void Qgs3DUtils::clampAltitudes( QgsLineString *lineString, Qgs3DTypes::AltitudeClamping altClamp, Qgs3DTypes::AltitudeBinding altBind, const QgsPoint ¢roid, float height, const Qgs3DMapSettings &map )
{
for ( int i = 0; i < lineString->nCoordinates(); ++i )
{
float terrainZ = 0;
if ( altClamp == Qgs3DTypes::AltClampRelative || altClamp == Qgs3DTypes::AltClampTerrain )
{
QgsPointXY pt;
if ( altBind == Qgs3DTypes::AltBindVertex )
{
pt.setX( lineString->xAt( i ) );
pt.setY( lineString->yAt( i ) );
}
else
{
pt.set( centroid.x(), centroid.y() );
}
terrainZ = map.terrainGenerator()->heightAt( pt.x(), pt.y(), map );
}
float geomZ = 0;
if ( altClamp == Qgs3DTypes::AltClampAbsolute || altClamp == Qgs3DTypes::AltClampRelative )
geomZ = lineString->zAt( i );
float z = ( terrainZ + geomZ ) * map.terrainVerticalScale() + height;
lineString->setZAt( i, z );
}
}
// TODO: move to geometry utils (if not already there)
static bool lineCircleIntersection( const QgsPointXY ¢er, const double radius, const QgsPointXY &edgePt0, const QgsPointXY &edgePt1, QgsPointXY &intersection )
{
// formula taken from http://mathworld.wolfram.com/Circle-LineIntersection.html
const double x1 = edgePt0.x() - center.x();
const double y1 = edgePt0.y() - center.y();
const double x2 = edgePt1.x() - center.x();
const double y2 = edgePt1.y() - center.y();
const double dx = x2 - x1;
const double dy = y2 - y1;
const double dr = std::sqrt( std::pow( dx, 2 ) + std::pow( dy, 2 ) );
const double d = x1 * y2 - x2 * y1;
const double disc = std::pow( radius, 2 ) * std::pow( dr, 2 ) - std::pow( d, 2 );
if ( disc < 0 )
{
//no intersection or tangent
return false;
}
else
{
// two solutions
const int sgnDy = dy < 0 ? -1 : 1;
const double ax = center.x() + ( d * dy + sgnDy * dx * std::sqrt( std::pow( radius, 2 ) * std::pow( dr, 2 ) - std::pow( d, 2 ) ) ) / ( std::pow( dr, 2 ) );
const double ay = center.y() + ( -d * dx + std::fabs( dy ) * std::sqrt( std::pow( radius, 2 ) * std::pow( dr, 2 ) - std::pow( d, 2 ) ) ) / ( std::pow( dr, 2 ) );
const QgsPointXY p1( ax, ay );
const double bx = center.x() + ( d * dy - sgnDy * dx * std::sqrt( std::pow( radius, 2 ) * std::pow( dr, 2 ) - std::pow( d, 2 ) ) ) / ( std::pow( dr, 2 ) );
const double by = center.y() + ( -d * dx - std::fabs( dy ) * std::sqrt( std::pow( radius, 2 ) * std::pow( dr, 2 ) - std::pow( d, 2 ) ) ) / ( std::pow( dr, 2 ) );
const QgsPointXY p2( bx, by );
// snap to nearest intersection
if ( intersection.sqrDist( p1 ) < intersection.sqrDist( p2 ) )
{
intersection.set( p1.x(), p1.y() );
}
else
{
intersection.set( p2.x(), p2.y() );
}
return true;
}
}
QgsCadUtils::AlignMapPointOutput QgsCadUtils::alignMapPoint( const QgsPointXY &originalMapPoint, const QgsCadUtils::AlignMapPointContext &ctx )
{
QgsCadUtils::AlignMapPointOutput res;
res.valid = true;
res.softLockCommonAngle = -1;
// try to snap to anything
QgsPointLocator::Match snapMatch = ctx.snappingUtils->snapToMap( originalMapPoint );
QgsPointXY point = snapMatch.isValid() ? snapMatch.point() : originalMapPoint;
// try to snap explicitly to a segment - useful for some constraints
QgsPointXY edgePt0, edgePt1;
EdgesOnlyFilter edgesOnlyFilter;
QgsPointLocator::Match edgeMatch = ctx.snappingUtils->snapToMap( originalMapPoint, &edgesOnlyFilter );
if ( edgeMatch.hasEdge() )
edgeMatch.edgePoints( edgePt0, edgePt1 );
res.edgeMatch = edgeMatch;
QgsPointXY previousPt, penultimatePt;
if ( ctx.cadPointList.count() >= 2 )
previousPt = ctx.cadPointList.at( 1 );
if ( ctx.cadPointList.count() >= 3 )
penultimatePt = ctx.cadPointList.at( 2 );
// *****************************
// ---- X constraint
if ( ctx.xConstraint.locked )
{
if ( !ctx.xConstraint.relative )
{
point.setX( ctx.xConstraint.value );
}
else if ( ctx.cadPointList.count() >= 2 )
{
point.setX( previousPt.x() + ctx.xConstraint.value );
}
if ( edgeMatch.hasEdge() && !ctx.yConstraint.locked )
{
// intersect with snapped segment line at X ccordinate
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 );
}
}
}
// *****************************
// ---- Y constraint
if ( ctx.yConstraint.locked )
{
if ( !ctx.yConstraint.relative )
{
point.setY( ctx.yConstraint.value );
}
else if ( ctx.cadPointList.count() >= 2 )
{
point.setY( previousPt.y() + ctx.yConstraint.value );
}
if ( edgeMatch.hasEdge() && !ctx.xConstraint.locked )
{
// intersect with snapped segment line at Y ccordinate
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 );
}
}
}
// *****************************
// ---- Common Angle constraint
if ( !ctx.angleConstraint.locked && ctx.cadPointList.count() >= 2 && ctx.commonAngleConstraint.locked && ctx.commonAngleConstraint.value != 0 )
{
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.cadPointList.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;
}
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;
int 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.cadPointList.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() );
}
double cosa = std::cos( angleValue );
double sina = std::sin( angleValue );
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 )
{
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 )
{
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 ( edgeMatch.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 );
}
}
}
// *****************************
// ---- Distance constraint
if ( ctx.distanceConstraint.locked && ctx.cadPointList.count() >= 2 )
{
if ( ctx.xConstraint.locked || ctx.yConstraint.locked )
{
// perform both to detect errors in constraints
if ( ctx.xConstraint.locked )
{
QgsPointXY verticalPt0( ctx.xConstraint.value, point.y() );
QgsPointXY verticalPt1( ctx.xConstraint.value, point.y() + 1 );
res.valid &= lineCircleIntersection( previousPt, ctx.distanceConstraint.value, verticalPt0, verticalPt1, point );
}
if ( ctx.yConstraint.locked )
{
QgsPointXY horizontalPt0( point.x(), ctx.yConstraint.value );
QgsPointXY horizontalPt1( point.x() + 1, ctx.yConstraint.value );
res.valid &= lineCircleIntersection( previousPt, ctx.distanceConstraint.value, horizontalPt0, horizontalPt1, 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 ( edgeMatch.hasEdge() && !ctx.angleConstraint.locked )
{
// we will magnietize to the intersection of that segment and the lockedDistance !
res.valid &= lineCircleIntersection( previousPt, ctx.distanceConstraint.value, edgePt0, edgePt1, point );
}
}
}
// *****************************
// ---- calculate CAD values
QgsDebugMsgLevel( QString( "point: %1 %2" ).arg( point.x() ).arg( point.y() ), 4 );
QgsDebugMsgLevel( QString( "previous point: %1 %2" ).arg( previousPt.x() ).arg( previousPt.y() ), 4 );
QgsDebugMsgLevel( QString( "penultimate point: %1 %2" ).arg( penultimatePt.x() ).arg( penultimatePt.y() ), 4 );
//QgsDebugMsg( QString( "dx: %1 dy: %2" ).arg( point.x() - previousPt.x() ).arg( point.y() - previousPt.y() ) );
//QgsDebugMsg( QString( "ddx: %1 ddy: %2" ).arg( previousPt.x() - penultimatePt.x() ).arg( previousPt.y() - penultimatePt.y() ) );
res.finalMapPoint = point;
return res;
}
