Add support for read/write of CorelDraw 3.0 palettes

src/PixiEditor/Helpers/Extensions/ServiceCollectionHelpers.cs

@@ -1,5 +1,4 @@
 using Microsoft.Extensions.DependencyInjection;
-using PixiEditor.Extensions;
 using PixiEditor.Extensions.Common.Localization;
 using PixiEditor.Extensions.Common.UserPreferences;
 using PixiEditor.Extensions.Palettes;
@@ -10,15 +9,12 @@ using PixiEditor.Models.AppExtensions.Services;
 using PixiEditor.Models.Commands;
 using PixiEditor.Models.Controllers;
 using PixiEditor.Models.DataProviders;
-using PixiEditor.Models.IO;
 using PixiEditor.Models.IO.PaletteParsers;
 using PixiEditor.Models.IO.PaletteParsers.JascPalFile;
 using PixiEditor.Models.Localization;
 using PixiEditor.Models.Preferences;
-using PixiEditor.ViewModels;
 using PixiEditor.ViewModels.SubViewModels.AdditionalContent;
 using PixiEditor.ViewModels.SubViewModels.Document;
-using PixiEditor.ViewModels.SubViewModels.Main;
 using PixiEditor.ViewModels.SubViewModels.Tools;
 using PixiEditor.ViewModels.SubViewModels.Tools.Tools;
 
@@ -75,6 +71,7 @@ internal static class ServiceCollectionHelpers
         // Palette Parsers
         .AddSingleton<PaletteFileParser, JascFileParser>()
         .AddSingleton<PaletteFileParser, ClsFileParser>()
+        .AddSingleton<PaletteFileParser, CorelDrawPalParser>()
         .AddSingleton<PaletteFileParser, PngPaletteParser>()
         .AddSingleton<PaletteFileParser, PaintNetTxtParser>()
         .AddSingleton<PaletteFileParser, HexPaletteParser>()

src/PixiEditor/Models/IO/PaletteParsers/CorelDrawPalParser.cs

@@ -0,0 +1,218 @@
+using System.IO;
+using System.Text;
+using PixiEditor.Extensions.Palettes;
+using PixiEditor.Extensions.Palettes.Parsers;
+
+namespace PixiEditor.Models.IO.PaletteParsers;
+
+internal class CorelDrawPalParser : PaletteFileParser
+{
+    public override string FileName { get; } = "CorelDRAW! 3.0 Palette";
+    public override string[] SupportedFileExtensions { get; } = { ".pal" };
+
+    // Default name to use for colors (color name is required by format)
+    private const string SWATCH_NAME = "PixiEditor Color";
+
+    public override async Task<PaletteFileData> Parse(string path)
+    {
+        try
+        {
+            return await ParseFile(path);
+        }
+        catch
+        {
+            return PaletteFileData.Corrupted;
+        }
+    }
+
+    private async Task<PaletteFileData> ParseFile(string path)
+    {
+        string name = Path.GetFileNameWithoutExtension(path);
+
+        List<PaletteColor> colors = new();
+
+        await using (Stream stream = File.OpenRead(path))
+        {
+            using (TextReader reader = new StreamReader(stream, Encoding.ASCII))
+            {
+                string line;
+
+                while ((line = reader.ReadLine()) != null && (line.Length == 0 || line[0] != (char)26))
+                {
+                    if (!string.IsNullOrEmpty(line))
+                    {
+                        int lastQuote;
+                        int numberPosition;
+                        byte cyan;
+                        byte magenta;
+                        byte yellow;
+                        byte black;
+
+                        lastQuote = line.LastIndexOf('"');
+
+                        if (lastQuote == -1)
+                        {
+                            return PaletteFileData.Corrupted; // Unable to parse line
+                        }
+
+                        numberPosition = lastQuote + 1;
+                        cyan = this.NextNumber(line, ref numberPosition);
+                        magenta = this.NextNumber(line, ref numberPosition);
+                        yellow = this.NextNumber(line, ref numberPosition);
+                        black = this.NextNumber(line, ref numberPosition);
+
+                        colors.Add(this.ConvertCmykToRgb(cyan, magenta, yellow, black));
+                    }
+                }
+            }
+        }
+
+        return new PaletteFileData(name, colors.ToArray());
+    }
+
+    // NOTE: saving data works but PixiEditor defaults to first .pal parser which
+    //       is JASC so saving to an actual file is currently not available.
+    //       Palette exporter needs to be refactored to support multiple formats of
+    //       same file extension.
+    public override async Task<bool> Save(string path, PaletteFileData data)
+    {
+        StringBuilder sb = new StringBuilder(SWATCH_NAME.Length + 20);
+
+        try
+        {
+            await using (Stream stream = File.OpenWrite(path))
+            {
+                using (TextWriter writer = new StreamWriter(stream, Encoding.ASCII, 1024, true))
+                {
+                    foreach (var color in data.Colors)
+                    {
+                        this.ConvertRgbToCmyk(color, out byte c, out byte m, out byte y, out byte k);
+
+                        this.WriteName(sb, SWATCH_NAME);
+                        this.WriteNumber(sb, c);
+                        this.WriteNumber(sb, m);
+                        this.WriteNumber(sb, y);
+                        this.WriteNumber(sb, k);
+
+                        writer.WriteLine(sb.ToString());
+                        sb.Length = 0;
+                    }
+                }
+            }
+            return true;
+        }
+        catch
+        {
+            return false;
+        }
+    }
+
+    private static byte ClampCmyk(float value)
+    {
+        if (value < 0 || float.IsNaN(value))
+        {
+            value = 0;
+        }
+
+        return Convert.ToByte(value * 100);
+    }
+
+    private PaletteColor ConvertCmykToRgb(int c, int m, int y, int k)
+    {
+        int r, g, b;
+        float multiplier;
+
+        multiplier = 1 - k / 100F;
+
+        r = Convert.ToInt32(255 * (1 - c / 100F) * multiplier);
+        g = Convert.ToInt32(255 * (1 - m / 100F) * multiplier);
+        b = Convert.ToInt32(255 * (1 - y / 100F) * multiplier);
+
+        return new PaletteColor((byte)r, (byte)g, (byte)b);
+    }
+
+    private void ConvertRgbToCmyk(PaletteColor color, out byte c, out byte m, out byte y, out byte k)
+    {
+        float r, g, b;
+        float divisor;
+
+        r = color.R / 255F;
+        g = color.G / 255F;
+        b = color.B / 255F;
+
+        divisor = 1 - Math.Max(Math.Max(r, g), b);
+
+        c = ClampCmyk((1 - r - divisor) / (1 - divisor));
+        m = ClampCmyk((1 - g - divisor) / (1 - divisor));
+        y = ClampCmyk((1 - b - divisor) / (1 - divisor));
+        k = ClampCmyk(divisor);
+    }
+
+    private byte NextNumber(string line, ref int start)
+    {
+        int length;
+        int valueLength;
+        int maxLength;
+        byte result;
+
+        // skip any leading spaces
+        while (char.IsWhiteSpace(line[start]))
+        {
+            start++;
+        }
+
+        length = line.Length;
+        maxLength = Math.Min(3, length - start);
+        valueLength = 0;
+
+        for (int i = 0; i < maxLength; i++)
+        {
+            if (char.IsDigit(line[start + i]))
+            {
+                valueLength++;
+            }
+            else
+            {
+                break;
+            }
+        }
+
+        result = byte.Parse(line.Substring(start, valueLength));
+
+        start += valueLength;
+
+        return result;
+    }
+
+    private void WriteName(StringBuilder sb, string name)
+    {
+        sb.Append('"');
+        sb.Append(name);
+        sb.Append('"');
+
+        for (int j = (name ?? string.Empty).Length; j < name.Length; j++)
+        {
+            sb.Append(' ');
+        }
+    }
+
+    private void WriteNumber(StringBuilder sb, byte value)
+    {
+        if (value == 100)
+        {
+            sb.Append("100 ");
+        }
+        else
+        {
+            sb.Append(' ');
+            if (value < 10)
+            {
+                sb.Append(' ');
+            }
+
+            sb.Append(value);
+
+            sb.Append(' ');
+        }
+    }
+}