ImageSharp/src/ImageSharp.Drawing/Text/DrawText.cs

// <copyright file="DrawText.cs" company="James Jackson-South">
// Copyright (c) James Jackson-South and contributors.
// Licensed under the Apache License, Version 2.0.
// </copyright>

namespace ImageSharp
{
    using System.Numerics;

    using Drawing;
    using Drawing.Brushes;
    using Drawing.Pens;

    using SixLabors.Fonts;

    /// <summary>
    /// Extension methods for the <see cref="Image{TColor}"/> type.
    /// </summary>
    public static partial class ImageExtensions
    {
        private static readonly Vector2 DefaultTextDpi = new Vector2(72);

        /// <summary>
        /// Draws the text onto the the image filled via the brush.
        /// </summary>
        /// <typeparam name="TColor">The type of the color.</typeparam>
        /// <param name="source">The image this method extends.</param>
        /// <param name="text">The text.</param>
        /// <param name="font">The font.</param>
        /// <param name="color">The color.</param>
        /// <param name="location">The location.</param>
        /// <returns>
        /// The <see cref="Image{TColor}" />.
        /// </returns>
        public static Image<TColor> DrawText<TColor>(this Image<TColor> source, string text, Font font, TColor color, Vector2 location)
           where TColor : struct, IPixel<TColor>
        {
            return source.DrawText(text, font, color, location, TextGraphicsOptions.Default);
        }

        /// <summary>
        /// Draws the text onto the the image filled via the brush.
        /// </summary>
        /// <typeparam name="TColor">The type of the color.</typeparam>
        /// <param name="source">The image this method extends.</param>
        /// <param name="text">The text.</param>
        /// <param name="font">The font.</param>
        /// <param name="color">The color.</param>
        /// <param name="location">The location.</param>
        /// <param name="options">The options.</param>
        /// <returns>
        /// The <see cref="Image{TColor}" />.
        /// </returns>
        public static Image<TColor> DrawText<TColor>(this Image<TColor> source, string text, Font font, TColor color, Vector2 location, TextGraphicsOptions options)
           where TColor : struct, IPixel<TColor>
        {
            return source.DrawText(text, font, Brushes<TColor>.Solid(color), null, location, options);
        }

        /// <summary>
        /// Draws the text onto the the image filled via the brush.
        /// </summary>
        /// <typeparam name="TColor">The type of the color.</typeparam>
        /// <param name="source">The image this method extends.</param>
        /// <param name="text">The text.</param>
        /// <param name="font">The font.</param>
        /// <param name="brush">The brush.</param>
        /// <param name="location">The location.</param>
        /// <returns>
        /// The <see cref="Image{TColor}" />.
        /// </returns>
        public static Image<TColor> DrawText<TColor>(this Image<TColor> source, string text, Font font, IBrush<TColor> brush, Vector2 location)
           where TColor : struct, IPixel<TColor>
        {
            return source.DrawText(text, font, brush, location, TextGraphicsOptions.Default);
        }

        /// <summary>
        /// Draws the text onto the the image filled via the brush.
        /// </summary>
        /// <typeparam name="TColor">The type of the color.</typeparam>
        /// <param name="source">The image this method extends.</param>
        /// <param name="text">The text.</param>
        /// <param name="font">The font.</param>
        /// <param name="brush">The brush.</param>
        /// <param name="location">The location.</param>
        /// <param name="options">The options.</param>
        /// <returns>
        /// The <see cref="Image{TColor}" />.
        /// </returns>
        public static Image<TColor> DrawText<TColor>(this Image<TColor> source, string text, Font font, IBrush<TColor> brush, Vector2 location, TextGraphicsOptions options)
           where TColor : struct, IPixel<TColor>
        {
            return source.DrawText(text, font, brush, null, location, options);
        }

        /// <summary>
        /// Draws the text onto the the image outlined via the pen.
        /// </summary>
        /// <typeparam name="TColor">The type of the color.</typeparam>
        /// <param name="source">The image this method extends.</param>
        /// <param name="text">The text.</param>
        /// <param name="font">The font.</param>
        /// <param name="pen">The pen.</param>
        /// <param name="location">The location.</param>
        /// <returns>
        /// The <see cref="Image{TColor}" />.
        /// </returns>
        public static Image<TColor> DrawText<TColor>(this Image<TColor> source, string text, Font font, IPen<TColor> pen, Vector2 location)
           where TColor : struct, IPixel<TColor>
        {
            return source.DrawText(text, font, pen, location, TextGraphicsOptions.Default);
        }

        /// <summary>
        /// Draws the text onto the the image outlined via the pen.
        /// </summary>
        /// <typeparam name="TColor">The type of the color.</typeparam>
        /// <param name="source">The image this method extends.</param>
        /// <param name="text">The text.</param>
        /// <param name="font">The font.</param>
        /// <param name="pen">The pen.</param>
        /// <param name="location">The location.</param>
        /// <param name="options">The options.</param>
        /// <returns>
        /// The <see cref="Image{TColor}" />.
        /// </returns>
        public static Image<TColor> DrawText<TColor>(this Image<TColor> source, string text, Font font, IPen<TColor> pen, Vector2 location, TextGraphicsOptions options)
           where TColor : struct, IPixel<TColor>
        {
            return source.DrawText(text, font, null, pen, location, options);
        }

        /// <summary>
        /// Draws the text onto the the image filled via the brush then outlined via the pen.
        /// </summary>
        /// <typeparam name="TColor">The type of the color.</typeparam>
        /// <param name="source">The image this method extends.</param>
        /// <param name="text">The text.</param>
        /// <param name="font">The font.</param>
        /// <param name="brush">The brush.</param>
        /// <param name="pen">The pen.</param>
        /// <param name="location">The location.</param>
        /// <returns>
        /// The <see cref="Image{TColor}" />.
        /// </returns>
        public static Image<TColor> DrawText<TColor>(this Image<TColor> source, string text, Font font, IBrush<TColor> brush, IPen<TColor> pen, Vector2 location)
           where TColor : struct, IPixel<TColor>
        {
            return source.DrawText(text, font, brush, pen, location, TextGraphicsOptions.Default);
        }

        /// <summary>
        /// Draws the text onto the the image filled via the brush then outlined via the pen.
        /// </summary>
        /// <typeparam name="TColor">The type of the color.</typeparam>
        /// <param name="source">The image this method extends.</param>
        /// <param name="text">The text.</param>
        /// <param name="font">The font.</param>
        /// <param name="brush">The brush.</param>
        /// <param name="pen">The pen.</param>
        /// <param name="location">The location.</param>
        /// <param name="options">The options.</param>
        /// <returns>
        /// The <see cref="Image{TColor}" />.
        /// </returns>
        public static Image<TColor> DrawText<TColor>(this Image<TColor> source, string text, Font font, IBrush<TColor> brush, IPen<TColor> pen, Vector2 location, TextGraphicsOptions options)
           where TColor : struct, IPixel<TColor>
        {
            GlyphBuilder glyphBuilder = new GlyphBuilder(location);

            TextRenderer renderer = new TextRenderer(glyphBuilder);

            Vector2 dpi = DefaultTextDpi;
            if (options.UseImageResolution)
            {
                dpi = new Vector2((float)source.MetaData.HorizontalResolution, (float)source.MetaData.VerticalResolution);
            }

            FontSpan style = new FontSpan(font, dpi)
            {
                ApplyKerning = options.ApplyKerning,
                TabWidth = options.TabWidth,
                WrappingWidth = options.WrapTextWidth
            };

            renderer.RenderText(text, style);

            System.Collections.Generic.IEnumerable<SixLabors.Shapes.IPath> shapesToDraw = glyphBuilder.Paths;

            GraphicsOptions pathOptions = (GraphicsOptions)options;
            if (brush != null)
            {
                foreach (SixLabors.Shapes.IPath s in shapesToDraw)
                {
                    source.Fill(brush, s, pathOptions);
                }
            }

            if (pen != null)
            {
                foreach (SixLabors.Shapes.IPath s in shapesToDraw)
                {
                    source.Draw(pen, s, pathOptions);
                }
            }

            return source;
        }
    }
}