qgscadutils.cpp

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/***************************************************************************
                              qgscadutils.cpp
                             -------------------
    begin                : September 2017
    copyright            : (C) 2017 by Martin Dobias
    email                : wonder dot sk at gmail dot com
 ***************************************************************************/
/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include <QQueue>
 
#include "qgscadutils.h"
 
#include "qgslogger.h"
#include "qgssnappingutils.h"
#include "qgsgeometryutils.h"
 
// tolerances for soft constraints (last values, and common angles)
// for angles, both tolerance in pixels and degrees are used for better performance
static const double SOFT_CONSTRAINT_TOLERANCE_PIXEL = 15;
static const double SOFT_CONSTRAINT_TOLERANCE_DEGREES = 10;
 
 
struct EdgesOnlyFilter : public QgsPointLocator::MatchFilter
{
  bool acceptMatch( const QgsPointLocator::Match &m ) override { return m.hasEdge(); }
};
 
 
QgsCadUtils::AlignMapPointOutput QgsCadUtils::alignMapPoint( const QgsPointXY &originalMapPoint, const QgsCadUtils::AlignMapPointContext &ctx )
{
  QgsCadUtils::AlignMapPointOutput res;
  res.valid = true;
  res.softLockCommonAngle = -1;
 
  res.softLockLineExtension = Qgis::LineExtensionSide::NoVertex;
  res.softLockX = std::numeric_limits<double>::quiet_NaN();
  res.softLockY = std::numeric_limits<double>::quiet_NaN();
 
  // try to snap to anything
  const QgsPointLocator::Match snapMatch = ctx.snappingUtils->snapToMap( originalMapPoint, nullptr, true );
  res.snapMatch = snapMatch;
  QgsPointXY point = snapMatch.isValid() ? snapMatch.point() : originalMapPoint;
  QgsPointXY edgePt0, edgePt1;
  if ( snapMatch.hasEdge() )
  {
    snapMatch.edgePoints( edgePt0, edgePt1 );
    // note : res.edgeMatch should be removed, as we can just check snapMatch.hasEdge()
    res.edgeMatch = snapMatch;
  }
  else
  {
    res.edgeMatch = QgsPointLocator::Match();
  }
 
  int numberOfHardLock = 0;
  if ( ctx.xConstraint.locked ) ++numberOfHardLock;
  if ( ctx.yConstraint.locked ) ++numberOfHardLock;
  if ( ctx.angleConstraint.locked ) ++numberOfHardLock;
  if ( ctx.distanceConstraint.locked ) ++numberOfHardLock;
 
  QgsPointXY previousPt, penultimatePt;
  if ( ctx.cadPoints().count() >= 2 )
    previousPt = ctx.cadPoint( 1 );
  if ( ctx.cadPoints().count() >= 3 )
    penultimatePt = ctx.cadPoint( 2 );
 
  // *****************************
  // ---- X constraint
  if ( ctx.xConstraint.locked )
  {
    if ( !ctx.xConstraint.relative )
    {
      point.setX( ctx.xConstraint.value );
    }
    else if ( ctx.cadPoints().count() >= 2 )
    {
      point.setX( previousPt.x() + ctx.xConstraint.value );
    }
    if ( snapMatch.hasEdge() && !ctx.yConstraint.locked )
    {
      // intersect with snapped segment line at X coordinate
      const double dx = edgePt1.x() - edgePt0.x();
      if ( dx == 0 )
      {
        point.setY( edgePt0.y() );
      }
      else
      {
        const double dy = edgePt1.y() - edgePt0.y();
        point.setY( edgePt0.y() + ( dy * ( point.x() - edgePt0.x() ) ) / dx );
      }
    }
  }
  else if ( numberOfHardLock < 2 && ctx.xyVertexConstraint.locked )
  {
    for ( QgsPointLocator::Match snapMatch : ctx.lockedSnapVertices() )
    {
      const QgsPointXY vertex = snapMatch.point();
      if ( vertex.isEmpty() )
        continue;
 
      if ( std::abs( point.x() - vertex.x() ) / ctx.mapUnitsPerPixel < SOFT_CONSTRAINT_TOLERANCE_PIXEL )
      {
        point.setX( vertex.x() );
        res.softLockX = vertex.x();
      }
    }
  }
 
  // *****************************
  // ---- Y constraint
  if ( ctx.yConstraint.locked )
  {
    if ( !ctx.yConstraint.relative )
    {
      point.setY( ctx.yConstraint.value );
    }
    else if ( ctx.cadPoints().count() >= 2 )
    {
      point.setY( previousPt.y() + ctx.yConstraint.value );
    }
    if ( snapMatch.hasEdge() && !ctx.xConstraint.locked )
    {
      // intersect with snapped segment line at Y coordinate
      const double dy = edgePt1.y() - edgePt0.y();
      if ( dy == 0 )
      {
        point.setX( edgePt0.x() );
      }
      else
      {
        const double dx = edgePt1.x() - edgePt0.x();
        point.setX( edgePt0.x() + ( dx * ( point.y() - edgePt0.y() ) ) / dy );
      }
    }
  }
  else if ( numberOfHardLock < 2 && ctx.xyVertexConstraint.locked )
  {
    for ( QgsPointLocator::Match snapMatch : ctx.lockedSnapVertices() )
    {
      const QgsPointXY vertex = snapMatch.point();
      if ( vertex.isEmpty() )
        continue;
 
      if ( std::abs( point.y() - vertex.y() ) / ctx.mapUnitsPerPixel < SOFT_CONSTRAINT_TOLERANCE_PIXEL )
      {
        point.setY( vertex.y() );
        res.softLockY = vertex.y();
      }
    }
  }
 
  // *****************************
  // ---- Common Angle constraint
  if ( numberOfHardLock < 2 && !ctx.angleConstraint.locked && ctx.cadPoints().count() >= 2 && ctx.commonAngleConstraint.locked && ctx.commonAngleConstraint.value != 0 )
  {
    const double commonAngle = ctx.commonAngleConstraint.value * M_PI / 180;
    // see if soft common angle constraint should be performed
    // only if not in HardLock mode
    double softAngle = std::atan2( point.y() - previousPt.y(),
                                   point.x() - previousPt.x() );
    double deltaAngle = 0;
    if ( ctx.commonAngleConstraint.relative && ctx.cadPoints().count() >= 3 )
    {
      // compute the angle relative to the last segment (0° is aligned with last segment)
      deltaAngle = std::atan2( previousPt.y() - penultimatePt.y(),
                               previousPt.x() - penultimatePt.x() );
      softAngle -= deltaAngle;
    }
    const int quo = std::round( softAngle / commonAngle );
    if ( std::fabs( softAngle - quo * commonAngle ) * 180.0 * M_1_PI <= SOFT_CONSTRAINT_TOLERANCE_DEGREES )
    {
      // also check the distance in pixel to the line, otherwise it's too sticky at long ranges
      softAngle = quo * commonAngle;
      // http://mathworld.wolfram.com/Point-LineDistance2-Dimensional.html
      // use the direction vector (cos(a),sin(a)) from previous point. |x2-x1|=1 since sin2+cos2=1
      const double dist = std::fabs( std::cos( softAngle + deltaAngle ) * ( previousPt.y() - point.y() )
                                     - std::sin( softAngle + deltaAngle ) * ( previousPt.x() - point.x() ) );
      if ( dist / ctx.mapUnitsPerPixel < SOFT_CONSTRAINT_TOLERANCE_PIXEL )
      {
        res.softLockCommonAngle = 180.0 / M_PI * softAngle;
      }
    }
  }
 
  // angle can be locked in one of the two ways:
  // 1. "hard" lock defined by the user
  // 2. "soft" lock from common angle (e.g. 45 degrees)
  bool angleLocked = false, angleRelative = false;
  double angleValueDeg = 0;
  if ( ctx.angleConstraint.locked )
  {
    angleLocked = true;
    angleRelative = ctx.angleConstraint.relative;
    angleValueDeg = ctx.angleConstraint.value;
  }
  else if ( res.softLockCommonAngle != -1 )
  {
    angleLocked = true;
    angleRelative = ctx.commonAngleConstraint.relative;
    angleValueDeg = res.softLockCommonAngle;
  }
 
  // *****************************
  // ---- Angle constraint
  // input angles are in degrees
  if ( angleLocked )
  {
    double angleValue = angleValueDeg * M_PI / 180;
    if ( angleRelative && ctx.cadPoints().count() >= 3 )
    {
      // compute the angle relative to the last segment (0° is aligned with last segment)
      angleValue += std::atan2( previousPt.y() - penultimatePt.y(),
                                previousPt.x() - penultimatePt.x() );
    }
 
    const double cosa = std::cos( angleValue );
    const double sina = std::sin( angleValue );
    const double v = ( point.x() - previousPt.x() ) * cosa + ( point.y() - previousPt.y() ) * sina;
    if ( ctx.xConstraint.locked && ctx.yConstraint.locked )
    {
      // do nothing if both X,Y are already locked
    }
    else if ( ctx.xConstraint.locked || !std::isnan( res.softLockX ) )
    {
      if ( qgsDoubleNear( cosa, 0.0 ) )
      {
        res.valid = false;
      }
      else
      {
        double x = ctx.xConstraint.value;
        if ( !ctx.xConstraint.relative )
        {
          x -= previousPt.x();
        }
        point.setY( previousPt.y() + x * sina / cosa );
      }
    }
    else if ( ctx.yConstraint.locked || !std::isnan( res.softLockY ) )
    {
      if ( qgsDoubleNear( sina, 0.0 ) )
      {
        res.valid = false;
      }
      else
      {
        double y = ctx.yConstraint.value;
        if ( !ctx.yConstraint.relative )
        {
          y -= previousPt.y();
        }
        point.setX( previousPt.x() + y * cosa / sina );
      }
    }
    else
    {
      point.setX( previousPt.x() + cosa * v );
      point.setY( previousPt.y() + sina * v );
    }
 
    if ( snapMatch.hasEdge() && !ctx.distanceConstraint.locked )
    {
      // magnetize to the intersection of the snapped segment and the lockedAngle
 
      // line of previous point + locked angle
      const double x1 = previousPt.x();
      const double y1 = previousPt.y();
      const double x2 = previousPt.x() + cosa;
      const double y2 = previousPt.y() + sina;
      // line of snapped segment
      const double x3 = edgePt0.x();
      const double y3 = edgePt0.y();
      const double x4 = edgePt1.x();
      const double y4 = edgePt1.y();
 
      const double d = ( x1 - x2 ) * ( y3 - y4 ) - ( y1 - y2 ) * ( x3 - x4 );
 
      // do not compute intersection if lines are almost parallel
      // this threshold might be adapted
      if ( std::fabs( d ) > 0.01 )
      {
        point.setX( ( ( x3 - x4 ) * ( x1 * y2 - y1 * x2 ) - ( x1 - x2 ) * ( x3 * y4 - y3 * x4 ) ) / d );
        point.setY( ( ( y3 - y4 ) * ( x1 * y2 - y1 * x2 ) - ( y1 - y2 ) * ( x3 * y4 - y3 * x4 ) ) / d );
      }
    }
  }
 
  // *****************************
  // ---- Line Extension Constraint
 
  if ( numberOfHardLock < 2 && ctx.lineExtensionConstraint.locked && ctx.lockedSnapVertices().length() != 0 )
  {
    const QgsPointLocator::Match snap = ctx.lockedSnapVertices().last();
    const QgsPointXY extensionPoint = snap.point();
 
    if ( snap.layer() && !extensionPoint.isEmpty() )
    {
      auto checkLineExtension = [&]( QgsPoint vertex )
      {
        if ( vertex.isEmpty() )
        {
          return false;
        }
 
        const double distance = QgsGeometryUtils::distToInfiniteLine(
                                  QgsPoint( point ), QgsPoint( extensionPoint ), vertex );
 
        if ( distance / ctx.mapUnitsPerPixel < SOFT_CONSTRAINT_TOLERANCE_PIXEL )
        {
          if ( ctx.xConstraint.locked || !std::isnan( res.softLockX ) )
          {
            QgsPoint intersection;
            const bool intersect = QgsGeometryUtils::lineIntersection(
                                     QgsPoint( point ), QgsVector( 0, 1 ),
                                     QgsPoint( extensionPoint ), QgsPoint( extensionPoint ) - vertex,
                                     intersection
                                   );
            if ( intersect )
            {
              point = QgsPointXY( intersection );
            }
          }
          else if ( ctx.yConstraint.locked || !std::isnan( res.softLockY ) )
          {
            QgsPoint intersection;
            const bool intersect = QgsGeometryUtils::lineIntersection(
                                     QgsPoint( point ), QgsVector( 1, 0 ),
                                     QgsPoint( extensionPoint ), QgsPoint( extensionPoint ) - vertex,
                                     intersection
                                   );
            if ( intersect )
            {
              point = QgsPointXY( intersection );
            }
          }
          else if ( angleLocked )
          {
            const double angleValue = angleValueDeg * M_PI / 180;
            const double cosa = std::cos( angleValue );
            const double sina = std::sin( angleValue );
 
            QgsPoint intersection;
            QgsGeometryUtils::lineIntersection(
              QgsPoint( previousPt ), QgsVector( cosa, sina ),
              QgsPoint( extensionPoint ), QgsPoint( extensionPoint ) - vertex,
              intersection
            );
            point = QgsPointXY( intersection );
          }
          else
          {
            double angleValue = std::atan2( extensionPoint.y() - vertex.y(),
                                            extensionPoint.x() - vertex.x() );
 
            const double cosa = std::cos( angleValue );
            const double sina = std::sin( angleValue );
            const double v = ( point.x() - extensionPoint.x() ) * cosa + ( point.y() - extensionPoint.y() ) * sina;
 
            point.setX( extensionPoint.x() + cosa * v );
            point.setY( extensionPoint.y() + sina * v );
          }
 
          return true;
        }
        return false;
      };
 
      const QgsFeature feature = snap.layer()->getFeature( snap.featureId() );
      const QgsGeometry geom = feature.geometry();
 
      bool checked = checkLineExtension( geom.vertexAt( snap.vertexIndex() - 1 ) );
      if ( checked )
      {
        res.softLockLineExtension = Qgis::LineExtensionSide::BeforeVertex;
      }
 
      checked = checkLineExtension( geom.vertexAt( snap.vertexIndex() + 1 ) );
      if ( checked )
      {
        res.softLockLineExtension = Qgis::LineExtensionSide::AfterVertex;
      }
    }
  }
 
  // *****************************
  // ---- Distance constraint
  if ( ctx.distanceConstraint.locked && ctx.cadPoints().count() >= 2 )
  {
    if ( ctx.xConstraint.locked || ctx.yConstraint.locked
         || !std::isnan( res.softLockX ) || !std::isnan( res.softLockY ) )
    {
      // perform both to detect errors in constraints
      if ( ctx.xConstraint.locked || !std::isnan( res.softLockX ) )
      {
        const QgsPointXY verticalPt0( point.x(), point.y() );
        const QgsPointXY verticalPt1( point.x(), point.y() + 1 );
        const bool intersect = QgsGeometryUtils::lineCircleIntersection( previousPt, ctx.distanceConstraint.value, verticalPt0, verticalPt1, point );
 
        if ( ctx.xConstraint.locked )
        {
          res.valid &= intersect;
        }
        else if ( !intersect )
        {
          res.softLockX = std::numeric_limits<double>::quiet_NaN();
          res.softLockY = std::numeric_limits<double>::quiet_NaN(); // in the case of the 2 soft locks are activated
          res.valid &= QgsGeometryUtils::lineCircleIntersection( previousPt, ctx.distanceConstraint.value, previousPt, point, point );
        }
      }
      if ( ctx.yConstraint.locked || !std::isnan( res.softLockY ) )
      {
        const QgsPointXY horizontalPt0( point.x(), point.y() );
        const QgsPointXY horizontalPt1( point.x() + 1, point.y() );
        const bool intersect = QgsGeometryUtils::lineCircleIntersection( previousPt, ctx.distanceConstraint.value, horizontalPt0, horizontalPt1, point );
 
        if ( ctx.yConstraint.locked )
        {
          res.valid &= intersect;
        }
        else if ( !intersect )
        {
          res.softLockY = std::numeric_limits<double>::quiet_NaN();
          res.valid &= QgsGeometryUtils::lineCircleIntersection( previousPt, ctx.distanceConstraint.value, previousPt, point, point );
        }
      }
    }
    else if ( res.softLockLineExtension != Qgis::LineExtensionSide::NoVertex )
    {
      const QgsPointLocator::Match snap = ctx.lockedSnapVertices().last();
      const QgsFeature feature = snap.layer()->getFeature( snap.featureId() );
      const QgsGeometry geom = feature.geometry();
 
 
      const QgsPointXY lineExtensionPt1 = snap.point();
 
      QgsPointXY lineExtensionPt2;
      if ( res.softLockLineExtension == Qgis::LineExtensionSide::AfterVertex )
      {
        lineExtensionPt2 = QgsPointXY( geom.vertexAt( snap.vertexIndex() + 1 ) );
      }
      else
      {
        lineExtensionPt2 = QgsPointXY( geom.vertexAt( snap.vertexIndex() - 1 ) );
      }
 
      const bool intersect = QgsGeometryUtils::lineCircleIntersection( previousPt, ctx.distanceConstraint.value, lineExtensionPt1, lineExtensionPt2, point );
      if ( !intersect )
      {
        res.softLockLineExtension = Qgis::LineExtensionSide::NoVertex;
        res.valid &= QgsGeometryUtils::lineCircleIntersection( previousPt, ctx.distanceConstraint.value, previousPt, point, point );
      }
    }
    else
    {
      const double dist = std::sqrt( point.sqrDist( previousPt ) );
      if ( dist == 0 )
      {
        // handle case where mouse is over origin and distance constraint is enabled
        // take arbitrary horizontal line
        point.set( previousPt.x() + ctx.distanceConstraint.value, previousPt.y() );
      }
      else
      {
        const double vP = ctx.distanceConstraint.value / dist;
        point.set( previousPt.x() + ( point.x() - previousPt.x() ) * vP,
                   previousPt.y() + ( point.y() - previousPt.y() ) * vP );
      }
 
      if ( snapMatch.hasEdge() && !ctx.angleConstraint.locked )
      {
        // we will magnietize to the intersection of that segment and the lockedDistance !
        res.valid &= QgsGeometryUtils::lineCircleIntersection( previousPt, ctx.distanceConstraint.value, edgePt0, edgePt1, point );
      }
    }
  }
 
  // *****************************
  // ---- calculate CAD values
  QgsDebugMsgLevel( QStringLiteral( "point:             %1 %2" ).arg( point.x() ).arg( point.y() ), 4 );
  QgsDebugMsgLevel( QStringLiteral( "previous point:    %1 %2" ).arg( previousPt.x() ).arg( previousPt.y() ), 4 );
  QgsDebugMsgLevel( QStringLiteral( "penultimate point: %1 %2" ).arg( penultimatePt.x() ).arg( penultimatePt.y() ), 4 );
  //QgsDebugMsg( QStringLiteral( "dx: %1 dy: %2" ).arg( point.x() - previousPt.x() ).arg( point.y() - previousPt.y() ) );
  //QgsDebugMsg( QStringLiteral( "ddx: %1 ddy: %2" ).arg( previousPt.x() - penultimatePt.x() ).arg( previousPt.y() - penultimatePt.y() ) );
 
  res.finalMapPoint = point;
 
  return res;
}
 
void QgsCadUtils::AlignMapPointContext::dump() const
{
  QgsDebugMsg( QStringLiteral( "Constraints (locked / relative / value" ) );
  QgsDebugMsg( QStringLiteral( "Angle:    %1 %2 %3" ).arg( angleConstraint.locked ).arg( angleConstraint.relative ).arg( angleConstraint.value ) );
  QgsDebugMsg( QStringLiteral( "Distance: %1 %2 %3" ).arg( distanceConstraint.locked ).arg( distanceConstraint.relative ).arg( distanceConstraint.value ) );
  QgsDebugMsg( QStringLiteral( "X:        %1 %2 %3" ).arg( xConstraint.locked ).arg( xConstraint.relative ).arg( xConstraint.value ) );
  QgsDebugMsg( QStringLiteral( "Y:        %1 %2 %3" ).arg( yConstraint.locked ).arg( yConstraint.relative ).arg( yConstraint.value ) );
}