'''' This code is part of Document Solutions for Imaging demos.'' Copyright (c) MESCIUS inc. All rights reserved.''Imports SystemImports System.IOImports System.DrawingImports System.Collections.GenericImports System.LinqImports System.NumericsImports GrapeCity.Documents.DrawingImports GrapeCity.Documents.TextImports GrapeCity.Documents.ImagingImports GCTEXT = GrapeCity.Documents.TextImports GCDRAW = GrapeCity.Documents.Drawing
'' This sample demonstrates how to create a Glow effect using DsImaging.'' The Glow effect inflates all non-transparent areas of an image by a specified amount,'' then applies a Gaussian blur to make the border smooth. It is one of the effects'' that are found in MS Word for example.'' '' To achieve this effect in DsImaging, the GrayscaleBitmap.ApplyGlow() method is used'' on the transparency mask built from the color image on which we want the glow to appear,'' along with a few other simple steps as illustrated by this code.'''' This example shows how to achieve the glow effect without drawing the content'' (text and image) twice. See @{Glow} for an alternative way to achieve the same effect.Public Class GlowAlt    Private _font As GCTEXT.Font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "FreeSans.ttf"))
    Public Function GenerateImage(            ByVal pixelSize As Size,            ByVal dpi As Single,            ByVal opaque As Boolean,            Optional ByVal sampleParams As String() = Nothing) As GcBitmap
        '' Draw text and logo on a transparent bitmap:        Using bmpTemp As New GcBitmap(pixelSize.Width, pixelSize.Height, False)            bmpTemp.Clear(Color.Transparent)
            Dim renderer = bmpTemp.EnsureRendererCreated()            DrawText(renderer, pixelSize, dpi)            DrawLogo(renderer, New PointF(pixelSize.Width / 2, CInt(pixelSize.Height * 0.8)), pixelSize.Width / 2)
            '' Convert the image to a transparency mask:            Using gs = bmpTemp.ToGrayscaleBitmap(ColorChannel.Alpha)
                '' Apply the Glow effect; for Glow the inflation radius is positive (6), blur radius is 9:                gs.ApplyGlow(6, 9)
                '' Map a shadow from the transparency mask to a new bitmap,                '' drawing opaque pixels with glow color (Yellow) and some additional transparency:                Dim bmp = gs.ToShadowBitmap(Color.Yellow, 0.8F)
                '' Draw the text and logo over the glow.                bmp.AlphaBlend(bmpTemp, 0, 0)
                '' Fill the background:                bmp.ConvertToOpaque(Color.Gray)
                '' Done                Return bmp            End Using        End Using    End Function
    Private Sub DrawText(ByVal renderer As BitmapRenderer, ByVal pixelSize As Size, ByVal dpi As Single)        Dim f1 = New TextFormat With {            .Font = _font,            .FontSize = pixelSize.Height / 7,            .ForeColor = Color.DarkOrchid,            .FontBold = True        }        Dim f2 = New TextFormat(f1) With {            .ForeColor = Color.White,            .StrokePen = New GCDRAW.Pen(Color.DarkOrchid, 3)        }        Dim tl = New TextLayout(dpi) With {            .MaxWidth = pixelSize.Width,            .MaxHeight = pixelSize.Height,            .ParagraphAlignment = ParagraphAlignment.Near,            .TextAlignment = TextAlignment.Center,            .MarginTop = dpi * 2,            .LineSpacingScaleFactor = 0.7F        }        tl.AppendLine("Document", f1)        tl.AppendLine("Solutions", f2)
        '' Draw the text:        renderer.SlowAntialiasing = True        renderer.DrawTextLayout(tl, 0, 0)    End Sub
    Private Sub DrawLogo(ByVal renderer As BitmapRenderer, ByVal center As PointF, ByVal width As Single)        Dim pb = New PathBuilder()        pb.BeginFigure(100, 350)        pb.AddLine(210, 310)        Dim arc = New ArcSegment With {            .Size = New SizeF(183, 173),            .SweepDirection = SweepDirection.Clockwise,            .Point = New PointF(550, 205)        }        pb.AddArc(arc)        pb.AddLine(650, 170)        pb.AddLine(680, 250)        pb.AddLine(575, 285)        arc.Point = New PointF(240, 390)        pb.AddArc(arc)        pb.AddLine(130, 430)        pb.EndFigure(True)        pb.Figures.Add(New EllipticFigure(New RectangleF(295, 197, 200, 190)))        Dim gpFill = pb.ToPath()        Dim gpStroke = gpFill.Widen(New GCDRAW.Pen(Color.Black, 20))
        '' Our 'base' size is 800 x 600 pixels:        Dim scale As Single = width / 800        renderer.Transform = Matrix3x2.CreateScale(scale) *                             Matrix3x2.CreateTranslation(center.X - 400 * scale, center.Y - 300 * scale)        renderer.FillPath(gpFill, Color.CornflowerBlue)        renderer.FillPath(gpStroke, Color.DarkOrchid)        renderer.Transform = Matrix3x2.Identity    End SubEnd Class