| Flutter Impeller |

gaussian_blur_filter_contents_unittests.cc
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "flutter/testing/testing.h"
6 #include "fml/status_or.h"
7 #include "gmock/gmock.h"
8 #include "impeller/entity/contents/content_context.h"
9 #include "impeller/entity/contents/filters/gaussian_blur_filter_contents.h"
10 #include "impeller/entity/contents/texture_contents.h"
11 #include "impeller/entity/entity_playground.h"
12 #include "impeller/geometry/color.h"
13 #include "impeller/geometry/geometry_asserts.h"
14 #include "impeller/renderer/testing/mocks.h"
15
16 #if FML_OS_MACOSX
17 #define IMPELLER_RAND arc4random
18 #else
19 #define IMPELLER_RAND rand
20 #endif
21
22 namespace impeller {
23 namespace testing {
24
25 namespace {
26
27 // Use newtonian method to give the closest answer to target where
28 // f(x) is less than the target. We do this because the value is `ceil`'d to
29 // grab fractional pixels.
30 fml::StatusOr<float> LowerBoundNewtonianMethod(
31 const std::function<float(float)>& func,
32 float target,
33 float guess,
34 float tolerance) {
35 const double delta = 1e-6;
36 double x = guess;
37 double fx;
38 static const int kMaxIterations = 1000;
39 int count = 0;
40
41 do {
42 fx = func(x) - target;
43 double derivative = (func(x + delta) - func(x)) / delta;
44 x = x - fx / derivative;
45 if (++count > kMaxIterations) {
46 return fml::Status(fml::StatusCode::kDeadlineExceeded,
47 "Did not converge on answer.");
48 }
49 } while (std::abs(fx) > tolerance ||
50 fx < 0.0); // fx < 0.0 makes this lower bound.
51
52 return x;
53 }
54
55 Scalar GetCoefficient(const Vector4& vec) {
56 return vec.z;
57 }
58
59 Vector2 GetUVOffset(const Vector4& vec) {
60 return vec.xy();
61 }
62
63 fml::StatusOr<Scalar> CalculateSigmaForBlurRadius(
64 Scalar radius,
65 const Matrix& effect_transform) {
66 auto f = [effect_transform](Scalar x) -> Scalar {
67 Vector2 scaled_sigma = (effect_transform.Basis() *
68 Vector2(GaussianBlurFilterContents::ScaleSigma(x),
69 GaussianBlurFilterContents::ScaleSigma(x)))
70 .Abs();
71 Vector2 blur_radius = Vector2(
72 GaussianBlurFilterContents::CalculateBlurRadius(scaled_sigma.x),
73 GaussianBlurFilterContents::CalculateBlurRadius(scaled_sigma.y));
74 return std::max(blur_radius.x, blur_radius.y);
75 };
76 // The newtonian method is used here since inverting the function is
77 // non-trivial because of conditional logic and would be fragile to changes.
78 return LowerBoundNewtonianMethod(f, radius, 2.f, 0.001f);
79 }
80
81 } // namespace
82
83 class GaussianBlurFilterContentsTest : public EntityPlayground {
84 public:
85 /// Create a texture that has been cleared to transparent black.
86 std::shared_ptr<Texture> MakeTexture(ISize size) {
87 std::shared_ptr<CommandBuffer> command_buffer =
88 GetContentContext()->GetContext()->CreateCommandBuffer();
89 if (!command_buffer) {
90 return nullptr;
91 }
92
93 auto render_target = GetContentContext()->MakeSubpass(
94 "Clear Subpass", size, command_buffer,
95 [](const ContentContext&, RenderPass&) { return true; });
96
97 if (!GetContentContext()
98 ->GetContext()
99 ->GetCommandQueue()
100 ->Submit(/*buffers=*/{command_buffer})
101 .ok()) {
102 return nullptr;
103 }
104
105 if (render_target.ok()) {
106 return render_target.value().GetRenderTargetTexture();
107 }
108 return nullptr;
109 }
110 };
111 INSTANTIATE_PLAYGROUND_SUITE(GaussianBlurFilterContentsTest);
112
113 TEST(GaussianBlurFilterContentsTest, Create) {
114 GaussianBlurFilterContents contents(
115 /*sigma_x=*/0.0, /*sigma_y=*/0.0, Entity::TileMode::kDecal,
116 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
117 EXPECT_EQ(contents.GetSigmaX(), 0.0);
118 EXPECT_EQ(contents.GetSigmaY(), 0.0);
119 }
120
121 TEST(GaussianBlurFilterContentsTest, CoverageEmpty) {
122 GaussianBlurFilterContents contents(
123 /*sigma_x=*/0.0, /*sigma_y=*/0.0, Entity::TileMode::kDecal,
124 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
125 FilterInput::Vector inputs = {};
126 Entity entity;
127 std::optional<Rect> coverage =
128 contents.GetFilterCoverage(inputs, entity, /*effect_transform=*/Matrix());
129 ASSERT_FALSE(coverage.has_value());
130 }
131
132 TEST(GaussianBlurFilterContentsTest, CoverageSimple) {
133 GaussianBlurFilterContents contents(
134 /*sigma_x=*/0.0, /*sigma_y=*/0.0, Entity::TileMode::kDecal,
135 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
136 FilterInput::Vector inputs = {
137 FilterInput::Make(Rect::MakeLTRB(10, 10, 110, 110))};
138 Entity entity;
139 std::optional<Rect> coverage =
140 contents.GetFilterCoverage(inputs, entity, /*effect_transform=*/Matrix());
141
142 ASSERT_EQ(coverage, Rect::MakeLTRB(10, 10, 110, 110));
143 }
144
145 TEST(GaussianBlurFilterContentsTest, CoverageWithSigma) {
146 fml::StatusOr<Scalar> sigma_radius_1 =
147 CalculateSigmaForBlurRadius(1.0, Matrix());
148 ASSERT_TRUE(sigma_radius_1.ok());
149 GaussianBlurFilterContents contents(
150 /*sigma_x=*/sigma_radius_1.value(),
151 /*sigma_y=*/sigma_radius_1.value(), Entity::TileMode::kDecal,
152 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
153 FilterInput::Vector inputs = {
154 FilterInput::Make(Rect::MakeLTRB(100, 100, 200, 200))};
155 Entity entity;
156 std::optional<Rect> coverage =
157 contents.GetFilterCoverage(inputs, entity, /*effect_transform=*/Matrix());
158
159 EXPECT_TRUE(coverage.has_value());
160 if (coverage.has_value()) {
161 EXPECT_RECT_NEAR(coverage.value(), Rect::MakeLTRB(99, 99, 201, 201));
162 }
163 }
164
165 TEST_P(GaussianBlurFilterContentsTest, CoverageWithTexture) {
166 fml::StatusOr<Scalar> sigma_radius_1 =
167 CalculateSigmaForBlurRadius(1.0, Matrix());
168 ASSERT_TRUE(sigma_radius_1.ok());
169 GaussianBlurFilterContents contents(
170 /*sigma_X=*/sigma_radius_1.value(),
171 /*sigma_y=*/sigma_radius_1.value(), Entity::TileMode::kDecal,
172 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
173 std::shared_ptr<Texture> texture = MakeTexture(ISize(100, 100));
174 FilterInput::Vector inputs = {FilterInput::Make(texture)};
175 Entity entity;
176 entity.SetTransform(Matrix::MakeTranslation({100, 100, 0}));
177 std::optional<Rect> coverage =
178 contents.GetFilterCoverage(inputs, entity, /*effect_transform=*/Matrix());
179
180 EXPECT_TRUE(coverage.has_value());
181 if (coverage.has_value()) {
182 EXPECT_RECT_NEAR(coverage.value(), Rect::MakeLTRB(99, 99, 201, 201));
183 }
184 }
185
186 TEST_P(GaussianBlurFilterContentsTest, CoverageWithEffectTransform) {
187 Matrix effect_transform = Matrix::MakeScale({2.0, 2.0, 1.0});
188 fml::StatusOr<Scalar> sigma_radius_1 =
189 CalculateSigmaForBlurRadius(1.0, effect_transform);
190 ASSERT_TRUE(sigma_radius_1.ok());
191 GaussianBlurFilterContents contents(
192 /*sigma_x=*/sigma_radius_1.value(),
193 /*sigma_y=*/sigma_radius_1.value(), Entity::TileMode::kDecal,
194 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
195 std::shared_ptr<Texture> texture = MakeTexture(ISize(100, 100));
196 FilterInput::Vector inputs = {FilterInput::Make(texture)};
197 Entity entity;
198 entity.SetTransform(Matrix::MakeTranslation({100, 100, 0}));
199 std::optional<Rect> coverage =
200 contents.GetFilterCoverage(inputs, entity, effect_transform);
201 EXPECT_TRUE(coverage.has_value());
202 if (coverage.has_value()) {
203 EXPECT_RECT_NEAR(coverage.value(),
204 Rect::MakeLTRB(100 - 1, 100 - 1, 200 + 1, 200 + 1));
205 }
206 }
207
208 TEST(GaussianBlurFilterContentsTest, FilterSourceCoverage) {
209 fml::StatusOr<Scalar> sigma_radius_1 =
210 CalculateSigmaForBlurRadius(1.0, Matrix());
211 ASSERT_TRUE(sigma_radius_1.ok());
212 auto contents = std::make_unique<GaussianBlurFilterContents>(
213 sigma_radius_1.value(), sigma_radius_1.value(), Entity::TileMode::kDecal,
214 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
215 std::optional<Rect> coverage = contents->GetFilterSourceCoverage(
216 /*effect_transform=*/Matrix::MakeScale({2.0, 2.0, 1.0}),
217 /*output_limit=*/Rect::MakeLTRB(100, 100, 200, 200));
218 EXPECT_TRUE(coverage.has_value());
219 if (coverage.has_value()) {
220 EXPECT_RECT_NEAR(coverage.value(),
221 Rect::MakeLTRB(100 - 2, 100 - 2, 200 + 2, 200 + 2));
222 }
223 }
224
225 TEST(GaussianBlurFilterContentsTest, CalculateSigmaValues) {
226 EXPECT_EQ(GaussianBlurFilterContents::CalculateScale(1.0f), 1);
227 EXPECT_EQ(GaussianBlurFilterContents::CalculateScale(2.0f), 1);
228 EXPECT_EQ(GaussianBlurFilterContents::CalculateScale(3.0f), 1);
229 EXPECT_EQ(GaussianBlurFilterContents::CalculateScale(4.0f), 1);
230 EXPECT_EQ(GaussianBlurFilterContents::CalculateScale(16.0f), 0.25);
231 // Hang on to 1/8 as long as possible.
232 EXPECT_EQ(GaussianBlurFilterContents::CalculateScale(95.0f), 0.125);
233 EXPECT_EQ(GaussianBlurFilterContents::CalculateScale(96.0f), 0.0625);
234 // Downsample clamped to 1/16th.
235 EXPECT_EQ(GaussianBlurFilterContents::CalculateScale(1024.0f), 0.0625);
236 }
237
238 TEST_P(GaussianBlurFilterContentsTest, RenderCoverageMatchesGetCoverage) {
239 std::shared_ptr<Texture> texture = MakeTexture(ISize(100, 100));
240 fml::StatusOr<Scalar> sigma_radius_1 =
241 CalculateSigmaForBlurRadius(1.0, Matrix());
242 ASSERT_TRUE(sigma_radius_1.ok());
243 auto contents = std::make_unique<GaussianBlurFilterContents>(
244 sigma_radius_1.value(), sigma_radius_1.value(), Entity::TileMode::kDecal,
245 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
246 contents->SetInputs({FilterInput::Make(texture)});
247 std::shared_ptr<ContentContext> renderer = GetContentContext();
248
249 Entity entity;
250 std::optional<Entity> result =
251 contents->GetEntity(*renderer, entity, /*coverage_hint=*/{});
252 EXPECT_TRUE(result.has_value());
253 if (result.has_value()) {
254 EXPECT_EQ(result.value().GetBlendMode(), BlendMode::kSourceOver);
255 std::optional<Rect> result_coverage = result.value().GetCoverage();
256 std::optional<Rect> contents_coverage = contents->GetCoverage(entity);
257 EXPECT_TRUE(result_coverage.has_value());
258 EXPECT_TRUE(contents_coverage.has_value());
259 if (result_coverage.has_value() && contents_coverage.has_value()) {
260 EXPECT_TRUE(RectNear(contents_coverage.value(),
261 Rect::MakeLTRB(-1, -1, 101, 101)));
262 EXPECT_TRUE(
263 RectNear(result_coverage.value(), Rect::MakeLTRB(-1, -1, 101, 101)));
264 }
265 }
266 }
267
268 TEST_P(GaussianBlurFilterContentsTest,
269 RenderCoverageMatchesGetCoverageTranslate) {
270 std::shared_ptr<Texture> texture = MakeTexture(ISize(100, 100));
271 fml::StatusOr<Scalar> sigma_radius_1 =
272 CalculateSigmaForBlurRadius(1.0, Matrix());
273 ASSERT_TRUE(sigma_radius_1.ok());
274 auto contents = std::make_unique<GaussianBlurFilterContents>(
275 sigma_radius_1.value(), sigma_radius_1.value(), Entity::TileMode::kDecal,
276 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
277 contents->SetInputs({FilterInput::Make(texture)});
278 std::shared_ptr<ContentContext> renderer = GetContentContext();
279
280 Entity entity;
281 entity.SetTransform(Matrix::MakeTranslation({100, 200, 0}));
282 std::optional<Entity> result =
283 contents->GetEntity(*renderer, entity, /*coverage_hint=*/{});
284
285 EXPECT_TRUE(result.has_value());
286 if (result.has_value()) {
287 EXPECT_EQ(result.value().GetBlendMode(), BlendMode::kSourceOver);
288 std::optional<Rect> result_coverage = result.value().GetCoverage();
289 std::optional<Rect> contents_coverage = contents->GetCoverage(entity);
290 EXPECT_TRUE(result_coverage.has_value());
291 EXPECT_TRUE(contents_coverage.has_value());
292 if (result_coverage.has_value() && contents_coverage.has_value()) {
293 EXPECT_TRUE(RectNear(contents_coverage.value(),
294 Rect::MakeLTRB(99, 199, 201, 301)));
295 EXPECT_TRUE(
296 RectNear(result_coverage.value(), Rect::MakeLTRB(99, 199, 201, 301)));
297 }
298 }
299 }
300
301 TEST_P(GaussianBlurFilterContentsTest,
302 RenderCoverageMatchesGetCoverageRotated) {
303 std::shared_ptr<Texture> texture = MakeTexture(ISize(400, 300));
304 fml::StatusOr<Scalar> sigma_radius_1 =
305 CalculateSigmaForBlurRadius(1.0, Matrix());
306 auto contents = std::make_unique<GaussianBlurFilterContents>(
307 sigma_radius_1.value(), sigma_radius_1.value(), Entity::TileMode::kDecal,
308 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
309 contents->SetInputs({FilterInput::Make(texture)});
310 std::shared_ptr<ContentContext> renderer = GetContentContext();
311
312 Entity entity;
313 // Rotate around the top left corner, then push it over to (100, 100).
314 entity.SetTransform(Matrix::MakeTranslation({400, 100, 0}) *
315 Matrix::MakeRotationZ(Degrees(90.0)));
316 std::optional<Entity> result =
317 contents->GetEntity(*renderer, entity, /*coverage_hint=*/{});
318 EXPECT_TRUE(result.has_value());
319 if (result.has_value()) {
320 EXPECT_EQ(result.value().GetBlendMode(), BlendMode::kSourceOver);
321 std::optional<Rect> result_coverage = result.value().GetCoverage();
322 std::optional<Rect> contents_coverage = contents->GetCoverage(entity);
323 EXPECT_TRUE(result_coverage.has_value());
324 EXPECT_TRUE(contents_coverage.has_value());
325 if (result_coverage.has_value() && contents_coverage.has_value()) {
326 EXPECT_TRUE(RectNear(contents_coverage.value(),
327 Rect::MakeLTRB(99, 99, 401, 501)));
328 EXPECT_TRUE(
329 RectNear(result_coverage.value(), Rect::MakeLTRB(99, 99, 401, 501)));
330 }
331 }
332 }
333
334 TEST_P(GaussianBlurFilterContentsTest, CalculateUVsSimple) {
335 std::shared_ptr<Texture> texture = MakeTexture(ISize(100, 100));
336 auto filter_input = FilterInput::Make(texture);
337 Entity entity;
338 Quad uvs = GaussianBlurFilterContents::CalculateUVs(
339 filter_input, entity, Rect::MakeSize(ISize(100, 100)), ISize(100, 100));
340 std::optional<Rect> uvs_bounds = Rect::MakePointBounds(uvs);
341 EXPECT_TRUE(uvs_bounds.has_value());
342 if (uvs_bounds.has_value()) {
343 EXPECT_TRUE(RectNear(uvs_bounds.value(), Rect::MakeXYWH(0, 0, 1, 1)));
344 }
345 }
346
347 TEST_P(GaussianBlurFilterContentsTest, TextureContentsWithDestinationRect) {
348 std::shared_ptr<Texture> texture = MakeTexture(ISize(100, 100));
349 auto texture_contents = std::make_shared<TextureContents>();
350 texture_contents->SetSourceRect(Rect::MakeSize(texture->GetSize()));
351 texture_contents->SetTexture(texture);
352 texture_contents->SetDestinationRect(Rect::MakeXYWH(
353 50, 40, texture->GetSize().width, texture->GetSize().height));
354
355 fml::StatusOr<Scalar> sigma_radius_1 =
356 CalculateSigmaForBlurRadius(1.0, Matrix());
357 auto contents = std::make_unique<GaussianBlurFilterContents>(
358 sigma_radius_1.value(), sigma_radius_1.value(), Entity::TileMode::kDecal,
359 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
360 contents->SetInputs({FilterInput::Make(texture_contents)});
361 std::shared_ptr<ContentContext> renderer = GetContentContext();
362
363 Entity entity;
364 std::optional<Entity> result =
365 contents->GetEntity(*renderer, entity, /*coverage_hint=*/{});
366 EXPECT_TRUE(result.has_value());
367 if (result.has_value()) {
368 EXPECT_EQ(result.value().GetBlendMode(), BlendMode::kSourceOver);
369 std::optional<Rect> result_coverage = result.value().GetCoverage();
370 std::optional<Rect> contents_coverage = contents->GetCoverage(entity);
371 EXPECT_TRUE(result_coverage.has_value());
372 EXPECT_TRUE(contents_coverage.has_value());
373 if (result_coverage.has_value() && contents_coverage.has_value()) {
374 EXPECT_TRUE(RectNear(result_coverage.value(), contents_coverage.value()));
375 EXPECT_TRUE(RectNear(result_coverage.value(),
376 Rect::MakeLTRB(49.f, 39.f, 151.f, 141.f)));
377 }
378 }
379 }
380
381 TEST_P(GaussianBlurFilterContentsTest,
382 TextureContentsWithDestinationRectScaled) {
383 std::shared_ptr<Texture> texture = MakeTexture(ISize(100, 100));
384 auto texture_contents = std::make_shared<TextureContents>();
385 texture_contents->SetSourceRect(Rect::MakeSize(texture->GetSize()));
386 texture_contents->SetTexture(texture);
387 texture_contents->SetDestinationRect(Rect::MakeXYWH(
388 50, 40, texture->GetSize().width, texture->GetSize().height));
389
390 fml::StatusOr<Scalar> sigma_radius_1 =
391 CalculateSigmaForBlurRadius(1.0, Matrix());
392 auto contents = std::make_unique<GaussianBlurFilterContents>(
393 sigma_radius_1.value(), sigma_radius_1.value(), Entity::TileMode::kDecal,
394 FilterContents::BlurStyle::kNormal,
395 /*mask_geometry=*/nullptr);
396 contents->SetInputs({FilterInput::Make(texture_contents)});
397 std::shared_ptr<ContentContext> renderer = GetContentContext();
398
399 Entity entity;
400 entity.SetTransform(Matrix::MakeScale({2.0, 2.0, 1.0}));
401 std::optional<Entity> result =
402 contents->GetEntity(*renderer, entity, /*coverage_hint=*/{});
403 EXPECT_TRUE(result.has_value());
404 if (result.has_value()) {
405 EXPECT_EQ(result.value().GetBlendMode(), BlendMode::kSourceOver);
406 std::optional<Rect> result_coverage = result.value().GetCoverage();
407 std::optional<Rect> contents_coverage = contents->GetCoverage(entity);
408 EXPECT_TRUE(result_coverage.has_value());
409 EXPECT_TRUE(contents_coverage.has_value());
410 if (result_coverage.has_value() && contents_coverage.has_value()) {
411 EXPECT_TRUE(RectNear(result_coverage.value(), contents_coverage.value()));
412 // Scaling a blurred entity doesn't seem to scale the blur radius linearly
413 // when comparing results with rrect_blur. That's why this is not
414 // Rect::MakeXYWH(98.f, 78.f, 204.0f, 204.f).
415 EXPECT_TRUE(RectNear(contents_coverage.value(),
416 Rect::MakeXYWH(94.f, 74.f, 212.0f, 212.f)));
417 }
418 }
419 }
420
421 TEST_P(GaussianBlurFilterContentsTest, TextureContentsWithEffectTransform) {
422 Matrix effect_transform = Matrix::MakeScale({2.0, 2.0, 1.0});
423 std::shared_ptr<Texture> texture = MakeTexture(ISize(100, 100));
424 auto texture_contents = std::make_shared<TextureContents>();
425 texture_contents->SetSourceRect(Rect::MakeSize(texture->GetSize()));
426 texture_contents->SetTexture(texture);
427 texture_contents->SetDestinationRect(Rect::MakeXYWH(
428 50, 40, texture->GetSize().width, texture->GetSize().height));
429
430 fml::StatusOr<Scalar> sigma_radius_1 =
431 CalculateSigmaForBlurRadius(1.0, effect_transform);
432 ASSERT_TRUE(sigma_radius_1.ok());
433 auto contents = std::make_unique<GaussianBlurFilterContents>(
434 sigma_radius_1.value(), sigma_radius_1.value(), Entity::TileMode::kDecal,
435 FilterContents::BlurStyle::kNormal, /*mask_geometry=*/nullptr);
436 contents->SetInputs({FilterInput::Make(texture_contents)});
437 contents->SetEffectTransform(effect_transform);
438 std::shared_ptr<ContentContext> renderer = GetContentContext();
439
440 Entity entity;
441 std::optional<Entity> result =
442 contents->GetEntity(*renderer, entity, /*coverage_hint=*/{});
443 EXPECT_TRUE(result.has_value());
444 if (result.has_value()) {
445 EXPECT_EQ(result.value().GetBlendMode(), BlendMode::kSourceOver);
446 std::optional<Rect> result_coverage = result.value().GetCoverage();
447 std::optional<Rect> contents_coverage = contents->GetCoverage(entity);
448 EXPECT_TRUE(result_coverage.has_value());
449 EXPECT_TRUE(contents_coverage.has_value());
450 if (result_coverage.has_value() && contents_coverage.has_value()) {
451 EXPECT_TRUE(RectNear(result_coverage.value(), contents_coverage.value()));
452 EXPECT_TRUE(RectNear(contents_coverage.value(),
453 Rect::MakeXYWH(49.f, 39.f, 102.f, 102.f)));
454 }
455 }
456 }
457
458 TEST(GaussianBlurFilterContentsTest, CalculateSigmaForBlurRadius) {
459 Scalar sigma = 1.0;
460 Scalar radius = GaussianBlurFilterContents::CalculateBlurRadius(
461 GaussianBlurFilterContents::ScaleSigma(sigma));
462 fml::StatusOr<Scalar> derived_sigma =
463 CalculateSigmaForBlurRadius(radius, Matrix());
464 ASSERT_TRUE(derived_sigma.ok());
465 EXPECT_NEAR(sigma, derived_sigma.value(), 0.01f);
466 }
467
468 TEST(GaussianBlurFilterContentsTest, Coefficients) {
469 BlurParameters parameters = {.blur_uv_offset = Point(1, 0),
470 .blur_sigma = 1,
471 .blur_radius = 5,
472 .step_size = 1};
473 KernelSamples samples = GenerateBlurInfo(parameters);
474 EXPECT_EQ(samples.sample_count, 9);
475
476 // Coefficients should add up to 1.
477 Scalar tally = 0;
478 for (int i = 0; i < samples.sample_count; ++i) {
479 tally += samples.samples[i].coefficient;
480 }
481 EXPECT_FLOAT_EQ(tally, 1.0f);
482
483 // Verify the shape of the curve.
484 for (int i = 0; i < 4; ++i) {
485 EXPECT_FLOAT_EQ(samples.samples[i].coefficient,
486 samples.samples[8 - i].coefficient);
487 EXPECT_TRUE(samples.samples[i + 1].coefficient >
488 samples.samples[i].coefficient);
489 }
490 }
491
492 TEST(GaussianBlurFilterContentsTest, LerpHackKernelSamplesSimple) {
493 KernelSamples kernel_samples = {
494 .sample_count = 5,
495 .samples =
496 {
497 {
498 .uv_offset = Vector2(-2, 0),
499 .coefficient = 0.1f,
500 },
501 {
502 .uv_offset = Vector2(-1, 0),
503 .coefficient = 0.2f,
504 },
505 {
506 .uv_offset = Vector2(0, 0),
507 .coefficient = 0.4f,
508 },
509 {
510 .uv_offset = Vector2(1, 0),
511 .coefficient = 0.2f,
512 },
513 {
514 .uv_offset = Vector2(2, 0),
515 .coefficient = 0.1f,
516 },
517 },
518 };
519
520 GaussianBlurPipeline::FragmentShader::KernelSamples blur_info =
521 LerpHackKernelSamples(kernel_samples);
522 EXPECT_EQ(blur_info.sample_count, 3);
523
524 KernelSample* samples = kernel_samples.samples;
525
526 //////////////////////////////////////////////////////////////////////////////
527 // Check output kernel.
528
529 EXPECT_POINT_NEAR(GetUVOffset(blur_info.sample_data[0]),
530 Point(-1.3333333, 0));
531 EXPECT_FLOAT_EQ(GetCoefficient(blur_info.sample_data[0]), 0.3);
532
533 EXPECT_POINT_NEAR(GetUVOffset(blur_info.sample_data[1]), Point(0, 0));
534 EXPECT_FLOAT_EQ(GetCoefficient(blur_info.sample_data[1]), 0.4);
535
536 EXPECT_POINT_NEAR(GetUVOffset(blur_info.sample_data[2]), Point(1.333333, 0));
537 EXPECT_FLOAT_EQ(GetCoefficient(blur_info.sample_data[2]), 0.3);
538
539 //////////////////////////////////////////////////////////////////////////////
540 // Check output of fast kernel versus original kernel.
541
542 Scalar data[5] = {0.25, 0.5, 0.5, 1.0, 0.2};
543 Scalar original_output =
544 samples[0].coefficient * data[0] + samples[1].coefficient * data[1] +
545 samples[2].coefficient * data[2] + samples[3].coefficient * data[3] +
546 samples[4].coefficient * data[4];
547
548 auto lerp = [](const Point& point, Scalar left, Scalar right) {
549 Scalar int_part;
550 Scalar fract = fabsf(modf(point.x, &int_part));
551 if (point.x < 0) {
552 return left * fract + right * (1.0 - fract);
553 } else {
554 return left * (1.0 - fract) + right * fract;
555 }
556 };
557 Scalar fast_output =
558 /*1st*/ lerp(GetUVOffset(blur_info.sample_data[0]), data[0], data[1]) *
559 GetCoefficient(blur_info.sample_data[0]) +
560 /*2nd*/ data[2] * GetCoefficient(blur_info.sample_data[1]) +
561 /*3rd*/ lerp(GetUVOffset(blur_info.sample_data[2]), data[3], data[4]) *
562 GetCoefficient(blur_info.sample_data[2]);
563
564 EXPECT_NEAR(original_output, fast_output, 0.01);
565 }
566
567 TEST(GaussianBlurFilterContentsTest, LerpHackKernelSamplesComplex) {
568 Scalar sigma = 10.0f;
569 int32_t blur_radius = static_cast<int32_t>(
570 std::ceil(GaussianBlurFilterContents::CalculateBlurRadius(sigma)));
571 BlurParameters parameters = {.blur_uv_offset = Point(1, 0),
572 .blur_sigma = sigma,
573 .blur_radius = blur_radius,
574 .step_size = 1};
575 KernelSamples kernel_samples = GenerateBlurInfo(parameters);
576 EXPECT_EQ(kernel_samples.sample_count, 33);
577 GaussianBlurPipeline::FragmentShader::KernelSamples fast_kernel_samples =
578 LerpHackKernelSamples(kernel_samples);
579 EXPECT_EQ(fast_kernel_samples.sample_count, 17);
580 float data[33];
581 srand(0);
582 for (int i = 0; i < 33; i++) {
583 data[i] = 255.0 * static_cast<double>(IMPELLER_RAND()) / RAND_MAX;
584 }
585
586 auto sampler = [data](Point point) -> Scalar {
587 FML_CHECK(point.y == 0.0f);
588 FML_CHECK(point.x >= -16);
589 FML_CHECK(point.x <= 16);
590 Scalar fint_part;
591 Scalar fract = fabsf(modf(point.x, &fint_part));
592 if (fract == 0) {
593 int32_t int_part = static_cast<int32_t>(fint_part) + 16;
594 return data[int_part];
595 } else {
596 int32_t left = static_cast<int32_t>(floor(point.x)) + 16;
597 int32_t right = static_cast<int32_t>(ceil(point.x)) + 16;
598 if (point.x < 0) {
599 return fract * data[left] + (1.0 - fract) * data[right];
600 } else {
601 return (1.0 - fract) * data[left] + fract * data[right];
602 }
603 }
604 };
605
606 Scalar output = 0.0;
607 for (int i = 0; i < kernel_samples.sample_count; ++i) {
608 auto sample = kernel_samples.samples[i];
609 output += sample.coefficient * sampler(sample.uv_offset);
610 }
611
612 Scalar fast_output = 0.0;
613 for (int i = 0; i < fast_kernel_samples.sample_count; i++) {
614 fast_output += GetCoefficient(fast_kernel_samples.sample_data[i]) *
615 sampler(GetUVOffset(fast_kernel_samples.sample_data[i]));
616 }
617
618 EXPECT_NEAR(output, fast_output, 0.1);
619 }
620
621 TEST(GaussianBlurFilterContentsTest, ChopHugeBlurs) {
622 Scalar sigma = 30.5f;
623 int32_t blur_radius = static_cast<int32_t>(
624 std::ceil(GaussianBlurFilterContents::CalculateBlurRadius(sigma)));
625 BlurParameters parameters = {.blur_uv_offset = Point(1, 0),
626 .blur_sigma = sigma,
627 .blur_radius = blur_radius,
628 .step_size = 1};
629 KernelSamples kernel_samples = GenerateBlurInfo(parameters);
630 GaussianBlurPipeline::FragmentShader::KernelSamples frag_kernel_samples =
631 LerpHackKernelSamples(kernel_samples);
632 EXPECT_TRUE(frag_kernel_samples.sample_count <= kGaussianBlurMaxKernelSize);
633 }
634
635 } // namespace testing
636 } // namespace impeller
impeller::ISize
ISize64 ISize
Definition: size.h:140
impeller::KernelSamples
Definition: gaussian_blur_filter_contents.h:39
impeller::Scalar
float Scalar
Definition: scalar.h:18
impeller::KernelSamples::sample_count
int sample_count
Definition: gaussian_blur_filter_contents.h:41
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geometry_asserts.h
uvs
Quad uvs
Definition: gaussian_blur_filter_contents.cc:204
impeller::BlurParameters::blur_uv_offset
Point blur_uv_offset
Definition: gaussian_blur_filter_contents.h:23
impeller::TRect< Scalar >::MakeXYWH
constexpr static TRect MakeXYWH(Type x, Type y, Type width, Type height)
Definition: rect.h:136
impeller::FilterInput::Make
static FilterInput::Ref Make(Variant input, bool msaa_enabled=true)
Definition: filter_input.cc:19
data
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Definition: texture_gles.cc:63
impeller::Entity::TileMode::kDecal
@ kDecal
impeller::Vector2
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Definition: point.h:331
EXPECT_POINT_NEAR
#define EXPECT_POINT_NEAR(a, b)
Definition: geometry_asserts.h:205
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float coefficient
Definition: gaussian_blur_filter_contents.h:31
gaussian_blur_filter_contents.h
impeller::FilterContents::BlurStyle::kNormal
@ kNormal
Blurred inside and outside.
impeller::kGaussianBlurMaxKernelSize
static constexpr int32_t kGaussianBlurMaxKernelSize
Definition: gaussian_blur_filter_contents.h:17
impeller::GaussianBlurFilterContents::CalculateBlurRadius
static Scalar CalculateBlurRadius(Scalar sigma)
Definition: gaussian_blur_filter_contents.cc:856
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static constexpr Matrix MakeTranslation(const Vector3 &t)
Definition: matrix.h:95
EXPECT_RECT_NEAR
#define EXPECT_RECT_NEAR(a, b)
Definition: geometry_asserts.h:203
impeller::TRect< Scalar >::MakePointBounds
constexpr static std::optional< TRect > MakePointBounds(const U &value)
Definition: rect.h:155
impeller::GaussianBlurFilterContents::GetSigmaX
Scalar GetSigmaX() const
Definition: gaussian_blur_filter_contents.h:64
impeller::testing::INSTANTIATE_PLAYGROUND_SUITE
INSTANTIATE_PLAYGROUND_SUITE(AiksTest)
impeller::GaussianBlurFilterContents::GetFilterCoverage
std::optional< Rect > GetFilterCoverage(const FilterInput::Vector &inputs, const Entity &entity, const Matrix &effect_transform) const override
Internal utility method for |GetLocalCoverage| that computes the output coverage of this filter acros...
Definition: gaussian_blur_filter_contents.cc:661
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Definition: entity.h:20
impeller::TSize
Definition: size.h:19
impeller::Point
TPoint< Scalar > Point
Definition: point.h:327
impeller::Quad
std::array< Point, 4 > Quad
Definition: point.h:332
impeller::testing::GaussianBlurFilterContentsTest::MakeTexture
std::shared_ptr< Texture > MakeTexture(ISize size)
Create a texture that has been cleared to transparent black.
Definition: gaussian_blur_filter_contents_unittests.cc:86
impeller::KernelSample
Definition: gaussian_blur_filter_contents.h:29
impeller::BlurParameters
Definition: gaussian_blur_filter_contents.h:22
IMPELLER_RAND
#define IMPELLER_RAND
Definition: gaussian_blur_filter_contents_unittests.cc:19
impeller::TPoint::x
Type x
Definition: point.h:30
impeller::GenerateBlurInfo
KernelSamples GenerateBlurInfo(BlurParameters parameters)
Definition: gaussian_blur_filter_contents.cc:886
impeller::testing::TEST_P
TEST_P(AiksTest, DrawAtlasNoColor)
Definition: aiks_dl_atlas_unittests.cc:78
impeller::RenderPass
Render passes encode render commands directed as one specific render target into an underlying comman...
Definition: render_pass.h:33
impeller::testing::GaussianBlurFilterContentsTest
Definition: gaussian_blur_filter_contents_unittests.cc:83
impeller::GaussianBlurFilterContents::GetSigmaY
Scalar GetSigmaY() const
Definition: gaussian_blur_filter_contents.h:65
content_context.h
impeller::EntityPlayground
Definition: entity_playground.h:16
impeller::Entity::SetTransform
void SetTransform(const Matrix &transform)
Set the global transform matrix for this Entity.
Definition: entity.cc:63
impeller::Matrix::MakeRotationZ
static Matrix MakeRotationZ(Radians r)
Definition: matrix.h:213
scaled_sigma
Vector2 scaled_sigma
Sigma when considering an entity's scale and the effect transform.
Definition: gaussian_blur_filter_contents.cc:81
RectNear
inline ::testing::AssertionResult RectNear(impeller::Rect a, impeller::Rect b)
Definition: geometry_asserts.h:89
impeller::TRect< Scalar >::MakeSize
constexpr static TRect MakeSize(const TSize< U > &size)
Definition: rect.h:150
impeller::TPoint< Scalar >
blur_radius
Vector2 blur_radius
Blur radius in source pixels based on scaled_sigma.
Definition: gaussian_blur_filter_contents.cc:83
impeller::GaussianBlurFilterContents::CalculateScale
static Scalar CalculateScale(Scalar sigma)
Definition: gaussian_blur_filter_contents.cc:623
impeller::LerpHackKernelSamples
GaussianBlurPipeline::FragmentShader::KernelSamples LerpHackKernelSamples(KernelSamples parameters)
Definition: gaussian_blur_filter_contents.cc:933
impeller::Degrees
Definition: scalar.h:51
color.h
impeller::TRect< Scalar >::MakeLTRB
constexpr static TRect MakeLTRB(Type left, Type top, Type right, Type bottom)
Definition: rect.h:129
impeller::GaussianBlurFilterContents::CalculateUVs
static Quad CalculateUVs(const std::shared_ptr< FilterInput > &filter_input, const Entity &entity, const Rect &source_rect, const ISize &texture_size)
Definition: gaussian_blur_filter_contents.cc:860
impeller::FilterInput::Vector
std::vector< FilterInput::Ref > Vector
Definition: filter_input.h:33
impeller::Playground::GetContext
std::shared_ptr< Context > GetContext() const
Definition: playground.cc:90
impeller::interop::Create
ScopedObject< Object > Create(CtorArgs &&... args)
Definition: object.h:160
impeller::GaussianBlurFilterContents
Definition: gaussian_blur_filter_contents.h:56
impeller
Definition: allocation.cc:12
impeller::Matrix::MakeScale
static constexpr Matrix MakeScale(const Vector3 &s)
Definition: matrix.h:104
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TEST(AllocationSizeTest, CanCreateTypedAllocations)
Definition: allocation_size_unittests.cc:10
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Definition: content_context.h:366
impeller::EntityPlayground::GetContentContext
std::shared_ptr< ContentContext > GetContentContext() const
Definition: entity_playground.cc:23
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A 4x4 matrix using column-major storage.
Definition: matrix.h:37
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@ kSourceOver
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KernelSample samples[kMaxKernelSize]
Definition: gaussian_blur_filter_contents.h:42
entity_playground.h
impeller::GaussianBlurFilterContents::ScaleSigma
static Scalar ScaleSigma(Scalar sigma)
Definition: gaussian_blur_filter_contents.cc:876