SvgMarkerGraphicsNode.cs :  » GUI » SharpVectorGraphics » SharpVectors » Renderer » Gdi » C# / CSharp Open Source

using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Diagnostics;
using System.Xml;

using SharpVectors.Dom.Svg;
using SharpVectors.Dom.Svg.Rendering;

namespace SharpVectors.Renderer.Gdi{
  public enum SvgMarkerPosition{Start, Mid, End}

  public class SvgMarkerGraphicsNode : GraphicsNode
  {
        #region Constructor
    public SvgMarkerGraphicsNode(SvgElement element) : base(element)
    {
    }
        #endregion

        #region Public Methods
        // disable default rendering
    public override void BeforeRender(ISvgRenderer renderer)
    {
    }
        public override void Render(ISvgRenderer renderer)
        {
        }
        public override void AfterRender(ISvgRenderer renderer)
        {
        }

    public void PaintMarker(GdiRenderer renderer, GraphicsWrapper gr, SvgMarkerPosition markerPos, SvgStyleableElement refElement)
    {
      ISharpMarkerHost markerHostElm = (ISharpMarkerHost)refElement;
      SvgMarkerElement markerElm = (SvgMarkerElement) element;

      PointF[] vertexPositions = markerHostElm.MarkerPositions;
      int start;
      int len;

      // Choose which part of the position array to use
      switch (markerPos)
      {
        case SvgMarkerPosition.Start:
          start = 0;
          len = 1;
          break;
        case SvgMarkerPosition.Mid:
          start = 1;
          len = vertexPositions.Length - 2;
          break;
        default:
          // == MarkerPosition.End
          start = vertexPositions.Length-1;
          len = 1;
          break;
      }

      for ( int i = start; i<start+len; i++ )
      {
        PointF point = vertexPositions[i];

        GraphicsContainerWrapper gc = gr.BeginContainer();

        gr.TranslateTransform(point.X, point.Y);

        if ( markerElm.OrientType.AnimVal.Equals(SvgMarkerOrient.Angle) )
        {
          gr.RotateTransform((float)markerElm.OrientAngle.AnimVal.Value);
        }
        else
        {
          float angle;

          switch(markerPos)
          {
            case SvgMarkerPosition.Start:
              angle = markerHostElm.GetStartAngle(i + 1);
              break;
            case SvgMarkerPosition.Mid:
              //angle = (markerHostElm.GetEndAngle(i) + markerHostElm.GetStartAngle(i + 1)) / 2;
              angle = SvgNumber.CalcAngleBisection(markerHostElm.GetEndAngle(i), markerHostElm.GetStartAngle(i + 1));
              break;
            default:
              angle = markerHostElm.GetEndAngle(i);
              break;
          }
          gr.RotateTransform(angle);
        }

        if ( markerElm.MarkerUnits.AnimVal.Equals(SvgMarkerUnit.StrokeWidth) )
        {
          SvgLength strokeWidthLength = new SvgLength(refElement, "stroke-width", SvgLengthSource.Css, SvgLengthDirection.Viewport, "1");
          float strokeWidth = (float)strokeWidthLength.Value;
          gr.ScaleTransform(strokeWidth, strokeWidth);
        }

        SvgPreserveAspectRatio spar = (SvgPreserveAspectRatio)markerElm.PreserveAspectRatio.AnimVal;
        float[] translateAndScale = spar.FitToViewBox(
          (SvgRect)markerElm.ViewBox.AnimVal,
          new SvgRect(
            0, 
            0, 
            (float)markerElm.MarkerWidth.AnimVal.Value,
            (float)markerElm.MarkerHeight.AnimVal.Value)
          );


        gr.TranslateTransform(
          -(float)markerElm.RefX.AnimVal.Value * translateAndScale[2],
          -(float)markerElm.RefY.AnimVal.Value * translateAndScale[3]
          );

        gr.ScaleTransform(translateAndScale[2], translateAndScale[3]);

        Clip(gr);

                markerElm.RenderChildren(renderer);

        gr.EndContainer(gc);
      }
    }
        #endregion
  }
}