Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

timage rotation

Posted on 1998-04-09
1
Medium Priority
?
425 Views
Last Modified: 2010-04-06
question
how can a timage be rotated in a fix angle say 90 degress
can any body help me..
this is an easy point.
may the force be with you.....
0
Comment
Question by:SABOG7
1 Comment
 
LVL 2

Accepted Solution

by:
Waldek earned 40 total points
ID: 1361363
Maybe this : from UDDF :}
From: Dave Shapiro <daves@cyber-fx.com>

Counterclockwise, that is. This rotates a 640x480 24-bit bitmap 90 degrees
in about 2/10 of sec on my P133 (4MB video card, 128MB RAM). It works
for Delphi 2, and should work for 1 and 3, too.

One thing: This does not work for bitmaps that aren't an integral number of
colors per pixel. If that's the case, you'll have to do some bit twiddling. I'm
working on that part right now (I need it too), but it'll be a few days. Anyways,
suggestions, comments, etc., always welcome.

Special thanks to David Ullrich (ooh, I hope I spelled that correctly) for
pointing out the non-published-but-public-anyway SaveToStream method for
the TBitmap class.

Advance apologies for any formatting problems. Netscape's editor is so
ridiculously crippled that I can't accomplish anything (give me rtin and vim
any day).



procedure RotateBitmap90Degrees(ABitmap: TBitmap);

const
  BITMAP_HEADER_SIZE = SizeOf(TBitmapFileHeader) +
SizeOf(TBitmapInfoHeader);

var
  { Things that end in R are for the rotated image. }
  PbmpInfoR: PBitmapInfoHeader;
  bmpBuffer, bmpBufferR: PByte;
  MemoryStream, MemoryStreamR: TMemoryStream;
  PbmpBuffer, PbmpBufferR: PByte;
  PbmpBufferRFirstScanLine, PbmpBufferColumnZero: PByte;
  BytesPerPixel, BytesPerScanLine, BytesPerScanLineR: Integer;
  X, Y, T: Integer;

begin
  {
    Don't *ever* call GetDIBSizes! It screws up your bitmap.
    I'll be posting about that shortly.
  }

  MemoryStream := TMemoryStream.Create;

  {
   To do: Put in a SetSize, which will eliminate any reallocation
   overhead.
  }

  ABitmap.SaveToStream(MemoryStream);

  {
   Don't need you anymore. We'll make a new one when the time comes.
  }
  ABitmap.Free;

  bmpBuffer := MemoryStream.Memory;

  { Set PbmpInfoR to point to the source bitmap's info header. }
  { Boy, these headers are getting annoying. }
  Inc( bmpBuffer, SizeOf(TBitmapFileHeader) );
  PbmpInfoR := PBitmapInfoHeader(bmpBuffer);

  { Set bmpBuffer to point to the original bitmap bits. }
  Inc(bmpBuffer, SizeOf(PbmpInfoR^));
  { Set the ColumnZero pointer to point to, uh, column zero. }
  PbmpBufferColumnZero := bmpBuffer;

  with PbmpInfoR^ do
  begin
    BytesPerPixel := biBitCount shr 3;
    { ScanLines are DWORD aligned. }
    BytesPerScanLine := ((((biWidth * biBitCount) + 31) div 32) * SizeOf(DWORD));
    BytesPerScanLineR := ((((biHeight * biBitCount) + 31) div 32) * SizeOf(DWORD));

    { The TMemoryStream that will hold the rotated bits. }
    MemoryStreamR := TMemoryStream.Create;
    {
     Set size for rotated bitmap. Might be different from source size
     due to DWORD aligning.
    }
    MemoryStreamR.SetSize(BITMAP_HEADER_SIZE  + BytesPerScanLineR * biWidth);
  end;

  { Copy the headers from the source bitmap. }
  MemoryStream.Seek(0, soFromBeginning);
  MemoryStreamR.CopyFrom(MemoryStream, BITMAP_HEADER_SIZE);

  { Here's the buffer we're going to rotate. }
  bmpBufferR := MemoryStreamR.Memory;
  { Skip the headers, yadda yadda yadda... }
  Inc(bmpBufferR, BITMAP_HEADER_SIZE);

  {
   Set up PbmpBufferRFirstScanLine and advance it to end of the first scan
   line of bmpBufferR.
  }
  PbmpBufferRFirstScanLine := bmpBufferR;
  Inc(PbmpBufferRFirstScanLine, (PbmpInfoR^.biHeight - 1) * BytesPerPixel);

  { Here's the meat. Loop through the pixels and rotate appropriately. }

  { Remember that DIBs have their origins opposite from DDBs. }
  for Y := 1 to PbmpInfoR^.biHeight do
  begin
    PbmpBuffer := PbmpBufferColumnZero;
    PbmpBufferR := PbmpBufferRFirstScanLine;

    for X := 1 to PbmpInfoR^.biWidth do
    begin
      for T := 1 to BytesPerPixel do
      begin
        PbmpBufferR^ := PbmpBuffer^;
        Inc(PbmpBufferR);
        Inc(PbmpBuffer);
      end;
      Dec(PbmpBufferR, BytesPerPixel);
      Inc(PbmpBufferR, BytesPerScanLineR);
    end;

    Inc(PbmpBufferColumnZero, BytesPerScanLine);
    Dec(PbmpBufferRFirstScanLine, BytesPerPixel);
  end;

  { Done with the source bits. }
  MemoryStream.Free;

  { Now set PbmpInfoR to point to the rotated bitmap's info header. }
  PbmpBufferR := MemoryStreamR.Memory;
  Inc( PbmpBufferR, SizeOf(TBitmapFileHeader) );
  PbmpInfoR := PBitmapInfoHeader(PbmpBufferR);

  { Swap the width and height of the rotated bitmap's info header. }
  with PbmpInfoR^ do
  begin
    T := biHeight;
    biHeight := biWidth;
    biWidth := T;
  end;

  ABitmap := TBitmap.Create;

  { Spin back to the very beginning. }
  MemoryStreamR.Seek(0, soFromBeginning);
  ABitmap.LoadFromStream(MemoryStreamR);

  MemoryStreamR.Free;
end;
0

Featured Post

Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

A lot of questions regard threads in Delphi.   One of the more specific questions is how to show progress of the thread.   Updating a progressbar from inside a thread is a mistake. A solution to this would be to send a synchronized message to the…
Hello everybody This Article will show you how to validate number with TEdit control, What's the TEdit control? TEdit is a standard Windows edit control on a form, it allows to user to write, read and copy/paste single line of text. Usua…
this video summaries big data hadoop online training demo (http://onlineitguru.com/big-data-hadoop-online-training-placement.html) , and covers basics in big data hadoop .
In a question here at Experts Exchange (https://www.experts-exchange.com/questions/29062564/Adobe-acrobat-reader-DC.html), a member asked how to create a signature in Adobe Acrobat Reader DC (the free Reader product, not the paid, full Acrobat produ…
Suggested Courses

972 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question