aboutsummaryrefslogtreecommitdiffhomepage
path: root/gm/imagemasksubset.cpp
blob: adfea6b8e97fe9650e589e5affcc0a23d3dee4a8 (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
/*
 * Copyright 2016 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"
#include "sk_tool_utils.h"
#include "SkCanvas.h"
#include "SkImage.h"
#include "SkImageGenerator.h"
#include "SkMakeUnique.h"
#include "SkSurface.h"

namespace {

const SkISize   kSize = SkISize::Make(100, 100);
const SkIRect kSubset = SkIRect::MakeLTRB(25, 25, 75, 75);
const SkRect    kDest = SkRect::MakeXYWH(10, 10, 100, 100);

sk_sp<SkImage> make_mask(const sk_sp<SkSurface>& surface) {
    sk_tool_utils::draw_checkerboard(surface->getCanvas(), 0x80808080, 0x00000000, 5);
    return surface->makeImageSnapshot();
}

class MaskGenerator final : public SkImageGenerator {
public:
    MaskGenerator(const SkImageInfo& info) : INHERITED(info) {}

    bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, const Options&)
    override {
        SkImageInfo surfaceInfo = info;
        if (kAlpha_8_SkColorType == info.colorType()) {
            surfaceInfo = surfaceInfo.makeColorSpace(nullptr);
        }

        make_mask(SkSurface::MakeRasterDirect(surfaceInfo, pixels, rowBytes));
        return true;
    }

private:
    typedef SkImageGenerator INHERITED;
};

using MakerT = sk_sp<SkImage>(*)(SkCanvas*, const SkImageInfo&);
const MakerT makers[] = {
    // SkImage_Raster
    [](SkCanvas*, const SkImageInfo& info) -> sk_sp<SkImage> {
        return make_mask(SkSurface::MakeRaster(info));
    },

    // SkImage_Gpu
    [](SkCanvas* c, const SkImageInfo& info) -> sk_sp<SkImage> {
        sk_sp<SkSurface> surface;
        surface = SkSurface::MakeRenderTarget(c->getGrContext(), SkBudgeted::kNo, info);
        return make_mask(surface ? surface : SkSurface::MakeRaster(info));
    },

    // SkImage_Lazy
    [](SkCanvas*, const SkImageInfo& info) -> sk_sp<SkImage> {
        return SkImage::MakeFromGenerator(skstd::make_unique<MaskGenerator>(info));
    },
};

} // anonymous ns

// Checks whether subset SkImages preserve the original color type (A8 in this case).
DEF_SIMPLE_GM(imagemasksubset, canvas, 480, 480) {
    SkPaint paint;
    paint.setColor(0xff00ff00);

    const SkImageInfo info = SkImageInfo::MakeA8(kSize.width(), kSize.height());

    for (size_t i = 0; i < SK_ARRAY_COUNT(makers); ++i) {
        sk_sp<SkImage> image = makers[i](canvas, info);
        if (image) {
            canvas->drawImageRect(image, SkRect::Make(kSubset), kDest, &paint);
            sk_sp<SkImage> subset = image->makeSubset(kSubset);
            canvas->drawImageRect(subset, kDest.makeOffset(kSize.width() * 1.5f, 0), &paint);
        }
        canvas->translate(0, kSize.height() * 1.5f);
    }
}