1/*
2 * Copyright 2013 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 SkPaintPriv_DEFINED
9#define SkPaintPriv_DEFINED
10
11#include "include/core/SkPaint.h"
12
13class SkFont;
14class SkReadBuffer;
15class SkWriteBuffer;
16
17enum SkReadPaintResult {
18 kFailed_ReadPaint,
19 kSuccess_JustPaint,
20 kSuccess_PaintAndFont,
21};
22
23class SkPaintPriv {
24public:
25 enum ShaderOverrideOpacity {
26 kNone_ShaderOverrideOpacity, //!< there is no overriding shader (bitmap or image)
27 kOpaque_ShaderOverrideOpacity, //!< the overriding shader is opaque
28 kNotOpaque_ShaderOverrideOpacity, //!< the overriding shader may not be opaque
29 };
30
31 /**
32 * Returns true if drawing with this paint (or nullptr) will ovewrite all affected pixels.
33 *
34 * Note: returns conservative true, meaning it may return false even though the paint might
35 * in fact overwrite its pixels.
36 */
37 static bool Overwrites(const SkPaint* paint, ShaderOverrideOpacity);
38
39 static bool ShouldDither(const SkPaint&, SkColorType);
40
41 /*
42 * The luminance color is used to determine which Gamma Canonical color to map to. This is
43 * really only used by backends which want to cache glyph masks, and need some way to know if
44 * they need to generate new masks based off a given color.
45 */
46 static SkColor ComputeLuminanceColor(const SkPaint&);
47
48 /** Serializes SkPaint into a buffer. A companion unflatten() call
49 can reconstitute the paint at a later time.
50
51 @param buffer SkWriteBuffer receiving the flattened SkPaint data
52 */
53 static void Flatten(const SkPaint& paint, SkWriteBuffer& buffer);
54
55 /** Populates SkPaint, typically from a serialized stream, created by calling
56 flatten() at an earlier time.
57
58 SkReadBuffer class is not public, so unflatten() cannot be meaningfully called
59 by the client.
60
61 Older formats also stored font info in the serialized data. On success, this
62 returns if it deserialized just a paint, or both a font and paint. The font
63 param is optional.
64
65 @param buffer serialized data describing SkPaint content
66 @return false if the buffer contains invalid data
67 */
68 static SkReadPaintResult Unflatten(SkPaint* paint, SkReadBuffer& buffer, SkFont* font);
69
70 // If this paint has any color filter, fold it into the shader and/or paint color
71 // so that it draws the same but getColorFilter() returns nullptr.
72 //
73 // Since we may be filtering now, we need to know what color space to filter in,
74 // typically the color space of the device we're drawing into.
75 static void RemoveColorFilter(SkPaint*, SkColorSpace* dstCS);
76
77private:
78 static SkReadPaintResult Unflatten_PreV68(SkPaint* paint, SkReadBuffer& buffer, SkFont*);
79};
80
81#endif
82