'''' This code is part of Document Solutions for Imaging demos.'' Copyright (c) MESCIUS inc. All rights reserved.''Imports System.IOImports System.DrawingImports GrapeCity.Documents.DrawingImports GrapeCity.Documents.TextImports GrapeCity.Documents.ImagingImports GCTEXT = GrapeCity.Documents.TextImports GCDRAW = GrapeCity.Documents.Drawing
Public Class BlendText    Function GenerateImage(            ByVal pixelSize As Size,            ByVal dpi As Single,            ByVal opaque As Boolean,            Optional ByVal sampleParams As String() = Nothing) As GcBitmap
        Dim ispectr = GCDRAW.Image.FromFile(Path.Combine("Resources", "ImagesBis", "spectrum-500x500.png"))        Const margin As Integer = 36        Const NCOLS As Integer = 4        Dim w As Integer = CInt((pixelSize.Width - margin * 2) / NCOLS)        Dim h As Integer = w \ 2        Dim row As Integer = 0, col As Integer = 0        Dim bottomy As Single = 0.0F
        Dim bmp = New GcBitmap(pixelSize.Width, pixelSize.Height, opaque, dpi, dpi)        Using g = bmp.CreateGraphics(Color.White)            ' Text layout for captions:            Dim tl = g.CreateTextLayout()            tl.DefaultFormat.Font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "FreeMonoBold.ttf"))            tl.DefaultFormat.FontSize = 22            tl.ParagraphAlignment = ParagraphAlignment.Center            tl.TextAlignment = TextAlignment.Center            tl.MaxWidth = w            tl.MaxHeight = h            tl.MarginTop = CSng((h - h / 1.4F) / 2.0F)            tl.DefaultFormat.ForeColor = Color.Black            Dim tfWhite = New TextFormat(tl.DefaultFormat) With {.ForeColor = Color.White}
            ' Render all blend modes in a grid:            For Each mode In [Enum].GetValues(GetType(BlendMode))                Dim blendMode As BlendMode = CType(mode, BlendMode)                If Not g.IsBlendModeSupported(blendMode) Then Continue For
                Dim x As Integer = margin + w * col                Dim y As Integer = margin + h * row                Dim r = New RectangleF(x, y, w, h)
                ' Draw spectrum image normally:                g.BlendMode = BlendMode.Normal                g.DrawImage(ispectr, r, Nothing, ImageAlign.StretchImage)
                ' Draw blend mode name using the current blend mode:                tl.Clear()                tl.AppendLine("B: " & blendMode.ToString())                tl.Append("W: " & blendMode.ToString(), tfWhite)                tl.PerformLayout(True)                Dim rc = tl.ContentRectangle                rc.Offset(x, y)                rc.Inflate(4, 2)
                ' Current blend mode:                g.BlendMode = blendMode                g.DrawTextLayout(tl, New PointF(x, y))
                ' Draw spectrum image again using BlendMode.Difference                ' to produce (mostly) colorful text on black background:                g.BlendMode = BlendMode.Difference                g.DrawImage(ispectr, r, Nothing, ImageAlign.StretchImage)
                ' Draw a rectangle to mark the current area:                g.BlendMode = BlendMode.Normal                g.DrawRectangle(r, Color.Gray)
                bottomy = r.Bottom                col += 1                If col = NCOLS Then                    col = 0                    row += 1                End If            Next
            ' For reference, draw the backdrop:            tl.Clear()            tl.MarginAll = 0            tl.MaxWidth = bmp.PixelWidth            tl.MaxHeight = Nothing            tl.DefaultFormat.FontSize = 14            tl.TextAlignment = TextAlignment.Leading            tl.ParagraphAlignment = ParagraphAlignment.Near            tl.Append("The spectrum image used as the backdrop for the texts above:")            g.DrawTextLayout(tl, New PointF(margin, bottomy + margin))            g.DrawImage(ispectr,                        New RectangleF(margin, bottomy + margin + tl.ContentHeight + 24, w, w),                        Nothing, ImageAlign.StretchImage)        End Using
        Return bmp    End FunctionEnd Class