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:
AnisotropicGM()15     AnisotropicGM() : fFilterQuality(kHigh_SkFilterQuality) {
16         this->setBGColor(0xFFCCCCCC);
17     }
18 
19 protected:
20 
onShortName()21     SkString onShortName() override { return SkString("anisotropic_hq"); }
22 
onISize()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
onOnceBeforeDraw()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 
draw(SkCanvas * canvas,int x,int y,int xSize,int ySize)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 
onDraw(SkCanvas * canvas)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 SkNEW(AnisotropicGM); )
113 
114 }
115