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      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 "GrDrawOpAtlas.h"
     12 #include "GrRect.h"
     13 #include "GrTypes.h"
     14 
     15 #include "SkChecksum.h"
     16 #include "SkFixed.h"
     17 #include "SkPath.h"
     18 
     19 class GrPlot;
     20 
     21 /*  Need this to be quad-state:
     22     - complete w/ image
     23     - just metrics
     24     - failed to get image, but has metrics
     25     - failed to get metrics
     26  */
     27 struct GrGlyph {
     28     enum MaskStyle {
     29         kCoverage_MaskStyle,
     30         kDistance_MaskStyle
     31     };
     32 
     33     typedef uint32_t PackedID;
     34 
     35     GrDrawOpAtlas::AtlasID fID;
     36     SkPath*               fPath;
     37     PackedID              fPackedID;
     38     GrMaskFormat          fMaskFormat;
     39     GrIRect16             fBounds;
     40     SkIPoint16            fAtlasLocation;
     41     bool                  fTooLargeForAtlas;
     42 
     43     void init(GrGlyph::PackedID packed, const SkIRect& bounds, GrMaskFormat format) {
     44         fID = GrDrawOpAtlas::kInvalidAtlasID;
     45         fPath = nullptr;
     46         fPackedID = packed;
     47         fBounds.set(bounds);
     48         fMaskFormat = format;
     49         fAtlasLocation.set(0, 0);
     50         fTooLargeForAtlas = GrDrawOpAtlas::GlyphTooLargeForAtlas(bounds.width(), bounds.height());
     51     }
     52 
     53     void reset() {
     54         if (fPath) {
     55             delete fPath;
     56             fPath = nullptr;
     57         }
     58     }
     59 
     60     int width() const { return fBounds.width(); }
     61     int height() const { return fBounds.height(); }
     62     bool isEmpty() const { return fBounds.isEmpty(); }
     63     uint16_t glyphID() const { return UnpackID(fPackedID); }
     64 
     65     ///////////////////////////////////////////////////////////////////////////
     66 
     67     static inline unsigned ExtractSubPixelBitsFromFixed(SkFixed pos) {
     68         // two most significant fraction bits from fixed-point
     69         return (pos >> 14) & 3;
     70     }
     71 
     72     static inline PackedID Pack(uint16_t glyphID, SkFixed x, SkFixed y, MaskStyle ms) {
     73         x = ExtractSubPixelBitsFromFixed(x);
     74         y = ExtractSubPixelBitsFromFixed(y);
     75         int dfFlag = (ms == kDistance_MaskStyle) ? 0x1 : 0x0;
     76         return (dfFlag << 20) | (x << 18) | (y << 16) | glyphID;
     77     }
     78 
     79     static inline SkFixed UnpackFixedX(PackedID packed) {
     80         return ((packed >> 18) & 3) << 14;
     81     }
     82 
     83     static inline SkFixed UnpackFixedY(PackedID packed) {
     84         return ((packed >> 16) & 3) << 14;
     85     }
     86 
     87     static inline MaskStyle UnpackMaskStyle(PackedID packed) {
     88         return ((packed >> 20) & 1) ? kDistance_MaskStyle : kCoverage_MaskStyle;
     89     }
     90 
     91     static inline uint16_t UnpackID(PackedID packed) {
     92         return (uint16_t)packed;
     93     }
     94 
     95     static inline const GrGlyph::PackedID& GetKey(const GrGlyph& glyph) {
     96         return glyph.fPackedID;
     97     }
     98 
     99     static inline uint32_t Hash(GrGlyph::PackedID key) {
    100         return SkChecksum::Mix(key);
    101     }
    102 };
    103 
    104 #endif
    105