && SK_Scalar1 * 2 == scales[0] && SK_Scalar1 * 4 == scales[1]);
178 
179     SkMatrix rot90Scale;
180     rot90Scale.setRotate(90 * SK_Scalar1);
181     rot90Scale.postScale(SK_Scalar1 / 4, SK_Scalar1 / 2);
182     REPORTER_ASSERT(reporter, SK_Scalar1 / 4 == rot90Scale.getMinScale());
183     REPORTER_ASSERT(reporter, SK_Scalar1 / 2 == rot90Scale.getMaxScale());
184     success = rot90Scale.getMinMaxScales(scales);
185     REPORTER_ASSERT(reporter, success && SK_Scalar1 / 4  == scales[0] && SK_Scalar1 / 2 == scales[1]);
186 
187     SkMatrix rotate;
188     rotate.setRotate(128 * SK_Scalar1);
189     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, rotate.getMinScale(), SK_ScalarNearlyZero));
190     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, rotate.getMaxScale(), SK_ScalarNearlyZero));
191     success = rotate.getMinMaxScales(scales);
192     REPORTER_ASSERT(reporter, success);
193     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, scales[0], SK_ScalarNearlyZero));
194     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(SK_Scalar1, scales[1], SK_ScalarNearlyZero));
195 
196     SkMatrix translate;
197     translate.setTranslate(10 * SK_Scalar1, -5 * SK_Scalar1);
198     REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMinScale());
199     REPORTER_ASSERT(reporter, SK_Scalar1 == translate.getMaxScale());
200     success = translate.getMinMaxScales(scales);
201     REPORTER_ASSERT(reporter, success && SK_Scalar1 == scales[0] && SK_Scalar1 == scales[1]);
202 
203     SkMatrix perspX;
204     perspX.reset();
205     perspX.setPerspX(SK_Scalar1 / 1000);
206     REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMinScale());
207     REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMaxScale());
208     success = perspX.getMinMaxScales(scales);
209     REPORTER_ASSERT(reporter, !success);
210 
211     // skbug.com/4718
212     SkMatrix big;
213     big.setAll(2.39394089e+36f, 8.85347779e+36f, 9.26526204e+36f,
214                3.9159619e+36f, 1.44823453e+37f, 1.51559342e+37f,
215                0.f, 0.f, 1.f);
216     REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMinScale());
217     REPORTER_ASSERT(reporter, -SK_Scalar1 == perspX.getMaxScale());
218     success = big.getMinMaxScales(scales);
219     REPORTER_ASSERT(reporter, !success);
220 
221     SkMatrix perspY;
222     perspY.reset();
223     perspY.setPerspY(-SK_Scalar1 / 500);
224     REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMinScale());
225     REPORTER_ASSERT(reporter, -SK_Scalar1 == perspY.getMaxScale());
226     scales[0] = -5;
227     scales[1] = -5;
228     success = perspY.getMinMaxScales(scales);
229     REPORTER_ASSERT(reporter, !success && -5 * SK_Scalar1 == scales[0] && -5 * SK_Scalar1  == scales[1]);
230 
231     SkMatrix baseMats[] = {scale, rot90Scale, rotate,
232                            translate, perspX, perspY};
233     SkMatrix mats[2*SK_ARRAY_COUNT(baseMats)];
234     for (size_t i = 0; i < SK_ARRAY_COUNT(baseMats); ++i) {
235         mats[i] = baseMats[i];
236         bool invertable = mats[i].invert(&mats[i + SK_ARRAY_COUNT(baseMats)]);
237         REPORTER_ASSERT(reporter, invertable);
238     }
239     SkRandom rand;
240     for (int m = 0; m < 1000; ++m) {
241         SkMatrix mat;
242         mat.reset();
243         for (int i = 0; i < 4; ++i) {
244             int x = rand.nextU() % SK_ARRAY_COUNT(mats);
245             mat.postConcat(mats[x]);
246         }
247 
248         SkScalar minScale = mat.getMinScale();
249         SkScalar maxScale = mat.getMaxScale();
250         REPORTER_ASSERT(reporter, (minScale < 0) == (maxScale < 0));
251         REPORTER_ASSERT(reporter, (maxScale < 0) == mat.hasPerspective());
252 
253         SkScalar scales[2];
254         bool success = mat.getMinMaxScales(scales);
255         REPORTER_ASSERT(reporter, success == !mat.hasPerspective());
256         REPORTER_ASSERT(reporter, !success || (scales[0] == minScale && scales[1] == maxScale));
257 
258         if (mat.hasPerspective()) {
259             m -= 1; // try another non-persp matrix
260             continue;
261         }
262 
263         // test a bunch of vectors. All should be scaled by between minScale and maxScale
264         // (modulo some error) and we should find a vector that is scaled by almost each.
265         static const SkScalar gVectorScaleTol = (105 * SK_Scalar1) / 100;
266         static const SkScalar gCloseScaleTol = (97 * SK_Scalar1) / 100;
267         SkScalar max = 0, min = SK_ScalarMax;
268         SkVector vectors[1000];
269         for (size_t i = 0; i < SK_ARRAY_COUNT(vectors); ++i) {
270             vectors[i].fX = rand.nextSScalar1();
271             vectors[i].fY = rand.nextSScalar1();
272             if (!vectors[i].normalize()) {
273                 i -= 1;
274                 continue;
275             }
276         }
277         mat.mapVectors(vectors, SK_ARRAY_COUNT(vectors));
278         for (size_t i = 0; i < SK_ARRAY_COUNT(vectors); ++i) {
279             SkScalar d = vectors[i].length();
280             REPORTER_ASSERT(reporter, d / maxScale < gVectorScaleTol);
281             REPORTER_ASSERT(reporter, minScale / d < gVectorScaleTol);
282             if (max < d) {
283                 max = d;
284             }
285             if (min > d) {
286                 min = d;
287             }
288         }
289         REPORTER_ASSERT(reporter, max / maxScale >= gCloseScaleTol);
290         REPORTER_ASSERT(reporter, minScale / min >= gCloseScaleTol);
291     }
292 }
293 
test_matrix_preserve_shape(skiatest::Reporter * reporter)294 static void test_matrix_preserve_shape(skiatest::Reporter* reporter) {
295     SkMatrix mat;
296 
297     // identity
298     mat.setIdentity();
299     REPORTER_ASSERT(reporter, mat.isSimilarity());
300     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
301 
302     // translation only
303     mat.reset();
304     mat.setTranslate(SkIntToScalar(100), SkIntToScalar(100));
305     REPORTER_ASSERT(reporter, mat.isSimilarity());
306     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
307 
308     // scale with same size
309     mat.reset();
310     mat.setScale(SkIntToScalar(15), SkIntToScalar(15));
311     REPORTER_ASSERT(reporter, mat.isSimilarity());
312     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
313 
314     // scale with one negative
315     mat.reset();
316     mat.setScale(SkIntToScalar(-15), SkIntToScalar(15));
317     REPORTER_ASSERT(reporter, mat.isSimilarity());
318     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
319 
320     // scale with different size
321     mat.reset();
322     mat.setScale(SkIntToScalar(15), SkIntToScalar(20));
323     REPORTER_ASSERT(reporter, !mat.isSimilarity());
324     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
325 
326     // scale with same size at a pivot point
327     mat.reset();
328     mat.setScale(SkIntToScalar(15), SkIntToScalar(15),
329                  SkIntToScalar(2), SkIntToScalar(2));
330     REPORTER_ASSERT(reporter, mat.isSimilarity());
331     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
332 
333     // scale with different size at a pivot point
334     mat.reset();
335     mat.setScale(SkIntToScalar(15), SkIntToScalar(20),
336                  SkIntToScalar(2), SkIntToScalar(2));
337     REPORTER_ASSERT(reporter, !mat.isSimilarity());
338     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
339 
340     // skew with same size
341     mat.reset();
342     mat.setSkew(SkIntToScalar(15), SkIntToScalar(15));
343     REPORTER_ASSERT(reporter, !mat.isSimilarity());
344     REPORTER_ASSERT(reporter, !mat.preservesRightAngles());
345 
346     // skew with different size
347     mat.reset();
348     mat.setSkew(SkIntToScalar(15), SkIntToScalar(20));
349     REPORTER_ASSERT(reporter, !mat.isSimilarity());
350     REPORTER_ASSERT(reporter, !mat.preservesRightAngles());
351 
352     // skew with same size at a pivot point
353     mat.reset();
354     mat.setSkew(SkIntToScalar(15), SkIntToScalar(15),
355                 SkIntToScalar(2), SkIntToScalar(2));
356     REPORTER_ASSERT(reporter, !mat.isSimilarity());
357     REPORTER_ASSERT(reporter, !mat.preservesRightAngles());
358 
359     // skew with different size at a pivot point
360     mat.reset();
361     mat.setSkew(SkIntToScalar(15), SkIntToScalar(20),
362                 SkIntToScalar(2), SkIntToScalar(2));
363     REPORTER_ASSERT(reporter, !mat.isSimilarity());
364     REPORTER_ASSERT(reporter, !mat.preservesRightAngles());
365 
366     // perspective x
367     mat.reset();
368     mat.setPerspX(SK_Scalar1 / 2);
369     REPORTER_ASSERT(reporter, !mat.isSimilarity());
370     REPORTER_ASSERT(reporter, !mat.preservesRightAngles());
371 
372     // perspective y
373     mat.reset();
374     mat.setPerspY(SK_Scalar1 / 2);
375     REPORTER_ASSERT(reporter, !mat.isSimilarity());
376     REPORTER_ASSERT(reporter, !mat.preservesRightAngles());
377 
378     // rotate
379     for (int angle = 0; angle < 360; ++angle) {
380         mat.reset();
381         mat.setRotate(SkIntToScalar(angle));
382         REPORTER_ASSERT(reporter, mat.isSimilarity());
383         REPORTER_ASSERT(reporter, mat.preservesRightAngles());
384     }
385 
386     // see if there are any accumulated precision issues
387     mat.reset();
388     for (int i = 1; i < 360; i++) {
389         mat.postRotate(SkIntToScalar(1));
390     }
391     REPORTER_ASSERT(reporter, mat.isSimilarity());
392     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
393 
394     // rotate + translate
395     mat.reset();
396     mat.setRotate(SkIntToScalar(30));
397     mat.postTranslate(SkIntToScalar(10), SkIntToScalar(20));
398     REPORTER_ASSERT(reporter, mat.isSimilarity());
399     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
400 
401     // rotate + uniform scale
402     mat.reset();
403     mat.setRotate(SkIntToScalar(30));
404     mat.postScale(SkIntToScalar(2), SkIntToScalar(2));
405     REPORTER_ASSERT(reporter, mat.isSimilarity());
406     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
407 
408     // rotate + non-uniform scale
409     mat.reset();
410     mat.setRotate(SkIntToScalar(30));
411     mat.postScale(SkIntToScalar(3), SkIntToScalar(2));
412     REPORTER_ASSERT(reporter, !mat.isSimilarity());
413     REPORTER_ASSERT(reporter, !mat.preservesRightAngles());
414 
415     // non-uniform scale + rotate
416     mat.reset();
417     mat.setScale(SkIntToScalar(3), SkIntToScalar(2));
418     mat.postRotate(SkIntToScalar(30));
419     REPORTER_ASSERT(reporter, !mat.isSimilarity());
420     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
421 
422     // all zero
423     mat.setAll(0, 0, 0, 0, 0, 0, 0, 0, 0);
424     REPORTER_ASSERT(reporter, !mat.isSimilarity());
425     REPORTER_ASSERT(reporter, !mat.preservesRightAngles());
426 
427     // all zero except perspective
428     mat.reset();
429     mat.setAll(0, 0, 0, 0, 0, 0, 0, 0, SK_Scalar1);
430     REPORTER_ASSERT(reporter, !mat.isSimilarity());
431     REPORTER_ASSERT(reporter, !mat.preservesRightAngles());
432 
433     // scales zero, only skews (rotation)
434     mat.setAll(0, SK_Scalar1, 0,
435                -SK_Scalar1, 0, 0,
436                0, 0, SkMatrix::I()[8]);
437     REPORTER_ASSERT(reporter, mat.isSimilarity());
438     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
439 
440     // scales zero, only skews (reflection)
441     mat.setAll(0, SK_Scalar1, 0,
442                SK_Scalar1, 0, 0,
443                0, 0, SkMatrix::I()[8]);
444     REPORTER_ASSERT(reporter, mat.isSimilarity());
445     REPORTER_ASSERT(reporter, mat.preservesRightAngles());
446 }
447 
448 // For test_matrix_decomposition, below.
scalar_nearly_equal_relative(SkScalar a,SkScalar b,SkScalar tolerance=SK_ScalarNearlyZero)449 static bool scalar_nearly_equal_relative(SkScalar a, SkScalar b,
450                                          SkScalar tolerance = SK_ScalarNearlyZero) {
451     // from Bruce Dawson
452     // absolute check
453     SkScalar diff = SkScalarAbs(a - b);
454     if (diff < tolerance) {
455         return true;
456     }
457 
458     // relative check
459     a = SkScalarAbs(a);
460     b = SkScalarAbs(b);
461     SkScalar largest = (b > a) ? b : a;
462 
463     if (diff <= largest*tolerance) {
464         return true;
465     }
466 
467     return false;
468 }
469 
check_matrix_recomposition(const SkMatrix & mat,const SkPoint & rotation1,const SkPoint & scale,const SkPoint & rotation2)470 static bool check_matrix_recomposition(const SkMatrix& mat,
471                                        const SkPoint& rotation1,
472                                        const SkPoint& scale,
473                                        const SkPoint& rotation2) {
474     SkScalar c1 = rotation1.fX;
475     SkScalar s1 = rotation1.fY;
476     SkScalar scaleX = scale.fX;
477     SkScalar scaleY = scale.fY;
478     SkScalar c2 = rotation2.fX;
479     SkScalar s2 = rotation2.fY;
480 
481     // We do a relative check here because large scale factors cause problems with an absolute check
482     bool result = scalar_nearly_equal_relative(mat[SkMatrix::kMScaleX],
483                                                scaleX*c1*c2 - scaleY*s1*s2) &&
484                   scalar_nearly_equal_relative(mat[SkMatrix::kMSkewX],
485                                                -scaleX*s1*c2 - scaleY*c1*s2) &&
486                   scalar_nearly_equal_relative(mat[SkMatrix::kMSkewY],
487                                                scaleX*c1*s2 + scaleY*s1*c2) &&
488                   scalar_nearly_equal_relative(mat[SkMatrix::kMScaleY],
489                                                -scaleX*s1*s2 + scaleY*c1*c2);
490     return result;
491 }
492 
test_matrix_decomposition(skiatest::Reporter * reporter)493 static void test_matrix_decomposition(skiatest::Reporter* reporter) {
494     SkMatrix mat;
495     SkPoint rotation1, scale, rotation2;
496 
497     const float kRotation0 = 15.5f;
498     const float kRotation1 = -50.f;
499     const float kScale0 = 5000.f;
500     const float kScale1 = 0.001f;
501 
502     // identity
503     mat.reset();
504     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
505     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
506     // make sure it doesn't crash if we pass in NULLs
507     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, nullptr, nullptr, nullptr));
508 
509     // rotation only
510     mat.setRotate(kRotation0);
511     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
512     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
513 
514     // uniform scale only
515     mat.setScale(kScale0, kScale0);
516     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
517     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
518 
519     // anisotropic scale only
520     mat.setScale(kScale1, kScale0);
521     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
522     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
523 
524     // rotation then uniform scale
525     mat.setRotate(kRotation1);
526     mat.postScale(kScale0, kScale0);
527     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
528     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
529 
530     // uniform scale then rotation
531     mat.setScale(kScale0, kScale0);
532     mat.postRotate(kRotation1);
533     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
534     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
535 
536     // rotation then uniform scale+reflection
537     mat.setRotate(kRotation0);
538     mat.postScale(kScale1, -kScale1);
539     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
540     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
541 
542     // uniform scale+reflection, then rotate
543     mat.setScale(kScale0, -kScale0);
544     mat.postRotate(kRotation1);
545     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
546     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
547 
548     // rotation then anisotropic scale
549     mat.setRotate(kRotation1);
550     mat.postScale(kScale1, kScale0);
551     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
552     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
553 
554     // rotation then anisotropic scale
555     mat.setRotate(90);
556     mat.postScale(kScale1, kScale0);
557     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
558     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
559 
560     // anisotropic scale then rotation
561     mat.setScale(kScale1, kScale0);
562     mat.postRotate(kRotation0);
563     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
564     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
565 
566     // anisotropic scale then rotation
567     mat.setScale(kScale1, kScale0);
568     mat.postRotate(90);
569     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
570     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
571 
572     // rotation, uniform scale, then different rotation
573     mat.setRotate(kRotation1);
574     mat.postScale(kScale0, kScale0);
575     mat.postRotate(kRotation0);
576     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
577     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
578 
579     // rotation, anisotropic scale, then different rotation
580     mat.setRotate(kRotation0);
581     mat.postScale(kScale1, kScale0);
582     mat.postRotate(kRotation1);
583     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
584     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
585 
586     // rotation, anisotropic scale + reflection, then different rotation
587     mat.setRotate(kRotation0);
588     mat.postScale(-kScale1, kScale0);
589     mat.postRotate(kRotation1);
590     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
591     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
592 
593     // try some random matrices
594     SkRandom rand;
595     for (int m = 0; m < 1000; ++m) {
596         SkScalar rot0 = rand.nextRangeF(-180, 180);
597         SkScalar sx = rand.nextRangeF(-3000.f, 3000.f);
598         SkScalar sy = rand.nextRangeF(-3000.f, 3000.f);
599         SkScalar rot1 = rand.nextRangeF(-180, 180);
600         mat.setRotate(rot0);
601         mat.postScale(sx, sy);
602         mat.postRotate(rot1);
603 
604         if (SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2)) {
605             REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
606         } else {
607             // if the matrix is degenerate, the basis vectors should be near-parallel or near-zero
608             SkScalar perpdot = mat[SkMatrix::kMScaleX]*mat[SkMatrix::kMScaleY] -
609                                mat[SkMatrix::kMSkewX]*mat[SkMatrix::kMSkewY];
610             REPORTER_ASSERT(reporter, SkScalarNearlyZero(perpdot));
611         }
612     }
613 
614     // translation shouldn't affect this
615     mat.postTranslate(-1000.f, 1000.f);
616     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
617     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
618 
619     // perspective shouldn't affect this
620     mat[SkMatrix::kMPersp0] = 12.f;
621     mat[SkMatrix::kMPersp1] = 4.f;
622     mat[SkMatrix::kMPersp2] = 1872.f;
623     REPORTER_ASSERT(reporter, SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
624     REPORTER_ASSERT(reporter, check_matrix_recomposition(mat, rotation1, scale, rotation2));
625 
626     // degenerate matrices
627     // mostly zero entries
628     mat.reset();
629     mat[SkMatrix::kMScaleX] = 0.f;
630     REPORTER_ASSERT(reporter, !SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
631     mat.reset();
632     mat[SkMatrix::kMScaleY] = 0.f;
633     REPORTER_ASSERT(reporter, !SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
634     mat.reset();
635     // linearly dependent entries
636     mat[SkMatrix::kMScaleX] = 1.f;
637     mat[SkMatrix::kMSkewX] = 2.f;
638     mat[SkMatrix::kMSkewY] = 4.f;
639     mat[SkMatrix::kMScaleY] = 8.f;
640     REPORTER_ASSERT(reporter, !SkDecomposeUpper2x2(mat, &rotation1, &scale, &rotation2));
641 }
642 
643 // For test_matrix_homogeneous, below.
scalar_array_nearly_equal_relative(const SkScalar a[],const SkScalar b[],int count)644 static bool scalar_array_nearly_equal_relative(const SkScalar a[], const SkScalar b[], int count) {
645     for (int i = 0; i < count; ++i) {
646         if (!scalar_nearly_equal_relative(a[i], b[i])) {
647             return false;
648         }
649     }
650     return true;
651 }
652 
653 // For test_matrix_homogeneous, below.
654 // Maps a single triple in src using m and compares results to those in dst
naive_homogeneous_mapping(const SkMatrix & m,const SkScalar src[3],const SkScalar dst[3])655 static bool naive_homogeneous_mapping(const SkMatrix& m, const SkScalar src[3],
656                                       const SkScalar dst[3]) {
657     SkScalar res[3];
658     SkScalar ms[9] = {m[0], m[1], m[2],
659                       m[3], m[4], m[5],
660                       m[6], m[7], m[8]};
661     res[0] = src[0] * ms[0] + src[1] * ms[1] + src[2] * ms[2];
662     res[1] = src[0] * ms[3] + src[1] * ms[4] + src[2] * ms[5];
663     res[2] = src[0] * ms[6] + src[1] * ms[7] + src[2] * ms[8];
664     return scalar_array_nearly_equal_relative(res, dst, 3);
665 }
666 
test_matrix_homogeneous(skiatest::Reporter * reporter)667 static void test_matrix_homogeneous(skiatest::Reporter* reporter) {
668     SkMatrix mat;
669 
670     const float kRotation0 = 15.5f;
671     const float kRotation1 = -50.f;
672     const float kScale0 = 5000.f;
673 
674 #if defined(GOOGLE3)
675     // Stack frame size is limited in GOOGLE3.
676     const int kTripleCount = 100;
677     const int kMatrixCount = 100;
678 #else
679     const int kTripleCount = 1000;
680     const int kMatrixCount = 1000;
681 #endif
682     SkRandom rand;
683 
684     SkScalar randTriples[3*kTripleCount];
685     for (int i = 0; i < 3*kTripleCount; ++i) {
686         randTriples[i] = rand.nextRangeF(-3000.f, 3000.f);
687     }
688 
689     SkMatrix mats[kMatrixCount];
690     for (int i = 0; i < kMatrixCount; ++i) {
691         for (int j = 0; j < 9; ++j) {
692             mats[i].set(j, rand.nextRangeF(-3000.f, 3000.f));
693         }
694     }
695 
696     // identity
697     {
698     mat.reset();
699     SkScalar dst[3*kTripleCount];
700     mat.mapHomogeneousPoints(dst, randTriples, kTripleCount);
701     REPORTER_ASSERT(reporter, scalar_array_nearly_equal_relative(randTriples, dst, kTripleCount*3));
702     }
703 
704     // zero matrix
705     {
706     mat.setAll(0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f, 0.f);
707     SkScalar dst[3*kTripleCount];
708     mat.mapHomogeneousPoints(dst, randTriples, kTripleCount);
709     SkScalar zeros[3] = {0.f, 0.f, 0.f};
710     for (int i = 0; i < kTripleCount; ++i) {
711         REPORTER_ASSERT(reporter, scalar_array_nearly_equal_relative(&dst[i*3], zeros, 3));
712     }
713     }
714 
715     // zero point
716     {
717     SkScalar zeros[3] = {0.f, 0.f, 0.f};
718     for (int i = 0; i < kMatrixCount; ++i) {
719         SkScalar dst[3];
720         mats[i].mapHomogeneousPoints(dst, zeros, 1);
721         REPORTER_ASSERT(reporter, scalar_array_nearly_equal_relative(dst, zeros, 3));
722     }
723     }
724 
725     // doesn't crash with null dst, src, count == 0
726     {
727     mats[0].mapHomogeneousPoints(nullptr, nullptr, 0);
728     }
729 
730     // uniform scale of point
731     {
732     mat.setScale(kScale0, kScale0);
733     SkScalar dst[3];
734     SkScalar src[3] = {randTriples[0], randTriples[1], 1.f};
735     SkPoint pnt;
736     pnt.set(src[0], src[1]);
737     mat.mapHomogeneousPoints(dst, src, 1);
738     mat.mapPoints(&pnt, &pnt, 1);
739     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[0], pnt.fX));
740     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[1], pnt.fY));
741     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[2], SK_Scalar1));
742     }
743 
744     // rotation of point
745     {
746     mat.setRotate(kRotation0);
747     SkScalar dst[3];
748     SkScalar src[3] = {randTriples[0], randTriples[1], 1.f};
749     SkPoint pnt;
750     pnt.set(src[0], src[1]);
751     mat.mapHomogeneousPoints(dst, src, 1);
752     mat.mapPoints(&pnt, &pnt, 1);
753     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[0], pnt.fX));
754     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[1], pnt.fY));
755     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[2], SK_Scalar1));
756     }
757 
758     // rotation, scale, rotation of point
759     {
760     mat.setRotate(kRotation1);
761     mat.postScale(kScale0, kScale0);
762     mat.postRotate(kRotation0);
763     SkScalar dst[3];
764     SkScalar src[3] = {randTriples[0], randTriples[1], 1.f};
765     SkPoint pnt;
766     pnt.set(src[0], src[1]);
767     mat.mapHomogeneousPoints(dst, src, 1);
768     mat.mapPoints(&pnt, &pnt, 1);
769     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[0], pnt.fX));
770     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[1], pnt.fY));
771     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dst[2], SK_Scalar1));
772     }
773 
774     // compare with naive approach
775     {
776     for (int i = 0; i < kMatrixCount; ++i) {
777         for (int j = 0; j < kTripleCount; ++j) {
778             SkScalar dst[3];
779             mats[i].mapHomogeneousPoints(dst, &randTriples[j*3], 1);
780             REPORTER_ASSERT(reporter, naive_homogeneous_mapping(mats[i], &randTriples[j*3], dst));
781         }
782     }
783     }
784 
785 }
786 
check_decompScale(const SkMatrix & matrix)787 static bool check_decompScale(const SkMatrix& matrix) {
788     SkSize scale;
789     SkMatrix remaining;
790 
791     if (!matrix.decomposeScale(&scale, &remaining)) {
792         return false;
793     }
794     if (scale.width() <= 0 || scale.height() <= 0) {
795         return false;
796     }
797     remaining.preScale(scale.width(), scale.height());
798     return nearly_equal(matrix, remaining);
799 }
800 
test_decompScale(skiatest::Reporter * reporter)801 static void test_decompScale(skiatest::Reporter* reporter) {
802     SkMatrix m;
803 
804     m.reset();
805     REPORTER_ASSERT(reporter, check_decompScale(m));
806     m.setScale(2, 3);
807     REPORTER_ASSERT(reporter, check_decompScale(m));
808     m.setRotate(35, 0, 0);
809     REPORTER_ASSERT(reporter, check_decompScale(m));
810 
811     m.setScale(1, 0);
812     REPORTER_ASSERT(reporter, !check_decompScale(m));
813 }
814 
DEF_TEST(Matrix,reporter)815 DEF_TEST(Matrix, reporter) {
816     SkMatrix    mat, inverse, iden1, iden2;
817 
818     mat.reset();
819     mat.setTranslate(SK_Scalar1, SK_Scalar1);
820     REPORTER_ASSERT(reporter, mat.invert(&inverse));
821     iden1.setConcat(mat, inverse);
822     REPORTER_ASSERT(reporter, is_identity(iden1));
823 
824     mat.setScale(SkIntToScalar(2), SkIntToScalar(4));
825     REPORTER_ASSERT(reporter, mat.invert(&inverse));
826     iden1.setConcat(mat, inverse);
827     REPORTER_ASSERT(reporter, is_identity(iden1));
828     test_flatten(reporter, mat);
829 
830     mat.setScale(SK_Scalar1/2, SkIntToScalar(2));
831     REPORTER_ASSERT(reporter, mat.invert(&inverse));
832     iden1.setConcat(mat, inverse);
833     REPORTER_ASSERT(reporter, is_identity(iden1));
834     test_flatten(reporter, mat);
835 
836     mat.setScale(SkIntToScalar(3), SkIntToScalar(5), SkIntToScalar(20), 0);
837     mat.postRotate(SkIntToScalar(25));
838     REPORTER_ASSERT(reporter, mat.invert(nullptr));
839     REPORTER_ASSERT(reporter, mat.invert(&inverse));
840     iden1.setConcat(mat, inverse);
841     REPORTER_ASSERT(reporter, is_identity(iden1));
842     iden2.setConcat(inverse, mat);
843     REPORTER_ASSERT(reporter, is_identity(iden2));
844     test_flatten(reporter, mat);
845     test_flatten(reporter, iden2);
846 
847     mat.setScale(0, SK_Scalar1);
848     REPORTER_ASSERT(reporter, !mat.invert(nullptr));
849     REPORTER_ASSERT(reporter, !mat.invert(&inverse));
850     mat.setScale(SK_Scalar1, 0);
851     REPORTER_ASSERT(reporter, !mat.invert(nullptr));
852     REPORTER_ASSERT(reporter, !mat.invert(&inverse));
853 
854     // Inverting this matrix results in a non-finite matrix
855     mat.setAll(0.0f, 1.0f, 2.0f,
856                0.0f, 1.0f, -3.40277175e+38f,
857                1.00003040f, 1.0f, 0.0f);
858     REPORTER_ASSERT(reporter, !mat.invert(nullptr));
859     REPORTER_ASSERT(reporter, !mat.invert(&inverse));
860 
861     // rectStaysRect test
862     {
863         static const struct {
864             SkScalar    m00, m01, m10, m11;
865             bool        mStaysRect;
866         }
867         gRectStaysRectSamples[] = {
868             {          0,          0,          0,           0, false },
869             {          0,          0,          0,  SK_Scalar1, false },
870             {          0,          0, SK_Scalar1,           0, false },
871             {          0,          0, SK_Scalar1,  SK_Scalar1, false },
872             {          0, SK_Scalar1,          0,           0, false },
873             {          0, SK_Scalar1,          0,  SK_Scalar1, false },
874             {          0, SK_Scalar1, SK_Scalar1,           0, true },
875             {          0, SK_Scalar1, SK_Scalar1,  SK_Scalar1, false },
876             { SK_Scalar1,          0,          0,           0, false },
877             { SK_Scalar1,          0,          0,  SK_Scalar1, true },
878             { SK_Scalar1,          0, SK_Scalar1,           0, false },
879             { SK_Scalar1,          0, SK_Scalar1,  SK_Scalar1, false },
880             { SK_Scalar1, SK_Scalar1,          0,           0, false },
881             { SK_Scalar1, SK_Scalar1,          0,  SK_Scalar1, false },
882             { SK_Scalar1, SK_Scalar1, SK_Scalar1,           0, false },
883             { SK_Scalar1, SK_Scalar1, SK_Scalar1,  SK_Scalar1, false }
884         };
885 
886         for (size_t i = 0; i < SK_ARRAY_COUNT(gRectStaysRectSamples); i++) {
887             SkMatrix    m;
888 
889             m.reset();
890             m.set(SkMatrix::kMScaleX, gRectStaysRectSamples[i].m00);
891             m.set(SkMatrix::kMSkewX,  gRectStaysRectSamples[i].m01);
892             m.set(SkMatrix::kMSkewY,  gRectStaysRectSamples[i].m10);
893             m.set(SkMatrix::kMScaleY, gRectStaysRectSamples[i].m11);
894             REPORTER_ASSERT(reporter,
895                     m.rectStaysRect() == gRectStaysRectSamples[i].mStaysRect);
896         }
897     }
898 
899     mat.reset();
900     mat.set(SkMatrix::kMScaleX, SkIntToScalar(1));
901     mat.set(SkMatrix::kMSkewX,  SkIntToScalar(2));
902     mat.set(SkMatrix::kMTransX, SkIntToScalar(3));
903     mat.set(SkMatrix::kMSkewY,  SkIntToScalar(4));
904     mat.set(SkMatrix::kMScaleY, SkIntToScalar(5));
905     mat.set(SkMatrix::kMTransY, SkIntToScalar(6));
906     SkScalar affine[6];
907     REPORTER_ASSERT(reporter, mat.asAffine(affine));
908 
909     #define affineEqual(e) affine[SkMatrix::kA##e] == mat.get(SkMatrix::kM##e)
910     REPORTER_ASSERT(reporter, affineEqual(ScaleX));
911     REPORTER_ASSERT(reporter, affineEqual(SkewY));
912     REPORTER_ASSERT(reporter, affineEqual(SkewX));
913     REPORTER_ASSERT(reporter, affineEqual(ScaleY));
914     REPORTER_ASSERT(reporter, affineEqual(TransX));
915     REPORTER_ASSERT(reporter, affineEqual(TransY));
916     #undef affineEqual
917 
918     mat.set(SkMatrix::kMPersp1, SK_Scalar1 / 2);
919     REPORTER_ASSERT(reporter, !mat.asAffine(affine));
920 
921     SkMatrix mat2;
922     mat2.reset();
923     mat.reset();
924     SkScalar zero = 0;
925     mat.set(SkMatrix::kMSkewX, -zero);
926     REPORTER_ASSERT(reporter, are_equal(reporter, mat, mat2));
927 
928     mat2.reset();
929     mat.reset();
930     mat.set(SkMatrix::kMSkewX, SK_ScalarNaN);
931     mat2.set(SkMatrix::kMSkewX, SK_ScalarNaN);
932     REPORTER_ASSERT(reporter, !are_equal(reporter, mat, mat2));
933 
934     test_matrix_min_max_scale(reporter);
935     test_matrix_preserve_shape(reporter);
936     test_matrix_recttorect(reporter);
937     test_matrix_decomposition(reporter);
938     test_matrix_homogeneous(reporter);
939     test_set9(reporter);
940 
941     test_decompScale(reporter);
942 }
943 
DEF_TEST(Matrix_Concat,r)944 DEF_TEST(Matrix_Concat, r) {
945     SkMatrix a;
946     a.setTranslate(10, 20);
947 
948     SkMatrix b;
949     b.setScale(3, 5);
950 
951     SkMatrix expected;
952     expected.setConcat(a,b);
953 
954     REPORTER_ASSERT(r, expected == SkMatrix::Concat(a, b));
955 }
956