1 /*
2 * Copyright 2014 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 SkSurfaceProps_DEFINED
9 #define SkSurfaceProps_DEFINED
10
11 #include "include/core/SkScalar.h"
12 #include "include/core/SkTypes.h"
13 #include "include/private/base/SkTo.h"
14
15 /**
16 * Description of how the LCD strips are arranged for each pixel. If this is unknown, or the
17 * pixels are meant to be "portable" and/or transformed before showing (e.g. rotated, scaled)
18 * then use kUnknown_SkPixelGeometry.
19 */
20 enum SkPixelGeometry {
21 kUnknown_SkPixelGeometry,
22 kRGB_H_SkPixelGeometry,
23 kBGR_H_SkPixelGeometry,
24 kRGB_V_SkPixelGeometry,
25 kBGR_V_SkPixelGeometry,
26 };
27
28 // Returns true iff geo is a known geometry and is RGB.
SkPixelGeometryIsRGB(SkPixelGeometry geo)29 static inline bool SkPixelGeometryIsRGB(SkPixelGeometry geo) {
30 return kRGB_H_SkPixelGeometry == geo || kRGB_V_SkPixelGeometry == geo;
31 }
32
33 // Returns true iff geo is a known geometry and is BGR.
SkPixelGeometryIsBGR(SkPixelGeometry geo)34 static inline bool SkPixelGeometryIsBGR(SkPixelGeometry geo) {
35 return kBGR_H_SkPixelGeometry == geo || kBGR_V_SkPixelGeometry == geo;
36 }
37
38 // Returns true iff geo is a known geometry and is horizontal.
SkPixelGeometryIsH(SkPixelGeometry geo)39 static inline bool SkPixelGeometryIsH(SkPixelGeometry geo) {
40 return kRGB_H_SkPixelGeometry == geo || kBGR_H_SkPixelGeometry == geo;
41 }
42
43 // Returns true iff geo is a known geometry and is vertical.
SkPixelGeometryIsV(SkPixelGeometry geo)44 static inline bool SkPixelGeometryIsV(SkPixelGeometry geo) {
45 return kRGB_V_SkPixelGeometry == geo || kBGR_V_SkPixelGeometry == geo;
46 }
47
48 /**
49 * Describes properties and constraints of a given SkSurface. The rendering engine can parse these
50 * during drawing, and can sometimes optimize its performance (e.g. disabling an expensive
51 * feature).
52 */
53 class SK_API SkSurfaceProps {
54 public:
55 enum Flags {
56 kDefault_Flag = 0,
57 kUseDeviceIndependentFonts_Flag = 1 << 0,
58 // Use internal MSAA to render to non-MSAA GPU surfaces.
59 kDynamicMSAA_Flag = 1 << 1,
60 // If set, all rendering will have dithering enabled
61 // Currently this only impacts GPU backends
62 kAlwaysDither_Flag = 1 << 2,
63 };
64
65 /** No flags, unknown pixel geometry, platform-default contrast/gamma. */
66 SkSurfaceProps();
67 /** TODO(kschmi): Remove this constructor and replace with the one below. **/
68 SkSurfaceProps(uint32_t flags, SkPixelGeometry);
69 /** Specified pixel geometry, text contrast, and gamma **/
70 SkSurfaceProps(uint32_t flags, SkPixelGeometry, SkScalar textContrast, SkScalar textGamma);
71
72 SkSurfaceProps(const SkSurfaceProps&) = default;
73 SkSurfaceProps& operator=(const SkSurfaceProps&) = default;
74
cloneWithPixelGeometry(SkPixelGeometry newPixelGeometry)75 SkSurfaceProps cloneWithPixelGeometry(SkPixelGeometry newPixelGeometry) const {
76 return SkSurfaceProps(fFlags, newPixelGeometry, fTextContrast, fTextGamma);
77 }
78
79 static constexpr SkScalar kMaxContrastInclusive = 1;
80 static constexpr SkScalar kMinContrastInclusive = 0;
81 static constexpr SkScalar kMaxGammaExclusive = 4;
82 static constexpr SkScalar kMinGammaInclusive = 0;
83
flags()84 uint32_t flags() const { return fFlags; }
pixelGeometry()85 SkPixelGeometry pixelGeometry() const { return fPixelGeometry; }
textContrast()86 SkScalar textContrast() const { return fTextContrast; }
textGamma()87 SkScalar textGamma() const { return fTextGamma; }
88
isUseDeviceIndependentFonts()89 bool isUseDeviceIndependentFonts() const {
90 return SkToBool(fFlags & kUseDeviceIndependentFonts_Flag);
91 }
92
isAlwaysDither()93 bool isAlwaysDither() const {
94 return SkToBool(fFlags & kAlwaysDither_Flag);
95 }
96
97 bool operator==(const SkSurfaceProps& that) const {
98 return fFlags == that.fFlags && fPixelGeometry == that.fPixelGeometry &&
99 fTextContrast == that.fTextContrast && fTextGamma == that.fTextGamma;
100 }
101
102 bool operator!=(const SkSurfaceProps& that) const {
103 return !(*this == that);
104 }
105
106 private:
107 uint32_t fFlags;
108 SkPixelGeometry fPixelGeometry;
109
110 // This gamma value is specifically about blending of mask coverage.
111 // The surface also has a color space, but that applies to the colors.
112 SkScalar fTextContrast;
113 SkScalar fTextGamma;
114 };
115
116 #endif
117