#region License

// Copyright (c) 2010, ClearCanvas Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, 
// are permitted provided that the following conditions are met:
//
//    * Redistributions of source code must retain the above copyright notice, 
//      this list of conditions and the following disclaimer.
//    * Redistributions in binary form must reproduce the above copyright notice, 
//      this list of conditions and the following disclaimer in the documentation 
//      and/or other materials provided with the distribution.
//    * Neither the name of ClearCanvas Inc. nor the names of its contributors 
//      may be used to endorse or promote products derived from this software without 
//      specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 
// OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 
// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
// OF SUCH DAMAGE.

#endregion

using System;
using System.Drawing;
using ClearCanvas.Dicom.Iod.Sequences;
using ClearCanvas.ImageViewer.Graphics;
using ClearCanvas.ImageViewer.InteractiveGraphics;
using ClearCanvas.ImageViewer.Mathematics;
using ClearCanvas.ImageViewer.PresentationStates.Dicom;
using GraphicObject = ClearCanvas.Dicom.Iod.Sequences.GraphicAnnotationSequenceItem.GraphicObjectSequenceItem;
using TextObject = ClearCanvas.Dicom.Iod.Sequences.GraphicAnnotationSequenceItem.TextObjectSequenceItem;

...

public static void SerializeDashedLine(ILineSegmentGraphic lineSegmentGraphic, GraphicAnnotationSequenceItem serializationState)
{
    lineSegmentGraphic.CoordinateSystem = CoordinateSystem.Source;
    try
    {
        DoSerializeDashedLine(lineSegmentGraphic.Point1, lineSegmentGraphic.Point2, lineSegmentGraphic.SpatialTransform, serializationState, false);
    }
    finally
    {
        lineSegmentGraphic.ResetCoordinateSystem();
    }
}

private static void DoSerializeDashedLine(PointF point1, PointF point2, SpatialTransform spatialTransform, GraphicAnnotationSequenceItem serializationState, bool showHashes)
{
    // these control parameters are in screen pixels at the nominal presentation zoom level
    const float period = 8;
    const float amplitude = 0.5f;

    SizeF normalVector;
    SizeF dashVector;
    float periods;

    // compute the dash vector and cross hash vector to be sized relative to screen pixels at nominal presentation zoom level
    {
        PointF dstLineVector = spatialTransform.ConvertToDestination(new SizeF(point2) - new SizeF(point1)).ToPointF();
        float dstMagnitude = (float) Math.Sqrt(dstLineVector.X*dstLineVector.X + dstLineVector.Y*dstLineVector.Y);
        periods = dstMagnitude/period;
        dstLineVector.X /= dstMagnitude;
        dstLineVector.Y /= dstMagnitude;
        dashVector = spatialTransform.ConvertToSource(new SizeF(dstLineVector.X*period/2, dstLineVector.Y*period/2));
        normalVector = spatialTransform.ConvertToSource(new SizeF(-dstLineVector.Y*amplitude, dstLineVector.X*amplitude));
    }

    PointF start = point1;
    int limit = (int) periods;
    for (int n = 0; n < limit; n++)
    {
        PointF midPeriod = start + dashVector;
        start = midPeriod + dashVector;

        GraphicObject dash = new GraphicObject();
        dash.GraphicAnnotationUnits = GraphicAnnotationSequenceItem.GraphicAnnotationUnits.Pixel;
        dash.GraphicData = new PointF[] {midPeriod, start};
        dash.GraphicDimensions = 2;
        dash.GraphicFilled = GraphicAnnotationSequenceItem.GraphicFilled.N;
        dash.GraphicType = GraphicAnnotationSequenceItem.GraphicType.Polyline;
        dash.NumberOfGraphicPoints = 2;
        serializationState.AppendGraphicObjectSequence(dash);
    }

    // the first half of each period has no line, so this is only necessary if the residual is over half a period
    if (periods - limit > 0.5f)
    {
        GraphicObject dash = new GraphicObject();
        dash.GraphicAnnotationUnits = GraphicAnnotationSequenceItem.GraphicAnnotationUnits.Pixel;
        dash.GraphicData = new PointF[] {start + dashVector, point2};
        dash.GraphicDimensions = 2;
        dash.GraphicFilled = GraphicAnnotationSequenceItem.GraphicFilled.N;
        dash.GraphicType = GraphicAnnotationSequenceItem.GraphicType.Polyline;
        dash.NumberOfGraphicPoints = 2;
        serializationState.AppendGraphicObjectSequence(dash);
    }

    if (showHashes)
    {
        GraphicObject hash1 = new GraphicObject();
        hash1.GraphicAnnotationUnits = GraphicAnnotationSequenceItem.GraphicAnnotationUnits.Pixel;
        hash1.GraphicData = new PointF[] {point1 - normalVector, point1 + normalVector};
        hash1.GraphicDimensions = 2;
        hash1.GraphicFilled = GraphicAnnotationSequenceItem.GraphicFilled.N;
        hash1.GraphicType = GraphicAnnotationSequenceItem.GraphicType.Polyline;
        hash1.NumberOfGraphicPoints = 2;
        serializationState.AppendGraphicObjectSequence(hash1);

        GraphicObject hash2 = new GraphicObject();
        hash2.GraphicAnnotationUnits = GraphicAnnotationSequenceItem.GraphicAnnotationUnits.Pixel;
        hash2.GraphicData = new PointF[] {point2 - normalVector, point2 + normalVector};
        hash2.GraphicDimensions = 2;
        hash2.GraphicFilled = GraphicAnnotationSequenceItem.GraphicFilled.N;
        hash2.GraphicType = GraphicAnnotationSequenceItem.GraphicType.Polyline;
        hash2.NumberOfGraphicPoints = 2;
        serializationState.AppendGraphicObjectSequence(hash2);
    }
}