C# XMatrix.Invert方法代码示例

        public RenderContext(ResourceManager resourceManager, Selector selector, RectangleF tileRect,
            double scale, MapOptions options, Stylesheet styles, Size tileSize)
        {
            this.resourceManager = resourceManager;
            this.selector = selector;
            this.tileRect = tileRect;
            this.scale = scale;
            this.options = options;
            this.styles = styles;
            this.tileSize = tileSize;

            XMatrix m = new XMatrix();
            m.TranslatePrepend((float)(-tileRect.Left * scale * Astrometrics.ParsecScaleX), (float)(-tileRect.Top * scale * Astrometrics.ParsecScaleY));
            m.ScalePrepend((float)scale * Astrometrics.ParsecScaleX, (float)scale * Astrometrics.ParsecScaleY);
            imageSpaceToWorldSpace = m;
            m.Invert();
            worldSpaceToImageSpace = m;
        }

        /// <summary>
        /// Creates between 1 and 5 Béziers curves from parameters specified like in WPF.
        /// </summary>
        public static List<XPoint> BezierCurveFromArc(XPoint point1, XPoint point2, XSize size,
            double rotationAngle, bool isLargeArc, bool clockwise, PathStart pathStart)
        {
            // See also http://www.charlespetzold.com/blog/blog.xml from January 2, 2008: 
            // http://www.charlespetzold.com/blog/2008/01/Mathematics-of-ArcSegment.html
            double δx = size.Width;
            double δy = size.Height;
            Debug.Assert(δx * δy > 0);
            double factor = δy / δx;
            bool isCounterclockwise = !clockwise;

            // Adjust for different radii and rotation angle.
            XMatrix matrix = new XMatrix();
            matrix.RotateAppend(-rotationAngle);
            matrix.ScaleAppend(δy / δx, 1);
            XPoint pt1 = matrix.Transform(point1);
            XPoint pt2 = matrix.Transform(point2);

            // Get info about chord that connects both points.
            XPoint midPoint = new XPoint((pt1.X + pt2.X) / 2, (pt1.Y + pt2.Y) / 2);
            XVector vect = pt2 - pt1;
            double halfChord = vect.Length / 2;

            // Get vector from chord to center.
            XVector vectRotated;

            // (comparing two Booleans here!)
            if (isLargeArc == isCounterclockwise)
                vectRotated = new XVector(-vect.Y, vect.X);
            else
                vectRotated = new XVector(vect.Y, -vect.X);

            vectRotated.Normalize();

            // Distance from chord to center.
            double centerDistance = Math.Sqrt(δy * δy - halfChord * halfChord);
            if (double.IsNaN(centerDistance))
                centerDistance = 0;

            // Calculate center point.
            XPoint center = midPoint + centerDistance * vectRotated;

            // Get angles from center to the two points.
            double α = Math.Atan2(pt1.Y - center.Y, pt1.X - center.X);
            double β = Math.Atan2(pt2.Y - center.Y, pt2.X - center.X);

            // (another comparison of two Booleans!)
            if (isLargeArc == (Math.Abs(β - α) < Math.PI))
            {
                if (α < β)
                    α += 2 * Math.PI;
                else
                    β += 2 * Math.PI;
            }

            // Invert matrix for final point calculation.
            matrix.Invert();
            double sweepAngle = β - α;

            // Let the algorithm of GDI+ DrawArc to Bézier curves do the rest of the job
            return BezierCurveFromArc(center.X - δx * factor, center.Y - δy, 2 * δx * factor, 2 * δy,
              α / Calc.Deg2Rad, sweepAngle / Calc.Deg2Rad, pathStart, ref matrix);
        }

    /// <summary>
    /// Some test code to check that there are no typing errors in the formulars.
    /// </summary>
    public static void Test()
    {
      XMatrix xm1 = new XMatrix(23, -35, 837, 332, -3, 12);
      Matrix  m1 = new Matrix(23, -35, 837, 332, -3, 12);
      DumpMatrix(xm1, m1);
      XMatrix xm2 = new XMatrix(12, 235, 245, 42, 33, -56);
      Matrix  m2 = xm2.ToMatrix();
      DumpMatrix(xm2, m2);

//      xm1.Multiply(xm2, XMatrixOrder.Prepend);
//      m1.Multiply(m2, MatrixOrder.Append);
      xm1.Multiply(xm2, XMatrixOrder.Append);
      m1.Multiply(m2, MatrixOrder.Append);
      DumpMatrix(xm1, m1);

      xm1.Translate(-243, 342, XMatrixOrder.Append);
      m1.Translate(-243, 342, MatrixOrder.Append);
      DumpMatrix(xm1, m1);

      xm1.Scale(-5.66, 7.87);
      m1.Scale(-5.66f, 7.87f);
//      xm1.Scale(-5.66, 7.87, XMatrixOrder.Prepend);
//      m1.Scale(-5.66f, 7.87f, MatrixOrder.Prepend);
      DumpMatrix(xm1, m1);


      xm1.Rotate(135, XMatrixOrder.Append);
      m1.Rotate(135, MatrixOrder.Append);
      //      xm1.Scale(-5.66, 7.87, XMatrixOrder.Prepend);
      //      m1.Scale(-5.66f, 7.87f, MatrixOrder.Prepend);
      DumpMatrix(xm1, m1);

      xm1.RotateAt(177, new XPoint(-3456, 654), XMatrixOrder.Append);
      m1.RotateAt(177, new PointF(-3456, 654), MatrixOrder.Append);
      DumpMatrix(xm1, m1);

      xm1.Shear(0.76, -0.87, XMatrixOrder.Prepend);
      m1.Shear(0.76f, -0.87f, MatrixOrder.Prepend);
      DumpMatrix(xm1, m1);

      xm1 = new XMatrix(23, -35, 837, 332, -3, 12);
      m1 = new Matrix(23, -35, 837, 332, -3, 12);

      XPoint[] xpoints = new XPoint[3]{new XPoint(23, 10), new XPoint(-27, 120), new XPoint(-87, -55)};
      PointF[] points = new PointF[3]{new PointF(23, 10), new PointF(-27, 120), new PointF(-87, -55)};

      xm1.TransformPoints(xpoints);
      m1.TransformPoints(points);

      xm1.Invert();
      m1.Invert();
      DumpMatrix(xm1, m1);

    }