移除依赖库

SpineViewerCLI/CanvasImageAscii.cs

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+using SkiaSharp;
+using Spectre.Console;
+using Spectre.Console.Rendering;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace SpineViewerCLI
+{
+    internal class CanvasImageAscii : Renderable
+    {
+        private static readonly SKSamplingOptions _defaultSamplingOptions = new(new SKCubicResampler());
+
+        /// <summary>
+        /// Gets the image width.
+        /// </summary>
+        public int Width => Image.Width;
+
+        /// <summary>
+        /// Gets the image height.
+        /// </summary>
+        public int Height => Image.Height;
+
+        /// <summary>
+        /// Gets or sets the render width of the canvas.
+        /// </summary>
+        public int? MaxWidth { get; set; }
+
+        /// <summary>
+        /// Gets or sets the render width of the canvas.
+        /// </summary>
+        public int PixelWidth { get; set; } = 2;
+
+        /// <summary>
+        /// Gets or sets the <see cref="SKSamplingOptions"/> that should
+        /// be used when scaling the image. Defaults to bicubic sampling.
+        /// </summary>
+        public SKSamplingOptions? SamplingOptions { get; set; }
+
+        internal SKBitmap Image { get; }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CanvasImageAscii"/> class.
+        /// </summary>
+        /// <param name="filename">The image filename.</param>
+        public CanvasImageAscii(string filename)
+        {
+            Image = SKBitmap.Decode(filename);
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CanvasImageAscii"/> class.
+        /// </summary>
+        /// <param name="data">Buffer containing an image.</param>
+        public CanvasImageAscii(ReadOnlySpan<byte> data)
+        {
+            Image = SKBitmap.Decode(data);
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CanvasImageAscii"/> class.
+        /// </summary>
+        /// <param name="data">Stream containing an image.</param>
+        public CanvasImageAscii(Stream data)
+        {
+            Image = SKBitmap.Decode(data);
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CanvasImageAscii"/> class.
+        /// </summary>
+        /// <param name="image">The <see cref="SKImage"/> object.</param>
+        public CanvasImageAscii(SKImage image)
+        {
+            Image = SKBitmap.FromImage(image);
+        }
+
+        /// <inheritdoc/>
+        protected override Measurement Measure(RenderOptions options, int maxWidth)
+        {
+            if (PixelWidth < 0)
+            {
+                throw new InvalidOperationException("Pixel width must be greater than zero.");
+            }
+
+            var width = MaxWidth ?? Width;
+            if (maxWidth < width * PixelWidth)
+            {
+                return new Measurement(maxWidth, maxWidth);
+            }
+
+            return new Measurement(width * PixelWidth, width * PixelWidth);
+        }
+
+        /// <inheritdoc/>
+        protected override IEnumerable<Segment> Render(RenderOptions options, int maxWidth)
+        {
+            var image = Image;
+
+            var width = Width;
+            var height = Height;
+
+            // Got a max width?
+            if (MaxWidth != null)
+            {
+                height = (int)(height * ((float)MaxWidth.Value) / Width);
+                width = MaxWidth.Value;
+            }
+
+            // Exceed the max width when we take pixel width into account?
+            if (width * PixelWidth > maxWidth)
+            {
+                height = (int)(height * (maxWidth / (float)(width * PixelWidth)));
+                width = maxWidth / PixelWidth;
+            }
+
+            // Need to rescale the pixel buffer?
+            if (width != Width || height != Height)
+            {
+                var samplingOptions = SamplingOptions ?? _defaultSamplingOptions;
+                image = image.Resize(new SKSizeI(width, height), samplingOptions);
+            }
+
+            var canvas = new CanvasAscii(width, height)
+            {
+                MaxWidth = MaxWidth,
+                PixelWidth = PixelWidth,
+                Scale = false,
+            };
+
+            // XXX: 也许是 SkiaSharp@3.119.0 的 bug, 此处像素值一定是非预乘的格式
+            for (var x = 0; x < image.Width; x++)
+            {
+                for (var y = 0; y < image.Height; y++)
+                {
+                    var p = image.GetPixel(x, y);
+                    if (p.Alpha == 0) continue;
+                    float a = p.Alpha / 255f;
+                    byte r = (byte)(p.Red * a);
+                    byte g = (byte)(p.Green * a);
+                    byte b = (byte)(p.Blue * a);
+                    canvas.SetPixel(x, y, new(r, g, b));
+                }
+            }
+
+            return ((IRenderable)canvas).Render(options, maxWidth);
+        }
+    }
+}