Merge pull request #79 from hig-dev/SimpleSoftwareBitmapLuminanceSource

Simpler SoftwareBitmapLuminanceSource
Redth · Oct 23, 2023 · bc10aa7 · bc10aa7
2 parents d32ca7a + 9fcfd6b
commit bc10aa7
Showing 1 changed file with 11 additions and 61 deletions.
diff --git a/ZXing.Net.MAUI/Platforms/Windows/SoftwareBitmapLuminanceSource.cs b/ZXing.Net.MAUI/Platforms/Windows/SoftwareBitmapLuminanceSource.cs
@@ -5,18 +5,11 @@
 using System.Text;
 using System.Threading.Tasks;
 using Windows.Graphics.Imaging;
+using System.Runtime.InteropServices.WindowsRuntime;
 using WinRT;
 
 namespace ZXing.Net.Maui;
 
-[ComImport]
-[Guid("5b0d3235-4dba-4d44-865e-8f1d0e4fd04d")]
-[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
-unsafe interface IMemoryBufferByteAccess
-{
-	void GetBuffer(out byte* buffer, out uint capacity);
-}
-
 public class SoftwareBitmapLuminanceSource : BaseLuminanceSource
 {
 	public SoftwareBitmapLuminanceSource(SoftwareBitmap softwareBitmap) : base(softwareBitmap.PixelWidth, softwareBitmap.PixelHeight)
@@ -33,59 +26,16 @@ protected SoftwareBitmapLuminanceSource(byte[] luminanceArray, int width, int he
 	protected override LuminanceSource CreateLuminanceSource(byte[] newLuminances, int width, int height)
 		=> new SoftwareBitmapLuminanceSource(width, height) { luminances = newLuminances };
 
-	unsafe void CalculateLuminance(SoftwareBitmap bitmap)
+	void CalculateLuminance(SoftwareBitmap bitmap)
 	{
-		// Effect is hard-coded to operate on BGRA8 format only
-		if (bitmap.BitmapPixelFormat == BitmapPixelFormat.Bgra8)
-		{
-			// In BGRA8 format, each pixel is defined by 4 bytes
-			const int BYTES_PER_PIXEL = 4;
-
-			using (var buffer = bitmap.LockBuffer(BitmapBufferAccessMode.Read))
-			using (var bufferRef = buffer.CreateReference())
-			{
-				//See https://github.com/microsoft/CsWinRT/issues/646#issuecomment-754161785
-				var reference = bufferRef.As<IMemoryBufferByteAccess>();
-				if (reference != null)
-				{
-					try
-					{
-						// Get a pointer to the pixel buffer
-						byte* data;
-						uint capacity;
-						reference.GetBuffer(out data, out capacity);
-
-						// Get information about the BitmapBuffer
-						var desc = buffer.GetPlaneDescription(0);
-						var luminanceIndex = 0;
-
-						// Iterate over all pixels
-						for (uint row = 0; row < desc.Height; row++)
-						{
-							for (uint col = 0; col < desc.Width; col++)
-							{
-								// Index of the current pixel in the buffer (defined by the next 4 bytes, BGRA8)
-								var currPixel = desc.StartIndex + desc.Stride * row + BYTES_PER_PIXEL * col;
-
-								// Read the current pixel information into b,g,r channels (leave out alpha channel)
-								var b = data[currPixel + 0]; // Blue
-								var g = data[currPixel + 1]; // Green
-								var r = data[currPixel + 2]; // Red
-
-								var luminance = (byte)((RChannelWeight * r + GChannelWeight * g + BChannelWeight * b) >> ChannelWeight);
-								var alpha = data[currPixel + 3];
-								luminance = (byte)(((luminance * alpha) >> 8) + (255 * (255 - alpha) >> 8));
-								luminances[luminanceIndex] = luminance;
-								luminanceIndex++;
-							}
-						}
-					}
-					catch (Exception ex)
-					{
-						System.Diagnostics.Debug.WriteLine("Luminance Source Failed: {0}", ex);
-					}
-				}
-			}
-		}
+		if (bitmap.BitmapPixelFormat != BitmapPixelFormat.Gray8)
+        {
+	        using SoftwareBitmap convertedSoftwareBitmap = SoftwareBitmap.Convert(bitmap, BitmapPixelFormat.Gray8);
+	        convertedSoftwareBitmap.CopyToBuffer(luminances.AsBuffer());
+        }
+        else
+        {
+            bitmap.CopyToBuffer(luminances.AsBuffer());
+        }
 	}
 }