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.h"
   9 #include "sk_tool_utils.h"
  10 #include "SkBlurImageFilter.h"
  11 #include "SkCanvas.h"
  12 #include "SkColorFilter.h"
  13 #include "SkColorFilterImageFilter.h"
  14 #include "SkDropShadowImageFilter.h"
  15 #include "SkSurface.h"
  16
  17 ///////////////////////////////////////////////////////////////////////////////
  18
  19 static void show_bounds(SkCanvas* canvas, const SkIRect& subset, const SkIRect& clip) {
  20     SkIRect rects[] { subset, clip };
  21     SkColor colors[] { SK_ColorRED, SK_ColorBLUE };
  22
  23     SkPaint paint;
  24     paint.setStyle(SkPaint::kStroke_Style);
  25
  26     for (size_t i = 0; i < SK_ARRAY_COUNT(rects); ++i) {
  27         paint.setColor(colors[i]);
  28         canvas->drawRect(SkRect::Make(rects[i]), paint);
  29     }
  30 }
  31
  32 // In this GM, we're going to feed the inner portion of a 100x100 checkboard
  33 // (i.e., strip off a 25-wide border) through the makeWithFilter method.
  34 // We'll then draw the appropriate subset of the result to the screen at the
  35 // given offset.
  36 class ImageMakeWithFilterGM : public skiagm::GM {
  37 public:
  38     ImageMakeWithFilterGM () {}
  39
  40 protected:
  41     SkString onShortName() override {
  42         return SkString("imagemakewithfilter");
  43     }
  44
  45     SkISize onISize() override { return SkISize::Make(440, 530); }
  46
  47     void onDraw(SkCanvas* canvas) override {
  48         auto cf = SkColorFilter::MakeModeFilter(SK_ColorGREEN, SkBlendMode::kSrc);
  49         sk_sp<SkImageFilter> filters[] = {
  50             SkColorFilterImageFilter::Make(std::move(cf), nullptr),
  51             SkBlurImageFilter::Make(2.0f, 2.0f, nullptr),
  52             SkDropShadowImageFilter::Make(
  53                 10.0f, 5.0f, 3.0f, 3.0f, SK_ColorBLUE,
  54                 SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode,
  55                 nullptr),
  56         };
  57
  58         SkIRect clipBounds[] {
  59             { -20, -20, 100, 100 },
  60             {   0,   0,  75,  75 },
  61             {  20,  20, 100, 100 },
  62             { -20, -20,  50,  50 },
  63             {  20,  20,  50,  50 },
  64         };
  65
  66         SkImageInfo info = SkImageInfo::MakeN32(100, 100, kPremul_SkAlphaType);
  67         SkScalar MARGIN = SkIntToScalar(40);
  68         SkScalar DX = info.width() + MARGIN;
  69         SkScalar DY = info.height() + MARGIN;
  70
  71         canvas->translate(MARGIN, MARGIN);
  72
  73         sk_sp<SkSurface> surface = canvas->makeSurface(info);
  74         if (!surface) {
  75             surface = SkSurface::MakeRaster(info);
  76         }
  77         sk_tool_utils::draw_checkerboard(surface->getCanvas());
  78         sk_sp<SkImage> source = surface->makeImageSnapshot();
  79
  80         for (auto clipBound : clipBounds) {
  81             canvas->save();
  82             for (size_t i = 0; i < SK_ARRAY_COUNT(filters); ++i) {
  83                 SkIRect subset = SkIRect::MakeXYWH(25, 25, 50, 50);
  84                 SkIRect outSubset;
  85                 SkIPoint offset;
  86                 sk_sp<SkImage> result = source->makeWithFilter(filters[i].get(), subset, clipBound,
  87                                                                &outSubset, &offset);
  88                 SkASSERT(result);
  89                 SkASSERT(source->isTextureBacked() == result->isTextureBacked());
  90                 result = result->makeSubset(outSubset);
  91                 canvas->drawImage(result.get(), SkIntToScalar(offset.fX), SkIntToScalar(offset.fY));
  92                 show_bounds(canvas, SkIRect::MakeXYWH(offset.x(), offset.y(), outSubset.width(),
  93                                                       outSubset.height()), clipBound);
  94                 canvas->translate(DX, 0);
  95             }
  96             canvas->restore();
  97             canvas->translate(0, DY);
  98         }
  99     }
 100
 101 private:
 102     typedef GM INHERITED;
 103 };
 104 DEF_GM( return new ImageMakeWithFilterGM; )