1 /*
2  * Copyright 2010 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 GrGlyph_DEFINED
9 #define GrGlyph_DEFINED
10 
11 #include "GrBatchAtlas.h"
12 #include "GrRect.h"
13 #include "GrTypes.h"
14 
15 #include "SkChecksum.h"
16 #include "SkPath.h"
17 
18 class GrPlot;
19 
20 /*  Need this to be quad-state:
21     - complete w/ image
22     - just metrics
23     - failed to get image, but has metrics
24     - failed to get metrics
25  */
26 struct GrGlyph {
27     enum MaskStyle {
28         kCoverage_MaskStyle,
29         kDistance_MaskStyle
30     };
31 
32     typedef uint32_t PackedID;
33 
34     // TODO either plot or AtlasID will be valid, not both
35     GrBatchAtlas::AtlasID fID;
36     GrPlot*               fPlot;
37     SkPath*               fPath;
38     PackedID              fPackedID;
39     GrMaskFormat          fMaskFormat;
40     GrIRect16             fBounds;
41     SkIPoint16            fAtlasLocation;
42     bool                  fTooLargeForAtlas;
43 
initGrGlyph44     void init(GrGlyph::PackedID packed, const SkIRect& bounds, GrMaskFormat format) {
45         fID = GrBatchAtlas::kInvalidAtlasID;
46         fPlot = NULL;
47         fPath = NULL;
48         fPackedID = packed;
49         fBounds.set(bounds);
50         fMaskFormat = format;
51         fAtlasLocation.set(0, 0);
52         fTooLargeForAtlas = GrBatchAtlas::GlyphTooLargeForAtlas(bounds.width(), bounds.height());
53     }
54 
freeGrGlyph55     void free() {
56         if (fPath) {
57             delete fPath;
58             fPath = NULL;
59         }
60     }
61 
widthGrGlyph62     int width() const { return fBounds.width(); }
heightGrGlyph63     int height() const { return fBounds.height(); }
isEmptyGrGlyph64     bool isEmpty() const { return fBounds.isEmpty(); }
glyphIDGrGlyph65     uint16_t glyphID() const { return UnpackID(fPackedID); }
66 
67     ///////////////////////////////////////////////////////////////////////////
68 
ExtractSubPixelBitsFromFixedGrGlyph69     static inline unsigned ExtractSubPixelBitsFromFixed(SkFixed pos) {
70         // two most significant fraction bits from fixed-point
71         return (pos >> 14) & 3;
72     }
73 
PackGrGlyph74     static inline PackedID Pack(uint16_t glyphID, SkFixed x, SkFixed y, MaskStyle ms) {
75         x = ExtractSubPixelBitsFromFixed(x);
76         y = ExtractSubPixelBitsFromFixed(y);
77         int dfFlag = (ms == kDistance_MaskStyle) ? 0x1 : 0x0;
78         return (dfFlag << 20) | (x << 18) | (y << 16) | glyphID;
79     }
80 
UnpackFixedXGrGlyph81     static inline SkFixed UnpackFixedX(PackedID packed) {
82         return ((packed >> 18) & 3) << 14;
83     }
84 
UnpackFixedYGrGlyph85     static inline SkFixed UnpackFixedY(PackedID packed) {
86         return ((packed >> 16) & 3) << 14;
87     }
88 
UnpackMaskStyleGrGlyph89     static inline MaskStyle UnpackMaskStyle(PackedID packed) {
90         return ((packed >> 20) & 1) ? kDistance_MaskStyle : kCoverage_MaskStyle;
91     }
92 
UnpackIDGrGlyph93     static inline uint16_t UnpackID(PackedID packed) {
94         return (uint16_t)packed;
95     }
96 
GetKeyGrGlyph97     static inline const GrGlyph::PackedID& GetKey(const GrGlyph& glyph) {
98         return glyph.fPackedID;
99     }
100 
HashGrGlyph101     static inline uint32_t Hash(GrGlyph::PackedID key) {
102         return SkChecksum::Mix(key);
103     }
104 };
105 
106 #endif
107