SkDeviceProperties.h revision 29c857d0f3a1cb837f73406eeb6ba9771879b5e7 
1#ifndef SkDeviceProperties_DEFINED
2#define SkDeviceProperties_DEFINED
3
4//TODO: get everyone to stop using SkFontLCDConfig::SetSubpixel* and remove this import.
5#include "SkFontLCDConfig.h"
6
7struct SkDeviceProperties {
8    struct Geometry {
9        /** The orientation of the pixel specifies the interpretation of the
10        *  layout. If the orientation is horizontal, the layout is interpreted as
11        *  left to right. It the orientation is vertical, the layout is
12        *  interpreted top to bottom (rotated 90deg cw from horizontal).
13        */
14        enum Orientation {
15            kUnknown_Orientation      = 0x0,
16            kKnown_Orientation        = 0x2,
17
18            kHorizontal_Orientation   = 0x2,  //!< this is the default
19            kVertical_Orientation     = 0x3,
20
21            kOrientationMask          = 0x3,
22        };
23
24        /** The layout of the pixel specifies its subpixel geometry.
25        *
26        *  kUnknown_Layout means that the subpixel elements are not spatially
27        *  separated in any known or usable fashion.
28        */
29        enum Layout {
30            kUnknown_Layout   = 0x0,
31            kKnown_Layout     = 0x8,
32
33            kRGB_Layout       = 0x8,  //!< this is the default
34            kBGR_Layout       = 0xC,
35
36            kLayoutMask       = 0xC,
37        };
38
39        Orientation getOrientation() {
40            return static_cast<Orientation>(fGeometry & kOrientationMask);
41        }
42        Layout getLayout() {
43            return static_cast<Layout>(fGeometry & kLayoutMask);
44        }
45
46        bool isOrientationKnown() {
47            return SkToBool(fGeometry & kKnown_Orientation);
48        }
49        bool isLayoutKnown() {
50            return SkToBool(fGeometry & kKnown_Layout);
51        }
52
53    private:
54        //TODO: get everyone to stop using SkFontLCDConfig::SetSubpixel* and replace these calls with constants.
55        static Orientation fromOldOrientation(SkFontLCDConfig::LCDOrientation orientation) {
56            switch (orientation) {
57            case SkFontLCDConfig::kHorizontal_LCDOrientation: return kHorizontal_Orientation;
58            case SkFontLCDConfig::kVertical_LCDOrientation: return kVertical_Orientation;
59            default: return kUnknown_Orientation;
60            }
61        }
62        static Layout fromOldLayout(SkFontLCDConfig::LCDOrder order) {
63            switch (order) {
64            case SkFontLCDConfig::kRGB_LCDOrder: return kRGB_Layout;
65            case SkFontLCDConfig::kBGR_LCDOrder: return kBGR_Layout;
66            default: return kUnknown_Layout;
67            }
68        }
69    public:
70        static Geometry MakeDefault() {
71            Orientation orientation = fromOldOrientation(SkFontLCDConfig::GetSubpixelOrientation()); //kHorizontal_Orientation
72            Layout layout = fromOldLayout(SkFontLCDConfig::GetSubpixelOrder()); //kRGB_Layout
73            Geometry ret = { SkToU8(orientation | layout) };
74            return ret;
75        }
76
77        static Geometry Make(Orientation orientation, Layout layout) {
78            Geometry ret = { SkToU8(orientation | layout) };
79            return ret;
80        }
81
82        uint8_t fGeometry;
83    };
84
85    static SkDeviceProperties MakeDefault() {
86        SkDeviceProperties ret = { Geometry::MakeDefault(), SK_GAMMA_EXPONENT };
87        return ret;
88    }
89
90    static SkDeviceProperties Make(Geometry geometry, SkScalar gamma) {
91        SkDeviceProperties ret = { geometry, gamma };
92        return ret;
93    }
94
95    /** Each pixel of an image will have some number of channels.
96     *  Can the layout of those channels be exploited? */
97    Geometry fGeometry;
98
99    /** Represents the color space of the image. This is a woefully inadequate beginning. */
100    SkScalar fGamma;
101};
102
103#endif
104