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