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 uint8_t fMaskFormat; 33 int8_t fRsbDelta, fLsbDelta; // used by auto-kerning 34 initSkGlyph35 void init(uint32_t id) { 36 fID = id; 37 fImage = NULL; 38 fPath = NULL; 39 fMaskFormat = MASK_FORMAT_UNKNOWN; 40 } 41 42 /** 43 * Compute the rowbytes for the specified width and mask-format. 44 */ ComputeRowBytesSkGlyph45 static unsigned ComputeRowBytes(unsigned width, SkMask::Format format) { 46 unsigned rb = width; 47 if (SkMask::kBW_Format == format) { 48 rb = (rb + 7) >> 3; 49 } else if (SkMask::kARGB32_Format == format || 50 SkMask::kLCD32_Format == format) 51 { 52 rb <<= 2; 53 } else if (SkMask::kLCD16_Format == format) { 54 rb = SkAlign4(rb << 1); 55 } else { 56 rb = SkAlign4(rb); 57 } 58 return rb; 59 } 60 rowBytesSkGlyph61 unsigned rowBytes() const { 62 return ComputeRowBytes(fWidth, (SkMask::Format)fMaskFormat); 63 } 64 isJustAdvanceSkGlyph65 bool isJustAdvance() const { 66 return MASK_FORMAT_JUST_ADVANCE == fMaskFormat; 67 } 68 isFullMetricsSkGlyph69 bool isFullMetrics() const { 70 return MASK_FORMAT_JUST_ADVANCE != fMaskFormat; 71 } 72 getGlyphIDSkGlyph73 uint16_t getGlyphID() const { 74 return ID2Code(fID); 75 } 76 getGlyphIDSkGlyph77 unsigned getGlyphID(unsigned baseGlyphCount) const { 78 unsigned code = ID2Code(fID); 79 SkASSERT(code >= baseGlyphCount); 80 return code - baseGlyphCount; 81 } 82 getSubXSkGlyph83 unsigned getSubX() const { 84 return ID2SubX(fID); 85 } 86 getSubXFixedSkGlyph87 SkFixed getSubXFixed() const { 88 return SubToFixed(ID2SubX(fID)); 89 } 90 getSubYFixedSkGlyph91 SkFixed getSubYFixed() const { 92 return SubToFixed(ID2SubY(fID)); 93 } 94 95 size_t computeImageSize() const; 96 97 /** Call this to set all of the metrics fields to 0 (e.g. if the scaler 98 encounters an error measuring a glyph). Note: this does not alter the 99 fImage, fPath, fID, fMaskFormat fields. 100 */ 101 void zeroMetrics(); 102 103 enum { 104 kSubBits = 2, 105 kSubMask = ((1 << kSubBits) - 1), 106 kSubShift = 24, // must be large enough for glyphs and unichars 107 kCodeMask = ((1 << kSubShift) - 1), 108 // relative offsets for X and Y subpixel bits 109 kSubShiftX = kSubBits, 110 kSubShiftY = 0 111 }; 112 ID2CodeSkGlyph113 static unsigned ID2Code(uint32_t id) { 114 return id & kCodeMask; 115 } 116 ID2SubXSkGlyph117 static unsigned ID2SubX(uint32_t id) { 118 return id >> (kSubShift + kSubShiftX); 119 } 120 ID2SubYSkGlyph121 static unsigned ID2SubY(uint32_t id) { 122 return (id >> (kSubShift + kSubShiftY)) & kSubMask; 123 } 124 FixedToSubSkGlyph125 static unsigned FixedToSub(SkFixed n) { 126 return (n >> (16 - kSubBits)) & kSubMask; 127 } 128 SubToFixedSkGlyph129 static SkFixed SubToFixed(unsigned sub) { 130 SkASSERT(sub <= kSubMask); 131 return sub << (16 - kSubBits); 132 } 133 MakeIDSkGlyph134 static uint32_t MakeID(unsigned code) { 135 return code; 136 } 137 MakeIDSkGlyph138 static uint32_t MakeID(unsigned code, SkFixed x, SkFixed y) { 139 SkASSERT(code <= kCodeMask); 140 x = FixedToSub(x); 141 y = FixedToSub(y); 142 return (x << (kSubShift + kSubShiftX)) | 143 (y << (kSubShift + kSubShiftY)) | 144 code; 145 } 146 147 void toMask(SkMask* mask) const; 148 }; 149 150 #endif 151