void Mesh::elementCentroid(int elemIndex, double& cx, double& cy) const
{
const Element& e = mElems[elemIndex];
if (e.eType() == Element::ENP)
{
const Node* nodes = projectedNodes();
QPolygonF pX(e.nodeCount());
for (int i=0; i<e.nodeCount(); i++) {
pX[i] = nodes[e.p(i)].toPointF();
}
ENP_centroid(pX, cx, cy);
}
else if (e.eType() == Element::E4Q)
{
int e4qIndex = mE4QtmpIndex[elemIndex];
E4Qtmp& e4q = mE4Qtmp[e4qIndex];
E4Q_centroid(e4q, cx, cy, *mE4Qnorm);
}
else if (e.eType() == Element::E3T)
{
const Node* nodes = projectedNodes();
E3T_centroid(nodes[e.p(0)].toPointF(), nodes[e.p(1)].toPointF(), nodes[e.p(2)].toPointF(), cx, cy);
}
else if (e.eType() == Element::E2L)
{
const Node* nodes = projectedNodes();
E2L_centroid(nodes[e.p(0)].toPointF(), nodes[e.p(1)].toPointF(), cx, cy);
}
else
Q_ASSERT(0 && "element not supported");
}
void QgsTriangularMesh::update( QgsMesh *nativeMesh, QgsRenderContext *context )
{
Q_ASSERT( nativeMesh );
Q_ASSERT( context );
// FIND OUT IF UPDATE IS NEEDED
if ( mTriangularMesh.vertices.size() >= nativeMesh->vertices.size() &&
mTriangularMesh.faces.size() >= nativeMesh->faces.size() &&
mCoordinateTransform.sourceCrs() == context->coordinateTransform().sourceCrs() &&
mCoordinateTransform.destinationCrs() == context->coordinateTransform().destinationCrs() )
return;
// CLEAN-UP
mTriangularMesh.vertices.clear();
mTriangularMesh.faces.clear();
mTrianglesToNativeFaces.clear();
mNativeMeshFaceCentroids.clear();
// TRANSFORM VERTICES
mCoordinateTransform = context->coordinateTransform();
mTriangularMesh.vertices.resize( nativeMesh->vertices.size() );
for ( int i = 0; i < nativeMesh->vertices.size(); ++i )
{
const QgsMeshVertex &vertex = nativeMesh->vertices.at( i );
if ( mCoordinateTransform.isValid() )
{
try
{
QgsPointXY mapPoint = mCoordinateTransform.transform( QgsPointXY( vertex.x(), vertex.y() ) );
QgsMeshVertex mapVertex( mapPoint );
mapVertex.addZValue( vertex.z() );
mapVertex.setM( vertex.m() );
mTriangularMesh.vertices[i] = mapVertex;
}
catch ( QgsCsException &cse )
{
Q_UNUSED( cse );
QgsDebugMsg( QStringLiteral( "Caught CRS exception %1" ).arg( cse.what() ) );
mTriangularMesh.vertices[i] = vertex;
}
}
else
{
mTriangularMesh.vertices[i] = vertex;
}
}
// CREATE TRIANGULAR MESH
for ( int i = 0; i < nativeMesh->faces.size(); ++i )
{
const QgsMeshFace &face = nativeMesh->faces.at( i ) ;
triangulate( face, i );
}
// CALCULATE CENTROIDS
mNativeMeshFaceCentroids.resize( nativeMesh->faces.size() );
for ( int i = 0; i < nativeMesh->faces.size(); ++i )
{
const QgsMeshFace &face = nativeMesh->faces.at( i ) ;
QVector<QPointF> points;
points.reserve( face.size() );
for ( int j = 0; j < face.size(); ++j )
{
int index = face.at( j );
const QgsMeshVertex &vertex = mTriangularMesh.vertices[index]; // we need projected vertices
points.push_back( vertex.toQPointF() );
}
QPolygonF poly( points );
double cx, cy;
ENP_centroid( poly, cx, cy );
mNativeMeshFaceCentroids[i] = QgsMeshVertex( cx, cy );
}
// CALCULATE SPATIAL INDEX
mSpatialIndex = QgsMeshSpatialIndex( mTriangularMesh );
}
