Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 1 | #Topic Text_Blob |
| 2 | #Alias Text_Blob_Reference ## |
| 3 | |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 4 | #Class SkTextBlob |
| 5 | |
Cary Clark | 61313f3 | 2018-10-08 14:57:48 -0400 | [diff] [blame] | 6 | #Code |
| 7 | #Populate |
| 8 | ## |
| 9 | |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 10 | SkTextBlob combines multiple text runs into an immutable container. Each text |
| 11 | run consists of Glyphs, Paint, and position. Only parts of Paint related to |
| 12 | fonts and text rendering are used by run. |
| 13 | |
| 14 | # ------------------------------------------------------------------------------ |
| 15 | |
| 16 | #Method const SkRect& bounds() const |
| 17 | #In Property |
| 18 | #Line # returns conservative bounding box ## |
Cary Clark | 09d80c0 | 2018-10-31 12:14:03 -0400 | [diff] [blame] | 19 | #Populate |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 20 | |
| 21 | #Example |
| 22 | #Height 70 |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 23 | SkTextBlobBuilder textBlobBuilder; |
| 24 | const char bunny[] = "/(^x^)\\"; |
| 25 | const int len = sizeof(bunny) - 1; |
| 26 | uint16_t glyphs[len]; |
| 27 | SkPaint paint; |
| 28 | paint.textToGlyphs(bunny, len, glyphs); |
| 29 | paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding); |
| 30 | int runs[] = { 3, 1, 3 }; |
| 31 | SkPoint textPos = { 20, 50 }; |
| 32 | int glyphIndex = 0; |
| 33 | for (auto runLen : runs) { |
| 34 | paint.setTextSize(1 == runLen ? 20 : 50); |
| 35 | const SkTextBlobBuilder::RunBuffer& run = |
| 36 | textBlobBuilder.allocRun(paint, runLen, textPos.fX, textPos.fY); |
| 37 | memcpy(run.glyphs, &glyphs[glyphIndex], sizeof(glyphs[0]) * runLen); |
| 38 | textPos.fX += paint.measureText(&glyphs[glyphIndex], sizeof(glyphs[0]) * runLen, nullptr); |
| 39 | glyphIndex += runLen; |
| 40 | } |
| 41 | sk_sp<const SkTextBlob> blob = textBlobBuilder.make(); |
| 42 | paint.reset(); |
| 43 | canvas->drawTextBlob(blob.get(), 0, 0, paint); |
| 44 | paint.setStyle(SkPaint::kStroke_Style); |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 45 | canvas->drawRect(blob->bounds(), paint); |
| 46 | ## |
| 47 | |
| 48 | #SeeAlso SkPath::getBounds |
| 49 | |
| 50 | #Method ## |
| 51 | |
| 52 | # ------------------------------------------------------------------------------ |
| 53 | |
| 54 | #Method uint32_t uniqueID() const |
| 55 | #In Property |
| 56 | #Line # returns identifier for Text_Blob ## |
Cary Clark | 09d80c0 | 2018-10-31 12:14:03 -0400 | [diff] [blame] | 57 | #Populate |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 58 | |
| 59 | #Example |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 60 | for (int index = 0; index < 2; ++index) { |
| 61 | SkTextBlobBuilder textBlobBuilder; |
| 62 | const char bunny[] = "/(^x^)\\"; |
| 63 | const int len = sizeof(bunny) - 1; |
| 64 | uint16_t glyphs[len]; |
| 65 | SkPaint paint; |
| 66 | paint.textToGlyphs(bunny, len, glyphs); |
| 67 | paint.setTextEncoding(SkPaint::kGlyphID_TextEncoding); |
| 68 | paint.setTextScaleX(0.5); |
| 69 | int runs[] = { 3, 1, 3 }; |
| 70 | SkPoint textPos = { 20, 50 }; |
| 71 | int glyphIndex = 0; |
| 72 | for (auto runLen : runs) { |
| 73 | paint.setTextSize(1 == runLen ? 20 : 50); |
| 74 | const SkTextBlobBuilder::RunBuffer& run = |
| 75 | textBlobBuilder.allocRun(paint, runLen, textPos.fX, textPos.fY); |
| 76 | memcpy(run.glyphs, &glyphs[glyphIndex], sizeof(glyphs[0]) * runLen); |
| 77 | textPos.fX += paint.measureText(&glyphs[glyphIndex], sizeof(glyphs[0]) * runLen, nullptr); |
| 78 | glyphIndex += runLen; |
| 79 | } |
| 80 | sk_sp<const SkTextBlob> blob = textBlobBuilder.make(); |
| 81 | paint.reset(); |
| 82 | canvas->drawTextBlob(blob.get(), 0, 0, paint); |
| 83 | std::string id = "unique ID:" + std::to_string(blob->uniqueID()); |
| 84 | canvas->drawString(id.c_str(), 30, blob->bounds().fBottom + 15, paint); |
| 85 | canvas->translate(blob->bounds().fRight + 10, 0); |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 86 | } |
| 87 | ## |
| 88 | |
| 89 | #SeeAlso SkRefCnt |
| 90 | |
| 91 | #Method ## |
| 92 | |
| 93 | # ------------------------------------------------------------------------------ |
| 94 | |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 95 | #Method static sk_sp<SkTextBlob> MakeFromText(const void* text, size_t byteLength, const SkFont& font, |
| 96 | SkPaint::TextEncoding encoding = SkPaint::kUTF8_TextEncoding) |
Cary Clark | 61313f3 | 2018-10-08 14:57:48 -0400 | [diff] [blame] | 97 | #In Constructors |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 98 | #Line # constructs Text_Blob with one run ## |
| 99 | |
| 100 | Creates Text_Blob with a single run. text meaning depends on Paint_Text_Encoding; |
| 101 | by default, text is encoded as UTF-8. |
| 102 | |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 103 | font contains attributes used to define the run text: #paint_font_metrics#. |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 104 | |
| 105 | #Param text character code points or Glyphs drawn ## |
| 106 | #Param byteLength byte length of text array ## |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 107 | #Param font text size, typeface, text scale, and so on, used to draw ## |
| 108 | #Param encoding one of: kUTF8_SkTextEncoding, kUTF16_SkTextEncoding, |
| 109 | kUTF32_SkTextEncoding, kGlyphID_SkTextEncoding |
| 110 | ## |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 111 | |
| 112 | #Return Text_Blob constructed from one run ## |
| 113 | |
| 114 | #Example |
| 115 | #Height 24 |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 116 | SkFont font; |
| 117 | font.setSize(24); |
| 118 | SkPaint canvasPaint; |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 119 | canvasPaint.setColor(SK_ColorBLUE); // respected |
| 120 | canvasPaint.setTextSize(2); // ignored |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 121 | sk_sp<SkTextBlob> blob = SkTextBlob::MakeFromText("Hello World", 11, font); |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 122 | canvas->drawTextBlob(blob, 20, 20, canvasPaint); |
| 123 | ## |
| 124 | |
Cary Clark | 77b3f3a | 2018-11-07 14:59:03 -0500 | [diff] [blame] | 125 | #SeeAlso MakeFromString SkTextBlobBuilder |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 126 | |
| 127 | ## |
| 128 | |
| 129 | # ------------------------------------------------------------------------------ |
| 130 | |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 131 | #Method static sk_sp<SkTextBlob> MakeFromString(const char* string, const SkFont& font, |
| 132 | SkPaint::TextEncoding encoding = SkPaint::kUTF8_TextEncoding) |
Cary Clark | 61313f3 | 2018-10-08 14:57:48 -0400 | [diff] [blame] | 133 | #In Constructors |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 134 | #Line # constructs Text_Blob with one run ## |
| 135 | |
| 136 | Creates Text_Blob with a single run. string meaning depends on Paint_Text_Encoding; |
| 137 | by default, string is encoded as UTF-8. |
| 138 | |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 139 | font contains Paint_Font_Metrics used to define the run text: #paint_font_metrics#. |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 140 | |
| 141 | #Param string character code points or Glyphs drawn ## |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 142 | #Param font text size, typeface, text scale, and so on, used to draw ## |
| 143 | #Param encoding one of: kUTF8_SkTextEncoding, kUTF16_SkTextEncoding, |
| 144 | kUTF32_SkTextEncoding, kGlyphID_SkTextEncoding |
| 145 | ## |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 146 | |
| 147 | #Return Text_Blob constructed from one run ## |
| 148 | |
| 149 | #Example |
| 150 | #Height 24 |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 151 | SkFont font; |
| 152 | font.setSize(24); |
| 153 | SkPaint canvasPaint; |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 154 | canvasPaint.setColor(SK_ColorBLUE); // respected |
| 155 | canvasPaint.setTextSize(2); // ignored |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 156 | sk_sp<SkTextBlob> blob = SkTextBlob::MakeFromString("Hello World", font); |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 157 | canvas->drawTextBlob(blob, 20, 20, canvasPaint); |
| 158 | ## |
| 159 | |
Cary Clark | 77b3f3a | 2018-11-07 14:59:03 -0500 | [diff] [blame] | 160 | #SeeAlso MakeFromText SkTextBlobBuilder |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 161 | |
| 162 | ## |
| 163 | |
| 164 | # ------------------------------------------------------------------------------ |
| 165 | |
| 166 | #Method size_t serialize(const SkSerialProcs& procs, void* memory, size_t memory_size) const |
| 167 | #In Utility |
| 168 | #Line # writes Text_Blob to memory ## |
Cary Clark | 09d80c0 | 2018-10-31 12:14:03 -0400 | [diff] [blame] | 169 | #Populate |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 170 | |
| 171 | #Example |
| 172 | #Height 64 |
| 173 | ###$ |
| 174 | $Function |
| 175 | #include "SkSerialProcs.h" |
| 176 | $$ |
| 177 | $$$# |
Cary Clark | 09d80c0 | 2018-10-31 12:14:03 -0400 | [diff] [blame] | 178 | SkFont blobFont; |
| 179 | blobFont.setSize(24); |
| 180 | sk_sp<SkTextBlob> blob = SkTextBlob::MakeFromText("Hello World", 11, blobFont); |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 181 | char storage[2048]; |
| 182 | size_t used = blob->serialize(SkSerialProcs(), storage, sizeof(storage)); |
| 183 | sk_sp<SkTextBlob> copy = SkTextBlob::Deserialize(storage, used, SkDeserialProcs()); |
| 184 | canvas->drawTextBlob(copy, 20, 20, SkPaint()); |
| 185 | std::string usage = "size=" + std::to_string(sizeof(storage)) + " used=" + std::to_string(used); |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 186 | canvas->drawString(usage.c_str(), 20, 40, SkPaint()); |
| 187 | ## |
| 188 | |
| 189 | #SeeAlso Deserialize SkSerialProcs |
| 190 | |
| 191 | #Method ## |
| 192 | |
| 193 | # ------------------------------------------------------------------------------ |
| 194 | |
| 195 | #Method sk_sp<SkData> serialize(const SkSerialProcs& procs) const |
| 196 | #In Utility |
| 197 | #Line # writes Text_Blob to Data ## |
Cary Clark | 09d80c0 | 2018-10-31 12:14:03 -0400 | [diff] [blame] | 198 | #Populate |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 199 | |
| 200 | #Example |
| 201 | #Height 24 |
| 202 | ###$ |
| 203 | $Function |
| 204 | #include "SkSerialProcs.h" |
| 205 | $$ |
| 206 | $$$# |
Cary Clark | 09d80c0 | 2018-10-31 12:14:03 -0400 | [diff] [blame] | 207 | SkFont blobFont; |
| 208 | blobFont.setSize(24); |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 209 | sk_sp<SkTextBlob> blob = SkTextBlob::MakeFromText("Hello World", 11, blobFont); |
| 210 | sk_sp<SkData> data = blob->serialize(SkSerialProcs()); |
| 211 | sk_sp<SkTextBlob> copy = SkTextBlob::Deserialize(data->data(), data->size(), SkDeserialProcs()); |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 212 | canvas->drawTextBlob(copy, 20, 20, SkPaint()); |
| 213 | ## |
| 214 | |
| 215 | #SeeAlso Deserialize SkData SkSerialProcs |
| 216 | |
| 217 | #Method ## |
| 218 | |
| 219 | # ------------------------------------------------------------------------------ |
| 220 | |
| 221 | #Method static sk_sp<SkTextBlob> Deserialize(const void* data, size_t size, const SkDeserialProcs& procs) |
Cary Clark | 61313f3 | 2018-10-08 14:57:48 -0400 | [diff] [blame] | 222 | #In Constructors |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 223 | #Line # constructs Text_Blob from memory ## |
Cary Clark | 09d80c0 | 2018-10-31 12:14:03 -0400 | [diff] [blame] | 224 | #Populate |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 225 | |
| 226 | #Example |
| 227 | #Height 24 |
| 228 | #Description |
| 229 | Text "Hacker" replaces "World!", but does not update its metrics. |
| 230 | When drawn, "Hacker" uses the spacing computed for "World!". |
| 231 | ## |
| 232 | ###$ |
| 233 | $Function |
| 234 | #include "SkSerialProcs.h" |
| 235 | $$ |
| 236 | $$$# |
Cary Clark | 09d80c0 | 2018-10-31 12:14:03 -0400 | [diff] [blame] | 237 | SkFont blobFont; |
| 238 | blobFont.setSize(24); |
| 239 | sk_sp<SkTextBlob> blob = SkTextBlob::MakeFromText("Hello World!", 12, blobFont); |
| 240 | sk_sp<SkData> data = blob->serialize(SkSerialProcs()); |
| 241 | uint16_t glyphs[6]; |
| 242 | SkPaint blobPaint; |
Cary Clark | 14768f6 | 2018-10-29 20:33:51 -0400 | [diff] [blame] | 243 | blobPaint.textToGlyphs("Hacker", 6, glyphs); |
| 244 | memcpy((char*)data->writable_data() + 0x54, glyphs, sizeof(glyphs)); |
| 245 | sk_sp<SkTextBlob> copy = SkTextBlob::Deserialize(data->data(), data->size(), SkDeserialProcs()); |
Cary Clark | d2ca79c | 2018-08-10 13:09:13 -0400 | [diff] [blame] | 246 | canvas->drawTextBlob(copy, 20, 20, SkPaint()); |
| 247 | ## |
| 248 | |
| 249 | #SeeAlso serialize SkDeserialProcs |
| 250 | |
| 251 | #Method ## |
| 252 | |
| 253 | #Class SkTextBlob ## |
| 254 | |
| 255 | #Topic Text_Blob ## |