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libs/flake KoSnapStrategy.cpp Go to the documentation of this file. /* This file is part of the KDE project * Copyright (C) 2008 Jan Hambrecht <jaham@gmx.net> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public License * along with this library; see the file COPYING.LIB. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * Boston, MA 02110-1301, USA. */ #include "KoSnapStrategy.h" #include "KoSnapGuide.h" #include <KoPathShape.h> #include <KoPathPoint.h> #include <KoCanvasBase.h> #include <KoViewConverter.h> #include <KoGuidesData.h> #include <QtGui/QPainter> //#include <kdebug.h> #include <math.h> KoSnapStrategy::KoSnapStrategy(KoSnapStrategy::SnapType type) : m_snapType(type) { } QPointF KoSnapStrategy::snappedPosition() const { return m_snappedPosition; } void KoSnapStrategy::setSnappedPosition(const QPointF &position) { m_snappedPosition = position; } KoSnapStrategy::SnapType KoSnapStrategy::type() const { return m_snapType; } qreal KoSnapStrategy::squareDistance(const QPointF &p1, const QPointF &p2) { qreal dx = p1.x() - p2.x(); qreal dy = p1.y() - p2.y(); return dx*dx + dy*dy; } qreal KoSnapStrategy::scalarProduct(const QPointF &p1, const QPointF &p2) { return p1.x() * p2.x() + p1.y() * p2.y(); } OrthogonalSnapStrategy::OrthogonalSnapStrategy() : KoSnapStrategy(KoSnapStrategy::Orthogonal) { } bool OrthogonalSnapStrategy::snap(const QPointF &mousePosition, KoSnapProxy * proxy, qreal maxSnapDistance) { QPointF horzSnap, vertSnap; qreal minVertDist = HUGE_VAL; qreal minHorzDist = HUGE_VAL; QList<KoShape*> shapes = proxy->shapes(); foreach(KoShape * shape, shapes) { QList<QPointF> points = proxy->pointsFromShape(shape); foreach(const QPointF & point, points) { qreal dx = fabs(point.x() - mousePosition.x()); if (dx < minHorzDist && dx < maxSnapDistance) { minHorzDist = dx; horzSnap = point; } qreal dy = fabs(point.y() - mousePosition.y()); if (dy < minVertDist && dy < maxSnapDistance) { minVertDist = dy; vertSnap = point; } } } QPointF snappedPoint = mousePosition; if (minHorzDist < HUGE_VAL) snappedPoint.setX(horzSnap.x()); if (minVertDist < HUGE_VAL) snappedPoint.setY(vertSnap.y()); if (minHorzDist < HUGE_VAL) m_hLine = QLineF(horzSnap, snappedPoint); else m_hLine = QLineF(); if (minVertDist < HUGE_VAL) m_vLine = QLineF(vertSnap, snappedPoint); else m_vLine = QLineF(); setSnappedPosition(snappedPoint); return (minHorzDist < HUGE_VAL || minVertDist < HUGE_VAL); } QPainterPath OrthogonalSnapStrategy::decoration(const KoViewConverter &converter) const { Q_UNUSED(converter); QPainterPath decoration; if (! m_hLine.isNull()) { decoration.moveTo(m_hLine.p1()); decoration.lineTo(m_hLine.p2()); } if (! m_vLine.isNull()) { decoration.moveTo(m_vLine.p1()); decoration.lineTo(m_vLine.p2()); } return decoration; } NodeSnapStrategy::NodeSnapStrategy() : KoSnapStrategy(KoSnapStrategy::Node) { } bool NodeSnapStrategy::snap(const QPointF &mousePosition, KoSnapProxy * proxy, qreal maxSnapDistance) { qreal maxDistance = maxSnapDistance * maxSnapDistance; qreal minDistance = HUGE_VAL; QRectF rect(-maxSnapDistance, -maxSnapDistance, maxSnapDistance, maxSnapDistance); rect.moveCenter(mousePosition); QList<QPointF> points = proxy->pointsInRect(rect); QPointF snappedPoint = mousePosition; foreach(const QPointF & point, points) { qreal distance = squareDistance(mousePosition, point); if (distance < maxDistance && distance < minDistance) { snappedPoint = point; minDistance = distance; } } setSnappedPosition(snappedPoint); return (minDistance < HUGE_VAL); } QPainterPath NodeSnapStrategy::decoration(const KoViewConverter &converter) const { QRectF unzoomedRect = converter.viewToDocument(QRectF(0, 0, 11, 11)); unzoomedRect.moveCenter(snappedPosition()); QPainterPath decoration; decoration.addEllipse(unzoomedRect); return decoration; } ExtensionSnapStrategy::ExtensionSnapStrategy() : KoSnapStrategy(KoSnapStrategy::Extension) { } bool ExtensionSnapStrategy::snap(const QPointF &mousePosition, KoSnapProxy * proxy, qreal maxSnapDistance) { qreal maxDistance = maxSnapDistance * maxSnapDistance; qreal minDistances[2] = { HUGE_VAL, HUGE_VAL }; QPointF snappedPoints[2] = { mousePosition, mousePosition }; QPointF startPoints[2]; QList<KoShape*> shapes = proxy->shapes(true); foreach(KoShape * shape, shapes) { KoPathShape * path = dynamic_cast<KoPathShape*>(shape); if (! path) continue; QMatrix matrix = path->absoluteTransformation(0); int subpathCount = path->subpathCount(); for (int subpathIndex = 0; subpathIndex < subpathCount; ++subpathIndex) { if (path->isClosedSubpath(subpathIndex)) continue; int pointCount = path->pointCountSubpath(subpathIndex); // check the extension from the start point KoPathPoint * first = path->pointByIndex(KoPathPointIndex(subpathIndex, 0)); QPointF firstSnapPosition = mousePosition; if (snapToExtension(firstSnapPosition, first, matrix)) { qreal distance = squareDistance(firstSnapPosition, mousePosition); if (distance < maxDistance) { if (distance < minDistances[0]) { minDistances[1] = minDistances[0]; snappedPoints[1] = snappedPoints[0]; startPoints[1] = startPoints[0]; minDistances[0] = distance; snappedPoints[0] = firstSnapPosition; startPoints[0] = matrix.map(first->point()); } else if (distance < minDistances[1]) { minDistances[1] = distance; snappedPoints[1] = firstSnapPosition; startPoints[1] = matrix.map(first->point()); } } } // now check the extension from the last point KoPathPoint * last = path->pointByIndex(KoPathPointIndex(subpathIndex, pointCount - 1)); QPointF lastSnapPosition = mousePosition; if (snapToExtension(lastSnapPosition, last, matrix)) { qreal distance = squareDistance(lastSnapPosition, mousePosition); if (distance < maxDistance) { if (distance < minDistances[0]) { minDistances[1] = minDistances[0]; snappedPoints[1] = snappedPoints[0]; startPoints[1] = startPoints[0]; minDistances[0] = distance; snappedPoints[0] = lastSnapPosition; startPoints[0] = matrix.map(last->point()); } else if (distance < minDistances[1]) { minDistances[1] = distance; snappedPoints[1] = lastSnapPosition; startPoints[1] = matrix.map(last->point()); } } } } } m_lines.clear(); // if we have to extension near our mouse position, they might have an intersection // near our mouse position which we want to use as the snapped position if (minDistances[0] < HUGE_VAL && minDistances[1] < HUGE_VAL ) { // check if intersection of extension lines is near mouse position KoPathSegment s1( startPoints[0], snappedPoints[0] + snappedPoints[0]-startPoints[0] ); KoPathSegment s2( startPoints[1], snappedPoints[1] + snappedPoints[1]-startPoints[1] ); QList<QPointF> isects = s1.intersections( s2 ); if (isects.count() == 1 && squareDistance(isects[0], mousePosition) < maxDistance) { // add both extension lines m_lines.append( QLineF(startPoints[0], isects[0]) ); m_lines.append( QLineF(startPoints[1], isects[0]) ); setSnappedPosition(isects[0]); } else { // only add nearest extension line of both uint index = minDistances[0] < minDistances[1] ? 0 : 1; m_lines.append( QLineF(startPoints[index], snappedPoints[index]) ); setSnappedPosition(snappedPoints[index]); } } else if (minDistances[0] < HUGE_VAL) { m_lines.append( QLineF(startPoints[0], snappedPoints[0]) ); setSnappedPosition(snappedPoints[0]); } else if (minDistances[1] < HUGE_VAL) { m_lines.append( QLineF(startPoints[1], snappedPoints[1]) ); setSnappedPosition(snappedPoints[1]); } else { // none of the extension lines is near our mouse position return false; } return true; } QPainterPath ExtensionSnapStrategy::decoration(const KoViewConverter &converter) const { Q_UNUSED(converter); QPainterPath decoration; foreach( const QLineF & line, m_lines ) { decoration.moveTo(line.p1()); decoration.lineTo(line.p2()); } return decoration; } bool ExtensionSnapStrategy::snapToExtension(QPointF &position, KoPathPoint * point, const QMatrix &matrix) { QPointF direction = extensionDirection(point, matrix); if (direction.isNull()) return false; QPointF extensionStart = matrix.map(point->point()); QPointF extensionStop = matrix.map(point->point()) + direction; float posOnExtension = project(extensionStart, extensionStop, position); if (posOnExtension < 0.0) return false; position = extensionStart + posOnExtension * direction; return true; } qreal ExtensionSnapStrategy::project(const QPointF &lineStart, const QPointF &lineEnd, const QPointF &point) { QPointF diff = lineEnd - lineStart; QPointF relPoint = point - lineStart; qreal diffLength = sqrt(diff.x() * diff.x() + diff.y() * diff.y()); if (diffLength == 0.0) return 0.0; diff /= diffLength; // project mouse position relative to stop position on extension line qreal scalar = relPoint.x() * diff.x() + relPoint.y() * diff.y(); return scalar /= diffLength; } QPointF ExtensionSnapStrategy::extensionDirection(KoPathPoint * point, const QMatrix &matrix) { KoPathShape * path = point->parent(); KoPathPointIndex index = path->pathPointIndex(point); if (point->properties() & KoPathPoint::StartSubpath) { if (point->activeControlPoint2()) { return matrix.map(point->point()) - matrix.map(point->controlPoint2()); } else { KoPathPoint * next = path->pointByIndex(KoPathPointIndex(index.first, index.second + 1)); if (! next) return QPointF(); else if (next->activeControlPoint1()) return matrix.map(point->point()) - matrix.map(next->controlPoint1()); else return matrix.map(point->point()) - matrix.map(next->point()); } } else { if (point->activeControlPoint1()) { return matrix.map(point->point()) - matrix.map(point->controlPoint1()); } else { KoPathPoint * prev = path->pointByIndex(KoPathPointIndex(index.first, index.second - 1)); if (! prev) return QPointF(); else if (prev->activeControlPoint2()) return matrix.map(point->point()) - matrix.map(prev->controlPoint2()); else return matrix.map(point->point()) - matrix.map(prev->point()); } } } IntersectionSnapStrategy::IntersectionSnapStrategy() : KoSnapStrategy(KoSnapStrategy::Intersection) { } bool IntersectionSnapStrategy::snap(const QPointF &mousePosition, KoSnapProxy * proxy, qreal maxSnapDistance) { qreal maxDistance = maxSnapDistance * maxSnapDistance; qreal minDistance = HUGE_VAL; QRectF rect(-maxSnapDistance, -maxSnapDistance, maxSnapDistance, maxSnapDistance); rect.moveCenter(mousePosition); QPointF snappedPoint = mousePosition; QList<KoPathSegment> segments = proxy->segmentsInRect(rect); //kDebug() << "found" << segments.count() << "segments in roi"; int segmentCount = segments.count(); for (int i = 0; i < segmentCount; ++i) { const KoPathSegment& s1 = segments[i]; for (int j = i + 1; j < segmentCount; ++j) { QList<QPointF> isects = s1.intersections(segments[j]); //kDebug() << isects.count() << "intersections found"; foreach(const QPointF &point, isects) { if (! rect.contains(point)) continue; qreal distance = squareDistance(mousePosition, point); if (distance < maxDistance && distance < minDistance) { snappedPoint = point; minDistance = distance; } } } } setSnappedPosition(snappedPoint); return (minDistance < HUGE_VAL); } QPainterPath IntersectionSnapStrategy::decoration(const KoViewConverter &converter) const { QRectF unzoomedRect = converter.viewToDocument(QRectF(0, 0, 11, 11)); unzoomedRect.moveCenter(snappedPosition()); QPainterPath decoration; decoration.addRect(unzoomedRect); return decoration; } GridSnapStrategy::GridSnapStrategy() : KoSnapStrategy(KoSnapStrategy::Grid) { } bool GridSnapStrategy::snap(const QPointF &mousePosition, KoSnapProxy * proxy, qreal maxSnapDistance) { if (! proxy->canvas()->snapToGrid()) return false; // The 1e-10 here is a workaround for some weird division problem. // 360.00062366 / 2.83465058 gives 127 'exactly' when shown as a qreal, // but when casting into an int, we get 126. In fact it's 127 - 5.64e-15 ! qreal gridX, gridY; proxy->canvas()->gridSize(&gridX, &gridY); // we want to snap to the nearest grid point, so calculate // the grid rows/columns before and after the points position int col = static_cast<int>(mousePosition.x() / gridX + 1e-10); int nextCol = col + 1; int row = static_cast<int>(mousePosition.y() / gridY + 1e-10); int nextRow = row + 1; // now check which grid line has less distance to the point qreal distToCol = qAbs(col * gridX - mousePosition.x()); qreal distToNextCol = qAbs(nextCol * gridX - mousePosition.x()); if (distToCol > distToNextCol) { col = nextCol; distToCol = distToNextCol; } qreal distToRow = qAbs(row * gridY - mousePosition.y()); qreal distToNextRow = qAbs(nextRow * gridY - mousePosition.y()); if (distToRow > distToNextRow) { row = nextRow; distToRow = distToNextRow; } QPointF snappedPoint = mousePosition; qreal distance = distToCol * distToCol + distToRow * distToRow; qreal maxDistance = maxSnapDistance * maxSnapDistance; // now check if we are inside the snap distance if (distance < maxDistance) { snappedPoint = QPointF(col * gridX, row * gridY); } setSnappedPosition(snappedPoint); return (distance < maxDistance); } QPainterPath GridSnapStrategy::decoration(const KoViewConverter &converter) const { QSizeF unzoomedSize = converter.viewToDocument(QSizeF(5, 5)); QPainterPath decoration; decoration.moveTo(snappedPosition() - QPointF(unzoomedSize.width(), 0)); decoration.lineTo(snappedPosition() + QPointF(unzoomedSize.width(), 0)); decoration.moveTo(snappedPosition() - QPointF(0, unzoomedSize.height())); decoration.lineTo(snappedPosition() + QPointF(0, unzoomedSize.height())); return decoration; } BoundingBoxSnapStrategy::BoundingBoxSnapStrategy() : KoSnapStrategy(KoSnapStrategy::BoundingBox) { } bool BoundingBoxSnapStrategy::snap(const QPointF &mousePosition, KoSnapProxy * proxy, qreal maxSnapDistance) { qreal maxDistance = maxSnapDistance * maxSnapDistance; qreal minDistance = HUGE_VAL; QRectF rect(-maxSnapDistance, -maxSnapDistance, maxSnapDistance, maxSnapDistance); rect.moveCenter(mousePosition); QPointF snappedPoint = mousePosition; KoFlake::Position pointId[5] = { KoFlake::TopLeftCorner, KoFlake::TopRightCorner, KoFlake::BottomRightCorner, KoFlake::BottomLeftCorner, KoFlake::CenteredPosition }; QList<KoShape*> shapes = proxy->shapesInRect(rect, true); foreach(KoShape * shape, shapes) { qreal shapeMinDistance = HUGE_VAL; // first check the corner and center points for (int i = 0; i < 5; ++i) { m_boxPoints[i] = shape->absolutePosition(pointId[i]); qreal d = squareDistance(mousePosition, m_boxPoints[i]); if (d < minDistance && d < maxDistance) { shapeMinDistance = d; minDistance = d; snappedPoint = m_boxPoints[i]; } } // prioritize points over edges if (shapeMinDistance < maxDistance) continue; // now check distances to edges of bounding box for (int i = 0; i < 4; ++i) { QPointF pointOnLine; qreal d = squareDistanceToLine(m_boxPoints[i], m_boxPoints[(i+1)%4], mousePosition, pointOnLine); if (d < minDistance && d < maxDistance) { minDistance = d; snappedPoint = pointOnLine; } } } setSnappedPosition(snappedPoint); return (minDistance < maxDistance); } qreal BoundingBoxSnapStrategy::squareDistanceToLine(const QPointF &lineA, const QPointF &lineB, const QPointF &point, QPointF &pointOnLine) { QPointF diff = lineB - lineA; qreal diffLength = sqrt(diff.x() * diff.x() + diff.y() * diff.y()); if (diffLength == 0.0f) return HUGE_VAL; // project mouse position relative to start position on line qreal scalar = KoSnapStrategy::scalarProduct(point - lineA, diff / diffLength); if (scalar < 0.0 || scalar > diffLength) return HUGE_VAL; // calculate vector between relative mouse position and projected mouse position pointOnLine = lineA + scalar / diffLength * diff; QPointF distVec = pointOnLine - point; return distVec.x()*distVec.x() + distVec.y()*distVec.y(); } QPainterPath BoundingBoxSnapStrategy::decoration(const KoViewConverter &converter) const { QSizeF unzoomedSize = converter.viewToDocument(QSizeF(5, 5)); QPainterPath decoration; decoration.moveTo(snappedPosition() - QPointF(unzoomedSize.width(), unzoomedSize.height())); decoration.lineTo(snappedPosition() + QPointF(unzoomedSize.width(), unzoomedSize.height())); decoration.moveTo(snappedPosition() - QPointF(unzoomedSize.width(), -unzoomedSize.height())); decoration.lineTo(snappedPosition() + QPointF(unzoomedSize.width(), -unzoomedSize.height())); return decoration; } LineGuideSnapStrategy::LineGuideSnapStrategy() : KoSnapStrategy(KoSnapStrategy::GuideLine) { } bool LineGuideSnapStrategy::snap(const QPointF &mousePosition, KoSnapProxy * proxy, qreal maxSnapDistance) { KoGuidesData * guidesData = proxy->canvas()->guidesData(); if (! guidesData || ! guidesData->showGuideLines()) return false; QPointF snappedPoint = mousePosition; m_orientation = 0; qreal minHorzDistance = maxSnapDistance; foreach(qreal guidePos, guidesData->horizontalGuideLines()) { qreal distance = qAbs(guidePos - mousePosition.y()); if (distance < minHorzDistance) { snappedPoint.setY(guidePos); minHorzDistance = distance; m_orientation |= Qt::Horizontal; } } qreal minVertSnapDistance = maxSnapDistance; foreach(qreal guidePos, guidesData->verticalGuideLines()) { qreal distance = qAbs(guidePos - mousePosition.x()); if (distance < minVertSnapDistance) { snappedPoint.setX(guidePos); minVertSnapDistance = distance; m_orientation |= Qt::Vertical; } } setSnappedPosition(snappedPoint); return (minHorzDistance < maxSnapDistance || minVertSnapDistance < maxSnapDistance); } QPainterPath LineGuideSnapStrategy::decoration(const KoViewConverter &converter) const { QSizeF unzoomedSize = converter.viewToDocument(QSizeF(5, 5)); QPainterPath decoration; if (m_orientation & Qt::Horizontal) { decoration.moveTo(snappedPosition() - QPointF(unzoomedSize.width(), 0)); decoration.lineTo(snappedPosition() + QPointF(unzoomedSize.width(), 0)); } if (m_orientation & Qt::Vertical) { decoration.moveTo(snappedPosition() - QPointF(0, unzoomedSize.height())); decoration.lineTo(snappedPosition() + QPointF(0, unzoomedSize.height())); } return decoration; } libs/flake Skip menu "libs/flake" Main Page Namespace List Class Hierarchy Alphabetical List Class List File List Namespace Members Class Members API Reference Skip menu "API Reference" kdgantt Kexi   KoProperty   flake kplato krita   image   plugins       libbrush       libpaintop   ui kspread   part     scripting libs   flake   kotext   main   pigment   store   musicshape Generated for API Reference by doxygen 1.5.9-20090814 This website is maintained by Adriaan de Groot and Allen Winter. 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