1/*
2 * Copyright 2017 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 "SkColorSpacePriv.h"
9#include "SkImage.h"
10#include "SkPngEncoder.h"
11
12#include "Resources.h"
13
14/**
15 *  Create a color space that swaps the red, green, and blue channels.
16 */
17static sk_sp<SkColorSpace> gbr_color_space() {
18    return SkColorSpace::MakeSRGB()->makeColorSpin();
19}
20
21/**
22 *  Create a color space with a steep transfer function.
23 */
24static sk_sp<SkColorSpace> tf_color_space() {
25    SkColorSpaceTransferFn fn;
26    fn.fA = 1.f; fn.fB = 0.f; fn.fC = 0.f; fn.fD = 0.f; fn.fE = 0.f; fn.fF = 0.f; fn.fG = 50.f;
27    return SkColorSpace::MakeRGB(fn, SkColorSpace::kSRGB_Gamut);
28}
29
30/**
31 *  Create a wide gamut color space.
32 */
33static sk_sp<SkColorSpace> wide_gamut_color_space() {
34    return SkColorSpace::MakeRGB(SkColorSpace::kSRGB_RenderTargetGamma,
35                                 SkColorSpace::kRec2020_Gamut);
36}
37
38int main(int argc, char** argv) {
39    sk_sp<SkImage> image = GetResourceAsImage("images/flutter_logo.jpg");
40    if (!image) {
41        SkDebugf("Cannot find flutter_logo.jpg in resources.\n");
42        return 1;
43    }
44
45    // Encode an image with a gbr color space.
46    SkImageInfo info = SkImageInfo::MakeN32(image->width(), image->height(), kOpaque_SkAlphaType,
47                                            gbr_color_space());
48    size_t rowBytes = info.minRowBytes();
49    SkAutoTMalloc<uint8_t> storage(rowBytes * image->height());
50    SkPixmap src(info, storage.get(), rowBytes);
51    image->readPixels(src, 0, 0, SkImage::kDisallow_CachingHint);
52    SkFILEWStream dst0("gbr.png");
53    SkPngEncoder::Options opts;
54    opts.fUnpremulBehavior = SkTransferFunctionBehavior::kIgnore; // Does not matter for opaque src
55    SkAssertResult(SkPngEncoder::Encode(&dst0, src, opts));
56
57    // Encode an image with steep transfer function.
58    src.setColorSpace(tf_color_space());
59    image->readPixels(src, 0, 0, SkImage::kDisallow_CachingHint);
60    SkFILEWStream dst1("tf.png");
61    SkAssertResult(SkPngEncoder::Encode(&dst1, src, opts));
62
63    // Encode a wide gamut image.
64    src.setColorSpace(wide_gamut_color_space());
65    image->readPixels(src, 0, 0, SkImage::kDisallow_CachingHint);
66    SkFILEWStream dst2("wide-gamut.png");
67    SkAssertResult(SkPngEncoder::Encode(&dst2, src, opts));
68
69    return 0;
70}
71