C# IPrecisionModel类代码示例

 /// <summary>
 /// Densifies a coordinate sequence.
 /// </summary>
 /// <param name="pts">The coordinate sequence to densify</param>
 /// <param name="distanceTolerance">The distance tolerance (<see cref="DistanceTolerance"/>)</param>
 /// <param name="precModel">The precision model to apply on the new coordinates</param>
 /// <returns>The densified coordinate sequence</returns>
 private static Coordinate[] DensifyPoints(Coordinate[] pts,
                                            double distanceTolerance, IPrecisionModel precModel)
 {
     var seg = new LineSegment();
     var coordList = new CoordinateList();
     for (int i = 0; i < pts.Length - 1; i++)
     {
         seg.P0 = pts[i];
         seg.P1 = pts[i + 1];
         coordList.Add(seg.P0, false);
         double len = seg.Length;
         int densifiedSegCount = (int) (len/distanceTolerance) + 1;
         if (densifiedSegCount > 1)
         {
             double densifiedSegLen = len/densifiedSegCount;
             for (int j = 1; j < densifiedSegCount; j++)
             {
                 double segFract = (j*densifiedSegLen)/len;
                 var p = seg.PointAlong(segFract);
                 precModel.MakePrecise(p);
                 coordList.Add(p, false);
             }
         }
     }
     coordList.Add(pts[pts.Length - 1], false);
     return coordList.ToCoordinateArray();
 }

 /// <summary>
 /// Constructs a GeometryFactory that generates Geometries having the given
 /// PrecisionModel, spatial-reference ID, and CoordinateSequence implementation.
 /// </summary>        
 /// <param name="precisionModel"></param>
 /// <param name="SRID"></param>
 /// <param name="coordinateSequenceFactory"></param>       
 public GeometryFactory(IPrecisionModel precisionModel, int SRID,
     ICoordinateSequenceFactory coordinateSequenceFactory)
 {
     this.precisionModel = precisionModel;
     this.coordinateSequenceFactory = coordinateSequenceFactory;
     this.srid = SRID;
 }

 public OffsetCurveBuilder(
     IPrecisionModel precisionModel,
     IBufferParameters bufParams
     )
 {
     _precisionModel = precisionModel;
     _bufParams = bufParams;
 }

 /// <summary>
 /// 
 /// </summary>
 /// <param name="precisionModel"></param>
 /// <param name="quadrantSegments"></param>
 public OffsetCurveBuilder(IPrecisionModel precisionModel, int quadrantSegments)
 {
     this.precisionModel = precisionModel;
     // compute intersections in full precision, to provide accuracy
     // the points are rounded as they are inserted into the curve line
     li = new RobustLineIntersector();
     var limitedQuadSegs = quadrantSegments < 1 ? 1 : quadrantSegments;
     filletAngleQuantum = Math.PI / 2.0 / limitedQuadSegs;
 }

        private static void PreciseCoordinateTester(IPrecisionModel pm,
            double x1, double y1,
            double x2, double y2)
        {
            var p = new Coordinate(x1, y1);
            pm.MakePrecise(p);

            var pPrecise = new Coordinate(x2, y2);
            Assert.IsTrue(p.Equals2D(pPrecise), "Expected {0}, but got {1}", pPrecise, p);
        }

        public OffsetSegmentGenerator(IPrecisionModel precisionModel,
            IBufferParameters bufParams, double distance)
        {
            _precisionModel = precisionModel;
            _bufParams = bufParams;

            // compute intersections in full precision, to provide accuracy
            // the points are rounded as they are inserted into the curve line
            _li = new RobustLineIntersector();
            _filletAngleQuantum = Math.PI / 2.0 / bufParams.QuadrantSegments;

            /**
             * Non-round joins cause issues with short closing segments, so don't use
             * them. In any case, non-round joins only really make sense for relatively
             * small buffer distances.
             */
            if (bufParams.QuadrantSegments >= 8
                && bufParams.JoinStyle == JoinStyle.Round)
                _closingSegLengthFactor = MaxClosingSegLenFactor;
            Init(distance);
        }

        public OldOffsetCurveBuilder(
                      IPrecisionModel precisionModel,
                      IBufferParameters bufParams
                      )
        {
            _precisionModel = precisionModel;
            _bufParams = bufParams;

            // compute intersections in full precision, to provide accuracy
            // the points are rounded as they are inserted into the curve line
            _li = new RobustLineIntersector();
            _filletAngleQuantum = Math.PI / 2.0 / bufParams.QuadrantSegments;

            /**
             * Non-round joins cause issues with short closing segments,
             * so don't use them.  In any case, non-round joins
             * only really make sense for relatively small buffer distances.
             */
            if (bufParams.QuadrantSegments >= 8
                && bufParams.JoinStyle == JoinStyle.Round)
                closingSegFactor = MAX_CLOSING_SEG_FRACTION;
        }

 /// <summary>
 /// Initializes a new instance of the <see cref="IteratedNoder"/> class.
 /// </summary>
 /// <param name="pm"></param>
 public IteratedNoder(IPrecisionModel pm)
 {
     _li = new RobustLineIntersector {PrecisionModel = pm};
 }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="fixedPM"></param>
        private void BufferFixedPrecision(IPrecisionModel fixedPM)
        {
            INoder noder = new ScaledNoder(new MCIndexSnapRounder(new PrecisionModel(1.0)), fixedPM.Scale);

            var bufBuilder = new BufferBuilder
            {
                WorkingPrecisionModel = fixedPM,
                Noder = noder,
                QuadrantSegments = quadrantSegments,
                EndCapStyle = endCapStyle
            };
            // this may throw an exception, if robustness errors are encountered
            resultGeometry = bufBuilder.Buffer(argGeom, distance);
        }

 private static double RandomOrdinate(Ordinate o, IPrecisionModel pm)
 {
     switch (o)
     {
         case Ordinate.X:
             return pm.MakePrecise(-180 + 360 * Rnd.NextDouble());
         case Ordinate.Y:
             return pm.MakePrecise(-90 + 180 * Rnd.NextDouble());
         case Ordinate.Z:
             return 200 * Rnd.NextDouble();
         case Ordinate.M:
             return 200 + 200 * Rnd.NextDouble();
         default:
             throw new NotSupportedException();
     }
 }

 /// <summary>
 /// Initializes a new instance of the <see cref="MCIndexSnapRounder"/> class.
 /// </summary>
 /// <param name="pm">The <see cref="PrecisionModel" /> to use.</param>
 public MCIndexSnapRounder(IPrecisionModel pm)
 {
     _li = new RobustLineIntersector { PrecisionModel = pm };
     _scaleFactor = pm.Scale;
 }

        //private bool isValidityChecked = false;

        /// <summary>
        /// Creates a new noder which snap-rounds to a grid specified by the given <see cref="IPrecisionModel"/>
        /// </summary>
        /// <param name="pm">The precision model for the grid to snap-round to.</param>
        public GeometryNoder(IPrecisionModel pm)
        {
            _pm = pm;
        }

        /// <summary>
        /// Get Envelope in external coordinates.
        /// </summary>
        /// <param name="precisionModel">The precision model to use</param>
        /// <param name="envelope">The envelope to get</param>
        /// <returns></returns>
        public static Envelope GetEnvelopeExternal(IPrecisionModel precisionModel, Envelope envelope)
        {
            // Get envelope in external coordinates
            var min = new Coordinate(envelope.MinX, envelope.MinY);
            precisionModel.MakePrecise(min);
            var max = new Coordinate(envelope.MaxX, envelope.MaxY);
            precisionModel.MakePrecise(max);
            var bounds = new Envelope(min.X, max.X, min.Y, max.Y);

            return bounds;

            //return GetEnvelopeExternal(envelope);
        }

 /// <summary>
 ///
 /// </summary>
 /// <param name="other"></param>
 /// <returns></returns>
 public int CompareTo(IPrecisionModel other)
 {
     int sigDigits = MaximumSignificantDigits;
     int otherSigDigits = other.MaximumSignificantDigits;
     return (sigDigits).CompareTo(otherSigDigits);
 }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="precisionModel"></param>
        /// <returns></returns>
        private INoder GetNoder(IPrecisionModel precisionModel)
        {
            if (workingNoder != null) 
                return workingNoder;

            // otherwise use a fast (but non-robust) noder
            LineIntersector li = new RobustLineIntersector();
            li.PrecisionModel = precisionModel;
            MCIndexNoder noder = new MCIndexNoder(new IntersectionAdder(li));                     
            return noder;
        }