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      1 /*
      2  * Copyright 2015 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 
     11 namespace skiagm {
     12 
     13 // This GM exercises HighQuality anisotropic filtering.
     14 class AnisotropicGM : public GM {
     15 public:
     16     AnisotropicGM() : fFilterQuality(kHigh_SkFilterQuality) {
     17         this->setBGColor(sk_tool_utils::color_to_565(0xFFCCCCCC));
     18     }
     19 
     20 protected:
     21 
     22     SkString onShortName() override { return SkString("anisotropic_hq"); }
     23 
     24     SkISize onISize() override {
     25         return SkISize::Make(2*kImageSize + 3*kSpacer,
     26                              kNumVertImages*kImageSize + (kNumVertImages+1)*kSpacer);
     27     }
     28 
     29     // Create an image consisting of lines radiating from its center
     30     void onOnceBeforeDraw() override {
     31         constexpr int kNumLines = 100;
     32         constexpr SkScalar kAngleStep = 360.0f / kNumLines;
     33         constexpr int kInnerOffset = 10;
     34 
     35         fBM.allocN32Pixels(kImageSize, kImageSize, true);
     36 
     37         SkCanvas canvas(fBM);
     38 
     39         canvas.clear(SK_ColorWHITE);
     40 
     41         SkPaint p;
     42         p.setAntiAlias(true);
     43 
     44         SkScalar angle = 0.0f, sin, cos;
     45 
     46         canvas.translate(kImageSize/2.0f, kImageSize/2.0f);
     47         for (int i = 0; i < kNumLines; ++i, angle += kAngleStep) {
     48             sin = SkScalarSinCos(angle, &cos);
     49             canvas.drawLine(cos * kInnerOffset, sin * kInnerOffset,
     50                             cos * kImageSize/2, sin * kImageSize/2, p);
     51         }
     52     }
     53 
     54     void draw(SkCanvas* canvas, int x, int y, int xSize, int ySize) {
     55         SkRect r = SkRect::MakeXYWH(SkIntToScalar(x), SkIntToScalar(y),
     56                                     SkIntToScalar(xSize), SkIntToScalar(ySize));
     57         SkPaint p;
     58         p.setFilterQuality(fFilterQuality);
     59         canvas->drawBitmapRect(fBM, r, &p);
     60     }
     61 
     62     void onDraw(SkCanvas* canvas) override {
     63         SkScalar gScales[] = { 0.9f, 0.8f, 0.75f, 0.6f, 0.5f, 0.4f, 0.25f, 0.2f, 0.1f };
     64 
     65         SkASSERT(kNumVertImages-1 == (int)SK_ARRAY_COUNT(gScales)/2);
     66 
     67         // Minimize vertically
     68         for (int i = 0; i < (int)SK_ARRAY_COUNT(gScales); ++i) {
     69             int height = SkScalarFloorToInt(fBM.height() * gScales[i]);
     70 
     71             int yOff;
     72             if (i <= (int)SK_ARRAY_COUNT(gScales)/2) {
     73                 yOff = kSpacer + i * (fBM.height() + kSpacer);
     74             } else {
     75                 // Position the more highly squashed images with their less squashed counterparts
     76                 yOff = (SK_ARRAY_COUNT(gScales) - i) * (fBM.height() + kSpacer) - height;
     77             }
     78 
     79             this->draw(canvas, kSpacer, yOff, fBM.width(), height);
     80         }
     81 
     82         // Minimize horizontally
     83         for (int i = 0; i < (int)SK_ARRAY_COUNT(gScales); ++i) {
     84             int width = SkScalarFloorToInt(fBM.width() * gScales[i]);
     85 
     86             int xOff, yOff;
     87             if (i <= (int)SK_ARRAY_COUNT(gScales)/2) {
     88                 xOff = fBM.width() + 2*kSpacer;
     89                 yOff = kSpacer + i * (fBM.height() + kSpacer);
     90             } else {
     91                 // Position the more highly squashed images with their less squashed counterparts
     92                 xOff = fBM.width() + 2*kSpacer + fBM.width() - width;
     93                 yOff = kSpacer + (SK_ARRAY_COUNT(gScales) - i - 1) * (fBM.height() + kSpacer);
     94             }
     95 
     96             this->draw(canvas, xOff, yOff, width, fBM.height());
     97         }
     98     }
     99 
    100 private:
    101     static constexpr int kImageSize     = 256;
    102     static constexpr int kSpacer        = 10;
    103     static constexpr int kNumVertImages = 5;
    104 
    105     SkBitmap         fBM;
    106     SkFilterQuality  fFilterQuality;
    107 
    108     typedef GM INHERITED;
    109 };
    110 
    111 //////////////////////////////////////////////////////////////////////////////
    112 
    113 DEF_GM(return new AnisotropicGM;)
    114 }
    115