aboutsummaryrefslogtreecommitdiffhomepage
path: root/gm/anisotropic.cpp
blob: d8f9181286f333c0112f9dca81373cb946b3f0bf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
/*
 * Copyright 2015 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "gm.h"

namespace skiagm {

// This GM exercises HighQuality anisotropic filtering.
class AnisotropicGM : public GM {
public:
    AnisotropicGM() : fFilterQuality(kHigh_SkFilterQuality) {
        this->setBGColor(sk_tool_utils::color_to_565(0xFFCCCCCC));
    }

protected:

    SkString onShortName() override { return SkString("anisotropic_hq"); }

    SkISize onISize() override {
        return SkISize::Make(2*kImageSize + 3*kSpacer,
                             kNumVertImages*kImageSize + (kNumVertImages+1)*kSpacer);
    }

    // Create an image consisting of lines radiating from its center
    void onOnceBeforeDraw() override {
        constexpr int kNumLines = 100;
        constexpr SkScalar kAngleStep = 360.0f / kNumLines;
        constexpr int kInnerOffset = 10;

        fBM.allocN32Pixels(kImageSize, kImageSize, true);

        SkCanvas canvas(fBM);

        canvas.clear(SK_ColorWHITE);

        SkPaint p;
        p.setAntiAlias(true);

        SkScalar angle = 0.0f, sin, cos;

        canvas.translate(kImageSize/2.0f, kImageSize/2.0f);
        for (int i = 0; i < kNumLines; ++i, angle += kAngleStep) {
            sin = SkScalarSinCos(angle, &cos);
            canvas.drawLine(cos * kInnerOffset, sin * kInnerOffset,
                            cos * kImageSize/2, sin * kImageSize/2, p);
        }
    }

    void draw(SkCanvas* canvas, int x, int y, int xSize, int ySize) {
        SkRect r = SkRect::MakeXYWH(SkIntToScalar(x), SkIntToScalar(y),
                                    SkIntToScalar(xSize), SkIntToScalar(ySize));
        SkPaint p;
        p.setFilterQuality(fFilterQuality);
        canvas->drawBitmapRect(fBM, r, &p);
    }

    void onDraw(SkCanvas* canvas) override {
        SkScalar gScales[] = { 0.9f, 0.8f, 0.75f, 0.6f, 0.5f, 0.4f, 0.25f, 0.2f, 0.1f };

        SkASSERT(kNumVertImages-1 == (int)SK_ARRAY_COUNT(gScales)/2);

        // Minimize vertically
        for (int i = 0; i < (int)SK_ARRAY_COUNT(gScales); ++i) {
            int height = SkScalarFloorToInt(fBM.height() * gScales[i]);

            int yOff;
            if (i <= (int)SK_ARRAY_COUNT(gScales)/2) {
                yOff = kSpacer + i * (fBM.height() + kSpacer);
            } else {
                // Position the more highly squashed images with their less squashed counterparts
                yOff = (SK_ARRAY_COUNT(gScales) - i) * (fBM.height() + kSpacer) - height;
            }

            this->draw(canvas, kSpacer, yOff, fBM.width(), height);
        }

        // Minimize horizontally
        for (int i = 0; i < (int)SK_ARRAY_COUNT(gScales); ++i) {
            int width = SkScalarFloorToInt(fBM.width() * gScales[i]);

            int xOff, yOff;
            if (i <= (int)SK_ARRAY_COUNT(gScales)/2) {
                xOff = fBM.width() + 2*kSpacer;
                yOff = kSpacer + i * (fBM.height() + kSpacer);
            } else {
                // Position the more highly squashed images with their less squashed counterparts
                xOff = fBM.width() + 2*kSpacer + fBM.width() - width;
                yOff = kSpacer + (SK_ARRAY_COUNT(gScales) - i - 1) * (fBM.height() + kSpacer);
            }

            this->draw(canvas, xOff, yOff, width, fBM.height());
        }
    }

private:
    static constexpr int kImageSize     = 256;
    static constexpr int kSpacer        = 10;
    static constexpr int kNumVertImages = 5;

    SkBitmap         fBM;
    SkFilterQuality  fFilterQuality;

    typedef GM INHERITED;
};

//////////////////////////////////////////////////////////////////////////////

DEF_GM(return new AnisotropicGM;)
}