1/*
2 * Copyright 2016 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#ifndef SkColorSpaceXform_DEFINED
9#define SkColorSpaceXform_DEFINED
10
11#include "SkImageInfo.h"
12
13class SkColorSpace;
14
15class SK_API SkColorSpaceXform : SkNoncopyable {
16public:
17
18    /**
19     *  Create an object to handle color space conversions.
20     *
21     *  @param srcSpace The encoded color space.
22     *  @param dstSpace The destination color space.
23     *
24     */
25    static std::unique_ptr<SkColorSpaceXform> New(SkColorSpace* srcSpace, SkColorSpace* dstSpace);
26
27    enum ColorFormat {
28        kRGBA_8888_ColorFormat,
29        kBGRA_8888_ColorFormat,
30
31        // Unsigned, big-endian, 16-bit integer
32        kRGB_U16_BE_ColorFormat,   // Src only
33        kRGBA_U16_BE_ColorFormat,  // Src only
34
35        kRGBA_F16_ColorFormat,
36        kRGBA_F32_ColorFormat,
37
38        kBGR_565_ColorFormat,      // Dst only, kOpaque only
39    };
40
41    /**
42     *  Apply the color conversion to a |src| buffer, storing the output in the |dst| buffer.
43     *
44     *  F16 and F32 are only supported when the color space is linear. This function will return
45     *  false in unsupported cases.
46     *
47     *  @param dst            Stored in the format described by |dstColorFormat|
48     *  @param src            Stored in the format described by |srcColorFormat|
49     *  @param len            Number of pixels in the buffers
50     *  @param dstColorFormat Describes color format of |dst|
51     *  @param srcColorFormat Describes color format of |src|
52     *  @param alphaType      Describes alpha properties of the |dst| (and |src|)
53     *                        kUnpremul preserves input alpha values
54     *                        kPremul   performs a premultiplication and also preserves alpha values
55     *                        kOpaque   optimization hint, |dst| alphas set to 1
56     *
57     */
58    bool apply(ColorFormat dstFormat, void* dst, ColorFormat srcFormat, const void* src, int count,
59               SkAlphaType alphaType) const;
60
61    virtual ~SkColorSpaceXform() {}
62
63    enum AlphaOp {
64        kPreserve_AlphaOp,      // just transfer src-alpha to dst-alpha
65        kPremul_AlphaOp,        // like kPreserve, but multiplies RGB by it
66        kSrcIsOpaque_AlphaOp,   // src alphas are all 1, this is a perf hint
67    };
68    static bool Apply(SkColorSpace* dstCS, ColorFormat dstFormat, void* dst,
69                      SkColorSpace* srcCS, ColorFormat srcFormat, const void* src,
70                      int count, AlphaOp);
71
72protected:
73    SkColorSpaceXform() {}
74};
75
76#endif
77