Draw 2D graphics

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Drawing engine for drawing of 2D graphics

VintaSoft Imaging .NET SDK provides DrawingEngine class that defines interface for drawing of 2D graphics:

draw/render image
draw/fill/blend graphic path
draw polygon/lines
draw/fill rectangle/ellipse/pie/arc
draw/measure text
clip the drawing region
apply transformation to the drawing engine

Also VintaSoft Imaging .NET SDK provides ready-to-use implementations of drawing engine:

SkiaSharpDrawingEngine - cross-platform raster drawing engine, which is based on SkiaSharp library and allows to draw 2D graphics on raster image in Windows, Linux, macOS.
GdiGraphics - raster drawing engine, which is based on System.Drawing.Common library and allows to draw 2D graphics on raster image in Windows only.
PdfDrawingEngine - vector PDF drawing engine that allows to draw 2D graphics on PDF page (this drawing engine uses drawing engine SkiaSharpDrawingEngine or GdiGraphics).
SvgDrawingEngine - vector drawing engine that allows to draw 2D graphics on SVG image (this drawing engine uses drawing engine SkiaSharpDrawingEngine or GdiGraphics).
CompositeDrawingEngine - drawing engine, which combines behaviour of two drawing engines.

The licensed version of VintaSoft Imaging .NET SDK allows to create custom drawing engine or override behaviour of existing drawing engine. The evaluation version of SDK does not allow to create custom drawing engine or override behaviour of existing drawing engine.

Here is C#/VB.NET code that shows how to draw 2D graphics and text on PDF page:

using System.Drawing;

using Vintasoft.Imaging;
using Vintasoft.Imaging.Drawing;
using Vintasoft.Imaging.Pdf;
using Vintasoft.Imaging.Pdf.Drawing;
using Vintasoft.Imaging.Pdf.Tree;

namespace CSHARP
{
    class PdfDrawingEngineExample
    {
        /// <summary>
        /// Creates PDF drawing engine on specified PDF page and performs drawing.
        /// </summary>
        /// <param name="width">PDF page width.</param>
        /// <param name="height">PDF page height.</param>
        /// <param name="resultImagePath">A path to save the drawing result.</param>
        public static void DrawWithPdfDrawingEngine(int width, int height, string resultImagePath)
        {
            // create empty PDF document
            using (PdfDocument document = new PdfDocument())
            {
                // page size
                RectangleF pageSize = new RectangleF(0, 0, width, height);
                // create new page of specified size
                PdfPage page = new PdfPage(document, pageSize);
                // add page to a PDF document
                document.Pages.Add(page);

                // create graphics from PDF page
                using (PdfGraphics graphics = PdfGraphics.FromPage(page))
                // create drawing engine
                using (PdfDrawingEngine drawingEngine = new PdfDrawingEngine(graphics, true))
                {
                    // create drawing area
                    RectangleF drawingArea = new RectangleF(0, 0, width, height);
                    // draw objects
                    DrawingExample(drawingEngine, drawingArea);
                }

                // save document
                document.Save(resultImagePath);
            }
        }

        /// <summary>
        /// Draws graphic objects using specified drawing engine.
        /// </summary>
        /// <param name="drawingEngine">Drawing engine.</param>
        /// <param name="drawingArea">Image area to draw objects in.</param>
        public static void DrawingExample(DrawingEngine drawingEngine, RectangleF drawingArea)
        {
            // create bounding rectangle for ellipse
            RectangleF ellipseRect = new RectangleF(
                drawingArea.X + drawingArea.Width * 0.3f,
                drawingArea.Y + drawingArea.Height * 0.3f,
                drawingArea.Width * 0.4f,
                drawingArea.Height * 0.4f);

            // create brush and pen to draw ellipse
            using (IDrawingSolidBrush brush = drawingEngine.DrawingFactory.CreateSolidBrush(Color.Blue))
            {
                using (IDrawingPen pen = drawingEngine.DrawingFactory.CreatePen(Color.Red, 4f))
                {
                    // fill ellipse
                    drawingEngine.FillEllipse(brush, ellipseRect);
                    // stroke ellipse
                    drawingEngine.DrawEllipse(pen, ellipseRect);
                }
            }

            // create brush and font to draw text
            using (IDrawingSolidBrush textBrush = drawingEngine.DrawingFactory.CreateSolidBrush(Color.Yellow))
            {
                using (IDrawingFont font = drawingEngine.DrawingFactory.CreateFont("Arial", 30, true, false))
                {
                    // create properties to layout text
                    TextLayoutProperties layoutProperties = new TextLayoutProperties(AnchorType.Center);
                    // draw text
                    drawingEngine.DrawText("Text", font, textBrush, ellipseRect, layoutProperties);
                }
            }
        }
    }
}

VB.NET

Imports System.Drawing

Imports Vintasoft.Imaging
Imports Vintasoft.Imaging.Drawing
Imports Vintasoft.Imaging.Pdf
Imports Vintasoft.Imaging.Pdf.Drawing
Imports Vintasoft.Imaging.Pdf.Tree

Class PdfDrawingEngineExample
    ''' <summary>
    ''' Creates PDF drawing engine on specified PDF page and performs drawing.
    ''' </summary>
    ''' <param name="width">PDF page width.</param>
    ''' <param name="height">PDF page height.</param>
    ''' <param name="resultImagePath">A path to save the drawing result.</param>
    Public Shared Sub DrawWithPdfDrawingEngine(width As Integer, height As Integer, resultImagePath As String)
        ' create empty PDF document
        Using document As New PdfDocument()
            ' page size
            Dim pageSize As New RectangleF(0, 0, width, height)
            ' create new page of specified size
            Dim page As New PdfPage(document, pageSize)
            ' add page to a PDF document
            document.Pages.Add(page)

            ' create graphics from PDF page
            Using graphics As PdfGraphics = PdfGraphics.FromPage(page)
                ' create drawing engine
                Using drawingEngine As New PdfDrawingEngine(graphics, True)
                    ' create drawing area
                    Dim drawingArea As New RectangleF(0, 0, width, height)
                    ' draw objects
                    DrawingExample(drawingEngine, drawingArea)
                End Using
            End Using

            ' save document
            document.Save(resultImagePath)
        End Using
    End Sub

    ''' <summary>
    ''' Draws graphic objects using specified drawing engine.
    ''' </summary>
    ''' <param name="drawingEngine">Drawing engine.</param>
    ''' <param name="drawingArea">Image area to draw objects in.</param>
    Public Shared Sub DrawingExample(drawingEngine As DrawingEngine, drawingArea As RectangleF)
        ' create bounding rectangle for ellipse
        Dim ellipseRect As New RectangleF(drawingArea.X + drawingArea.Width * 0.3F, drawingArea.Y + drawingArea.Height * 0.3F, drawingArea.Width * 0.4F, drawingArea.Height * 0.4F)

        ' create brush and pen to draw ellipse
        Using brush As IDrawingSolidBrush = drawingEngine.DrawingFactory.CreateSolidBrush(Color.Blue)
            Using pen As IDrawingPen = drawingEngine.DrawingFactory.CreatePen(Color.Red, 4F)
                ' fill ellipse
                drawingEngine.FillEllipse(brush, ellipseRect)
                ' stroke ellipse
                drawingEngine.DrawEllipse(pen, ellipseRect)
            End Using
        End Using

        ' create brush and font to draw text
        Using textBrush As IDrawingSolidBrush = drawingEngine.DrawingFactory.CreateSolidBrush(Color.Yellow)
            Using font As IDrawingFont = drawingEngine.DrawingFactory.CreateFont("Arial", 30, True, False)
                ' create properties to layout text
                Dim layoutProperties As New TextLayoutProperties(AnchorType.Center)
                ' draw text
                drawingEngine.DrawText("Text", font, textBrush, ellipseRect, layoutProperties)
            End Using
        End Using
    End Sub
End Class

Here is C#/VB.NET code that shows how to draw 2D graphics and text on SVG page:

using System.Drawing;
using System.Xml;

using Vintasoft.Imaging;
using Vintasoft.Imaging.Drawing;
using Vintasoft.Imaging.Drawing.Svg;

namespace CSHARP
{
    class SvgDrawingEngineExample
    {
        /// <summary>
        /// Creates SVG drawing engine on specified image and performs drawing.
        /// </summary>
        /// <param name="width">SVG image width.</param>
        /// <param name="height">SVG image height.</param>
        /// <param name="resultImagePath">A path to save the result SVG image.</param>
        public static void DrawWithSvgDrawingEngine(int width, int height, string resultImagePath)
        {
            // create drawing engine
            using (SvgDrawingEngine drawingEngine = new SvgDrawingEngine(width, height))
            {
                // create drawing area
                RectangleF drawingArea = new RectangleF(0, 0, width, height);
                // draw objects
                DrawingExample(drawingEngine, drawingArea);

                // create XML writer
                using (XmlWriter xmlWriter = XmlWriter.Create(resultImagePath))
                {
                    // get SVG content
                    SvgContent content = drawingEngine.GetContent();
                    // save SVG image
                    content.Save(xmlWriter);
                }
            }
        }

        /// <summary>
        /// Draws graphic objects using specified drawing engine.
        /// </summary>
        /// <param name="drawingEngine">Drawing engine.</param>
        /// <param name="drawingArea">Image area to draw objects in.</param>
        public static void DrawingExample(DrawingEngine drawingEngine, RectangleF drawingArea)
        {
            // create bounding rectangle for ellipse
            RectangleF ellipseRect = new RectangleF(
                drawingArea.X + drawingArea.Width * 0.3f,
                drawingArea.Y + drawingArea.Height * 0.3f,
                drawingArea.Width * 0.4f,
                drawingArea.Height * 0.4f);

            // create brush and pen to draw ellipse
            using (IDrawingSolidBrush brush = drawingEngine.DrawingFactory.CreateSolidBrush(Color.Blue))
            {
                using (IDrawingPen pen = drawingEngine.DrawingFactory.CreatePen(Color.Red, 4f))
                {
                    // fill ellipse
                    drawingEngine.FillEllipse(brush, ellipseRect);
                    // stroke ellipse
                    drawingEngine.DrawEllipse(pen, ellipseRect);
                }
            }

            // create brush and font to draw text
            using (IDrawingSolidBrush textBrush = drawingEngine.DrawingFactory.CreateSolidBrush(Color.Yellow))
            {
                using (IDrawingFont font = drawingEngine.DrawingFactory.CreateFont("Arial", 30, true, false))
                {
                    // create properties to layout text
                    TextLayoutProperties layoutProperties = new TextLayoutProperties(AnchorType.Center);
                    // draw text
                    drawingEngine.DrawText("Text", font, textBrush, ellipseRect, layoutProperties);
                }
            }
        }
    }
}

VB.NET

Imports System.Drawing
Imports System.Xml

Imports Vintasoft.Imaging
Imports Vintasoft.Imaging.Drawing
Imports Vintasoft.Imaging.Drawing.Svg

Class SvgDrawingEngineExample
    ''' <summary>
    ''' Creates SVG drawing engine on specified image and performs drawing.
    ''' </summary>
    ''' <param name="width">SVG image width.</param>
    ''' <param name="height">SVG image height.</param>
    ''' <param name="resultImagePath">A path to save the result SVG image.</param>
    Public Shared Sub DrawWithSvgDrawingEngine(width As Integer, height As Integer, resultImagePath As String)
        ' create drawing engine
        Using drawingEngine As New SvgDrawingEngine(width, height)
            ' create drawing area
            Dim drawingArea As New RectangleF(0, 0, width, height)
            ' draw objects
            DrawingExample(drawingEngine, drawingArea)

            ' create XML writer
            Using xmlWriter__1 As XmlWriter = XmlWriter.Create(resultImagePath)
                ' get SVG content
                Dim content As SvgContent = drawingEngine.GetContent()
                ' save SVG image
                content.Save(xmlWriter__1)
            End Using
        End Using
    End Sub

    ''' <summary>
    ''' Draws graphic objects using specified drawing engine.
    ''' </summary>
    ''' <param name="drawingEngine">Drawing engine.</param>
    ''' <param name="drawingArea">Image area to draw objects in.</param>
    Public Shared Sub DrawingExample(drawingEngine As DrawingEngine, drawingArea As RectangleF)
        ' create bounding rectangle for ellipse
        Dim ellipseRect As New RectangleF(drawingArea.X + drawingArea.Width * 0.3F, drawingArea.Y + drawingArea.Height * 0.3F, drawingArea.Width * 0.4F, drawingArea.Height * 0.4F)

        ' create brush and pen to draw ellipse
        Using brush As IDrawingSolidBrush = drawingEngine.DrawingFactory.CreateSolidBrush(Color.Blue)
            Using pen As IDrawingPen = drawingEngine.DrawingFactory.CreatePen(Color.Red, 4F)
                ' fill ellipse
                drawingEngine.FillEllipse(brush, ellipseRect)
                ' stroke ellipse
                drawingEngine.DrawEllipse(pen, ellipseRect)
            End Using
        End Using

        ' create brush and font to draw text
        Using textBrush As IDrawingSolidBrush = drawingEngine.DrawingFactory.CreateSolidBrush(Color.Yellow)
            Using font As IDrawingFont = drawingEngine.DrawingFactory.CreateFont("Arial", 30, True, False)
                ' create properties to layout text
                Dim layoutProperties As New TextLayoutProperties(AnchorType.Center)
                ' draw text
                drawingEngine.DrawText("Text", font, textBrush, ellipseRect, layoutProperties)
            End Using
        End Using
    End Sub
End Class

Drawing factory

VintaSoft Imaging .NET SDK provides DrawingFactory class that defines interface for creating of drawing primitives (pen, brush, font, bitmap, etc) for drawing engine:

create pen
create solid brush, image brush, linear gradient brush, hatch brush
create graphics path
create region
create bitmap
create font, create fallback font
create line cap

Also VintaSoft Imaging .NET SDK provides ready-to-use implementations of drawing factory:

SkiaSharpDrawingFactory - the drawing factory for SkiaSharpDrawingEngine drawing engine. This factory is used as the default drawing factory if application is executed in Linux or macOS.
GdiGraphicsFactory - the drawing factory for GdiGraphics drawing engine. This factory is used as the default drawing factory if application is executed in Windows.

The DrawingFactory.Default property allows to get or set the default drawing factory. For example, it is possible to set SkiaSharpDrawingFactory as the default drawing factory for Windows.

Here is C#/VB.NET code that shows how to set the default drawing factory:

/// <summary>
/// Sets the SKIA Sharp drawing factory as a default drawing factory.
/// </summary>
public static void SetSkiaSharpSdkDrawing()
{
    // Skia - cross platform drawing engine
    Vintasoft.Imaging.Drawing.SkiaSharp.SkiaSharpDrawingFactory.SetAsDefault();
}

/// <summary>
/// Sets the GDI drawing factory as a default drawing factory.
/// </summary>
public static void SetGdiSdkDrawing()
{
    // GDI - Windows graphics
    Vintasoft.Imaging.Drawing.Gdi.GdiGraphicsFactory.SetAsDefault();
}

VB.NET

''' <summary>
''' Sets the SKIA Sharp drawing factory as a default drawing factory.
''' </summary>
Public Shared Sub SetSkiaSharpSdkDrawing()
    ' Skia - cross platform drawing engine
    Vintasoft.Imaging.Drawing.SkiaSharp.SkiaSharpDrawingFactory.SetAsDefault()
End Sub

''' <summary>
''' Sets the GDI drawing factory as a default drawing factory.
''' </summary>
Public Shared Sub SetGdiSdkDrawing()
    ' GDI - Windows graphics
    Vintasoft.Imaging.Drawing.Gdi.GdiGraphicsFactory.SetAsDefault()
End Sub

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