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/core/SkPathMeasure.h" 40 #include "third_party/skia/include/pathops/SkPathOps.h" 41 #include "wtf/MathExtras.h" 42 43 namespace WebCore { 44 45 Path::Path() 46 : m_path() 47 { 48 } 49 50 Path::Path(const Path& other) 51 { 52 m_path = SkPath(other.m_path); 53 } 54 55 Path::~Path() 56 { 57 } 58 59 Path& Path::operator=(const Path& other) 60 { 61 m_path = SkPath(other.m_path); 62 return *this; 63 } 64 65 bool Path::operator==(const Path& other) const 66 { 67 return m_path == other.m_path; 68 } 69 70 bool Path::contains(const FloatPoint& point, WindRule rule) const 71 { 72 return SkPathContainsPoint(m_path, point, rule == RULE_NONZERO ? SkPath::kWinding_FillType : SkPath::kEvenOdd_FillType); 73 } 74 75 bool Path::strokeContains(const FloatPoint& point, const StrokeData& strokeData) const 76 { 77 SkPaint paint; 78 strokeData.setupPaint(&paint); 79 SkPath strokePath; 80 paint.getFillPath(m_path, &strokePath); 81 82 return SkPathContainsPoint(strokePath, point, SkPath::kWinding_FillType); 83 } 84 85 FloatRect Path::boundingRect() const 86 { 87 return m_path.getBounds(); 88 } 89 90 FloatRect Path::strokeBoundingRect(const StrokeData& strokeData) const 91 { 92 SkPaint paint; 93 strokeData.setupPaint(&paint); 94 SkPath boundingPath; 95 paint.getFillPath(m_path, &boundingPath); 96 97 return boundingPath.getBounds(); 98 } 99 100 static FloatPoint* convertPathPoints(FloatPoint dst[], const SkPoint src[], int count) 101 { 102 for (int i = 0; i < count; i++) { 103 dst[i].setX(SkScalarToFloat(src[i].fX)); 104 dst[i].setY(SkScalarToFloat(src[i].fY)); 105 } 106 return dst; 107 } 108 109 void Path::apply(void* info, PathApplierFunction function) const 110 { 111 SkPath::RawIter iter(m_path); 112 SkPoint pts[4]; 113 PathElement pathElement; 114 FloatPoint pathPoints[3]; 115 116 for (;;) { 117 switch (iter.next(pts)) { 118 case SkPath::kMove_Verb: 119 pathElement.type = PathElementMoveToPoint; 120 pathElement.points = convertPathPoints(pathPoints, &pts[0], 1); 121 break; 122 case SkPath::kLine_Verb: 123 pathElement.type = PathElementAddLineToPoint; 124 pathElement.points = convertPathPoints(pathPoints, &pts[1], 1); 125 break; 126 case SkPath::kQuad_Verb: 127 pathElement.type = PathElementAddQuadCurveToPoint; 128 pathElement.points = convertPathPoints(pathPoints, &pts[1], 2); 129 break; 130 case SkPath::kCubic_Verb: 131 pathElement.type = PathElementAddCurveToPoint; 132 pathElement.points = convertPathPoints(pathPoints, &pts[1], 3); 133 break; 134 case SkPath::kClose_Verb: 135 pathElement.type = PathElementCloseSubpath; 136 pathElement.points = convertPathPoints(pathPoints, 0, 0); 137 break; 138 case SkPath::kDone_Verb: 139 return; 140 default: // place-holder for kConic_Verb, when that lands from skia 141 break; 142 } 143 function(info, &pathElement); 144 } 145 } 146 147 void Path::transform(const AffineTransform& xform) 148 { 149 m_path.transform(affineTransformToSkMatrix(xform)); 150 } 151 152 float Path::length() const 153 { 154 SkScalar length = 0; 155 SkPathMeasure measure(m_path, false); 156 157 do { 158 length += measure.getLength(); 159 } while (measure.nextContour()); 160 161 return SkScalarToFloat(length); 162 } 163 164 FloatPoint Path::pointAtLength(float length, bool& ok) const 165 { 166 FloatPoint point; 167 float normal; 168 ok = pointAndNormalAtLength(length, point, normal); 169 return point; 170 } 171 172 float Path::normalAngleAtLength(float length, bool& ok) const 173 { 174 FloatPoint point; 175 float normal; 176 ok = pointAndNormalAtLength(length, point, normal); 177 return normal; 178 } 179 180 bool Path::pointAndNormalAtLength(float length, FloatPoint& point, float& normal) const 181 { 182 SkPathMeasure measure(m_path, false); 183 184 do { 185 SkScalar contourLength = measure.getLength(); 186 if (length <= contourLength) { 187 SkVector tangent; 188 SkPoint position; 189 190 if (measure.getPosTan(length, &position, &tangent)) { 191 normal = rad2deg(SkScalarToFloat(SkScalarATan2(tangent.fY, tangent.fX))); 192 point = FloatPoint(SkScalarToFloat(position.fX), SkScalarToFloat(position.fY)); 193 return true; 194 } 195 } 196 length -= contourLength; 197 } while (measure.nextContour()); 198 199 normal = 0; 200 point = FloatPoint(0, 0); 201 return false; 202 } 203 204 void Path::clear() 205 { 206 m_path.reset(); 207 } 208 209 bool Path::isEmpty() const 210 { 211 return m_path.isEmpty(); 212 } 213 214 bool Path::hasCurrentPoint() const 215 { 216 return m_path.getPoints(0, 0); 217 } 218 219 FloatPoint Path::currentPoint() const 220 { 221 if (m_path.countPoints() > 0) { 222 SkPoint skResult; 223 m_path.getLastPt(&skResult); 224 FloatPoint result; 225 result.setX(SkScalarToFloat(skResult.fX)); 226 result.setY(SkScalarToFloat(skResult.fY)); 227 return result; 228 } 229 230 // FIXME: Why does this return quietNaN? Other ports return 0,0. 231 float quietNaN = std::numeric_limits<float>::quiet_NaN(); 232 return FloatPoint(quietNaN, quietNaN); 233 } 234 235 WindRule Path::windRule() const 236 { 237 return m_path.getFillType() == SkPath::kEvenOdd_FillType 238 ? RULE_EVENODD 239 : RULE_NONZERO; 240 } 241 242 void Path::setWindRule(const WindRule rule) 243 { 244 m_path.setFillType(rule == RULE_EVENODD 245 ? SkPath::kEvenOdd_FillType 246 : SkPath::kWinding_FillType); 247 } 248 249 void Path::moveTo(const FloatPoint& point) 250 { 251 m_path.moveTo(point); 252 } 253 254 void Path::addLineTo(const FloatPoint& point) 255 { 256 m_path.lineTo(point); 257 } 258 259 void Path::addQuadCurveTo(const FloatPoint& cp, const FloatPoint& ep) 260 { 261 m_path.quadTo(cp, ep); 262 } 263 264 void Path::addBezierCurveTo(const FloatPoint& p1, const FloatPoint& p2, const FloatPoint& ep) 265 { 266 m_path.cubicTo(p1, p2, ep); 267 } 268 269 void Path::addArcTo(const FloatPoint& p1, const FloatPoint& p2, float radius) 270 { 271 m_path.arcTo(p1, p2, WebCoreFloatToSkScalar(radius)); 272 } 273 274 void Path::closeSubpath() 275 { 276 m_path.close(); 277 } 278 279 void Path::addEllipse(const FloatPoint& p, float radiusX, float radiusY, float startAngle, float endAngle, bool anticlockwise) 280 { 281 ASSERT(ellipseIsRenderable(startAngle, endAngle)); 282 ASSERT(startAngle >= 0 && startAngle < 2 * piFloat); 283 ASSERT((anticlockwise && (startAngle - endAngle) >= 0) || (!anticlockwise && (endAngle - startAngle) >= 0)); 284 285 SkScalar cx = WebCoreFloatToSkScalar(p.x()); 286 SkScalar cy = WebCoreFloatToSkScalar(p.y()); 287 SkScalar radiusXScalar = WebCoreFloatToSkScalar(radiusX); 288 SkScalar radiusYScalar = WebCoreFloatToSkScalar(radiusY); 289 290 SkRect oval; 291 oval.set(cx - radiusXScalar, cy - radiusYScalar, cx + radiusXScalar, cy + radiusYScalar); 292 293 float sweep = endAngle - startAngle; 294 SkScalar startDegrees = WebCoreFloatToSkScalar(startAngle * 180 / piFloat); 295 SkScalar sweepDegrees = WebCoreFloatToSkScalar(sweep * 180 / piFloat); 296 SkScalar s360 = SkIntToScalar(360); 297 298 // We can't use SkPath::addOval(), because addOval() makes new sub-path. addOval() calls moveTo() and close() internally. 299 300 // Use s180, not s360, because SkPath::arcTo(oval, angle, s360, false) draws nothing. 301 SkScalar s180 = SkIntToScalar(180); 302 if (SkScalarNearlyEqual(sweepDegrees, s360)) { 303 // SkPath::arcTo can't handle the sweepAngle that is equal to or greater than 2Pi. 304 m_path.arcTo(oval, startDegrees, s180, false); 305 m_path.arcTo(oval, startDegrees + s180, s180, false); 306 return; 307 } 308 if (SkScalarNearlyEqual(sweepDegrees, -s360)) { 309 m_path.arcTo(oval, startDegrees, -s180, false); 310 m_path.arcTo(oval, startDegrees - s180, -s180, false); 311 return; 312 } 313 314 m_path.arcTo(oval, startDegrees, sweepDegrees, false); 315 } 316 317 void Path::addArc(const FloatPoint& p, float radius, float startAngle, float endAngle, bool anticlockwise) 318 { 319 addEllipse(p, radius, radius, startAngle, endAngle, anticlockwise); 320 } 321 322 void Path::addRect(const FloatRect& rect) 323 { 324 m_path.addRect(rect); 325 } 326 327 void Path::addEllipse(const FloatPoint& p, float radiusX, float radiusY, float rotation, float startAngle, float endAngle, bool anticlockwise) 328 { 329 ASSERT(ellipseIsRenderable(startAngle, endAngle)); 330 ASSERT(startAngle >= 0 && startAngle < 2 * piFloat); 331 ASSERT((anticlockwise && (startAngle - endAngle) >= 0) || (!anticlockwise && (endAngle - startAngle) >= 0)); 332 333 if (!rotation) { 334 addEllipse(FloatPoint(p.x(), p.y()), radiusX, radiusY, startAngle, endAngle, anticlockwise); 335 return; 336 } 337 338 // Add an arc after the relevant transform. 339 AffineTransform ellipseTransform = AffineTransform::translation(p.x(), p.y()).rotate(rad2deg(rotation)); 340 ASSERT(ellipseTransform.isInvertible()); 341 AffineTransform inverseEllipseTransform = ellipseTransform.inverse(); 342 transform(inverseEllipseTransform); 343 addEllipse(FloatPoint::zero(), radiusX, radiusY, startAngle, endAngle, anticlockwise); 344 transform(ellipseTransform); 345 } 346 347 void Path::addEllipse(const FloatRect& rect) 348 { 349 m_path.addOval(rect); 350 } 351 352 void Path::addRoundedRect(const RoundedRect& r) 353 { 354 addRoundedRect(r.rect(), r.radii().topLeft(), r.radii().topRight(), r.radii().bottomLeft(), r.radii().bottomRight()); 355 } 356 357 void Path::addRoundedRect(const FloatRect& rect, const FloatSize& roundingRadii) 358 { 359 if (rect.isEmpty()) 360 return; 361 362 FloatSize radius(roundingRadii); 363 FloatSize halfSize(rect.width() / 2, rect.height() / 2); 364 365 // Apply the SVG corner radius constraints, per the rect section of the SVG shapes spec: if 366 // one of rx,ry is negative, then the other corner radius value is used. If both values are 367 // negative then rx = ry = 0. If rx is greater than half of the width of the rectangle 368 // then set rx to half of the width; ry is handled similarly. 369 370 if (radius.width() < 0) 371 radius.setWidth((radius.height() < 0) ? 0 : radius.height()); 372 373 if (radius.height() < 0) 374 radius.setHeight(radius.width()); 375 376 if (radius.width() > halfSize.width()) 377 radius.setWidth(halfSize.width()); 378 379 if (radius.height() > halfSize.height()) 380 radius.setHeight(halfSize.height()); 381 382 addPathForRoundedRect(rect, radius, radius, radius, radius); 383 } 384 385 void Path::addRoundedRect(const FloatRect& rect, const FloatSize& topLeftRadius, const FloatSize& topRightRadius, const FloatSize& bottomLeftRadius, const FloatSize& bottomRightRadius) 386 { 387 if (rect.isEmpty()) 388 return; 389 390 if (rect.width() < topLeftRadius.width() + topRightRadius.width() 391 || rect.width() < bottomLeftRadius.width() + bottomRightRadius.width() 392 || rect.height() < topLeftRadius.height() + bottomLeftRadius.height() 393 || rect.height() < topRightRadius.height() + bottomRightRadius.height()) { 394 // If all the radii cannot be accommodated, return a rect. 395 addRect(rect); 396 return; 397 } 398 399 addPathForRoundedRect(rect, topLeftRadius, topRightRadius, bottomLeftRadius, bottomRightRadius); 400 } 401 402 void Path::addPathForRoundedRect(const FloatRect& rect, const FloatSize& topLeftRadius, const FloatSize& topRightRadius, const FloatSize& bottomLeftRadius, const FloatSize& bottomRightRadius) 403 { 404 addBeziersForRoundedRect(rect, topLeftRadius, topRightRadius, bottomLeftRadius, bottomRightRadius); 405 } 406 407 // Approximation of control point positions on a bezier to simulate a quarter of a circle. 408 // This is 1-kappa, where kappa = 4 * (sqrt(2) - 1) / 3 409 static const float gCircleControlPoint = 0.447715f; 410 411 void Path::addBeziersForRoundedRect(const FloatRect& rect, const FloatSize& topLeftRadius, const FloatSize& topRightRadius, const FloatSize& bottomLeftRadius, const FloatSize& bottomRightRadius) 412 { 413 moveTo(FloatPoint(rect.x() + topLeftRadius.width(), rect.y())); 414 415 addLineTo(FloatPoint(rect.maxX() - topRightRadius.width(), rect.y())); 416 if (topRightRadius.width() > 0 || topRightRadius.height() > 0) 417 addBezierCurveTo(FloatPoint(rect.maxX() - topRightRadius.width() * gCircleControlPoint, rect.y()), 418 FloatPoint(rect.maxX(), rect.y() + topRightRadius.height() * gCircleControlPoint), 419 FloatPoint(rect.maxX(), rect.y() + topRightRadius.height())); 420 addLineTo(FloatPoint(rect.maxX(), rect.maxY() - bottomRightRadius.height())); 421 if (bottomRightRadius.width() > 0 || bottomRightRadius.height() > 0) 422 addBezierCurveTo(FloatPoint(rect.maxX(), rect.maxY() - bottomRightRadius.height() * gCircleControlPoint), 423 FloatPoint(rect.maxX() - bottomRightRadius.width() * gCircleControlPoint, rect.maxY()), 424 FloatPoint(rect.maxX() - bottomRightRadius.width(), rect.maxY())); 425 addLineTo(FloatPoint(rect.x() + bottomLeftRadius.width(), rect.maxY())); 426 if (bottomLeftRadius.width() > 0 || bottomLeftRadius.height() > 0) 427 addBezierCurveTo(FloatPoint(rect.x() + bottomLeftRadius.width() * gCircleControlPoint, rect.maxY()), 428 FloatPoint(rect.x(), rect.maxY() - bottomLeftRadius.height() * gCircleControlPoint), 429 FloatPoint(rect.x(), rect.maxY() - bottomLeftRadius.height())); 430 addLineTo(FloatPoint(rect.x(), rect.y() + topLeftRadius.height())); 431 if (topLeftRadius.width() > 0 || topLeftRadius.height() > 0) 432 addBezierCurveTo(FloatPoint(rect.x(), rect.y() + topLeftRadius.height() * gCircleControlPoint), 433 FloatPoint(rect.x() + topLeftRadius.width() * gCircleControlPoint, rect.y()), 434 FloatPoint(rect.x() + topLeftRadius.width(), rect.y())); 435 436 closeSubpath(); 437 } 438 439 void Path::translate(const FloatSize& size) 440 { 441 m_path.offset(WebCoreFloatToSkScalar(size.width()), WebCoreFloatToSkScalar(size.height())); 442 } 443 444 bool Path::unionPath(const Path& other) 445 { 446 return Op(m_path, other.m_path, kUnion_PathOp, &m_path); 447 } 448 449 #if !ASSERT_DISABLED 450 bool ellipseIsRenderable(float startAngle, float endAngle) 451 { 452 return (std::abs(endAngle - startAngle) < 2 * piFloat) 453 || WebCoreFloatNearlyEqual(std::abs(endAngle - startAngle), 2 * piFloat); 454 } 455 #endif 456 457 } 458
