submodule/skia/gm/imagemakewithfilter.cpp

   1 /*
   2  * Copyright 2016 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 "gm/gm.h"
   9
  10 #include "include/core/SkBlendMode.h"
  11 #include "include/core/SkCanvas.h"
  12 #include "include/core/SkColor.h"
  13 #include "include/core/SkColorFilter.h"
  14 #include "include/core/SkImage.h"
  15 #include "include/core/SkImageFilter.h"
  16 #include "include/core/SkImageInfo.h"
  17 #include "include/core/SkPaint.h"
  18 #include "include/core/SkPoint.h"
  19 #include "include/core/SkPoint3.h"
  20 #include "include/core/SkRect.h"
  21 #include "include/core/SkRefCnt.h"
  22 #include "include/core/SkRegion.h"
  23 #include "include/core/SkScalar.h"
  24 #include "include/core/SkSize.h"
  25 #include "include/core/SkString.h"
  26 #include "include/core/SkSurface.h"
  27 #include "include/core/SkTypes.h"
  28
  29 #include "include/effects/SkImageFilters.h"
  30
  31 #include "include/gpu/GrDirectContext.h"
  32
  33 #include "tools/Resources.h"
  34 #include "tools/ToolUtils.h"
  35
  36 #include <utility>
  37
  38 ///////////////////////////////////////////////////////////////////////////////
  39
  40 static void show_bounds(SkCanvas* canvas, const SkIRect* clip, const SkIRect* inSubset,
  41                         const SkIRect* outSubset) {
  42     const SkIRect* rects[] { clip, inSubset, outSubset };
  43     SkColor colors[] { SK_ColorBLUE, SK_ColorYELLOW, SK_ColorRED };
  44
  45     SkPaint paint;
  46     paint.setStyle(SkPaint::kStroke_Style);
  47
  48     for (size_t i = 0; i < SK_ARRAY_COUNT(rects); ++i) {
  49         // Skip null bounds rects, since not all methods have subsets
  50         if (rects[i]) {
  51             paint.setColor(colors[i]);
  52             canvas->drawRect(SkRect::Make(*(rects[i])), paint);
  53         }
  54     }
  55 }
  56
  57 // Factories for creating image filters, either with or without a cropRect
  58 // (this could go away if there was a SkImageFilter::makeWithCropRect() function, but that seems
  59 //  less generally useful).
  60 typedef sk_sp<SkImageFilter> (*FilterFactory)(sk_sp<SkImage> auxImage, const SkIRect* cropRect);
  61
  62 static sk_sp<SkImageFilter> color_filter_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
  63     // The color filter uses kSrcIn so that it respects the transparency introduced by clamping;
  64     // using kSrc would just turn the entire out rect to green regardless.
  65     auto cf = SkColorFilters::Blend(SK_ColorGREEN, SkBlendMode::kSrcIn);
  66     return SkImageFilters::ColorFilter(std::move(cf), nullptr, cropRect);
  67 }
  68
  69 static sk_sp<SkImageFilter> blur_filter_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
  70     return SkImageFilters::Blur(2.0f, 2.0f, nullptr, cropRect);
  71 }
  72
  73 static sk_sp<SkImageFilter> drop_shadow_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
  74     return SkImageFilters::DropShadow(10.0f, 5.0f, 3.0f, 3.0f, SK_ColorBLUE, nullptr, cropRect);
  75 }
  76
  77 static sk_sp<SkImageFilter> offset_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
  78     return SkImageFilters::Offset(10.f, 5.f, nullptr, cropRect);
  79 }
  80
  81 static sk_sp<SkImageFilter> dilate_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
  82     return SkImageFilters::Dilate(10.f, 5.f, nullptr, cropRect);
  83 }
  84
  85 static sk_sp<SkImageFilter> erode_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
  86     return SkImageFilters::Erode(10.f, 5.f, nullptr, cropRect);
  87 }
  88
  89 static sk_sp<SkImageFilter> displacement_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
  90     sk_sp<SkImageFilter> displacement = SkImageFilters::Image(std::move(auxImage));
  91     return SkImageFilters::DisplacementMap(SkColorChannel::kR, SkColorChannel::kG, 40.f,
  92                                            std::move(displacement), nullptr, cropRect);
  93 }
  94
  95 static sk_sp<SkImageFilter> arithmetic_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
  96     sk_sp<SkImageFilter> background = SkImageFilters::Image(std::move(auxImage));
  97     return SkImageFilters::Arithmetic(0.0f, .6f, 1.f, 0.f, false, std::move(background),
  98                                       nullptr, cropRect);
  99 }
 100
 101 static sk_sp<SkImageFilter> blend_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
 102     sk_sp<SkImageFilter> background = SkImageFilters::Image(std::move(auxImage));
 103     return SkImageFilters::Blend(
 104             SkBlendMode::kModulate, std::move(background), nullptr, cropRect);
 105 }
 106
 107 static sk_sp<SkImageFilter> convolution_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
 108     SkISize kernelSize = SkISize::Make(3, 3);
 109     SkIPoint kernelOffset = SkIPoint::Make(1, 1);
 110     // A Laplacian edge detector, ee https://en.wikipedia.org/wiki/Kernel_(image_processing)
 111     SkScalar kernel[9] = {-1.f, -1.f, -1.f,
 112                           -1.f, 8.f, -1.f,
 113                           -1.f, -1.f, -1.f};
 114     return SkImageFilters::MatrixConvolution(kernelSize, kernel, 1.f, 0.f, kernelOffset,
 115                                              SkTileMode::kClamp, false, nullptr, cropRect);
 116 }
 117
 118 static sk_sp<SkImageFilter> matrix_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
 119     SkMatrix matrix = SkMatrix::I();
 120     matrix.setRotate(45.f, 50.f, 50.f);
 121
 122     // This doesn't support a cropRect
 123     return SkImageFilters::MatrixTransform(matrix, SkSamplingOptions(SkFilterMode::kLinear), nullptr);
 124 }
 125
 126 static sk_sp<SkImageFilter> alpha_threshold_factory(sk_sp<SkImage> auxImage,
 127                                                     const SkIRect* cropRect) {
 128     // Centered cross with higher opacity
 129     SkRegion region(SkIRect::MakeLTRB(30, 45, 70, 55));
 130     region.op(SkIRect::MakeLTRB(45, 30, 55, 70), SkRegion::kUnion_Op);
 131
 132     return SkImageFilters::AlphaThreshold(region, 1.f, .2f, nullptr, cropRect);
 133 }
 134
 135 static sk_sp<SkImageFilter> lighting_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
 136     // Must convert the RGB values of the source to alpha, since that is what the lighting filters
 137     // use to estimate their normals. This color matrix changes the color to white and the alpha
 138     // to be equal to the approx. luminance of the original color.
 139     static const float kMatrix[20] = {
 140         0.f, 0.f, 0.f, 0.f, 1.f,
 141         0.f, 0.f, 0.f, 0.f, 1.f,
 142         0.f, 0.f, 0.f, 0.f, 1.f,
 143         0.2126f, 0.7152f, 0.0722f, 0.f, 0.f
 144     };
 145     sk_sp<SkImageFilter> srcToAlpha = SkImageFilters::ColorFilter(
 146             SkColorFilters::Matrix(kMatrix), nullptr);
 147
 148     // Combine both specular and diffuse into a single DAG since they use separate internal filter
 149     // implementations.
 150     SkScalar sinAzimuth = SkScalarSin(SkDegreesToRadians(225.f)),
 151              cosAzimuth = SkScalarCos(SkDegreesToRadians(225.f));
 152
 153     SkPoint3 spotTarget = SkPoint3::Make(SkIntToScalar(40), SkIntToScalar(40), 0);
 154     SkPoint3 diffLocation = SkPoint3::Make(spotTarget.fX + 50 * cosAzimuth,
 155                                            spotTarget.fY + 50 * sinAzimuth,
 156                                            SkIntToScalar(10));
 157     SkPoint3 specLocation = SkPoint3::Make(spotTarget.fX - 50 * sinAzimuth,
 158                                            spotTarget.fY + 50 * cosAzimuth,
 159                                            SkIntToScalar(10));
 160     sk_sp<SkImageFilter> diffuse = SkImageFilters::PointLitDiffuse(
 161             diffLocation, SK_ColorWHITE, /* scale */ 1.f, /* kd */ 2.f, srcToAlpha, cropRect);
 162     sk_sp<SkImageFilter> specular = SkImageFilters::PointLitSpecular(
 163             specLocation, SK_ColorRED, /* scale */ 1.f, /* ks */ 1.f, /* shine */ 8.f,
 164             srcToAlpha, cropRect);
 165     return SkImageFilters::Merge(std::move(diffuse), std::move(specular), cropRect);
 166 }
 167
 168 static sk_sp<SkImageFilter> tile_factory(sk_sp<SkImage> auxImage, const SkIRect* cropRect) {
 169     // Tile the subset over a large region
 170     return SkImageFilters::Tile(SkRect::MakeLTRB(25, 25, 75, 75), SkRect::MakeWH(100, 100),
 171                                 nullptr);
 172 }
 173
 174 namespace {
 175     enum class Strategy {
 176         // Uses makeWithFilter, passing in subset and clip directly
 177         kMakeWithFilter,
 178         // Uses saveLayer after clipRect() to filter on the restore (i.e. reference image)
 179         kSaveLayer
 180     };
 181 }  // namespace
 182
 183 // In this GM, we're going to feed the inner portion of a 100x100 mandrill (i.e., strip off a
 184 // 25-wide border) through the makeWithFilter method. We'll then draw the appropriate subset of the
 185 // result to the screen at the given offset. Some filters rely on a secondary image, which will be a
 186 // 100x100 checkerboard. The original image is drawn in the background so that alignment is clear
 187 // when drawing the result at its reported offset.
 188 class ImageMakeWithFilterGM : public skiagm::GM {
 189 public:
 190     ImageMakeWithFilterGM (Strategy strategy, bool filterWithCropRect = false)
 191             : fStrategy(strategy)
 192             , fFilterWithCropRect(filterWithCropRect)
 193             , fMainImage(nullptr)
 194             , fAuxImage(nullptr) {}
 195
 196 protected:
 197     SkString onShortName() override {
 198         SkString name = SkString("imagemakewithfilter");
 199
 200         if (fFilterWithCropRect) {
 201             name.append("_crop");
 202         }
 203         if (fStrategy == Strategy::kSaveLayer) {
 204             name.append("_ref");
 205         }
 206         return name;
 207     }
 208
 209     SkISize onISize() override { return SkISize::Make(1980, 860); }
 210
 211     void onOnceBeforeDraw() override {
 212         SkImageInfo info = SkImageInfo::MakeN32(100, 100, kUnpremul_SkAlphaType);
 213         auto surface = SkSurface::MakeRaster(info, nullptr);
 214
 215         sk_sp<SkImage> colorImage = GetResourceAsImage("images/mandrill_128.png");
 216         // Resize to 100x100
 217         surface->getCanvas()->drawImageRect(
 218                 colorImage, SkRect::MakeWH(colorImage->width(), colorImage->height()),
 219                 SkRect::MakeWH(info.width(), info.height()), SkSamplingOptions(), nullptr,
 220                                             SkCanvas::kStrict_SrcRectConstraint);
 221         fMainImage = surface->makeImageSnapshot();
 222
 223         ToolUtils::draw_checkerboard(surface->getCanvas());
 224         fAuxImage = surface->makeImageSnapshot();
 225     }
 226
 227     DrawResult onDraw(SkCanvas* canvas, SkString* errorMsg) override {
 228         FilterFactory filters[] = {
 229             color_filter_factory,
 230             blur_filter_factory,
 231             drop_shadow_factory,
 232             offset_factory,
 233             dilate_factory,
 234             erode_factory,
 235             displacement_factory,
 236             arithmetic_factory,
 237             blend_factory,
 238             convolution_factory,
 239             matrix_factory,
 240             alpha_threshold_factory,
 241             lighting_factory,
 242             tile_factory
 243         };
 244         const char* filterNames[] = {
 245             "Color",
 246             "Blur",
 247             "Drop Shadow",
 248             "Offset",
 249             "Dilate",
 250             "Erode",
 251             "Displacement",
 252             "Arithmetic",
 253             "Xfer Mode", // "blend"
 254             "Convolution",
 255             "Matrix Xform",
 256             "Alpha Threshold",
 257             "Lighting",
 258             "Tile"
 259         };
 260         static_assert(SK_ARRAY_COUNT(filters) == SK_ARRAY_COUNT(filterNames), "filter name length");
 261
 262         SkIRect clipBounds[] {
 263             { -20, -20, 100, 100 },
 264             {   0,   0,  75,  75 },
 265             {  20,  20, 100, 100 },
 266             { -20, -20,  50,  50 },
 267             {  20,  20,  50,  50 },
 268             {  30,  30,  75,  75 }
 269         };
 270
 271         auto rContext = canvas->recordingContext();
 272         // In a DDL context, we can't use the GPU code paths and we will drop the work – skip.
 273         auto dContext = GrAsDirectContext(rContext);
 274         if (rContext) {
 275             if (!dContext) {
 276                 *errorMsg = "Requires a direct context.";
 277                 return DrawResult::kSkip;
 278             }
 279             if (dContext->abandoned()) {
 280                 *errorMsg = "Direct context abandoned.";
 281                 return DrawResult::kSkip;
 282             }
 283         }
 284
 285         // These need to be GPU-backed when on the GPU to ensure that the image filters use the GPU
 286         // code paths (otherwise they may choose to do CPU filtering then upload)
 287         sk_sp<SkImage> mainImage = ToolUtils::MakeTextureImage(canvas, fMainImage);
 288         sk_sp<SkImage> auxImage = ToolUtils::MakeTextureImage(canvas, fAuxImage);
 289         if (!mainImage || !auxImage) {
 290             return DrawResult::kFail;
 291         }
 292         SkASSERT(mainImage && (mainImage->isTextureBacked() || !dContext));
 293         SkASSERT(auxImage && (auxImage->isTextureBacked() || !dContext));
 294
 295         SkScalar MARGIN = SkIntToScalar(40);
 296         SkScalar DX = mainImage->width() + MARGIN;
 297         SkScalar DY = auxImage->height() + MARGIN;
 298
 299         // Header hinting at what the filters do
 300         SkPaint textPaint;
 301         textPaint.setAntiAlias(true);
 302         SkFont font(nullptr, 12);
 303         for (size_t i = 0; i < SK_ARRAY_COUNT(filterNames); ++i) {
 304             canvas->drawString(filterNames[i], DX * i + MARGIN, 15, font, textPaint);
 305         }
 306
 307         canvas->translate(MARGIN, MARGIN);
 308
 309         for (auto clipBound : clipBounds) {
 310             canvas->save();
 311             for (size_t i = 0; i < SK_ARRAY_COUNT(filters); ++i) {
 312                 SkIRect subset = SkIRect::MakeXYWH(25, 25, 50, 50);
 313                 SkIRect outSubset;
 314
 315                 // Draw the original image faintly so that it aids in checking alignment of the
 316                 // filtered result.
 317                 SkPaint alpha;
 318                 alpha.setAlphaf(0.3f);
 319                 canvas->drawImage(mainImage, 0, 0, SkSamplingOptions(), &alpha);
 320
 321                 this->drawImageWithFilter(canvas, mainImage, auxImage, filters[i], clipBound,
 322                                           subset, &outSubset);
 323
 324                 // Draw outlines to highlight what was subset, what was cropped, and what was output
 325                 // (no output subset is displayed for kSaveLayer since that information isn't avail)
 326                 SkIRect* outSubsetBounds = nullptr;
 327                 if (fStrategy != Strategy::kSaveLayer) {
 328                     outSubsetBounds = &outSubset;
 329                 }
 330                 show_bounds(canvas, &clipBound, &subset, outSubsetBounds);
 331
 332                 canvas->translate(DX, 0);
 333             }
 334             canvas->restore();
 335             canvas->translate(0, DY);
 336         }
 337         return DrawResult::kOk;
 338     }
 339
 340 private:
 341     Strategy fStrategy;
 342     bool fFilterWithCropRect;
 343     sk_sp<SkImage> fMainImage;
 344     sk_sp<SkImage> fAuxImage;
 345
 346     void drawImageWithFilter(SkCanvas* canvas, sk_sp<SkImage> mainImage, sk_sp<SkImage> auxImage,
 347                              FilterFactory filterFactory, const SkIRect& clip,
 348                              const SkIRect& subset, SkIRect* dstRect) {
 349         // When creating the filter with a crop rect equal to the clip, we should expect to see no
 350         // difference from a filter without a crop rect. However, if the CTM isn't managed properly
 351         // by makeWithFilter, then the final result will be the incorrect intersection of the clip
 352         // and the transformed crop rect.
 353         sk_sp<SkImageFilter> filter = filterFactory(auxImage,
 354                                                     fFilterWithCropRect ? &clip : nullptr);
 355
 356         if (fStrategy == Strategy::kSaveLayer) {
 357             SkAutoCanvasRestore acr(canvas, true);
 358
 359             // Clip before the saveLayer with the filter
 360             canvas->clipRect(SkRect::Make(clip));
 361
 362             // Put the image filter on the layer
 363             SkPaint paint;
 364             paint.setImageFilter(filter);
 365             canvas->saveLayer(nullptr, &paint);
 366
 367             // Draw the original subset of the image
 368             SkRect r = SkRect::Make(subset);
 369             canvas->drawImageRect(mainImage, r, r, SkSamplingOptions(),
 370                                   nullptr, SkCanvas::kStrict_SrcRectConstraint);
 371
 372             *dstRect = subset;
 373         } else {
 374             sk_sp<SkImage> result;
 375             SkIRect outSubset;
 376             SkIPoint offset;
 377
 378             auto rContext = canvas->recordingContext();
 379             result = mainImage->makeWithFilter(rContext, filter.get(), subset, clip,
 380                                                &outSubset, &offset);
 381             if (!result) {
 382                 return;
 383             }
 384
 385             SkASSERT(mainImage->isTextureBacked() == result->isTextureBacked());
 386
 387             *dstRect = SkIRect::MakeXYWH(offset.x(), offset.y(),
 388                                          outSubset.width(), outSubset.height());
 389             canvas->drawImageRect(result, SkRect::Make(outSubset), SkRect::Make(*dstRect),
 390                                   SkSamplingOptions(), nullptr,
 391                                   SkCanvas::kStrict_SrcRectConstraint);
 392         }
 393     }
 394
 395     using INHERITED = GM;
 396 };
 397 // The different strategies should all look the same, with the exception of filters that affect
 398 // transparent black (i.e. the lighting filter). In the save layer case, the filter affects the
 399 // transparent pixels outside of the drawn subset, whereas the makeWithFilter is restricted. This
 400 // works as intended.
 401 DEF_GM( return new ImageMakeWithFilterGM(Strategy::kMakeWithFilter); )
 402 DEF_GM( return new ImageMakeWithFilterGM(Strategy::kSaveLayer); )
 403 // Test with crop rects on the image filters; should look identical to above if working correctly
 404 DEF_GM( return new ImageMakeWithFilterGM(Strategy::kMakeWithFilter, true); )
 405 DEF_GM( return new ImageMakeWithFilterGM(Strategy::kSaveLayer, true); )