Этап 9

Minint.Core/Services/Impl/ImageEffectsService.cs

@@ -0,0 +1,38 @@
+using System;
+using Minint.Core.Models;
+
+namespace Minint.Core.Services.Impl;
+
+public sealed class ImageEffectsService : IImageEffectsService
+{
+    public void ApplyContrast(MinintDocument doc, double factor)
+    {
+        for (int i = 1; i < doc.Palette.Count; i++)
+        {
+            var c = doc.Palette[i];
+            doc.Palette[i] = new RgbaColor(
+                ContrastByte(c.R, factor),
+                ContrastByte(c.G, factor),
+                ContrastByte(c.B, factor),
+                c.A);
+        }
+        doc.InvalidatePaletteCache();
+    }
+
+    public void ApplyGrayscale(MinintDocument doc)
+    {
+        for (int i = 1; i < doc.Palette.Count; i++)
+        {
+            var c = doc.Palette[i];
+            byte gray = (byte)Math.Clamp((int)(0.299 * c.R + 0.587 * c.G + 0.114 * c.B + 0.5), 0, 255);
+            doc.Palette[i] = new RgbaColor(gray, gray, gray, c.A);
+        }
+        doc.InvalidatePaletteCache();
+    }
+
+    private static byte ContrastByte(byte value, double factor)
+    {
+        double v = ((value / 255.0) - 0.5) * factor + 0.5;
+        return (byte)Math.Clamp((int)(v * 255 + 0.5), 0, 255);
+    }
+}

Minint.Core/Services/Impl/PatternGenerator.cs

@@ -0,0 +1,113 @@
+using System;
+using Minint.Core.Models;
+
+namespace Minint.Core.Services.Impl;
+
+public sealed class PatternGenerator : IPatternGenerator
+{
+    public MinintDocument Generate(PatternType type, int width, int height, RgbaColor[] colors, int param1, int param2 = 0)
+    {
+        ArgumentOutOfRangeException.ThrowIfLessThan(width, 1);
+        ArgumentOutOfRangeException.ThrowIfLessThan(height, 1);
+        if (colors.Length < 2)
+            throw new ArgumentException("At least two colors are required.", nameof(colors));
+
+        var doc = new MinintDocument($"Pattern ({type})");
+        var layer = new MinintLayer("Pattern", width * height);
+        doc.Layers.Add(layer);
+
+        int[] colorIndices = new int[colors.Length];
+        for (int i = 0; i < colors.Length; i++)
+            colorIndices[i] = doc.EnsureColorCached(colors[i]);
+
+        int cellSize = Math.Max(param1, 1);
+
+        switch (type)
+        {
+            case PatternType.Checkerboard:
+                FillCheckerboard(layer.Pixels, width, height, colorIndices, cellSize);
+                break;
+            case PatternType.HorizontalGradient:
+                FillGradient(layer.Pixels, width, height, colors[0], colors[1], doc, horizontal: true);
+                break;
+            case PatternType.VerticalGradient:
+                FillGradient(layer.Pixels, width, height, colors[0], colors[1], doc, horizontal: false);
+                break;
+            case PatternType.HorizontalStripes:
+                FillStripes(layer.Pixels, width, height, colorIndices, cellSize, horizontal: true);
+                break;
+            case PatternType.VerticalStripes:
+                FillStripes(layer.Pixels, width, height, colorIndices, cellSize, horizontal: false);
+                break;
+            case PatternType.ConcentricCircles:
+                FillCircles(layer.Pixels, width, height, colorIndices, cellSize);
+                break;
+            case PatternType.Tile:
+                FillTile(layer.Pixels, width, height, colorIndices, cellSize, Math.Max(param2, 1));
+                break;
+        }
+
+        return doc;
+    }
+
+    private static void FillCheckerboard(int[] pixels, int w, int h, int[] ci, int cell)
+    {
+        for (int y = 0; y < h; y++)
+            for (int x = 0; x < w; x++)
+                pixels[y * w + x] = ci[((x / cell) + (y / cell)) % 2 == 0 ? 0 : 1];
+    }
+
+    private static void FillGradient(int[] pixels, int w, int h, RgbaColor c0, RgbaColor c1,
+                                      MinintDocument doc, bool horizontal)
+    {
+        int steps = horizontal ? w : h;
+        for (int s = 0; s < steps; s++)
+        {
+            double t = steps > 1 ? (double)s / (steps - 1) : 0;
+            var c = new RgbaColor(
+                Lerp(c0.R, c1.R, t), Lerp(c0.G, c1.G, t),
+                Lerp(c0.B, c1.B, t), Lerp(c0.A, c1.A, t));
+            int idx = doc.EnsureColorCached(c);
+            if (horizontal)
+                for (int y = 0; y < h; y++) pixels[y * w + s] = idx;
+            else
+                for (int x = 0; x < w; x++) pixels[s * w + x] = idx;
+        }
+    }
+
+    private static void FillStripes(int[] pixels, int w, int h, int[] ci, int stripe, bool horizontal)
+    {
+        for (int y = 0; y < h; y++)
+            for (int x = 0; x < w; x++)
+            {
+                int coord = horizontal ? y : x;
+                pixels[y * w + x] = ci[(coord / stripe) % ci.Length];
+            }
+    }
+
+    private static void FillCircles(int[] pixels, int w, int h, int[] ci, int ringWidth)
+    {
+        double cx = (w - 1) / 2.0, cy = (h - 1) / 2.0;
+        for (int y = 0; y < h; y++)
+            for (int x = 0; x < w; x++)
+            {
+                double dist = Math.Sqrt((x - cx) * (x - cx) + (y - cy) * (y - cy));
+                int ring = (int)(dist / ringWidth);
+                pixels[y * w + x] = ci[ring % ci.Length];
+            }
+    }
+
+    private static void FillTile(int[] pixels, int w, int h, int[] ci, int tileW, int tileH)
+    {
+        for (int y = 0; y < h; y++)
+            for (int x = 0; x < w; x++)
+            {
+                int tx = (x / tileW) % ci.Length;
+                int ty = (y / tileH) % ci.Length;
+                pixels[y * w + x] = ci[(tx + ty) % ci.Length];
+            }
+    }
+
+    private static byte Lerp(byte a, byte b, double t)
+        => (byte)Math.Clamp((int)(a + (b - a) * t + 0.5), 0, 255);
+}