1 /* 2 * Copyright 2006 The Android Open Source Project 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 SkGlyph_DEFINED 9 #define SkGlyph_DEFINED 10 11 #include "SkTypes.h" 12 #include "SkFixed.h" 13 #include "SkMask.h" 14 15 class SkPath; 16 17 // needs to be != to any valid SkMask::Format 18 #define MASK_FORMAT_UNKNOWN (0xFF) 19 #define MASK_FORMAT_JUST_ADVANCE MASK_FORMAT_UNKNOWN 20 21 #define kMaxGlyphWidth (1<<13) 22 23 struct SkGlyph { 24 void* fImage; 25 SkPath* fPath; 26 SkFixed fAdvanceX, fAdvanceY; 27 28 uint32_t fID; 29 uint16_t fWidth, fHeight; 30 int16_t fTop, fLeft; 31 32 void* fDistanceField; 33 uint8_t fMaskFormat; 34 int8_t fRsbDelta, fLsbDelta; // used by auto-kerning 35 int8_t fForceBW; 36 37 void init(uint32_t id) { 38 fID = id; 39 fImage = NULL; 40 fPath = NULL; 41 fDistanceField = NULL; 42 fMaskFormat = MASK_FORMAT_UNKNOWN; 43 fForceBW = 0; 44 } 45 46 /** 47 * Compute the rowbytes for the specified width and mask-format. 48 */ 49 static unsigned ComputeRowBytes(unsigned width, SkMask::Format format) { 50 unsigned rb = width; 51 if (SkMask::kBW_Format == format) { 52 rb = (rb + 7) >> 3; 53 } else if (SkMask::kARGB32_Format == format || 54 SkMask::kLCD32_Format == format) 55 { 56 rb <<= 2; 57 } else if (SkMask::kLCD16_Format == format) { 58 rb = SkAlign4(rb << 1); 59 } else { 60 rb = SkAlign4(rb); 61 } 62 return rb; 63 } 64 65 unsigned rowBytes() const { 66 return ComputeRowBytes(fWidth, (SkMask::Format)fMaskFormat); 67 } 68 69 bool isJustAdvance() const { 70 return MASK_FORMAT_JUST_ADVANCE == fMaskFormat; 71 } 72 73 bool isFullMetrics() const { 74 return MASK_FORMAT_JUST_ADVANCE != fMaskFormat; 75 } 76 77 uint16_t getGlyphID() const { 78 return ID2Code(fID); 79 } 80 81 unsigned getSubX() const { 82 return ID2SubX(fID); 83 } 84 85 SkFixed getSubXFixed() const { 86 return SubToFixed(ID2SubX(fID)); 87 } 88 89 SkFixed getSubYFixed() const { 90 return SubToFixed(ID2SubY(fID)); 91 } 92 93 size_t computeImageSize() const; 94 95 /** Call this to set all of the metrics fields to 0 (e.g. if the scaler 96 encounters an error measuring a glyph). Note: this does not alter the 97 fImage, fPath, fID, fMaskFormat fields. 98 */ 99 void zeroMetrics(); 100 101 enum { 102 kSubBits = 2, 103 kSubMask = ((1 << kSubBits) - 1), 104 kSubShift = 24, // must be large enough for glyphs and unichars 105 kCodeMask = ((1 << kSubShift) - 1), 106 // relative offsets for X and Y subpixel bits 107 kSubShiftX = kSubBits, 108 kSubShiftY = 0 109 }; 110 111 static unsigned ID2Code(uint32_t id) { 112 return id & kCodeMask; 113 } 114 115 static unsigned ID2SubX(uint32_t id) { 116 return id >> (kSubShift + kSubShiftX); 117 } 118 119 static unsigned ID2SubY(uint32_t id) { 120 return (id >> (kSubShift + kSubShiftY)) & kSubMask; 121 } 122 123 static unsigned FixedToSub(SkFixed n) { 124 return (n >> (16 - kSubBits)) & kSubMask; 125 } 126 127 static SkFixed SubToFixed(unsigned sub) { 128 SkASSERT(sub <= kSubMask); 129 return sub << (16 - kSubBits); 130 } 131 132 static uint32_t MakeID(unsigned code) { 133 return code; 134 } 135 136 static uint32_t MakeID(unsigned code, SkFixed x, SkFixed y) { 137 SkASSERT(code <= kCodeMask); 138 x = FixedToSub(x); 139 y = FixedToSub(y); 140 return (x << (kSubShift + kSubShiftX)) | 141 (y << (kSubShift + kSubShiftY)) | 142 code; 143 } 144 145 void toMask(SkMask* mask) const; 146 }; 147 148 #endif 149