1 /* 2 * Copyright (C) 2003, 2006 Apple Computer, Inc. All rights reserved. 3 * 2006 Rob Buis <buis (at) kde.org> 4 * Copyright (C) 2007 Eric Seidel <eric (at) webkit.org> 5 * Copyright (C) 2013 Google Inc. All rights reserved. 6 * Copyright (C) 2013 Intel Corporation. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 21 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 24 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 25 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include "config.h" 31 #include "platform/graphics/Path.h" 32 33 #include <math.h> 34 #include "platform/geometry/FloatPoint.h" 35 #include "platform/geometry/FloatRect.h" 36 #include "platform/graphics/GraphicsContext.h" 37 #include "platform/graphics/skia/SkiaUtils.h" 38 #include "platform/transforms/AffineTransform.h" 39 #include "third_party/skia/include/pathops/SkPathOps.h" 40 #include "wtf/MathExtras.h" 41 42 namespace WebCore { 43 44 Path::Path() 45 : m_path() 46 { 47 } 48 49 Path::Path(const Path& other) 50 { 51 m_path = SkPath(other.m_path); 52 } 53 54 Path::~Path() 55 { 56 } 57 58 Path& Path::operator=(const Path& other) 59 { 60 m_path = SkPath(other.m_path); 61 return *this; 62 } 63 64 bool Path::operator==(const Path& other) const 65 { 66 return m_path == other.m_path; 67 } 68 69 bool Path::contains(const FloatPoint& point, WindRule rule) const 70 { 71 return SkPathContainsPoint(m_path, point, rule == RULE_NONZERO ? SkPath::kWinding_FillType : SkPath::kEvenOdd_FillType); 72 } 73 74 bool Path::strokeContains(const FloatPoint& point, const StrokeData& strokeData) const 75 { 76 SkPaint paint; 77 strokeData.setupPaint(&paint); 78 SkPath strokePath; 79 paint.getFillPath(m_path, &strokePath); 80 81 return SkPathContainsPoint(strokePath, point, SkPath::kWinding_FillType); 82 } 83 84 FloatRect Path::boundingRect() const 85 { 86 return m_path.getBounds(); 87 } 88 89 FloatRect Path::strokeBoundingRect(const StrokeData& strokeData) const 90 { 91 SkPaint paint; 92 strokeData.setupPaint(&paint); 93 SkPath boundingPath; 94 paint.getFillPath(m_path, &boundingPath); 95 96 return boundingPath.getBounds(); 97 } 98 99 static FloatPoint* convertPathPoints(FloatPoint dst[], const SkPoint src[], int count) 100 { 101 for (int i = 0; i < count; i++) { 102 dst[i].setX(SkScalarToFloat(src[i].fX)); 103 dst[i].setY(SkScalarToFloat(src[i].fY)); 104 } 105 return dst; 106 } 107 108 void Path::apply(void* info, PathApplierFunction function) const 109 { 110 SkPath::RawIter iter(m_path); 111 SkPoint pts[4]; 112 PathElement pathElement; 113 FloatPoint pathPoints[3]; 114 115 for (;;) { 116 switch (iter.next(pts)) { 117 case SkPath::kMove_Verb: 118 pathElement.type = PathElementMoveToPoint; 119 pathElement.points = convertPathPoints(pathPoints, &pts[0], 1); 120 break; 121 case SkPath::kLine_Verb: 122 pathElement.type = PathElementAddLineToPoint; 123 pathElement.points = convertPathPoints(pathPoints, &pts[1], 1); 124 break; 125 case SkPath::kQuad_Verb: 126 pathElement.type = PathElementAddQuadCurveToPoint; 127 pathElement.points = convertPathPoints(pathPoints, &pts[1], 2); 128 break; 129 case SkPath::kCubic_Verb: 130 pathElement.type = PathElementAddCurveToPoint; 131 pathElement.points = convertPathPoints(pathPoints, &pts[1], 3); 132 break; 133 case SkPath::kClose_Verb: 134 pathElement.type = PathElementCloseSubpath; 135 pathElement.points = convertPathPoints(pathPoints, 0, 0); 136 break; 137 case SkPath::kDone_Verb: 138 return; 139 default: // place-holder for kConic_Verb, when that lands from skia 140 break; 141 } 142 function(info, &pathElement); 143 } 144 } 145 146 void Path::transform(const AffineTransform& xform) 147 { 148 m_path.transform(affineTransformToSkMatrix(xform)); 149 } 150 151 float Path::length() const 152 { 153 SkScalar length = 0; 154 SkPathMeasure measure(m_path, false); 155 156 do { 157 length += measure.getLength(); 158 } while (measure.nextContour()); 159 160 return SkScalarToFloat(length); 161 } 162 163 FloatPoint Path::pointAtLength(float length, bool& ok) const 164 { 165 FloatPoint point; 166 float normal; 167 ok = pointAndNormalAtLength(length, point, normal); 168 return point; 169 } 170 171 float Path::normalAngleAtLength(float length, bool& ok) const 172 { 173 FloatPoint point; 174 float normal; 175 ok = pointAndNormalAtLength(length, point, normal); 176 return normal; 177 } 178 179 static bool calculatePointAndNormalOnPath(SkPathMeasure& measure, SkScalar length, FloatPoint& point, float& normalAngle, SkScalar* accumulatedLength = 0) 180 { 181 do { 182 SkScalar contourLength = measure.getLength(); 183 if (length <= contourLength) { 184 SkVector tangent; 185 SkPoint position; 186 187 if (measure.getPosTan(length, &position, &tangent)) { 188 normalAngle = rad2deg(SkScalarToFloat(SkScalarATan2(tangent.fY, tangent.fX))); 189 point = FloatPoint(SkScalarToFloat(position.fX), SkScalarToFloat(position.fY)); 190 return true; 191 } 192 } 193 length -= contourLength; 194 if (accumulatedLength) 195 *accumulatedLength += contourLength; 196 } while (measure.nextContour()); 197 return false; 198 } 199 200 bool Path::pointAndNormalAtLength(float length, FloatPoint& point, float& normal) const 201 { 202 SkPathMeasure measure(m_path, false); 203 204 if (calculatePointAndNormalOnPath(measure, WebCoreFloatToSkScalar(length), point, normal)) 205 return true; 206 207 normal = 0; 208 point = FloatPoint(0, 0); 209 return false; 210 } 211 212 Path::PositionCalculator::PositionCalculator(const Path& path) 213 : m_path(path.skPath()) 214 , m_pathMeasure(path.skPath(), false) 215 , m_accumulatedLength(0) 216 { 217 } 218 219 bool Path::PositionCalculator::pointAndNormalAtLength(float length, FloatPoint& point, float& normalAngle) 220 { 221 SkScalar skLength = WebCoreFloatToSkScalar(length); 222 if (skLength >= 0) { 223 if (skLength < m_accumulatedLength) { 224 // Reset path measurer to rewind (and restart from 0). 225 m_pathMeasure.setPath(&m_path, false); 226 m_accumulatedLength = 0; 227 } else { 228 skLength -= m_accumulatedLength; 229 } 230 231 if (calculatePointAndNormalOnPath(m_pathMeasure, skLength, point, normalAngle, &m_accumulatedLength)) 232 return true; 233 } 234 235 normalAngle = 0; 236 point = FloatPoint(0, 0); 237 return false; 238 } 239 240 void Path::clear() 241 { 242 m_path.reset(); 243 } 244 245 bool Path::isEmpty() const 246 { 247 return m_path.isEmpty(); 248 } 249 250 bool Path::hasCurrentPoint() const 251 { 252 return m_path.getPoints(0, 0); 253 } 254 255 FloatPoint Path::currentPoint() const 256 { 257 if (m_path.countPoints() > 0) { 258 SkPoint skResult; 259 m_path.getLastPt(&skResult); 260 FloatPoint result; 261 result.setX(SkScalarToFloat(skResult.fX)); 262 result.setY(SkScalarToFloat(skResult.fY)); 263 return result; 264 } 265 266 // FIXME: Why does this return quietNaN? Other ports return 0,0. 267 float quietNaN = std::numeric_limits<float>::quiet_NaN(); 268 return FloatPoint(quietNaN, quietNaN); 269 } 270 271 WindRule Path::windRule() const 272 { 273 return m_path.getFillType() == SkPath::kEvenOdd_FillType 274 ? RULE_EVENODD 275 : RULE_NONZERO; 276 } 277 278 void Path::setWindRule(const WindRule rule) 279 { 280 m_path.setFillType(rule == RULE_EVENODD 281 ? SkPath::kEvenOdd_FillType 282 : SkPath::kWinding_FillType); 283 } 284 285 void Path::moveTo(const FloatPoint& point) 286 { 287 m_path.moveTo(point.data()); 288 } 289 290 void Path::addLineTo(const FloatPoint& point) 291 { 292 m_path.lineTo(point.data()); 293 } 294 295 void Path::addQuadCurveTo(const FloatPoint& cp, const FloatPoint& ep) 296 { 297 m_path.quadTo(cp.data(), ep.data()); 298 } 299 300 void Path::addBezierCurveTo(const FloatPoint& p1, const FloatPoint& p2, const FloatPoint& ep) 301 { 302 m_path.cubicTo(p1.data(), p2.data(), ep.data()); 303 } 304 305 void Path::addArcTo(const FloatPoint& p1, const FloatPoint& p2, float radius) 306 { 307 m_path.arcTo(p1.data(), p2.data(), WebCoreFloatToSkScalar(radius)); 308 } 309 310 void Path::closeSubpath() 311 { 312 m_path.close(); 313 } 314 315 void Path::addEllipse(const FloatPoint& p, float radiusX, float radiusY, float startAngle, float endAngle, bool anticlockwise) 316 { 317 ASSERT(ellipseIsRenderable(startAngle, endAngle)); 318 ASSERT(startAngle >= 0 && startAngle < twoPiFloat); 319 ASSERT((anticlockwise && (startAngle - endAngle) >= 0) || (!anticlockwise && (endAngle - startAngle) >= 0)); 320 321 SkScalar cx = WebCoreFloatToSkScalar(p.x()); 322 SkScalar cy = WebCoreFloatToSkScalar(p.y()); 323 SkScalar radiusXScalar = WebCoreFloatToSkScalar(radiusX); 324 SkScalar radiusYScalar = WebCoreFloatToSkScalar(radiusY); 325 326 SkRect oval; 327 oval.set(cx - radiusXScalar, cy - radiusYScalar, cx + radiusXScalar, cy + radiusYScalar); 328 329 float sweep = endAngle - startAngle; 330 SkScalar startDegrees = WebCoreFloatToSkScalar(startAngle * 180 / piFloat); 331 SkScalar sweepDegrees = WebCoreFloatToSkScalar(sweep * 180 / piFloat); 332 SkScalar s360 = SkIntToScalar(360); 333 334 // We can't use SkPath::addOval(), because addOval() makes new sub-path. addOval() calls moveTo() and close() internally. 335 336 // Use s180, not s360, because SkPath::arcTo(oval, angle, s360, false) draws nothing. 337 SkScalar s180 = SkIntToScalar(180); 338 if (SkScalarNearlyEqual(sweepDegrees, s360)) { 339 // SkPath::arcTo can't handle the sweepAngle that is equal to or greater than 2Pi. 340 m_path.arcTo(oval, startDegrees, s180, false); 341 m_path.arcTo(oval, startDegrees + s180, s180, false); 342 return; 343 } 344 if (SkScalarNearlyEqual(sweepDegrees, -s360)) { 345 m_path.arcTo(oval, startDegrees, -s180, false); 346 m_path.arcTo(oval, startDegrees - s180, -s180, false); 347 return; 348 } 349 350 m_path.arcTo(oval, startDegrees, sweepDegrees, false); 351 } 352 353 void Path::addArc(const FloatPoint& p, float radius, float startAngle, float endAngle, bool anticlockwise) 354 { 355 addEllipse(p, radius, radius, startAngle, endAngle, anticlockwise); 356 } 357 358 void Path::addRect(const FloatRect& rect) 359 { 360 m_path.addRect(rect); 361 } 362 363 void Path::addEllipse(const FloatPoint& p, float radiusX, float radiusY, float rotation, float startAngle, float endAngle, bool anticlockwise) 364 { 365 ASSERT(ellipseIsRenderable(startAngle, endAngle)); 366 ASSERT(startAngle >= 0 && startAngle < twoPiFloat); 367 ASSERT((anticlockwise && (startAngle - endAngle) >= 0) || (!anticlockwise && (endAngle - startAngle) >= 0)); 368 369 if (!rotation) { 370 addEllipse(FloatPoint(p.x(), p.y()), radiusX, radiusY, startAngle, endAngle, anticlockwise); 371 return; 372 } 373 374 // Add an arc after the relevant transform. 375 AffineTransform ellipseTransform = AffineTransform::translation(p.x(), p.y()).rotateRadians(rotation); 376 ASSERT(ellipseTransform.isInvertible()); 377 AffineTransform inverseEllipseTransform = ellipseTransform.inverse(); 378 transform(inverseEllipseTransform); 379 addEllipse(FloatPoint::zero(), radiusX, radiusY, startAngle, endAngle, anticlockwise); 380 transform(ellipseTransform); 381 } 382 383 void Path::addEllipse(const FloatRect& rect) 384 { 385 m_path.addOval(rect); 386 } 387 388 void Path::addRoundedRect(const RoundedRect& r) 389 { 390 addRoundedRect(r.rect(), r.radii().topLeft(), r.radii().topRight(), r.radii().bottomLeft(), r.radii().bottomRight()); 391 } 392 393 void Path::addRoundedRect(const FloatRect& rect, const FloatSize& roundingRadii) 394 { 395 if (rect.isEmpty()) 396 return; 397 398 FloatSize radius(roundingRadii); 399 FloatSize halfSize(rect.width() / 2, rect.height() / 2); 400 401 // Apply the SVG corner radius constraints, per the rect section of the SVG shapes spec: if 402 // one of rx,ry is negative, then the other corner radius value is used. If both values are 403 // negative then rx = ry = 0. If rx is greater than half of the width of the rectangle 404 // then set rx to half of the width; ry is handled similarly. 405 406 if (radius.width() < 0) 407 radius.setWidth((radius.height() < 0) ? 0 : radius.height()); 408 409 if (radius.height() < 0) 410 radius.setHeight(radius.width()); 411 412 if (radius.width() > halfSize.width()) 413 radius.setWidth(halfSize.width()); 414 415 if (radius.height() > halfSize.height()) 416 radius.setHeight(halfSize.height()); 417 418 addPathForRoundedRect(rect, radius, radius, radius, radius); 419 } 420 421 void Path::addRoundedRect(const FloatRect& rect, const FloatSize& topLeftRadius, const FloatSize& topRightRadius, const FloatSize& bottomLeftRadius, const FloatSize& bottomRightRadius) 422 { 423 if (rect.isEmpty()) 424 return; 425 426 if (rect.width() < topLeftRadius.width() + topRightRadius.width() 427 || rect.width() < bottomLeftRadius.width() + bottomRightRadius.width() 428 || rect.height() < topLeftRadius.height() + bottomLeftRadius.height() 429 || rect.height() < topRightRadius.height() + bottomRightRadius.height()) { 430 // If all the radii cannot be accommodated, return a rect. 431 addRect(rect); 432 return; 433 } 434 435 addPathForRoundedRect(rect, topLeftRadius, topRightRadius, bottomLeftRadius, bottomRightRadius); 436 } 437 438 void Path::addPathForRoundedRect(const FloatRect& rect, const FloatSize& topLeftRadius, const FloatSize& topRightRadius, const FloatSize& bottomLeftRadius, const FloatSize& bottomRightRadius) 439 { 440 addBeziersForRoundedRect(rect, topLeftRadius, topRightRadius, bottomLeftRadius, bottomRightRadius); 441 } 442 443 // Approximation of control point positions on a bezier to simulate a quarter of a circle. 444 // This is 1-kappa, where kappa = 4 * (sqrt(2) - 1) / 3 445 static const float gCircleControlPoint = 0.447715f; 446 447 void Path::addBeziersForRoundedRect(const FloatRect& rect, const FloatSize& topLeftRadius, const FloatSize& topRightRadius, const FloatSize& bottomLeftRadius, const FloatSize& bottomRightRadius) 448 { 449 moveTo(FloatPoint(rect.x() + topLeftRadius.width(), rect.y())); 450 451 addLineTo(FloatPoint(rect.maxX() - topRightRadius.width(), rect.y())); 452 if (topRightRadius.width() > 0 || topRightRadius.height() > 0) 453 addBezierCurveTo(FloatPoint(rect.maxX() - topRightRadius.width() * gCircleControlPoint, rect.y()), 454 FloatPoint(rect.maxX(), rect.y() + topRightRadius.height() * gCircleControlPoint), 455 FloatPoint(rect.maxX(), rect.y() + topRightRadius.height())); 456 addLineTo(FloatPoint(rect.maxX(), rect.maxY() - bottomRightRadius.height())); 457 if (bottomRightRadius.width() > 0 || bottomRightRadius.height() > 0) 458 addBezierCurveTo(FloatPoint(rect.maxX(), rect.maxY() - bottomRightRadius.height() * gCircleControlPoint), 459 FloatPoint(rect.maxX() - bottomRightRadius.width() * gCircleControlPoint, rect.maxY()), 460 FloatPoint(rect.maxX() - bottomRightRadius.width(), rect.maxY())); 461 addLineTo(FloatPoint(rect.x() + bottomLeftRadius.width(), rect.maxY())); 462 if (bottomLeftRadius.width() > 0 || bottomLeftRadius.height() > 0) 463 addBezierCurveTo(FloatPoint(rect.x() + bottomLeftRadius.width() * gCircleControlPoint, rect.maxY()), 464 FloatPoint(rect.x(), rect.maxY() - bottomLeftRadius.height() * gCircleControlPoint), 465 FloatPoint(rect.x(), rect.maxY() - bottomLeftRadius.height())); 466 addLineTo(FloatPoint(rect.x(), rect.y() + topLeftRadius.height())); 467 if (topLeftRadius.width() > 0 || topLeftRadius.height() > 0) 468 addBezierCurveTo(FloatPoint(rect.x(), rect.y() + topLeftRadius.height() * gCircleControlPoint), 469 FloatPoint(rect.x() + topLeftRadius.width() * gCircleControlPoint, rect.y()), 470 FloatPoint(rect.x() + topLeftRadius.width(), rect.y())); 471 472 closeSubpath(); 473 } 474 475 void Path::addPath(const Path& src, const AffineTransform& transform) 476 { 477 m_path.addPath(src.skPath(), affineTransformToSkMatrix(transform)); 478 } 479 480 void Path::translate(const FloatSize& size) 481 { 482 m_path.offset(WebCoreFloatToSkScalar(size.width()), WebCoreFloatToSkScalar(size.height())); 483 } 484 485 bool Path::unionPath(const Path& other) 486 { 487 return Op(m_path, other.m_path, kUnion_PathOp, &m_path); 488 } 489 490 #if ASSERT_ENABLED 491 bool ellipseIsRenderable(float startAngle, float endAngle) 492 { 493 return (std::abs(endAngle - startAngle) < twoPiFloat) 494 || WebCoreFloatNearlyEqual(std::abs(endAngle - startAngle), twoPiFloat); 495 } 496 #endif 497 498 } 499