fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 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 SkTextBlob_DEFINED |
| 9 | #define SkTextBlob_DEFINED |
| 10 | |
| 11 | #include "SkPaint.h" |
| 12 | #include "SkRefCnt.h" |
| 13 | #include "SkTArray.h" |
| 14 | #include "SkTDArray.h" |
| 15 | |
fmalita | b742517 | 2014-08-26 07:56:44 -0700 | [diff] [blame] | 16 | class SkReadBuffer; |
| 17 | class SkWriteBuffer; |
| 18 | |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 19 | /** \class SkTextBlob |
| 20 | |
| 21 | SkTextBlob combines multiple text runs into an immutable, ref-counted structure. |
| 22 | */ |
jbroman | 3053dfa | 2014-08-25 06:22:12 -0700 | [diff] [blame] | 23 | class SK_API SkTextBlob : public SkRefCnt { |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 24 | public: |
| 25 | /** |
fmalita | 3dc40ac | 2015-01-28 10:56:06 -0800 | [diff] [blame] | 26 | * Returns a conservative blob bounding box. |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 27 | */ |
| 28 | const SkRect& bounds() const { return fBounds; } |
| 29 | |
| 30 | /** |
| 31 | * Return a non-zero, unique value representing the text blob. |
| 32 | */ |
joshualitt | 2af8583 | 2015-03-25 13:40:13 -0700 | [diff] [blame] | 33 | uint32_t uniqueID() const { return fUniqueID; } |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 34 | |
fmalita | 228a6f2 | 2014-08-28 13:59:42 -0700 | [diff] [blame] | 35 | /** |
| 36 | * Serialize to a buffer. |
| 37 | */ |
| 38 | void flatten(SkWriteBuffer&) const; |
| 39 | |
| 40 | /** |
| 41 | * Recreate an SkTextBlob that was serialized into a buffer. |
| 42 | * |
| 43 | * @param SkReadBuffer Serialized blob data. |
| 44 | * @return A new SkTextBlob representing the serialized data, or NULL if the buffer is |
| 45 | * invalid. |
| 46 | */ |
| 47 | static const SkTextBlob* CreateFromBuffer(SkReadBuffer&); |
| 48 | |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 49 | enum GlyphPositioning { |
| 50 | kDefault_Positioning = 0, // Default glyph advances -- zero scalars per glyph. |
| 51 | kHorizontal_Positioning = 1, // Horizontal positioning -- one scalar per glyph. |
| 52 | kFull_Positioning = 2 // Point positioning -- two scalars per glyph. |
| 53 | }; |
| 54 | |
halcanary | 3377975 | 2015-10-27 14:01:05 -0700 | [diff] [blame^] | 55 | private: |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 56 | class RunRecord; |
| 57 | |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 58 | SkTextBlob(int runCount, const SkRect& bounds); |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 59 | |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 60 | virtual ~SkTextBlob(); |
bsalomon | 0728031 | 2014-11-20 08:02:46 -0800 | [diff] [blame] | 61 | |
| 62 | // Memory for objects of this class is created with sk_malloc rather than operator new and must |
| 63 | // be freed with sk_free. |
| 64 | void operator delete(void* p) { sk_free(p); } |
| 65 | void* operator new(size_t) { |
| 66 | SkFAIL("All blobs are created by placement new."); |
| 67 | return sk_malloc_throw(0); |
| 68 | } |
| 69 | void* operator new(size_t, void* p) { return p; } |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 70 | |
fmalita | b742517 | 2014-08-26 07:56:44 -0700 | [diff] [blame] | 71 | static unsigned ScalarsPerGlyph(GlyphPositioning pos); |
| 72 | |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 73 | friend class SkTextBlobBuilder; |
halcanary | 3377975 | 2015-10-27 14:01:05 -0700 | [diff] [blame^] | 74 | friend class SkTextBlobRunIterator; |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 75 | |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 76 | const int fRunCount; |
| 77 | const SkRect fBounds; |
joshualitt | 2af8583 | 2015-03-25 13:40:13 -0700 | [diff] [blame] | 78 | const uint32_t fUniqueID; |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 79 | |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 80 | SkDEBUGCODE(size_t fStorageSize;) |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 81 | |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 82 | // The actual payload resides in externally-managed storage, following the object. |
| 83 | // (see the .cpp for more details) |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 84 | |
| 85 | typedef SkRefCnt INHERITED; |
| 86 | }; |
| 87 | |
| 88 | /** \class SkTextBlobBuilder |
| 89 | |
| 90 | Helper class for constructing SkTextBlobs. |
| 91 | */ |
jbroman | 3053dfa | 2014-08-25 06:22:12 -0700 | [diff] [blame] | 92 | class SK_API SkTextBlobBuilder { |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 93 | public: |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 94 | SkTextBlobBuilder(); |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 95 | |
| 96 | ~SkTextBlobBuilder(); |
| 97 | |
| 98 | /** |
| 99 | * Returns an immutable SkTextBlob for the current runs/glyphs. The builder is reset and |
| 100 | * can be reused. |
| 101 | */ |
| 102 | const SkTextBlob* build(); |
| 103 | |
| 104 | /** |
| 105 | * Glyph and position buffers associated with a run. |
| 106 | * |
| 107 | * A run is a sequence of glyphs sharing the same font metrics and positioning mode. |
| 108 | */ |
| 109 | struct RunBuffer { |
| 110 | uint16_t* glyphs; |
| 111 | SkScalar* pos; |
| 112 | }; |
| 113 | |
| 114 | /** |
| 115 | * Allocates a new default-positioned run and returns its writable glyph buffer |
| 116 | * for direct manipulation. |
| 117 | * |
| 118 | * @param font The font to be used for this run. |
| 119 | * @param count Number of glyphs. |
| 120 | * @param x,y Position within the blob. |
| 121 | * @param bounds Optional run bounding box. If known in advance (!= NULL), it will |
| 122 | * be used when computing the blob bounds, to avoid re-measuring. |
| 123 | * |
| 124 | * @return A writable glyph buffer, valid until the next allocRun() or |
| 125 | * build() call. The buffer is guaranteed to hold @count@ glyphs. |
| 126 | */ |
| 127 | const RunBuffer& allocRun(const SkPaint& font, int count, SkScalar x, SkScalar y, |
| 128 | const SkRect* bounds = NULL); |
| 129 | |
| 130 | /** |
| 131 | * Allocates a new horizontally-positioned run and returns its writable glyph and position |
| 132 | * buffers for direct manipulation. |
| 133 | * |
| 134 | * @param font The font to be used for this run. |
| 135 | * @param count Number of glyphs. |
| 136 | * @param y Vertical offset within the blob. |
| 137 | * @param bounds Optional run bounding box. If known in advance (!= NULL), it will |
| 138 | * be used when computing the blob bounds, to avoid re-measuring. |
| 139 | * |
| 140 | * @return Writable glyph and position buffers, valid until the next allocRun() |
| 141 | * or build() call. The buffers are guaranteed to hold @count@ elements. |
| 142 | */ |
| 143 | const RunBuffer& allocRunPosH(const SkPaint& font, int count, SkScalar y, |
| 144 | const SkRect* bounds = NULL); |
| 145 | |
| 146 | /** |
| 147 | * Allocates a new fully-positioned run and returns its writable glyph and position |
| 148 | * buffers for direct manipulation. |
| 149 | * |
| 150 | * @param font The font to be used for this run. |
| 151 | * @param count Number of glyphs. |
| 152 | * @param bounds Optional run bounding box. If known in advance (!= NULL), it will |
| 153 | * be used when computing the blob bounds, to avoid re-measuring. |
| 154 | * |
| 155 | * @return Writable glyph and position buffers, valid until the next allocRun() |
| 156 | * or build() call. The glyph buffer and position buffer are |
| 157 | * guaranteed to hold @count@ and 2 * @count@ elements, respectively. |
| 158 | */ |
| 159 | const RunBuffer& allocRunPos(const SkPaint& font, int count, const SkRect* bounds = NULL); |
| 160 | |
| 161 | private: |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 162 | void reserve(size_t size); |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 163 | void allocInternal(const SkPaint& font, SkTextBlob::GlyphPositioning positioning, |
| 164 | int count, SkPoint offset, const SkRect* bounds); |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 165 | bool mergeRun(const SkPaint& font, SkTextBlob::GlyphPositioning positioning, |
| 166 | int count, SkPoint offset); |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 167 | void updateDeferredBounds(); |
| 168 | |
fmalita | 3dc40ac | 2015-01-28 10:56:06 -0800 | [diff] [blame] | 169 | static SkRect ConservativeRunBounds(const SkTextBlob::RunRecord&); |
| 170 | static SkRect TightRunBounds(const SkTextBlob::RunRecord&); |
| 171 | |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 172 | SkAutoTMalloc<uint8_t> fStorage; |
| 173 | size_t fStorageSize; |
| 174 | size_t fStorageUsed; |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 175 | |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 176 | SkRect fBounds; |
| 177 | int fRunCount; |
| 178 | bool fDeferredBounds; |
| 179 | size_t fLastRun; // index into fStorage |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 180 | |
fmalita | 3c196de | 2014-09-20 05:40:22 -0700 | [diff] [blame] | 181 | RunBuffer fCurrentRunBuffer; |
fmalita | 00d5c2c | 2014-08-21 08:53:26 -0700 | [diff] [blame] | 182 | }; |
| 183 | |
| 184 | #endif // SkTextBlob_DEFINED |