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00018 #include "qgssnapper.h"
00019 #include "qgsmaprenderer.h"
00020 #include "qgsmaptopixel.h"
00021 #include "qgsvectorlayer.h"
00022 #include <QMultiMap>
00023 #include <QPoint>
00024 #include <cmath>
00025
00026
00027 QgsSnapper::QgsSnapper( QgsMapRenderer* mapRenderer ): mMapRenderer( mapRenderer )
00028 {
00029
00030 }
00031
00032 QgsSnapper::QgsSnapper()
00033 {
00034
00035 }
00036
00037 QgsSnapper::~QgsSnapper()
00038 {
00039
00040 }
00041
00042 int QgsSnapper::snapPoint( const QPoint& startPoint, QList<QgsSnappingResult>& snappingResult, const QList<QgsPoint>& excludePoints )
00043 {
00044 snappingResult.clear();
00045
00046 QMultiMap<double, QgsSnappingResult> snappingResultList;
00047 QMultiMap<double, QgsSnappingResult> currentResultList;
00048
00049
00050 QgsPoint mapCoordPoint = mMapRenderer->coordinateTransform()->toMapCoordinates( startPoint.x(), startPoint.y() );
00051 QgsPoint layerCoordPoint;
00052 QgsSnappingResult newResult;
00053
00054 QList<QgsSnapper::SnapLayer>::iterator snapLayerIt;
00055 for ( snapLayerIt = mSnapLayers.begin(); snapLayerIt != mSnapLayers.end(); ++snapLayerIt )
00056 {
00057
00058 layerCoordPoint = mMapRenderer->mapToLayerCoordinates( snapLayerIt->mLayer, mapCoordPoint );
00059
00060 double tolerance = QgsTolerance::toleranceInMapUnits( snapLayerIt->mTolerance, snapLayerIt->mLayer, mMapRenderer, snapLayerIt->mUnitType );
00061 if ( snapLayerIt->mLayer->snapWithContext( layerCoordPoint, tolerance,
00062 currentResultList, snapLayerIt->mSnapTo ) != 0 )
00063 {
00064
00065 }
00066
00067
00068 QMultiMap<double, QgsSnappingResult>::iterator currentResultIt;
00069 for ( currentResultIt = currentResultList.begin(); currentResultIt != currentResultList.end(); ++currentResultIt )
00070 {
00071
00072
00073 newResult = currentResultIt.value();
00074 newResult.snappedVertex = mMapRenderer->layerToMapCoordinates( snapLayerIt->mLayer, currentResultIt.value().snappedVertex );
00075 newResult.beforeVertex = mMapRenderer->layerToMapCoordinates( snapLayerIt->mLayer, currentResultIt.value().beforeVertex );
00076 newResult.afterVertex = mMapRenderer->layerToMapCoordinates( snapLayerIt->mLayer, currentResultIt.value().afterVertex );
00077 snappingResultList.insert( sqrt( newResult.snappedVertex.sqrDist( mapCoordPoint ) ), newResult );
00078 }
00079 }
00080
00081
00082 cleanResultList( snappingResultList, excludePoints );
00083
00084
00085 QMultiMap<double, QgsSnappingResult>::iterator evalIt = snappingResultList.begin();
00086 if ( evalIt == snappingResultList.end() )
00087 {
00088 return 0;
00089 }
00090
00091 if ( mSnapMode == QgsSnapper::SnapWithOneResult )
00092 {
00093
00094 snappingResult.push_back( evalIt.value() );
00095 }
00096 else if ( mSnapMode == QgsSnapper::SnapWithResultsForSamePosition )
00097 {
00098
00099 double tolerance = 0.000001;
00100 double minDistance = evalIt.key();
00101
00102 for ( evalIt = snappingResultList.begin(); evalIt != snappingResultList.end(); ++evalIt )
00103 {
00104 if ( evalIt.key() > ( minDistance + tolerance ) )
00105 {
00106 break;
00107 }
00108 snappingResult.push_back( evalIt.value() );
00109 }
00110
00111 }
00112
00113 else
00114 {
00115 for ( ; evalIt != snappingResultList.end(); ++evalIt )
00116 {
00117 snappingResult.push_back( evalIt.value() );
00118 }
00119 }
00120
00121 return 0;
00122 }
00123
00124 void QgsSnapper::setSnapLayers( const QList<QgsSnapper::SnapLayer>& snapLayers )
00125 {
00126 mSnapLayers = snapLayers;
00127 }
00128
00129
00130 void QgsSnapper::setSnapMode( QgsSnapper::SnappingMode snapMode )
00131 {
00132 mSnapMode = snapMode;
00133 }
00134
00135 void QgsSnapper::cleanResultList( QMultiMap<double, QgsSnappingResult>& list, const QList<QgsPoint>& excludeList ) const
00136 {
00137 QgsPoint currentResultPoint;
00138 QgsSnappingResult currentSnappingResult;
00139 QList<double> keysToRemove;
00140
00141 QMultiMap<double, QgsSnappingResult>::iterator result_it = list.begin();
00142 for ( ; result_it != list.end(); ++result_it )
00143 {
00144 currentSnappingResult = result_it.value();
00145 if ( currentSnappingResult.snappedVertexNr != -1 )
00146 {
00147 currentResultPoint = currentSnappingResult.snappedVertex;
00148 if ( excludeList.contains( currentResultPoint ) )
00149 {
00150 keysToRemove.push_back( result_it.key() );
00151 }
00152 }
00153 }
00154
00155 QList<double>::const_iterator remove_it = keysToRemove.constBegin();
00156 for ( ; remove_it != keysToRemove.constEnd(); ++remove_it )
00157 {
00158 list.remove( *remove_it );
00159 }
00160 }