1 /* 2 * Copyright 2014 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 SkFont_DEFINED 9 #define SkFont_DEFINED 10 11 #include "SkRefCnt.h" 12 #include "SkScalar.h" 13 14 class SkPaint; 15 class SkTypeface; 16 17 enum SkTextEncoding { 18 kUTF8_SkTextEncoding, 19 kUTF16_SkTextEncoding, 20 kUTF32_SkTextEncoding, 21 kGlyphID_SkTextEncoding, 22 }; 23 24 /* 25 1. The Hinting enum in SkPaint is gone entirely, absorbed into SkFont's flags. 26 27 2. SkPaint Flags look like this today 28 29 enum Flags { 30 kAntiAlias_Flag = 0x01, //!< mask to enable antialiasing 31 kDither_Flag = 0x04, //!< mask to enable dithering 32 kUnderlineText_Flag = 0x08, //!< mask to enable underline text 33 kStrikeThruText_Flag = 0x10, //!< mask to enable strike-thru text 34 kFakeBoldText_Flag = 0x20, //!< mask to enable fake-bold text 35 kLinearText_Flag = 0x40, //!< mask to enable linear-text 36 kSubpixelText_Flag = 0x80, //!< mask to enable subpixel text positioning 37 kDevKernText_Flag = 0x100, //!< mask to enable device kerning text 38 kLCDRenderText_Flag = 0x200, //!< mask to enable subpixel glyph renderering 39 kEmbeddedBitmapText_Flag = 0x400, //!< mask to enable embedded bitmap strikes 40 kAutoHinting_Flag = 0x800, //!< mask to force Freetype's autohinter 41 kVerticalText_Flag = 0x1000, 42 kGenA8FromLCD_Flag = 0x2000, // hack for GDI -- do not use if you can help it 43 }; 44 45 SkFont would absorb these: 46 47 kFakeBoldText_Flag = 0x20, //!< mask to enable fake-bold text 48 kLinearText_Flag = 0x40, //!< mask to enable linear-text 49 kSubpixelText_Flag = 0x80, //!< mask to enable subpixel text positioning 50 kDevKernText_Flag = 0x100, //!< mask to enable device kerning text 51 kLCDRenderText_Flag = 0x200, //!< mask to enable subpixel glyph renderering 52 kEmbeddedBitmapText_Flag = 0x400, //!< mask to enable embedded bitmap strikes 53 kAutoHinting_Flag = 0x800, //!< mask to force Freetype's autohinter 54 kVerticalText_Flag = 0x1000, 55 kGenA8FromLCD_Flag = 0x2000, // hack for GDI -- do not use if you can help it 56 57 leaving these still in paint 58 59 kAntiAlias_Flag = 0x01, //!< mask to enable antialiasing 60 kDither_Flag = 0x04, //!< mask to enable dithering 61 kUnderlineText_Flag = 0x08, //!< mask to enable underline text 62 kStrikeThruText_Flag = 0x10, //!< mask to enable strike-thru text 63 64 3. Antialiasing 65 66 SkFont has a mask-type: BW, AA, LCD 67 SkPaint has antialias boolean 68 69 What to do if the font's mask-type disagrees with the paint? 70 71 */ 72 73 class SkFont : public SkRefCnt { 74 public: 75 enum Flags { 76 /** 77 * Use the system's automatic hinting mechanism to hint the typeface. 78 * This is a last resort hinting method applied only if other hinting methods do not apply. 79 * TODO: where to put auto-normal vs auto-light? 80 */ 81 kEnableAutoHints_Flag = 1 << 0, 82 83 /** 84 * If the typeface contains explicit bytecodes for hinting, use them. 85 * If both bytecode and auto hints are specified, attempt to use the bytecodes first; 86 * if that fails (e.g. there are no codes), then attempt to autohint. 87 */ 88 kEnableByteCodeHints_Flag = 1 << 1, 89 90 /** 91 * If the typeface contains explicit bitmaps for hinting, use them. 92 * If both bytecode and auto hints are also specified, attempt to use the bitmaps first; 93 * if that fails (e.g. there are no bitmaps), then attempt to bytecode or autohint. 94 */ 95 kEmbeddedBitmaps_Flag = 1 << 2, 96 97 /** 98 * Use rounded metric values (e.g. advance). 99 * If either auto or bytecode hinting was used, apply those results to the metrics of the 100 * glyphs as well. If no hinting was applied, the metrics will just be rounded to the 101 * nearest integer. 102 * 103 * This applies to calls that return metrics (e.g. measureText) and to drawing the glyphs 104 * (see SkCanvas drawText and drawPosText). 105 */ 106 kUseNonlinearMetrics_Flag = 1 << 3, 107 108 kVertical_Flag = 1 << 4, 109 kGenA8FromLCD_Flag = 1 << 5, 110 kEmbolden_Flag = 1 << 6, 111 kDevKern_Flag = 1 << 7, // ifdef ANDROID ? 112 }; 113 114 enum MaskType { 115 kBW_MaskType, 116 kA8_MaskType, 117 kLCD_MaskType, 118 }; 119 120 static sk_sp<SkFont> Make(sk_sp<SkTypeface>, SkScalar size, MaskType, uint32_t flags); 121 static sk_sp<SkFont> Make(sk_sp<SkTypeface>, SkScalar size, SkScalar scaleX, SkScalar skewX, 122 MaskType, uint32_t flags); 123 124 /** 125 * Return a font with the same attributes of this font, but with the specified size. 126 * If size is not supported (e.g. <= 0 or non-finite) NULL will be returned. 127 */ 128 sk_sp<SkFont> makeWithSize(SkScalar size) const; 129 /** 130 * Return a font with the same attributes of this font, but with the flags. 131 */ 132 sk_sp<SkFont> makeWithFlags(uint32_t newFlags) const; 133 getTypeface()134 SkTypeface* getTypeface() const { return fTypeface.get(); } getSize()135 SkScalar getSize() const { return fSize; } getScaleX()136 SkScalar getScaleX() const { return fScaleX; } getSkewX()137 SkScalar getSkewX() const { return fSkewX; } getFlags()138 uint32_t getFlags() const { return fFlags; } getMaskType()139 MaskType getMaskType() const { return (MaskType)fMaskType; } 140 isVertical()141 bool isVertical() const { return SkToBool(fFlags & kVertical_Flag); } isEmbolden()142 bool isEmbolden() const { return SkToBool(fFlags & kEmbolden_Flag); } isEnableAutoHints()143 bool isEnableAutoHints() const { return SkToBool(fFlags & kEnableAutoHints_Flag); } isEnableByteCodeHints()144 bool isEnableByteCodeHints() const { return SkToBool(fFlags & kEnableByteCodeHints_Flag); } isUseNonLinearMetrics()145 bool isUseNonLinearMetrics() const { return SkToBool(fFlags & kUseNonlinearMetrics_Flag); } isDevKern()146 bool isDevKern() const { return SkToBool(fFlags & kDevKern_Flag); } 147 148 int textToGlyphs(const void* text, size_t byteLength, SkTextEncoding, 149 SkGlyphID glyphs[], int maxGlyphCount) const; 150 countText(const void * text,size_t byteLength,SkTextEncoding encoding)151 int countText(const void* text, size_t byteLength, SkTextEncoding encoding) { 152 return this->textToGlyphs(text, byteLength, encoding, nullptr, 0); 153 } 154 155 SkScalar measureText(const void* text, size_t byteLength, SkTextEncoding) const; 156 157 static sk_sp<SkFont> Testing_CreateFromPaint(const SkPaint&); 158 159 private: 160 enum { 161 kAllFlags = 0xFF, 162 }; 163 164 SkFont(sk_sp<SkTypeface>, SkScalar size, SkScalar scaleX, SkScalar skewX, MaskType, 165 uint32_t flags); 166 167 sk_sp<SkTypeface> fTypeface; 168 SkScalar fSize; 169 SkScalar fScaleX; 170 SkScalar fSkewX; 171 uint16_t fFlags; 172 uint8_t fMaskType; 173 // uint8_t fPad; 174 }; 175 176 #endif 177