gm/texteffects.cpp

   1 /*
   2  * Copyright 2011 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 #include "gm.h"
   9 #include "sk_tool_utils.h"
  10 #include "SkBlurMask.h"
  11 #include "SkBlurMaskFilter.h"
  12 #include "SkReadBuffer.h"
  13 #include "SkTextBlob.h"
  14 #include "SkWriteBuffer.h"
  15 #include "SkLayerRasterizer.h"
  16
  17 static void r0(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
  18     p.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle,
  19                                            SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(3))));
  20     rastBuilder->addLayer(p, SkIntToScalar(3), SkIntToScalar(3));
  21
  22     p.setMaskFilter(nullptr);
  23     p.setStyle(SkPaint::kStroke_Style);
  24     p.setStrokeWidth(SK_Scalar1);
  25     rastBuilder->addLayer(p);
  26
  27     p.setAlpha(0x11);
  28     p.setStyle(SkPaint::kFill_Style);
  29     p.setBlendMode(SkBlendMode::kSrc);
  30     rastBuilder->addLayer(p);
  31 }
  32
  33 static void r1(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
  34     rastBuilder->addLayer(p);
  35
  36     p.setAlpha(0x40);
  37     p.setBlendMode(SkBlendMode::kSrc);
  38     p.setStyle(SkPaint::kStroke_Style);
  39     p.setStrokeWidth(SK_Scalar1*2);
  40     rastBuilder->addLayer(p);
  41 }
  42
  43 static void r2(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
  44     p.setStyle(SkPaint::kStrokeAndFill_Style);
  45     p.setStrokeWidth(SK_Scalar1*4);
  46     rastBuilder->addLayer(p);
  47
  48     p.setStyle(SkPaint::kStroke_Style);
  49     p.setStrokeWidth(SK_Scalar1*3/2);
  50     p.setBlendMode(SkBlendMode::kClear);
  51     rastBuilder->addLayer(p);
  52 }
  53
  54 static void r3(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
  55     p.setStyle(SkPaint::kStroke_Style);
  56     p.setStrokeWidth(SK_Scalar1*3);
  57     rastBuilder->addLayer(p);
  58
  59     p.setAlpha(0x20);
  60     p.setStyle(SkPaint::kFill_Style);
  61     p.setBlendMode(SkBlendMode::kSrc);
  62     rastBuilder->addLayer(p);
  63 }
  64
  65 static void r4(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
  66     p.setAlpha(0x60);
  67     rastBuilder->addLayer(p, SkIntToScalar(3), SkIntToScalar(3));
  68
  69     p.setAlpha(0xFF);
  70     p.setBlendMode(SkBlendMode::kClear);
  71     rastBuilder->addLayer(p, SK_Scalar1*3/2, SK_Scalar1*3/2);
  72
  73     p.setBlendMode(SkBlendMode::kSrcOver);
  74     rastBuilder->addLayer(p);
  75 }
  76
  77 #include "SkDiscretePathEffect.h"
  78
  79 static void r5(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
  80     rastBuilder->addLayer(p);
  81
  82     p.setPathEffect(SkDiscretePathEffect::Make(SK_Scalar1*4, SK_Scalar1*3));
  83     p.setBlendMode(SkBlendMode::kSrcOut);
  84     rastBuilder->addLayer(p);
  85 }
  86
  87 static void r6(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
  88     rastBuilder->addLayer(p);
  89
  90     p.setAntiAlias(false);
  91     SkLayerRasterizer::Builder rastBuilder2;
  92     r5(&rastBuilder2, p);
  93     p.setRasterizer(rastBuilder2.detach());
  94     p.setBlendMode(SkBlendMode::kClear);
  95     rastBuilder->addLayer(p);
  96 }
  97
  98 #include "Sk2DPathEffect.h"
  99
 100 static sk_sp<SkPathEffect> MakeDotEffect(SkScalar radius, const SkMatrix& matrix) {
 101     SkPath path;
 102     path.addCircle(0, 0, radius);
 103     return SkPath2DPathEffect::Make(matrix, path);
 104 }
 105
 106 static void r7(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
 107     SkMatrix    lattice;
 108     lattice.setScale(SK_Scalar1*6, SK_Scalar1*6, 0, 0);
 109     lattice.postSkew(SK_Scalar1/3, 0, 0, 0);
 110     p.setPathEffect(MakeDotEffect(SK_Scalar1*4, lattice));
 111     rastBuilder->addLayer(p);
 112 }
 113
 114 static void r8(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
 115     rastBuilder->addLayer(p);
 116
 117     SkMatrix    lattice;
 118     lattice.setScale(SK_Scalar1*6, SK_Scalar1*6, 0, 0);
 119     lattice.postSkew(SK_Scalar1/3, 0, 0, 0);
 120     p.setPathEffect(MakeDotEffect(SK_Scalar1*2, lattice));
 121     p.setBlendMode(SkBlendMode::kClear);
 122     rastBuilder->addLayer(p);
 123
 124     p.setPathEffect(nullptr);
 125     p.setBlendMode(SkBlendMode::kSrcOver);
 126     p.setStyle(SkPaint::kStroke_Style);
 127     p.setStrokeWidth(SK_Scalar1);
 128     rastBuilder->addLayer(p);
 129 }
 130
 131 static void r9(SkLayerRasterizer::Builder* rastBuilder, SkPaint& p) {
 132     rastBuilder->addLayer(p);
 133
 134     SkMatrix    lattice;
 135     lattice.setScale(SK_Scalar1, SK_Scalar1*6, 0, 0);
 136     lattice.postRotate(SkIntToScalar(30), 0, 0);
 137     p.setPathEffect(SkLine2DPathEffect::Make(SK_Scalar1*2, lattice));
 138     p.setBlendMode(SkBlendMode::kClear);
 139     rastBuilder->addLayer(p);
 140
 141     p.setPathEffect(nullptr);
 142     p.setBlendMode(SkBlendMode::kSrcOver);
 143     p.setStyle(SkPaint::kStroke_Style);
 144     p.setStrokeWidth(SK_Scalar1);
 145     rastBuilder->addLayer(p);
 146 }
 147
 148 typedef void (*raster_proc)(SkLayerRasterizer::Builder*, SkPaint&);
 149
 150 constexpr raster_proc gRastProcs[] = {
 151     r0, r1, r2, r3, r4, r5, r6, r7, r8, r9
 152 };
 153
 154 static void apply_shader(SkPaint* paint, int index) {
 155     raster_proc proc = gRastProcs[index];
 156     if (proc) {
 157         SkPaint p;
 158         SkLayerRasterizer::Builder rastBuilder;
 159
 160         p.setAntiAlias(true);
 161         proc(&rastBuilder, p);
 162         paint->setRasterizer(rastBuilder.detach());
 163     }
 164
 165 #if 0
 166     SkScalar dir[] = { SK_Scalar1, SK_Scalar1, SK_Scalar1 };
 167     paint->setMaskFilter(SkBlurMaskFilter::CreateEmboss(dir, SK_Scalar1/4, SkIntToScalar(4), SkIntToScalar(3)))->unref();
 168 #endif
 169     paint->setColor(SK_ColorBLUE);
 170 }
 171
 172 DEF_SIMPLE_GM(texteffects, canvas, 460, 680) {
 173         canvas->save();
 174
 175         SkPaint     paint;
 176         paint.setAntiAlias(true);
 177         sk_tool_utils::set_portable_typeface(&paint);
 178         paint.setTextSize(SkIntToScalar(56));
 179
 180         SkScalar    x = SkIntToScalar(20);
 181         SkScalar    y = paint.getTextSize();
 182
 183         SkString str("Hamburgefons");
 184
 185         for (int i = 0; i < static_cast<int>(SK_ARRAY_COUNT(gRastProcs)); i++) {
 186             apply_shader(&paint, i);
 187
 188             //  paint.setMaskFilter(nullptr);
 189             //  paint.setColor(SK_ColorBLACK);
 190
 191             canvas->drawString(str, x, y, paint);
 192
 193             y += paint.getFontSpacing();
 194         }
 195
 196         canvas->restore();
 197 }
 198
 199 static SkPath create_underline(const SkTDArray<SkScalar>& intersections,
 200         SkScalar last, SkScalar finalPos,
 201         SkScalar uPos, SkScalar uWidth, SkScalar textSize) {
 202     SkPath underline;
 203     SkScalar end = last;
 204     for (int index = 0; index < intersections.count(); index += 2) {
 205         SkScalar start = intersections[index] - uWidth;;
 206         end = intersections[index + 1] + uWidth;
 207         if (start > last && last + textSize / 12 < start) {
 208             underline.moveTo(last, uPos);
 209             underline.lineTo(start, uPos);
 210         }
 211         last = end;
 212     }
 213     if (end < finalPos) {
 214         underline.moveTo(end, uPos);
 215         underline.lineTo(finalPos, uPos);
 216     }
 217     return underline;
 218 }
 219
 220 static void find_intercepts(const char* test, size_t len, SkScalar x, SkScalar y,
 221         const SkPaint& paint, SkScalar uWidth, SkTDArray<SkScalar>* intersections) {
 222     SkScalar uPos = y + uWidth;
 223     SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
 224     int count = paint.getTextIntercepts(test, len, x, y, bounds, nullptr);
 225     SkASSERT(!(count % 2));
 226     if (count) {
 227         intersections->setCount(count);
 228         paint.getTextIntercepts(test, len, x, y, bounds, intersections->begin());
 229     }
 230 }
 231
 232 DEF_SIMPLE_GM(fancyunderline, canvas, 900, 1350) {
 233     SkPaint paint;
 234     paint.setAntiAlias(true);
 235     const char* fam[] = { "sans-serif", "serif", "monospace" };
 236     const char test[] = "aAjJgGyY_|{-(~[,]qQ}pP}zZ";
 237     SkPoint textPt = { 10, 80 };
 238     for (size_t font = 0; font < SK_ARRAY_COUNT(fam); ++font) {
 239         sk_tool_utils::set_portable_typeface(&paint, fam[font]);
 240         for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
 241             paint.setTextSize(textSize);
 242             const SkScalar uWidth = textSize / 15;
 243             paint.setStrokeWidth(uWidth);
 244             paint.setStyle(SkPaint::kFill_Style);
 245             canvas->drawText(test, sizeof(test) - 1, textPt.fX, textPt.fY, paint);
 246
 247             SkTDArray<SkScalar> intersections;
 248             find_intercepts(test, sizeof(test) - 1, textPt.fX, textPt.fY, paint, uWidth,
 249                 &intersections);
 250
 251             SkScalar start = textPt.fX;
 252             SkScalar end = paint.measureText(test, sizeof(test) - 1) + textPt.fX;
 253             SkScalar uPos = textPt.fY + uWidth;
 254             SkPath underline = create_underline(intersections, start, end, uPos, uWidth, textSize);
 255             paint.setStyle(SkPaint::kStroke_Style);
 256             canvas->drawPath(underline, paint);
 257
 258             canvas->translate(0, textSize * 1.3f);
 259         }
 260         canvas->translate(0, 60);
 261     }
 262 }
 263
 264 static void find_intercepts(const char* test, size_t len, const SkPoint* pos, const SkPaint& paint,
 265         SkScalar uWidth, SkTDArray<SkScalar>* intersections) {
 266     SkScalar uPos = pos[0].fY + uWidth;
 267     SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
 268     int count = paint.getPosTextIntercepts(test, len, pos, bounds, nullptr);
 269     SkASSERT(!(count % 2));
 270     if (count) {
 271         intersections->setCount(count);
 272         paint.getPosTextIntercepts(test, len, pos, bounds, intersections->begin());
 273     }
 274 }
 275
 276 DEF_SIMPLE_GM(fancyposunderline, canvas, 900, 1350) {
 277     SkPaint paint;
 278     paint.setAntiAlias(true);
 279     const char* fam[] = { "sans-serif", "serif", "monospace" };
 280     const char test[] = "aAjJgGyY_|{-(~[,]qQ}pP}zZ";
 281     SkPoint textPt = { 10, 80 };
 282     for (size_t font = 0; font < SK_ARRAY_COUNT(fam); ++font) {
 283         sk_tool_utils::set_portable_typeface(&paint, fam[font]);
 284         for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
 285             paint.setTextSize(textSize);
 286             const SkScalar uWidth = textSize / 15;
 287             paint.setStrokeWidth(uWidth);
 288             paint.setStyle(SkPaint::kFill_Style);
 289             int widthCount = paint.getTextWidths(test, sizeof(test) - 1, nullptr);
 290             SkTDArray<SkScalar> widths;
 291             widths.setCount(widthCount);
 292             (void) paint.getTextWidths(test, sizeof(test) - 1, widths.begin());
 293             SkTDArray<SkPoint> pos;
 294             pos.setCount(widthCount);
 295             SkScalar posX = textPt.fX;
 296             for (int index = 0; index < widthCount; ++index) {
 297                 pos[index].fX = posX;
 298                 posX += widths[index];
 299                 pos[index].fY = textPt.fY + (textSize / 25) * (index % 4);
 300             }
 301             canvas->drawPosText(test, sizeof(test) - 1, pos.begin(), paint);
 302
 303             SkTDArray<SkScalar> intersections;
 304             find_intercepts(test, sizeof(test) - 1, pos.begin(), paint, uWidth, &intersections);
 305
 306             SkScalar start = textPt.fX;
 307             SkScalar end = posX;
 308             SkScalar uPos = textPt.fY + uWidth;
 309             SkPath underline = create_underline(intersections, start, end, uPos, uWidth, textSize);
 310             paint.setStyle(SkPaint::kStroke_Style);
 311             canvas->drawPath(underline, paint);
 312
 313             canvas->translate(0, textSize * 1.3f);
 314         }
 315         canvas->translate(0, 60);
 316     }
 317 }
 318
 319 namespace {
 320
 321 sk_sp<SkTextBlob> MakeFancyBlob(const SkPaint& paint, const char* text) {
 322     SkPaint blobPaint(paint);
 323
 324     const size_t textLen = strlen(text);
 325     const int glyphCount = blobPaint.textToGlyphs(text, textLen, nullptr);
 326     SkAutoTArray<SkGlyphID> glyphs(glyphCount);
 327     blobPaint.textToGlyphs(text, textLen, glyphs.get());
 328
 329     blobPaint.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
 330     const size_t glyphTextBytes = SkTo<uint32_t>(glyphCount) * sizeof(SkGlyphID);
 331     const int widthCount = blobPaint.getTextWidths(glyphs.get(), glyphTextBytes, nullptr);
 332     SkAssertResult(widthCount == glyphCount);
 333
 334     SkAutoTArray<SkScalar> widths(glyphCount);
 335     blobPaint.getTextWidths(glyphs.get(), glyphTextBytes, widths.get());
 336
 337     SkTextBlobBuilder blobBuilder;
 338     int glyphIndex = 0;
 339     SkScalar advance = 0;
 340
 341     // Default-positioned run.
 342     {
 343         const int defaultRunLen = glyphCount / 3;
 344         const SkTextBlobBuilder::RunBuffer& buf = blobBuilder.allocRun(blobPaint,
 345                                                                        defaultRunLen,
 346                                                                        advance, 0);
 347         memcpy(buf.glyphs, glyphs.get(), SkTo<uint32_t>(defaultRunLen) * sizeof(SkGlyphID));
 348
 349         for (int i = 0; i < defaultRunLen; ++i) {
 350             advance += widths[glyphIndex++];
 351         }
 352     }
 353
 354     // Horizontal-positioned run.
 355     {
 356         const int horizontalRunLen = glyphCount / 3;
 357         const SkTextBlobBuilder::RunBuffer& buf = blobBuilder.allocRunPosH(blobPaint,
 358                                                                            horizontalRunLen,
 359                                                                            0);
 360         memcpy(buf.glyphs, glyphs.get() + glyphIndex,
 361                SkTo<uint32_t>(horizontalRunLen) * sizeof(SkGlyphID));
 362         for (int i = 0; i < horizontalRunLen; ++i) {
 363             buf.pos[i] = advance;
 364             advance += widths[glyphIndex++];
 365         }
 366     }
 367
 368     // Full-positioned run.
 369     {
 370         const int fullRunLen = glyphCount - glyphIndex;
 371         const SkTextBlobBuilder::RunBuffer& buf = blobBuilder.allocRunPos(blobPaint, fullRunLen);
 372         memcpy(buf.glyphs, glyphs.get() + glyphIndex,
 373                SkTo<uint32_t>(fullRunLen) * sizeof(SkGlyphID));
 374         for (int i = 0; i < fullRunLen; ++i) {
 375             buf.pos[i * 2 + 0] = advance; // x offset
 376             buf.pos[i * 2 + 1] = 0;       // y offset
 377             advance += widths[glyphIndex++];
 378         }
 379     }
 380
 381     return blobBuilder.make();
 382 }
 383
 384 } // anonymous ns
 385
 386 DEF_SIMPLE_GM(fancyblobunderline, canvas, 1480, 1380) {
 387     SkPaint paint;
 388     paint.setAntiAlias(true);
 389     const char* fam[] = { "sans-serif", "serif", "monospace" };
 390     const char test[] = "aAjJgGyY_|{-(~[,]qQ}pP}zZ";
 391     const SkPoint blobOffset = { 10, 80 };
 392
 393     for (size_t font = 0; font < SK_ARRAY_COUNT(fam); ++font) {
 394         sk_tool_utils::set_portable_typeface(&paint, fam[font]);
 395         for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
 396             paint.setTextSize(textSize);
 397             const SkScalar uWidth = textSize / 15;
 398             paint.setStrokeWidth(uWidth);
 399             paint.setStyle(SkPaint::kFill_Style);
 400
 401             sk_sp<SkTextBlob> blob = MakeFancyBlob(paint, test);
 402             canvas->drawTextBlob(blob, blobOffset.x(), blobOffset.y(), paint);
 403
 404             const SkScalar uPos = uWidth;
 405             const SkScalar bounds[2] = { uPos - uWidth / 2, uPos + uWidth / 2 };
 406             const int interceptCount = paint.getTextBlobIntercepts(blob.get(), bounds, nullptr);
 407             SkASSERT(!(interceptCount % 2));
 408
 409             SkTDArray<SkScalar> intercepts;
 410             intercepts.setCount(interceptCount);
 411             paint.getTextBlobIntercepts(blob.get(), bounds, intercepts.begin());
 412
 413             const SkScalar start = blob->bounds().left();
 414             const SkScalar end = blob->bounds().right();
 415             SkPath underline = create_underline(intercepts, start, end, uPos, uWidth, textSize);
 416             underline.offset(blobOffset.x(), blobOffset.y());
 417             paint.setStyle(SkPaint::kStroke_Style);
 418             canvas->drawPath(underline, paint);
 419
 420             canvas->translate(0, textSize * 1.3f);
 421         }
 422
 423         canvas->translate(0, 60);
 424     }
 425 }
 426
 427 DEF_SIMPLE_GM(fancyunderlinebars, canvas, 1500, 460) {
 428     SkPaint paint;
 429     paint.setAntiAlias(true);
 430     const char test[] = " .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_ .}]_";
 431     SkPoint textPt = { 10, 80 };
 432     sk_tool_utils::set_portable_typeface(&paint, "serif");
 433     for (SkScalar textSize = 100; textSize > 10; textSize -= 20) {
 434         paint.setTextSize(textSize);
 435         SkScalar uWidth = textSize / 15;
 436         paint.setStrokeWidth(uWidth);
 437         paint.setStyle(SkPaint::kFill_Style);
 438         int widthCount = paint.getTextWidths(test, sizeof(test) - 1, nullptr);
 439         SkTDArray<SkScalar> widths;
 440         widths.setCount(widthCount);
 441         (void) paint.getTextWidths(test, sizeof(test) - 1, widths.begin());
 442         SkTDArray<SkPoint> pos;
 443         pos.setCount(widthCount);
 444         SkScalar posX = textPt.fX;
 445         pos[0] = textPt;
 446         posX += widths[0];
 447         for (int index = 1; index < widthCount; ++index) {
 448             pos[index].fX = posX;
 449             posX += widths[index];
 450             pos[index].fY = textPt.fY - (textSize / 50) * (index / 5) + textSize / 50 * 4;
 451         }
 452         canvas->drawPosText(test, sizeof(test) - 1, pos.begin(), paint);
 453
 454         SkTDArray<SkScalar> intersections;
 455         find_intercepts(test, sizeof(test) - 1, pos.begin(), paint, uWidth, &intersections);
 456
 457         SkScalar start = textPt.fX;
 458         SkScalar end = posX;
 459         SkScalar uPos = pos[0].fY + uWidth;
 460         SkPath underline = create_underline(intersections, start, end, uPos, uWidth, textSize);
 461         paint.setStyle(SkPaint::kStroke_Style);
 462         canvas->drawPath(underline, paint);
 463         canvas->translate(0, textSize * 1.3f);
 464     }
 465 }