/// <summary>
/// This operation is used to initiate the transfer of an image from the Source to the application via the
/// Buffered Memory transfer mechanism.
/// This operation supports the transfer of successive blocks of image data (in strips or,optionally,
/// tiles) from the Source into one or more main memory transfer buffers. These buffers(for strips)
/// are allocated and owned by the application. For tiled transfers, the source allocates the buffers.
/// The application should repeatedly invoke this operation while TWRC_SUCCESS is returned by the Source.
/// </summary>
/// <param name="length">The length.</param>
/// <param name="isMemFile">If set to <c>true</c> that transfer a MemFile.</param>
/// <returns>
/// Information about transmitting data.
/// </returns>
protected override ImageMemXfer OnImageMemXfer(long length, bool isMemFile)
{
// return new image 100x100
if (this._imageData == null || this._imageData.IsXferDone)
{
this._imageData = new ImageMemXfer {
Columns = 100,
Rows = 5,
BytesPerRow = 3 * 100,
XOffset = 0,
YOffset = 0,
Compression = TwCompression.None,
ImageData = new byte[3 * 100 * 5],
IsXferDone = false
};
}
else
{
this._imageData.YOffset += 5;
this._imageData.IsXferDone = this._imageData.YOffset + this._imageData.Rows == this.XferEnvironment.ImageInfo.ImageLength;
}
return(this._imageData);
}
/// <summary>
/// 把imageMemXfer.Memory內的記憶體向右移動
/// </summary>
/// <param name="imageMemXfer"></param>
/// <param name="bytePerPixel"></param>
private byte[] ShiftPixels(ref ImageMemXfer imageMemXfer, int bytePerPixel)
{
/// 參考:
/// https://stackoverflow.com/questions/2185944/why-must-stride-in-the-system-drawing-bitmap-constructor-be-a-multiple-of-4
/// https://stackoverflow.com/questions/47918451/creating-a-bitmap-from-rgb-array-in-c-result-image-difference/
byte[] managedArray = new byte[(int)imageMemXfer.Memory.Length];
Marshal.Copy(imageMemXfer.Memory.TheMem, managedArray, 0, (int)imageMemXfer.Memory.Length);
int bytesPerRow = (int)imageMemXfer.BytesPerRow;
byte[] newArray = null;
int? skipByte = null;
if (bytesPerRow % 4 != 0)
{
skipByte = 4 - (bytesPerRow % 4);
int newArrayLength = (int)imageMemXfer.Memory.Length + skipByte.Value * (int)imageMemXfer.Rows;
newArray = new byte[newArrayLength];
}
//for (int i = 0; i < imageMemXfer.Rows; i++)
//{
// managedArray[0 + i * bytesPerRow] = 0;
// managedArray[1 + i * bytesPerRow] = 255;
// managedArray[2 + i * bytesPerRow] = 0;
// managedArray[bytesPerRow - 3 + i * bytesPerRow] = 255;
// managedArray[bytesPerRow - 2 + i * bytesPerRow] = 0;
// managedArray[bytesPerRow - 1 + i * bytesPerRow] = 255;
//}
//Marshal.Copy(managedArray, 0, imageMemXfer.Memory.TheMem, (int)imageMemXfer.Memory.Length);
//return managedArray;
for (int i = 0; i < imageMemXfer.Rows; i++)
{
// get a single row
byte[] rowArray = new byte[bytesPerRow];
Buffer.BlockCopy(managedArray, i * bytesPerRow, rowArray, 0, bytesPerRow);
// right shift 3 bytes by i
byte[] tempArray = new byte[bytesPerRow];
int shiftAmount = i * bytePerPixel;
//for (int j = 0; j < bytesPerRow; j++)
//{
// each byte in rowArray[] is moved by i*bytePerPixel
//tempArray[(j + shiftAmount) % bytesPerRow] = rowArray[j];
//}
/*// copy the last shiftAmount pixels from previous line, to this line's tail
* if (i > 0)
* {
* int srcOffset = i * bytesPerRow - shiftAmount;
* int destOffset = bytesPerRow - shiftAmount;
* Buffer.BlockCopy(managedArray, srcOffset, tempArray, destOffset, shiftAmount);
* }*/
//// fill with a color
//for (int j = 0; j < bytesPerRow; j++)
//{
// int color1 = (i * 2) % 255;
// tempArray[j] = (byte)color1;
//}
// copy back
if (skipByte.HasValue)
{
Buffer.BlockCopy(rowArray, 0, newArray, i * (bytesPerRow + skipByte.Value), bytesPerRow);
}
else
{
Buffer.BlockCopy(rowArray, 0, managedArray, i * bytesPerRow, bytesPerRow);
}
}
/*// test the border
* int rows = (int)imageMemXfer.Rows;
* // 左上角
* managedArray[0] = 0;
* managedArray[1] = 255;
* managedArray[2] = 0;
* // 第二排第一個
* managedArray[0+ bytesPerRow] = 255;
* managedArray[1+ bytesPerRow] = 255;
* managedArray[2+ bytesPerRow] = 255;
* // 第二排第二個
* managedArray[3 + bytesPerRow] = 0;
* managedArray[4 + bytesPerRow] = 0;
* managedArray[5 + bytesPerRow] = 0;
* // 第一排最後一個
* managedArray[bytesPerRow - 1] = 255;
* managedArray[bytesPerRow - 2] = 0;
* managedArray[bytesPerRow - 3] = 0;
* // 最後一排第一個
* managedArray[0 + bytesPerRow * (rows - 1)] = 0;
* managedArray[1 + bytesPerRow * (rows - 1)] = 0;
* managedArray[2 + bytesPerRow * (rows - 1)] = 255;
* // 最後一排最後一個 red
* managedArray[(int)imageMemXfer.Memory.Length-1] = 0;
* managedArray[(int)imageMemXfer.Memory.Length-2] = 0;
* managedArray[(int)imageMemXfer.Memory.Length-3] = 255;*/
if (skipByte.HasValue)
{
Marshal.Copy(newArray, 0, imageMemXfer.Memory.TheMem, newArray.Length);
}
else
{
Marshal.Copy(managedArray, 0, imageMemXfer.Memory.TheMem, (int)imageMemXfer.Memory.Length);
}
//for (int i = 0; i < imageMemXfer.Rows; i++)
//{
// // fill with a color
// //managedArray[i] = (byte)((i * 2) % 255);
// managedArray[0 + i * bytesPerRow] = 0;
// managedArray[1 + i * bytesPerRow] = 255;
// managedArray[2 + i * bytesPerRow] = 0;
// managedArray[bytesPerRow - 3 + i * bytesPerRow] = 255;
// managedArray[bytesPerRow - 2 + i * bytesPerRow] = 0;
// managedArray[bytesPerRow - 1 + i * bytesPerRow] = 255;
//}
if (skipByte.HasValue)
{
return(newArray);
}
else
{
return(managedArray);
}
}
protected void TransferPicturesIncremental()
{
// see http://www.twain.org/wp-content/uploads/2017/03/TWAIN-2.4-Specification.pdf
// page 4-20
Console.WriteLine("TransferPicturesIncremental...");
Logger.WriteLog(LOG_LEVEL.LL_NORMAL_LOG, "TransferPicturesIncremental...");
if (DataSource.SourceId.Id == 0)
{
return;
}
PendingXfers pendingTransfer = new PendingXfers();
TwainResult result;
try
{
int recievedBlockCount = 1;
do
{
pendingTransfer.Count = 0; // the Twain source will fill this in during DsPendingTransfer
Console.WriteLine("Get the image info...");
// Get the image info
ImageInfo imageInfo = new ImageInfo();
result = Twain32Native.DsImageInfo(
ApplicationId,
DataSource.SourceId,
DataGroup.Image,
DataArgumentType.ImageInfo,
Message.Get,
imageInfo);
if (result != TwainResult.Success)
{
DataSource.Close();
break;
}
/*Console.WriteLine("Get the image layout...");
* ImageLayout imageLayout = new ImageLayout();
* result = Twain32Native.DsImageLayout(
* ApplicationId,
* DataSource.SourceId,
* DataGroup.Image,
* DataArgumentType.ImageLayout,
* Message.GetCurrent,
* imageLayout);
*
* if (result != TwainResult.Success)
* {
* DataSource.Close();
* break;
* }*/
// Setup Destination Bitmap
Bitmap bitmap = BitmapRenderer.NewBitmapForImageInfo(imageInfo);
Console.WriteLine("Setup incremental Memory XFer...");
// Setup incremental Memory XFer
SetupMemXfer setupMemXfer = new SetupMemXfer();
result = Twain32Native.DsSetupMemXfer(
ApplicationId,
DataSource.SourceId,
DataGroup.Control,
DataArgumentType.SetupMemXfer,
Message.Get,
setupMemXfer
);
if (result != TwainResult.Success)
{
DataSource.Close();
break;
}
Console.WriteLine("allocate the preferred buffer size...");
// allocate the preferred buffer size
// see twain spec pdf, page 4-21
ImageMemXfer imageMemXfer = new ImageMemXfer();
try
{
imageMemXfer.Memory.Flags = MemoryFlags.AppOwns | MemoryFlags.Pointer;
imageMemXfer.Memory.Length = setupMemXfer.MinBufSize; // 對於A8 scanner，Preferred = MaxBufSize，太大了，所以我們選小一點的
imageMemXfer.Memory.TheMem = Kernel32Native.GlobalAlloc(GlobalAllocFlags.MemFixed, (int)setupMemXfer.MinBufSize * 2); // 不知道為什麼原本她size寫要*2倍
imageMemXfer.Compression = Compression.None;
if (imageMemXfer.Memory.TheMem == IntPtr.Zero)
{
Logger.WriteLog(LOG_LEVEL.LL_SERIOUS_ERROR, "error allocating buffer for memory transfer");
throw new TwainException("error allocating buffer for memory transfer");
}
long pixels_written = 0;
long total_pixels = imageInfo.ImageWidth * imageInfo.ImageLength;
do
{
// perform a transfer
result = Twain32Native.DsImageMemXfer(
ApplicationId,
DataSource.SourceId,
DataGroup.Image,
DataArgumentType.ImageMemXfer,
Message.Get,
imageMemXfer
);
//string savePath = @"C:\Users\Tenny\Pictures\TwainTest\tempBitmap_";
//savePath += i.ToString() + @".bmp";
if (result == TwainResult.Success || result == TwainResult.XferDone)
{
// dibArray是這次Buffer的RGB陣列
byte[] dibArray = ShiftPixels(ref imageMemXfer, imageInfo.BitsPerPixel / 8);
BitmapRenderer.TransferPixels(bitmap, imageInfo, imageMemXfer);
pixels_written += (imageMemXfer.BytesWritten * 8) / imageInfo.BitsPerPixel;
double percent_complete = (double)pixels_written / (double)total_pixels;
if (result == TwainResult.XferDone)
{
percent_complete = 1.0;
// 算出空白區域的高度，裁切尾端部分
int blankHeight = GetCropHeight(bitmap);
if (blankHeight > 0 && blankHeight < imageInfo.ImageLength)
{
bitmap = cropImage(bitmap, blankHeight);
}
}
// fire the transfer event
TransferImageEventArgs args = new TransferImageEventArgs(bitmap, result != TwainResult.XferDone, (float)percent_complete);
TransferImage(this, args);
if (!args.ContinueScanning)
{
result = TwainResult.XferDone;
}
}
recievedBlockCount++;
} while (result == TwainResult.Success);
}
finally
{
if (imageMemXfer.Memory.TheMem != IntPtr.Zero)
{
Kernel32Native.GlobalFree(imageMemXfer.Memory.TheMem);
imageMemXfer.Memory.TheMem = IntPtr.Zero;
}
}
// End pending transfers
result = Twain32Native.DsPendingTransfer(
ApplicationId,
DataSource.SourceId,
DataGroup.Control,
DataArgumentType.PendingXfers,
Message.EndXfer,
pendingTransfer);
if (result != TwainResult.Success)
{
DataSource.Close();
break;
}
}while (pendingTransfer.Count != 0);
}
finally
{
// Reset any pending transfers
result = Twain32Native.DsPendingTransfer(
ApplicationId,
DataSource.SourceId,
DataGroup.Control,
DataArgumentType.PendingXfers,
Message.Reset,
pendingTransfer);
Logger.WriteLog(LOG_LEVEL.LL_NORMAL_LOG, "TransferPicturesIncremental...done.");
}
}
