示例#1
0
 void DrawCubicBezierSpline(IApiDraw api, Vertex pt)
 {
     Point midp = (pt.p1+pt.p2) / 2;
       // GDI equiv being curveto()
       // draw fake cubic bezier curve lines (in two parts)
       if (api!=null) api.curveTo(pt.p1,midp);
       if (api!=null) api.curveTo(pt.p2,pt.p3);
 }
示例#2
0
        static int SliceCubicBézierSegments( IApiDraw api, Vertex PT, double n1, double n2, Tuple<Point,LineObj> Tu1, Tuple<Point,LineObj> Tu2, int recursion )
        {
            // Tu1 may be null and cause Exception
              // Tu2 may be null and cause Exception

              // infinity recursion ?
              if (recursion > MAX_RECURSION)
              {
            Point P = Tu2.Item1;
            if (api!=null) api.lineTo(Tu2.Item1);
            return 1;
              }

              // process segment
              Point  CP = Tu1.Item2.GetLineCross(Tu2.Item2);

              // a controlpoint is considered misplaced if its distance
              // from one of the anchor is greater than the distance
              // between the two anchors.

              Point  PO = Tu1.Item1-Tu2.Item1;     // point
              double DN = PO.Pow();                // double
              double D0 = Tu1.Item1.To(CP);        // double
              double D1 = Tu1.Item1.To(Tu2.Item1); // double
              double D2 = Tu2.Item1.To(CP);        // double

              if ( CP == null || D1 > D0 || D2 > D0)
              {

            int    total = 0;                  // total for this subsegment starts at 0
            double umid  = (n1 + n2) / 2D;     // if misplaced control-point, slice segment more
            Vertex PM    = PT.CloneAt(Convert.ToInt64(umid));
            Tuple<Point,LineObj> tumid = PM.CubicTangent();
            // sub segment count
            total += SliceCubicBézierSegments(api, PT, n1, umid, Tu1, tumid, recursion+1);
            total += SliceCubicBézierSegments(api, PT, umid, n2, tumid, Tu2, recursion+1);
            return total;
              }
              else
              {
            // draw curve
            if (api!=null) api.curveTo(CP.X, CP.Y, Tu2.Item1.X, Tu2.Item1.Y);
            return 1;
              }
        }
示例#3
0
        int DrawCubicBézier(IApiDraw api, Vertex pt)
        {
            Tuple<Point,LineObj> curt = null; // Tangent Object (LineObj)?
              Tuple<Point,LineObj> next; // Tangent Object (LineObj)?
              int    total    = 0; // int or long
              int    nSegment = numSegments < 2 ? 4 : this.numSegments;
              double tstep    = 1 / nSegment;

              curt = new Tuple<Point,LineObj>(pt.p0,LineObj.GetLine(pt.p0,pt.p1));
              if (api!=null) api.moveTo(pt.p0);
              for (int i=1; i < nSegment; i++)
              {
            next = pt.CubicTangent(Convert.ToInt32(i * tstep)); // next tangent
            total += SliceCubicBézierSegments( api, pt, (i - 1) * tstep, i * tstep, curt, next, 0); // current segment
            if (total > numSegments) {} curt = next;
              }
              return total;
        }
示例#4
0
        void DrawCubicBézier2(IApiDraw api, Vertex pt)
        {
            // base-points
              Point PA = pt.p0.GetPointOnSegment(pt.p1, 3/4);
              Point PB = pt.p3.GetPointOnSegment(pt.p2, 3/4);

              Point d = (pt.p3 - pt.p0) / 16;
              Point Pc_1 = pt.p0.GetPointOnSegment(pt.p1, 3/8);
              Point Pc_2 = PA.GetPointOnSegment(PB, 3/8) - d;
              Point Pc_3 = PB.GetPointOnSegment(PA, 3/8) + d;
              Point Pc_4 = pt.p3.GetPointOnSegment(pt.p2, 3/8) + d;

              // three anchor points
              Point Pa_1 = Pc_1.GetMiddle(Pc_2);
              Point Pa_2 = PA.GetMiddle(PB);
              Point Pa_3 = Pc_3.GetMiddle(Pc_4);

              // draw four quadratic segments
              if (api!=null) api.curveTo(Pc_1, Pa_1);
              if (api!=null) api.curveTo(Pc_2, Pa_2);
              if (api!=null) api.curveTo(Pc_3, Pa_3);
              if (api!=null) api.curveTo(Pc_4, pt.p3);
        }