| 1 | /**************************************************************************** |
| 2 | ** |
| 3 | ** Copyright (C) 2016 The Qt Company Ltd. |
| 4 | ** Contact: https://www.qt.io/licensing/ |
| 5 | ** |
| 6 | ** This file is part of the QtGui module of the Qt Toolkit. |
| 7 | ** |
| 8 | ** $QT_BEGIN_LICENSE:LGPL$ |
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| 17 | ** GNU Lesser General Public License Usage |
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| 24 | ** |
| 25 | ** GNU General Public License Usage |
| 26 | ** Alternatively, this file may be used under the terms of the GNU |
| 27 | ** General Public License version 2.0 or (at your option) the GNU General |
| 28 | ** Public license version 3 or any later version approved by the KDE Free |
| 29 | ** Qt Foundation. The licenses are as published by the Free Software |
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| 35 | ** |
| 36 | ** $QT_END_LICENSE$ |
| 37 | ** |
| 38 | ****************************************************************************/ |
| 39 | |
| 40 | #include "qtriangulatingstroker_p.h" |
| 41 | #include <qmath.h> |
| 42 | |
| 43 | QT_BEGIN_NAMESPACE |
| 44 | |
| 45 | #define CURVE_FLATNESS Q_PI / 8 |
| 46 | |
| 47 | |
| 48 | |
| 49 | |
| 50 | void QTriangulatingStroker::endCapOrJoinClosed(const qreal *start, const qreal *cur, |
| 51 | bool implicitClose, bool endsAtStart) |
| 52 | { |
| 53 | Q_ASSERT(start); |
| 54 | if (endsAtStart) { |
| 55 | join(pts: start + 2); |
| 56 | } else if (implicitClose) { |
| 57 | join(pts: start); |
| 58 | lineTo(pts: start); |
| 59 | join(pts: start+2); |
| 60 | } else { |
| 61 | endCap(pts: cur); |
| 62 | } |
| 63 | int count = m_vertices.size(); |
| 64 | |
| 65 | // Copy the (x, y) values because QDataBuffer::add(const float& t) |
| 66 | // may resize the buffer, which will leave t pointing at the |
| 67 | // previous buffer's memory region if we don't copy first. |
| 68 | float x = m_vertices.at(i: count-2); |
| 69 | float y = m_vertices.at(i: count-1); |
| 70 | m_vertices.add(t: x); |
| 71 | m_vertices.add(t: y); |
| 72 | } |
| 73 | |
| 74 | static inline void skipDuplicatePoints(const qreal **pts, const qreal *endPts) |
| 75 | { |
| 76 | while ((*pts + 2) < endPts && float((*pts)[0]) == float((*pts)[2]) |
| 77 | && float((*pts)[1]) == float((*pts)[3])) |
| 78 | { |
| 79 | *pts += 2; |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | void QTriangulatingStroker::process(const QVectorPath &path, const QPen &pen, const QRectF &, QPainter::RenderHints hints) |
| 84 | { |
| 85 | const qreal *pts = path.points(); |
| 86 | const QPainterPath::ElementType *types = path.elements(); |
| 87 | int count = path.elementCount(); |
| 88 | m_vertices.reset(); |
| 89 | if (count < 2) |
| 90 | return; |
| 91 | |
| 92 | float realWidth = qpen_widthf(p: pen); |
| 93 | if (realWidth == 0) |
| 94 | realWidth = 1; |
| 95 | |
| 96 | m_width = realWidth / 2; |
| 97 | |
| 98 | bool cosmetic = qt_pen_is_cosmetic(pen, hints); |
| 99 | if (cosmetic) { |
| 100 | m_width = m_width * m_inv_scale; |
| 101 | } |
| 102 | |
| 103 | m_join_style = qpen_joinStyle(p: pen); |
| 104 | m_cap_style = qpen_capStyle(p: pen); |
| 105 | m_miter_limit = pen.miterLimit() * qpen_widthf(p: pen); |
| 106 | |
| 107 | // The curvyness is based on the notion that I originally wanted |
| 108 | // roughly one line segment pr 4 pixels. This may seem little, but |
| 109 | // because we sample at constantly incrementing B(t) E [0<t<1], we |
| 110 | // will get longer segments where the curvature is small and smaller |
| 111 | // segments when the curvature is high. |
| 112 | // |
| 113 | // To get a rough idea of the length of each curve, I pretend that |
| 114 | // the curve is a 90 degree arc, whose radius is |
| 115 | // qMax(curveBounds.width, curveBounds.height). Based on this |
| 116 | // logic we can estimate the length of the outline edges based on |
| 117 | // the radius + a pen width and adjusting for scale factors |
| 118 | // depending on if the pen is cosmetic or not. |
| 119 | // |
| 120 | // The curvyness value of PI/14 was based on, |
| 121 | // arcLength = 2*PI*r/4 = PI*r/2 and splitting length into somewhere |
| 122 | // between 3 and 8 where 5 seemed to be give pretty good results |
| 123 | // hence: Q_PI/14. Lower divisors will give more detail at the |
| 124 | // direct cost of performance. |
| 125 | |
| 126 | // simplfy pens that are thin in device size (2px wide or less) |
| 127 | if (realWidth < 2.5 && (cosmetic || m_inv_scale == 1)) { |
| 128 | if (m_cap_style == Qt::RoundCap) |
| 129 | m_cap_style = Qt::SquareCap; |
| 130 | if (m_join_style == Qt::RoundJoin) |
| 131 | m_join_style = Qt::MiterJoin; |
| 132 | m_curvyness_add = 0.5; |
| 133 | m_curvyness_mul = CURVE_FLATNESS / m_inv_scale; |
| 134 | m_roundness = 1; |
| 135 | } else if (cosmetic) { |
| 136 | m_curvyness_add = realWidth / 2; |
| 137 | m_curvyness_mul = float(CURVE_FLATNESS); |
| 138 | m_roundness = qMax<int>(a: 4, b: realWidth * CURVE_FLATNESS); |
| 139 | } else { |
| 140 | m_curvyness_add = m_width; |
| 141 | m_curvyness_mul = CURVE_FLATNESS / m_inv_scale; |
| 142 | m_roundness = qMax<int>(a: 4, b: realWidth * m_curvyness_mul); |
| 143 | } |
| 144 | |
| 145 | // Over this level of segmentation, there doesn't seem to be any |
| 146 | // benefit, even for huge penWidth |
| 147 | if (m_roundness > 24) |
| 148 | m_roundness = 24; |
| 149 | |
| 150 | m_sin_theta = qFastSin(x: Q_PI / m_roundness); |
| 151 | m_cos_theta = qFastCos(x: Q_PI / m_roundness); |
| 152 | |
| 153 | const qreal *endPts = pts + (count<<1); |
| 154 | const qreal *startPts = nullptr; |
| 155 | |
| 156 | Qt::PenCapStyle cap = m_cap_style; |
| 157 | |
| 158 | if (!types) { |
| 159 | skipDuplicatePoints(pts: &pts, endPts); |
| 160 | if ((pts + 2) == endPts) |
| 161 | return; |
| 162 | |
| 163 | startPts = pts; |
| 164 | |
| 165 | bool endsAtStart = float(startPts[0]) == float(endPts[-2]) |
| 166 | && float(startPts[1]) == float(endPts[-1]); |
| 167 | |
| 168 | if (endsAtStart || path.hasImplicitClose()) |
| 169 | m_cap_style = Qt::FlatCap; |
| 170 | moveTo(pts); |
| 171 | m_cap_style = cap; |
| 172 | pts += 2; |
| 173 | skipDuplicatePoints(pts: &pts, endPts); |
| 174 | lineTo(pts); |
| 175 | pts += 2; |
| 176 | skipDuplicatePoints(pts: &pts, endPts); |
| 177 | while (pts < endPts) { |
| 178 | join(pts); |
| 179 | lineTo(pts); |
| 180 | pts += 2; |
| 181 | skipDuplicatePoints(pts: &pts, endPts); |
| 182 | } |
| 183 | endCapOrJoinClosed(start: startPts, cur: pts-2, implicitClose: path.hasImplicitClose(), endsAtStart); |
| 184 | |
| 185 | } else { |
| 186 | bool endsAtStart = false; |
| 187 | QPainterPath::ElementType previousType = QPainterPath::MoveToElement; |
| 188 | const qreal *previousPts = pts; |
| 189 | while (pts < endPts) { |
| 190 | switch (*types) { |
| 191 | case QPainterPath::MoveToElement: { |
| 192 | int end = (endPts - pts) / 2; |
| 193 | int nextMoveElement = 1; |
| 194 | bool hasValidLineSegments = false; |
| 195 | while (nextMoveElement < end && types[nextMoveElement] != QPainterPath::MoveToElement) { |
| 196 | if (!hasValidLineSegments) { |
| 197 | hasValidLineSegments = |
| 198 | float(pts[0]) != float(pts[nextMoveElement * 2]) || |
| 199 | float(pts[1]) != float(pts[nextMoveElement * 2 + 1]); |
| 200 | } |
| 201 | ++nextMoveElement; |
| 202 | } |
| 203 | |
| 204 | /** |
| 205 | * 'LineToElement' may be skipped if it doesn't move the center point |
| 206 | * of the line. We should make sure that we don't end up with a lost |
| 207 | * 'MoveToElement' in the vertex buffer, not connected to anything. Since |
| 208 | * the buffer uses degenerate triangles trick to split the primitives, |
| 209 | * this spurious MoveToElement will create artifacts when rendering. |
| 210 | */ |
| 211 | if (!hasValidLineSegments) { |
| 212 | pts += 2 * nextMoveElement; |
| 213 | types += nextMoveElement; |
| 214 | continue; |
| 215 | } |
| 216 | |
| 217 | if (previousType != QPainterPath::MoveToElement) |
| 218 | endCapOrJoinClosed(start: startPts, cur: previousPts, implicitClose: path.hasImplicitClose(), endsAtStart); |
| 219 | |
| 220 | startPts = pts; |
| 221 | skipDuplicatePoints(pts: &startPts, endPts); // Skip duplicates to find correct normal. |
| 222 | if (startPts + 2 >= endPts) |
| 223 | return; // Nothing to see here... |
| 224 | |
| 225 | endsAtStart = float(startPts[0]) == float(pts[nextMoveElement * 2 - 2]) |
| 226 | && float(startPts[1]) == float(pts[nextMoveElement * 2 - 1]); |
| 227 | if (endsAtStart || path.hasImplicitClose()) |
| 228 | m_cap_style = Qt::FlatCap; |
| 229 | |
| 230 | moveTo(pts: startPts); |
| 231 | m_cap_style = cap; |
| 232 | previousType = QPainterPath::MoveToElement; |
| 233 | previousPts = pts; |
| 234 | pts+=2; |
| 235 | ++types; |
| 236 | break; } |
| 237 | case QPainterPath::LineToElement: |
| 238 | if (float(m_cx) != float(pts[0]) || float(m_cy) != float(pts[1])) { |
| 239 | if (previousType != QPainterPath::MoveToElement) |
| 240 | join(pts); |
| 241 | lineTo(pts); |
| 242 | previousType = QPainterPath::LineToElement; |
| 243 | previousPts = pts; |
| 244 | } |
| 245 | pts+=2; |
| 246 | ++types; |
| 247 | break; |
| 248 | case QPainterPath::CurveToElement: |
| 249 | if (float(m_cx) != float(pts[0]) || float(m_cy) != float(pts[1]) |
| 250 | || float(pts[0]) != float(pts[2]) || float(pts[1]) != float(pts[3]) |
| 251 | || float(pts[2]) != float(pts[4]) || float(pts[3]) != float(pts[5])) |
| 252 | { |
| 253 | if (float(m_cx) != float(pts[0]) || float(m_cy) != float(pts[1])) { |
| 254 | if (previousType != QPainterPath::MoveToElement) |
| 255 | join(pts); |
| 256 | } |
| 257 | cubicTo(pts); |
| 258 | previousType = QPainterPath::CurveToElement; |
| 259 | previousPts = pts + 4; |
| 260 | } |
| 261 | pts+=6; |
| 262 | types+=3; |
| 263 | break; |
| 264 | default: |
| 265 | Q_ASSERT(false); |
| 266 | break; |
| 267 | } |
| 268 | } |
| 269 | |
| 270 | if (previousType != QPainterPath::MoveToElement) |
| 271 | endCapOrJoinClosed(start: startPts, cur: previousPts, implicitClose: path.hasImplicitClose(), endsAtStart); |
| 272 | } |
| 273 | } |
| 274 | |
| 275 | void QTriangulatingStroker::moveTo(const qreal *pts) |
| 276 | { |
| 277 | m_cx = pts[0]; |
| 278 | m_cy = pts[1]; |
| 279 | |
| 280 | float x2 = pts[2]; |
| 281 | float y2 = pts[3]; |
| 282 | normalVector(x1: m_cx, y1: m_cy, x2, y2, nx: &m_nvx, ny: &m_nvy); |
| 283 | |
| 284 | |
| 285 | // To achieve jumps we insert zero-area tringles. This is done by |
| 286 | // adding two identical points in both the end of previous strip |
| 287 | // and beginning of next strip |
| 288 | bool invisibleJump = m_vertices.size(); |
| 289 | |
| 290 | switch (m_cap_style) { |
| 291 | case Qt::FlatCap: |
| 292 | if (invisibleJump) { |
| 293 | m_vertices.add(t: m_cx + m_nvx); |
| 294 | m_vertices.add(t: m_cy + m_nvy); |
| 295 | } |
| 296 | break; |
| 297 | case Qt::SquareCap: { |
| 298 | float sx = m_cx - m_nvy; |
| 299 | float sy = m_cy + m_nvx; |
| 300 | if (invisibleJump) { |
| 301 | m_vertices.add(t: sx + m_nvx); |
| 302 | m_vertices.add(t: sy + m_nvy); |
| 303 | } |
| 304 | emitLineSegment(x: sx, y: sy, vx: m_nvx, vy: m_nvy); |
| 305 | break; } |
| 306 | case Qt::RoundCap: { |
| 307 | QVarLengthArray<float> points; |
| 308 | arcPoints(cx: m_cx, cy: m_cy, fromX: m_cx + m_nvx, fromY: m_cy + m_nvy, toX: m_cx - m_nvx, toY: m_cy - m_nvy, points); |
| 309 | m_vertices.resize(size: m_vertices.size() + points.size() + 2 * int(invisibleJump)); |
| 310 | int count = m_vertices.size(); |
| 311 | int front = 0; |
| 312 | int end = points.size() / 2; |
| 313 | while (front != end) { |
| 314 | m_vertices.at(i: --count) = points[2 * end - 1]; |
| 315 | m_vertices.at(i: --count) = points[2 * end - 2]; |
| 316 | --end; |
| 317 | if (front == end) |
| 318 | break; |
| 319 | m_vertices.at(i: --count) = points[2 * front + 1]; |
| 320 | m_vertices.at(i: --count) = points[2 * front + 0]; |
| 321 | ++front; |
| 322 | } |
| 323 | |
| 324 | if (invisibleJump) { |
| 325 | m_vertices.at(i: count - 1) = m_vertices.at(i: count + 1); |
| 326 | m_vertices.at(i: count - 2) = m_vertices.at(i: count + 0); |
| 327 | } |
| 328 | break; } |
| 329 | default: break; // ssssh gcc... |
| 330 | } |
| 331 | emitLineSegment(x: m_cx, y: m_cy, vx: m_nvx, vy: m_nvy); |
| 332 | } |
| 333 | |
| 334 | void QTriangulatingStroker::cubicTo(const qreal *pts) |
| 335 | { |
| 336 | const QPointF *p = (const QPointF *) pts; |
| 337 | QBezier bezier = QBezier::fromPoints(p1: *(p - 1), p2: p[0], p3: p[1], p4: p[2]); |
| 338 | |
| 339 | QRectF bounds = bezier.bounds(); |
| 340 | float rad = qMax(a: bounds.width(), b: bounds.height()); |
| 341 | int threshold = qMin<float>(a: 64, b: (rad + m_curvyness_add) * m_curvyness_mul); |
| 342 | if (threshold < 4) |
| 343 | threshold = 4; |
| 344 | qreal threshold_minus_1 = threshold - 1; |
| 345 | float vx = 0, vy = 0; |
| 346 | |
| 347 | float cx = m_cx, cy = m_cy; |
| 348 | float x, y; |
| 349 | |
| 350 | for (int i=1; i<threshold; ++i) { |
| 351 | qreal t = qreal(i) / threshold_minus_1; |
| 352 | QPointF p = bezier.pointAt(t); |
| 353 | x = p.x(); |
| 354 | y = p.y(); |
| 355 | |
| 356 | normalVector(x1: cx, y1: cy, x2: x, y2: y, nx: &vx, ny: &vy); |
| 357 | |
| 358 | emitLineSegment(x, y, vx, vy); |
| 359 | |
| 360 | cx = x; |
| 361 | cy = y; |
| 362 | } |
| 363 | |
| 364 | m_cx = cx; |
| 365 | m_cy = cy; |
| 366 | |
| 367 | m_nvx = vx; |
| 368 | m_nvy = vy; |
| 369 | } |
| 370 | |
| 371 | void QTriangulatingStroker::join(const qreal *pts) |
| 372 | { |
| 373 | // Creates a join to the next segment (m_cx, m_cy) -> (pts[0], pts[1]) |
| 374 | normalVector(x1: m_cx, y1: m_cy, x2: pts[0], y2: pts[1], nx: &m_nvx, ny: &m_nvy); |
| 375 | |
| 376 | switch (m_join_style) { |
| 377 | case Qt::BevelJoin: |
| 378 | break; |
| 379 | case Qt::SvgMiterJoin: |
| 380 | case Qt::MiterJoin: { |
| 381 | // Find out on which side the join should be. |
| 382 | int count = m_vertices.size(); |
| 383 | float prevNvx = m_vertices.at(i: count - 2) - m_cx; |
| 384 | float prevNvy = m_vertices.at(i: count - 1) - m_cy; |
| 385 | float xprod = prevNvx * m_nvy - prevNvy * m_nvx; |
| 386 | float px, py, qx, qy; |
| 387 | |
| 388 | // If the segments are parallel, use bevel join. |
| 389 | if (qFuzzyIsNull(f: xprod)) |
| 390 | break; |
| 391 | |
| 392 | // Find the corners of the previous and next segment to join. |
| 393 | if (xprod < 0) { |
| 394 | px = m_vertices.at(i: count - 2); |
| 395 | py = m_vertices.at(i: count - 1); |
| 396 | qx = m_cx - m_nvx; |
| 397 | qy = m_cy - m_nvy; |
| 398 | } else { |
| 399 | px = m_vertices.at(i: count - 4); |
| 400 | py = m_vertices.at(i: count - 3); |
| 401 | qx = m_cx + m_nvx; |
| 402 | qy = m_cy + m_nvy; |
| 403 | } |
| 404 | |
| 405 | // Find intersection point. |
| 406 | float pu = px * prevNvx + py * prevNvy; |
| 407 | float qv = qx * m_nvx + qy * m_nvy; |
| 408 | float ix = (m_nvy * pu - prevNvy * qv) / xprod; |
| 409 | float iy = (prevNvx * qv - m_nvx * pu) / xprod; |
| 410 | |
| 411 | // Check that the distance to the intersection point is less than the miter limit. |
| 412 | if ((ix - px) * (ix - px) + (iy - py) * (iy - py) <= m_miter_limit * m_miter_limit) { |
| 413 | m_vertices.add(t: ix); |
| 414 | m_vertices.add(t: iy); |
| 415 | m_vertices.add(t: ix); |
| 416 | m_vertices.add(t: iy); |
| 417 | } |
| 418 | // else |
| 419 | // Do a plain bevel join if the miter limit is exceeded or if |
| 420 | // the lines are parallel. This is not what the raster |
| 421 | // engine's stroker does, but it is both faster and similar to |
| 422 | // what some other graphics API's do. |
| 423 | |
| 424 | break; } |
| 425 | case Qt::RoundJoin: { |
| 426 | QVarLengthArray<float> points; |
| 427 | int count = m_vertices.size(); |
| 428 | float prevNvx = m_vertices.at(i: count - 2) - m_cx; |
| 429 | float prevNvy = m_vertices.at(i: count - 1) - m_cy; |
| 430 | if (m_nvx * prevNvy - m_nvy * prevNvx < 0) { |
| 431 | arcPoints(cx: 0, cy: 0, fromX: m_nvx, fromY: m_nvy, toX: -prevNvx, toY: -prevNvy, points); |
| 432 | for (int i = points.size() / 2; i > 0; --i) |
| 433 | emitLineSegment(x: m_cx, y: m_cy, vx: points[2 * i - 2], vy: points[2 * i - 1]); |
| 434 | } else { |
| 435 | arcPoints(cx: 0, cy: 0, fromX: -prevNvx, fromY: -prevNvy, toX: m_nvx, toY: m_nvy, points); |
| 436 | for (int i = 0; i < points.size() / 2; ++i) |
| 437 | emitLineSegment(x: m_cx, y: m_cy, vx: points[2 * i + 0], vy: points[2 * i + 1]); |
| 438 | } |
| 439 | break; } |
| 440 | default: break; // gcc warn-- |
| 441 | } |
| 442 | |
| 443 | emitLineSegment(x: m_cx, y: m_cy, vx: m_nvx, vy: m_nvy); |
| 444 | } |
| 445 | |
| 446 | void QTriangulatingStroker::endCap(const qreal *) |
| 447 | { |
| 448 | switch (m_cap_style) { |
| 449 | case Qt::FlatCap: |
| 450 | break; |
| 451 | case Qt::SquareCap: |
| 452 | emitLineSegment(x: m_cx + m_nvy, y: m_cy - m_nvx, vx: m_nvx, vy: m_nvy); |
| 453 | break; |
| 454 | case Qt::RoundCap: { |
| 455 | QVarLengthArray<float> points; |
| 456 | int count = m_vertices.size(); |
| 457 | arcPoints(cx: m_cx, cy: m_cy, fromX: m_vertices.at(i: count - 2), fromY: m_vertices.at(i: count - 1), toX: m_vertices.at(i: count - 4), toY: m_vertices.at(i: count - 3), points); |
| 458 | int front = 0; |
| 459 | int end = points.size() / 2; |
| 460 | while (front != end) { |
| 461 | m_vertices.add(t: points[2 * end - 2]); |
| 462 | m_vertices.add(t: points[2 * end - 1]); |
| 463 | --end; |
| 464 | if (front == end) |
| 465 | break; |
| 466 | m_vertices.add(t: points[2 * front + 0]); |
| 467 | m_vertices.add(t: points[2 * front + 1]); |
| 468 | ++front; |
| 469 | } |
| 470 | break; } |
| 471 | default: break; // to shut gcc up... |
| 472 | } |
| 473 | } |
| 474 | |
| 475 | void QTriangulatingStroker::arcPoints(float cx, float cy, float fromX, float fromY, float toX, float toY, QVarLengthArray<float> &points) |
| 476 | { |
| 477 | float dx1 = fromX - cx; |
| 478 | float dy1 = fromY - cy; |
| 479 | float dx2 = toX - cx; |
| 480 | float dy2 = toY - cy; |
| 481 | |
| 482 | // while more than 180 degrees left: |
| 483 | while (dx1 * dy2 - dx2 * dy1 < 0) { |
| 484 | float tmpx = dx1 * m_cos_theta - dy1 * m_sin_theta; |
| 485 | float tmpy = dx1 * m_sin_theta + dy1 * m_cos_theta; |
| 486 | dx1 = tmpx; |
| 487 | dy1 = tmpy; |
| 488 | points.append(t: cx + dx1); |
| 489 | points.append(t: cy + dy1); |
| 490 | } |
| 491 | |
| 492 | // while more than 90 degrees left: |
| 493 | while (dx1 * dx2 + dy1 * dy2 < 0) { |
| 494 | float tmpx = dx1 * m_cos_theta - dy1 * m_sin_theta; |
| 495 | float tmpy = dx1 * m_sin_theta + dy1 * m_cos_theta; |
| 496 | dx1 = tmpx; |
| 497 | dy1 = tmpy; |
| 498 | points.append(t: cx + dx1); |
| 499 | points.append(t: cy + dy1); |
| 500 | } |
| 501 | |
| 502 | // while more than 0 degrees left: |
| 503 | while (dx1 * dy2 - dx2 * dy1 > 0) { |
| 504 | float tmpx = dx1 * m_cos_theta - dy1 * m_sin_theta; |
| 505 | float tmpy = dx1 * m_sin_theta + dy1 * m_cos_theta; |
| 506 | dx1 = tmpx; |
| 507 | dy1 = tmpy; |
| 508 | points.append(t: cx + dx1); |
| 509 | points.append(t: cy + dy1); |
| 510 | } |
| 511 | |
| 512 | // remove last point which was rotated beyond [toX, toY]. |
| 513 | if (!points.isEmpty()) |
| 514 | points.resize(asize: points.size() - 2); |
| 515 | } |
| 516 | |
| 517 | static void qdashprocessor_moveTo(qreal x, qreal y, void *data) |
| 518 | { |
| 519 | ((QDashedStrokeProcessor *) data)->addElement(type: QPainterPath::MoveToElement, x, y); |
| 520 | } |
| 521 | |
| 522 | static void qdashprocessor_lineTo(qreal x, qreal y, void *data) |
| 523 | { |
| 524 | ((QDashedStrokeProcessor *) data)->addElement(type: QPainterPath::LineToElement, x, y); |
| 525 | } |
| 526 | |
| 527 | static void qdashprocessor_cubicTo(qreal, qreal, qreal, qreal, qreal, qreal, void *) |
| 528 | { |
| 529 | Q_ASSERT(0); // The dasher should not produce curves... |
| 530 | } |
| 531 | |
| 532 | QDashedStrokeProcessor::QDashedStrokeProcessor() |
| 533 | : m_points(0), m_types(0), |
| 534 | m_dash_stroker(nullptr), m_inv_scale(1) |
| 535 | { |
| 536 | m_dash_stroker.setMoveToHook(qdashprocessor_moveTo); |
| 537 | m_dash_stroker.setLineToHook(qdashprocessor_lineTo); |
| 538 | m_dash_stroker.setCubicToHook(qdashprocessor_cubicTo); |
| 539 | } |
| 540 | |
| 541 | void QDashedStrokeProcessor::process(const QVectorPath &path, const QPen &pen, const QRectF &clip, QPainter::RenderHints hints) |
| 542 | { |
| 543 | |
| 544 | const qreal *pts = path.points(); |
| 545 | const QPainterPath::ElementType *types = path.elements(); |
| 546 | int count = path.elementCount(); |
| 547 | |
| 548 | bool cosmetic = qt_pen_is_cosmetic(pen, hints); |
| 549 | bool implicitClose = path.hasImplicitClose(); |
| 550 | |
| 551 | m_points.reset(); |
| 552 | m_types.reset(); |
| 553 | m_points.reserve(size: path.elementCount()); |
| 554 | m_types.reserve(size: path.elementCount()); |
| 555 | |
| 556 | qreal width = qpen_widthf(p: pen); |
| 557 | if (width == 0) |
| 558 | width = 1; |
| 559 | |
| 560 | m_dash_stroker.setDashPattern(pen.dashPattern()); |
| 561 | m_dash_stroker.setStrokeWidth(cosmetic ? width * m_inv_scale : width); |
| 562 | m_dash_stroker.setDashOffset(pen.dashOffset()); |
| 563 | m_dash_stroker.setMiterLimit(pen.miterLimit()); |
| 564 | m_dash_stroker.setClipRect(clip); |
| 565 | |
| 566 | float curvynessAdd, curvynessMul; |
| 567 | |
| 568 | // simplify pens that are thin in device size (2px wide or less) |
| 569 | if (width < 2.5 && (cosmetic || m_inv_scale == 1)) { |
| 570 | curvynessAdd = 0.5; |
| 571 | curvynessMul = CURVE_FLATNESS / m_inv_scale; |
| 572 | } else if (cosmetic) { |
| 573 | curvynessAdd= width / 2; |
| 574 | curvynessMul= float(CURVE_FLATNESS); |
| 575 | } else { |
| 576 | curvynessAdd = width * m_inv_scale; |
| 577 | curvynessMul = CURVE_FLATNESS / m_inv_scale; |
| 578 | } |
| 579 | |
| 580 | if (count < 2) |
| 581 | return; |
| 582 | |
| 583 | bool needsClose = false; |
| 584 | if (implicitClose) { |
| 585 | if (pts[0] != pts[count * 2 - 2] || pts[1] != pts[count * 2 - 1]) |
| 586 | needsClose = true; |
| 587 | } |
| 588 | |
| 589 | const qreal *firstPts = pts; |
| 590 | const qreal *endPts = pts + (count<<1); |
| 591 | m_dash_stroker.begin(data: this); |
| 592 | |
| 593 | if (!types) { |
| 594 | m_dash_stroker.moveTo(x: pts[0], y: pts[1]); |
| 595 | pts += 2; |
| 596 | while (pts < endPts) { |
| 597 | m_dash_stroker.lineTo(x: pts[0], y: pts[1]); |
| 598 | pts += 2; |
| 599 | } |
| 600 | } else { |
| 601 | while (pts < endPts) { |
| 602 | switch (*types) { |
| 603 | case QPainterPath::MoveToElement: |
| 604 | m_dash_stroker.moveTo(x: pts[0], y: pts[1]); |
| 605 | pts += 2; |
| 606 | ++types; |
| 607 | break; |
| 608 | case QPainterPath::LineToElement: |
| 609 | m_dash_stroker.lineTo(x: pts[0], y: pts[1]); |
| 610 | pts += 2; |
| 611 | ++types; |
| 612 | break; |
| 613 | case QPainterPath::CurveToElement: { |
| 614 | QBezier b = QBezier::fromPoints(p1: *(((const QPointF *) pts) - 1), |
| 615 | p2: *(((const QPointF *) pts)), |
| 616 | p3: *(((const QPointF *) pts) + 1), |
| 617 | p4: *(((const QPointF *) pts) + 2)); |
| 618 | QRectF bounds = b.bounds(); |
| 619 | float rad = qMax(a: bounds.width(), b: bounds.height()); |
| 620 | int threshold = qMin<float>(a: 64, b: (rad + curvynessAdd) * curvynessMul); |
| 621 | if (threshold < 4) |
| 622 | threshold = 4; |
| 623 | |
| 624 | qreal threshold_minus_1 = threshold - 1; |
| 625 | for (int i=0; i<threshold; ++i) { |
| 626 | QPointF pt = b.pointAt(t: i / threshold_minus_1); |
| 627 | m_dash_stroker.lineTo(x: pt.x(), y: pt.y()); |
| 628 | } |
| 629 | pts += 6; |
| 630 | types += 3; |
| 631 | break; } |
| 632 | default: break; |
| 633 | } |
| 634 | } |
| 635 | } |
| 636 | if (needsClose) |
| 637 | m_dash_stroker.lineTo(x: firstPts[0], y: firstPts[1]); |
| 638 | |
| 639 | m_dash_stroker.end(); |
| 640 | } |
| 641 | |
| 642 | QT_END_NAMESPACE |
| 643 | |