Этап 10

Minint.Infrastructure/Export/BmpExporter.cs

@@ -0,0 +1,80 @@
+using Minint.Core.Services;
+
+namespace Minint.Infrastructure.Export;
+
+/// <summary>
+/// Writes a 32-bit BGRA BMP (BITMAPV4HEADER) from an ARGB pixel buffer.
+/// BMP rows are bottom-up, so we flip vertically during write.
+/// </summary>
+public sealed class BmpExporter : IBmpExporter
+{
+    private const int BmpFileHeaderSize = 14;
+    private const int BitmapV4HeaderSize = 108;
+    private const int HeadersTotal = BmpFileHeaderSize + BitmapV4HeaderSize;
+
+    public void Export(Stream stream, uint[] pixels, int width, int height)
+    {
+        ArgumentNullException.ThrowIfNull(stream);
+        ArgumentNullException.ThrowIfNull(pixels);
+        if (pixels.Length != width * height)
+            throw new ArgumentException("Pixel buffer size does not match dimensions.");
+
+        int rowBytes = width * 4;
+        int imageSize = rowBytes * height;
+        int fileSize = HeadersTotal + imageSize;
+
+        using var w = new BinaryWriter(stream, System.Text.Encoding.UTF8, leaveOpen: true);
+
+        // BITMAPFILEHEADER (14 bytes)
+        w.Write((byte)'B');
+        w.Write((byte)'M');
+        w.Write(fileSize);
+        w.Write((ushort)0); // reserved1
+        w.Write((ushort)0); // reserved2
+        w.Write(HeadersTotal); // pixel data offset
+
+        // BITMAPV4HEADER (108 bytes)
+        w.Write(BitmapV4HeaderSize);
+        w.Write(width);
+        w.Write(height); // positive = bottom-up
+        w.Write((ushort)1); // planes
+        w.Write((ushort)32); // bpp
+        w.Write(3); // biCompression = BI_BITFIELDS
+        w.Write(imageSize);
+        w.Write(2835); // X pixels per meter (~72 DPI)
+        w.Write(2835); // Y pixels per meter
+        w.Write(0); // colors used
+        w.Write(0); // important colors
+
+        // Channel masks (BGRA order in file)
+        w.Write(0x00FF0000u); // red mask
+        w.Write(0x0000FF00u); // green mask
+        w.Write(0x000000FFu); // blue mask
+        w.Write(0xFF000000u); // alpha mask
+
+        // Color space type: LCS_sRGB
+        w.Write(0x73524742); // 'sRGB'
+        // CIEXYZTRIPLE endpoints (36 bytes zeroed)
+        w.Write(new byte[36]);
+        // Gamma RGB (12 bytes zeroed)
+        w.Write(new byte[12]);
+
+        // Pixel data: BMP is bottom-up, our buffer is top-down
+        for (int y = height - 1; y >= 0; y--)
+        {
+            int rowStart = y * width;
+            for (int x = 0; x < width; x++)
+            {
+                uint argb = pixels[rowStart + x];
+                byte a = (byte)(argb >> 24);
+                byte r = (byte)((argb >> 16) & 0xFF);
+                byte g = (byte)((argb >> 8) & 0xFF);
+                byte b = (byte)(argb & 0xFF);
+                w.Write(b);
+                w.Write(g);
+                w.Write(r);
+                w.Write(a);
+            }
+        }
+    }
+}