public override void OnDraw()
        {
#if SourceDepth24
            FormatRGB pixf = new FormatRGB(rbuf_window(), new BlenderBGR());
#else
            pixfmt_alpha_blend_rgba32 pixf      = new pixfmt_alpha_blend_rgba32(rbuf_window(), new blender_bgra32());
            pixfmt_alpha_blend_rgba32 pixfImage = new pixfmt_alpha_blend_rgba32(rbuf_img(0), new blender_bgra32());
#endif
            FormatClippingProxy clippingProxy = new FormatClippingProxy(pixf);

            clippingProxy.Clear(new RGBA_Doubles(1.0, 1.0, 1.0));
            clippingProxy.CopyFrom(rbuf_img(0), new RectInt(0, 0, (int)Width.ToInt(), (int)Height.ToInt()), 110, 35);

            string      buf = string.Format("NSteps={0:F0}", m_num_steps);
            GsvText <T> t   = new GsvText <T>();
            t.StartPoint(10.0, 295.0);
            t.SetFontSize(10.0);
            t.Text = buf;

            ConvStroke <T> pt = new ConvStroke <T>(t);
            pt.Width = M.New <T>(1.5);

            m_Rasterizer.AddPath(pt);
            Renderer <T> .RenderSolid(clippingProxy, m_Rasterizer, m_ScanlinePacked, new RGBA_Bytes(0, 0, 0));

            if (m_time1 != m_time2 && m_num_pix > 0.0)
            {
                buf = string.Format("{0:F2} Kpix/sec", m_num_pix / (m_time2 - m_time1));
                t.StartPoint(10.0, 310.0);
                t.Text = buf;
                m_Rasterizer.AddPath(pt);
                Renderer <T> .RenderSolid(clippingProxy, m_Rasterizer, m_ScanlinePacked, new RGBA_Bytes(0, 0, 0));
            }

            if (m_filters.cur_item() >= 14)
            {
                m_radius.Visible = true;
            }
            else
            {
                m_radius.Visible = true;
            }

            base.OnDraw();
        }
        void transform_image(double angle)
        {
            double width  = rbuf_img(0).Width;
            double height = rbuf_img(0).Height;

#if SourceDepth24
            FormatRGB pixf     = new FormatRGB(rbuf_img(0), new BlenderBGR());
            FormatRGB pixf_pre = new FormatRGB(rbuf_img(0), new BlenderPreMultBGR());
#else
            pixfmt_alpha_blend_rgba32 pixf     = new pixfmt_alpha_blend_rgba32(rbuf_img(0), new blender_bgra32());
            pixfmt_alpha_blend_rgba32 pixf_pre = new pixfmt_alpha_blend_rgba32(rbuf_img(0), new blender_bgra_pre());
#endif
            FormatClippingProxy rb     = new FormatClippingProxy(pixf);
            FormatClippingProxy rb_pre = new FormatClippingProxy(pixf_pre);

            rb.Clear(new RGBA_Doubles(1.0, 1.0, 1.0));

            IAffineTransformMatrix <T> src_mtx = MatrixFactory <T> .NewIdentity(VectorDimension.Two);

            src_mtx.Translate(MatrixFactory <T> .CreateVector2D(-width / 2.0, -height / 2.0));
            src_mtx.RotateAlong(MatrixFactory <T> .CreateVector2D(0, 0), angle * Math.PI / 180.0);
            src_mtx.Translate(MatrixFactory <T> .CreateVector2D(width / 2.0, height / 2.0));

            IAffineTransformMatrix <T> img_mtx = MatrixFactory <T> .CreateAffine(src_mtx);

            img_mtx = img_mtx.Inverse;

            double r = width;
            if (height < r)
            {
                r = height;
            }

            r *= 0.5;
            r -= 4.0;
            VertexSource.Ellipse <T> ell = new AGG.VertexSource.Ellipse <T>(width / 2.0, height / 2.0, r, r, 200);
            ConvTransform <T>        tr  = new ConvTransform <T>(ell, src_mtx);

            m_num_pix += r * r * Math.PI;

            SpanInterpolatorLinear <T> interpolator = new SpanInterpolatorLinear <T>(img_mtx);

            ImageFilterLookUpTable <T> filter = new ImageFilterLookUpTable <T>();
            bool norm = m_normalize.status();

#if SourceDepth24
            FormatRGB pixf_img = new FormatRGB(rbuf_img(1), new BlenderBGR());
#else
            pixfmt_alpha_blend_rgba32 pixf_img = new pixfmt_alpha_blend_rgba32(rbuf_img(1), new blender_bgra32());
#endif
            RasterBufferAccessorClip source = new RasterBufferAccessorClip(pixf_img, RGBA_Doubles.RgbaPre(0, 0, 0, 0));

            switch (m_filters.cur_item())
            {
            case 0:
            {
#if SourceDepth24
                SpanImageFilterRgbNN <T> sg = new SpanImageFilterRgbNN <T>(source, interpolator);
#else
                span_image_filter_rgba_nn sg = new span_image_filter_rgba_nn(source, interpolator);
#endif
                m_Rasterizer.AddPath(tr);
                Renderer <T> .GenerateAndRender(m_Rasterizer, m_ScanlineUnpacked, rb_pre, m_SpanAllocator, sg);
            }
            break;

            case 1:
            {
#if SourceDepth24
                //span_image_filter_rgb_bilinear_clip sg = new span_image_filter_rgb_bilinear_clip(pixf_img, rgba.rgba_pre(0, 0.4, 0, 0.5), interpolator);
                SpanImageFilterRgbBilinear <T> sg = new SpanImageFilterRgbBilinear <T>(source, interpolator);
#else
                //span_image_filter_rgba_bilinear_clip sg = new span_image_filter_rgba_bilinear_clip(pixf_img, rgba.rgba_pre(0, 0, 0, 0), interpolator);
                span_image_filter_rgba_bilinear sg = new span_image_filter_rgba_bilinear(source, interpolator);
#endif
                m_Rasterizer.AddPath(tr);
                Renderer <T> .GenerateAndRender(m_Rasterizer, m_ScanlineUnpacked, rb_pre, m_SpanAllocator, sg);
            }
            break;

            case 5:
            case 6:
            case 7:
            {
                switch (m_filters.cur_item())
                {
                case 5: filter.Calculate(new ImageFilterHanning <T>(), norm); break;

                case 6: filter.Calculate(new ImageFilterHamming <T>(), norm); break;

                case 7: filter.Calculate(new ImageFilterHermite <T>(), norm); break;
                }

                SpanImageFilterRgb2x2 <T> sg = new SpanImageFilterRgb2x2 <T>(source, interpolator, filter);
                m_Rasterizer.AddPath(tr);
                Renderer <T> .GenerateAndRender(m_Rasterizer, m_ScanlineUnpacked, rb_pre, m_SpanAllocator, sg);
            }
            break;

            case 2:
            case 3:
            case 4:
            case 8:
            case 9:
            case 10:
            case 11:
            case 12:
            case 13:
            case 14:
            case 15:
            case 16:
            {
                switch (m_filters.cur_item())
                {
                case 2: filter.Calculate(new ImageFilterBicubic <T>(), norm); break;

                case 3: filter.Calculate(new ImageFilterSpline16 <T>(), norm); break;

                case 4: filter.Calculate(new ImageFilterSpline36 <T>(), norm); break;

                case 8: filter.Calculate(new ImageFilterKaiser <T>(), norm); break;

                case 9: filter.Calculate(new ImageFilterQuadric <T>(), norm); break;

                case 10: filter.Calculate(new ImageFilterCatrom <T>(), norm); break;

                case 11: filter.Calculate(new ImageFilterGaussian <T>(), norm); break;

                case 12: filter.Calculate(new ImageFilterBessel <T>(), norm); break;

                case 13: filter.Calculate(new ImageFilterMitchell <T>(), norm); break;

                case 14: filter.Calculate(new ImageFilterSinc <T>(m_radius.value()), norm); break;

                case 15: filter.Calculate(new ImageFilterLanczos <T>(m_radius.value()), norm); break;

                case 16:
                    filter.Calculate(new ImageFilterBlackman <T>(m_radius.value()), norm);
                    break;
                }

#if SourceDepth24
                SpanImageFilterRgb <T> sg = new SpanImageFilterRgb <T>(source, interpolator, filter);
#else
                span_image_filter_rgb sg = new span_image_filter_rgba(source, interpolator, filter);
#endif
                m_Rasterizer.AddPath(tr);
                Renderer <T> .GenerateAndRender(m_Rasterizer, m_ScanlineUnpacked, rb_pre, m_SpanAllocator, sg);
            }
            break;
            }
        }