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
10namespace skiagm {
11
12// This GM exercises HighQuality anisotropic filtering.
13class AnisotropicGM : public GM {
14public:
15    AnisotropicGM() : fFilterQuality(kHigh_SkFilterQuality) {
16        this->setBGColor(0xFFCCCCCC);
17    }
18
19protected:
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
99private:
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
112DEF_GM( return SkNEW(AnisotropicGM); )
113
114}
115