diff options
Diffstat (limited to 'src/gui/painting/qstroker.cpp')
| -rw-r--r-- | src/gui/painting/qstroker.cpp | 116 |
1 files changed, 93 insertions, 23 deletions
diff --git a/src/gui/painting/qstroker.cpp b/src/gui/painting/qstroker.cpp index 16e3c38..9740fce 100644 --- a/src/gui/painting/qstroker.cpp +++ b/src/gui/painting/qstroker.cpp @@ -1043,6 +1043,47 @@ QVector<qfixed> QDashStroker::patternForStyle(Qt::PenStyle style) return pattern; } +static inline bool lineRectIntersectsRect(qfixed2d p1, qfixed2d p2, const qfixed2d &tl, const qfixed2d &br) +{ + return ((p1.x > tl.x || p2.x > tl.x) && (p1.x < br.x || p2.x < br.x) + && (p1.y > tl.y || p2.y > tl.y) && (p1.y < br.y || p2.y < br.y)); +} + +// If the line intersects the rectangle, this function will return true. +static bool lineIntersectsRect(qfixed2d p1, qfixed2d p2, const qfixed2d &tl, const qfixed2d &br) +{ + if (!lineRectIntersectsRect(p1, p2, tl, br)) + return false; + if (p1.x == p2.x || p1.y == p2.y) + return true; + + if (p1.y > p2.y) + qSwap(p1, p2); // make p1 above p2 + qfixed2d u; + qfixed2d v; + qfixed2d w = {p2.x - p1.x, p2.y - p1.y}; + if (p1.x < p2.x) { + // backslash + u.x = tl.x - p1.x; u.y = br.y - p1.y; + v.x = br.x - p1.x; v.y = tl.y - p1.y; + } else { + // slash + u.x = tl.x - p1.x; u.y = tl.y - p1.y; + v.x = br.x - p1.x; v.y = br.y - p1.y; + } +#if defined(QFIXED_IS_26_6) || defined(QFIXED_IS_16_16) + qint64 val1 = qint64(u.x) * qint64(w.y) - qint64(u.y) * qint64(w.x); + qint64 val2 = qint64(v.x) * qint64(w.y) - qint64(v.y) * qint64(w.x); + return (val1 < 0 && val2 > 0) || (val1 > 0 && val2 < 0); +#elif defined(QFIXED_IS_32_32) + // Cannot do proper test because it may overflow. + return true; +#else + qreal val1 = u.x * w.y - u.y * w.x; + qreal val2 = v.x * w.y - v.y * w.x; + return (val1 < 0 && val2 > 0) || (val1 > 0 && val2 < 0); +#endif +} void QDashStroker::processCurrentSubpath() { @@ -1067,9 +1108,11 @@ void QDashStroker::processCurrentSubpath() if (qFuzzyIsNull(sumLength)) return; + qreal invSumLength = qreal(1) / sumLength; + Q_ASSERT(dashCount > 0); - dashCount = (dashCount / 2) * 2; // Round down to even number + dashCount = dashCount & -2; // Round down to even number int idash = 0; // Index to current dash qreal pos = 0; // The position on the curve, 0 <= pos <= path.length @@ -1077,11 +1120,12 @@ void QDashStroker::processCurrentSubpath() qreal doffset = m_dashOffset * m_stroke_width; // make sure doffset is in range [0..sumLength) - doffset -= qFloor(doffset / sumLength) * sumLength; + doffset -= qFloor(doffset * invSumLength) * sumLength; while (doffset >= dashes[idash]) { doffset -= dashes[idash]; - idash = (idash + 1) % dashCount; + if (++idash >= dashCount) + idash = 0; } qreal estart = 0; // The elements starting position @@ -1119,12 +1163,41 @@ void QDashStroker::processCurrentSubpath() estop = estart + elen; bool done = pos >= estop; + + if (clipping) { + // Check if the entire line can be clipped away. + if (!lineIntersectsRect(prev, e, clip_tl, clip_br)) { + // Cut away full dash sequences. + elen -= qFloor(elen * invSumLength) * sumLength; + // Update dash offset. + while (!done) { + qreal dpos = pos + dashes[idash] - doffset - estart; + + Q_ASSERT(dpos >= 0); + + if (dpos > elen) { // dash extends this line + doffset = dashes[idash] - (dpos - elen); // subtract the part already used + pos = estop; // move pos to next path element + done = true; + } else { // Dash is on this line + pos = dpos + estart; + done = pos >= estop; + if (++idash >= dashCount) + idash = 0; + doffset = 0; // full segment so no offset on next. + } + } + hasMoveTo = false; + move_to_pos = e; + } + } + // Dash away... while (!done) { QPointF p2; - int idash_incr = 0; bool has_offset = doffset > 0; + bool evenDash = (idash & 1) == 0; qreal dpos = pos + dashes[idash] - doffset - estart; Q_ASSERT(dpos >= 0); @@ -1138,39 +1211,36 @@ void QDashStroker::processCurrentSubpath() p2 = cline.pointAt(dpos/elen); pos = dpos + estart; done = pos >= estop; - idash_incr = 1; + if (++idash >= dashCount) + idash = 0; doffset = 0; // full segment so no offset on next. } - if (idash % 2 == 0) { + if (evenDash) { line_to_pos.x = qt_real_to_fixed(p2.x()); line_to_pos.y = qt_real_to_fixed(p2.y()); - // If we have an offset, we're continuing a dash - // from a previous element and should only - // continue the current dash, without starting a - // new subpath. - if (!has_offset || !hasMoveTo) { - emitMoveTo(move_to_pos.x, move_to_pos.y); - hasMoveTo = true; - } - if (!clipping - // if move_to is inside... - || (move_to_pos.x > clip_tl.x && move_to_pos.x < clip_br.x - && move_to_pos.y > clip_tl.y && move_to_pos.y < clip_br.y) - // Or if line_to is inside... - || (line_to_pos.x > clip_tl.x && line_to_pos.x < clip_br.x - && line_to_pos.y > clip_tl.y && line_to_pos.y < clip_br.y)) + || lineRectIntersectsRect(move_to_pos, line_to_pos, clip_tl, clip_br)) { + // If we have an offset, we're continuing a dash + // from a previous element and should only + // continue the current dash, without starting a + // new subpath. + if (!has_offset || !hasMoveTo) { + emitMoveTo(move_to_pos.x, move_to_pos.y); + hasMoveTo = true; + } + emitLineTo(line_to_pos.x, line_to_pos.y); + } else { + hasMoveTo = false; } + move_to_pos = line_to_pos; } else { move_to_pos.x = qt_real_to_fixed(p2.x()); move_to_pos.y = qt_real_to_fixed(p2.y()); } - - idash = (idash + idash_incr) % dashCount; } // Shuffle to the next cycle... |