SRL Archive - Delphi/FPC Help and Tutorials

Has anyone here experimented with implenting ASM with Scanline functions?

From: DatSik
Has anyone here experimented with implenting ASM with Scanline functions?

Are you asking out of just sheer curiousity? Also.. What does "Scanline functions" mean? :l Not familiar with the terminology here..

Do you mean like scanf? getline? or Pixels[(Height - y) * Width + x]?

This is also in the delphi/fpc section so.. Are you sure you're talking about just ASM? Intel, AT&T, Mips, etc???? Missing a lot of details..

I'm really missing the question/reason..

Oh yes im very sorry, I do not mean strictley ASM, i meant Delphi + asm , and here is the scanline function i am speaking of. http://docwiki.embarcadero.com/CodeExamples/XE5/en/ScanLine_(Delphi) I was just wondering if anyone had ever mixed the 2 in order to get a more responsive function or any kind of Asm with it. I appreciate you help

You can look at the Simba sources, I think it uses scanline, or if not at the moment, at some point maybe it did.

From: DatSik
Oh yes im very sorry, I do not mean strictley ASM, i meant Delphi + asm , and here is the scanline function i am speaking of. http://docwiki.embarcadero.com/CodeExamples/XE5/en/ScanLine_(Delphi) I was just wondering if anyone had ever mixed the 2 in order to get a more responsive function or any kind of Asm with it. I appreciate you help

I'd need an assembler to check this but here goes (notepad ftw):

asm
  mov ecx, 0

  @@HeightLoop:
    cmp ecx, BmpHeight
    je @@EndHeight
    mov ebx, 0

    mov P, [ScanLine]
    add P, Y

    @@WidthLoop:
      mov eax, ecx
      add eax, ebx
      

      push ecx
      mov ecx, x
      mul ecx, $2
      mov x, ecx

      mov ecx, y
      mul ecx, $2
      mov y, ecx
      pop ecx

      mov bigP, [BigScanLine + $4]
      //.........
      //.........
      //.........

      cmp ebx, BmpWidth
      je @@EndWidth
      inc ebx
      jmp @@WidthLoop


    @@EndWidth:
      inc ecx
      jmp @@HeightLoop

  @@EndHeight:
end;

The above probably has some errors.. I'm rusty :(


I can write it in NASM syntax and you can translate that to Delphi's Assembly.. but.. too much work.

From: Brandon
I'd need an assembler to check this but here goes (notepad ftw):

asm
  mov ecx, 0

  @@HeightLoop:
    cmp ecx, BmpHeight
    je @@EndHeight
    mov ebx, 0

    mov P, [ScanLine]
    add P, Y

    @@WidthLoop:
      mov eax, ecx
      add eax, ebx
      

      push ecx
      mov ecx, x
      mul ecx, $2
      mov x, ecx

      mov ecx, y
      mul ecx, $2
      mov y, ecx
      pop ecx

      mov bigP, [BigScanLine + $4]
      //.........
      //.........
      //.........

      cmp ebx, BmpWidth
      je @@EndWidth
      inc ebx
      jmp @@WidthLoop


    @@EndWidth:
      inc ecx
      jmp @@HeightLoop

  @@EndHeight:
end;

The above probably has some errors.. I'm rusty :(


I can write it in NASM syntax and you can translate that to Delphi's Assembly.. but.. too much work.

Thats a fantastic example, Thank you very much.. it has been very helpful you actualy inspired me to mess with some animations , here is a little section of what i have so far..excuse my documentation i try to heavily document because as you know im still learning with asm and scanline/Delphi.

procedure TForm1.Button2Click(Sender: TObject);
var
  y,x,b,b2,z,ti: integer;
  p: pointer; // used to solve compatabilty problems between pa and pba
  pba: pbytearray;
  // used to temperarily store the address of the start of a row of pixels
begin
     panel1.hide;
     // -- store the information into arrays
     bit.pixelformat:=pf32bit; // make it so each pixel is stored in 4 bytes
     setlength(pa,bit.height);
     for x:=bit.height-1 downto 0 do
     begin // update pa
          pba:=bit.scanline[x]; // get the address of a row of pixels
          asm
             mov eax,dword ptr (pba);
             mov p,eax; // move the pointer value into p
             // this temperary value in p is just there because I don't know how
             // to move an address from a PByteArray into a normal pointer without
             // having incompatable errors
          end;
          pa[x]:=p;
     end;
     // -- finished storing the pointers
     x:=bit.width-1; // initial value in the loop through x-coordinates
     y:=high(pa); // initial value in the loop through y-coordinates
     ti:=gettickcount; // store the time
     for z:=0 to 300 do
     // loop through frames in the animation
     begin
       if z mod 10=0 then
          caption:='frame='+inttostr(z);
       asm
        // EAX stores the frame number
        // EBX stores the y-coordinate and the pixel colour
        // ECX stores the address of each row of pixels
        // EDX stores the x-coordinates
        mov b,ebx;
        // Ebx should be temperarily stored because Delphi uses its value.
        // If assembly code modifies ebx, it creates errors.
        mov ebx,y;
        mov eax,z;
        imul eax,eax;  // eax:=sqr(eax);
        // this is used to define the changing colours of the pixels for each frame
        @bigstart:  // loop through y-coordinates
             mov ecx,dword ptr (pa);        // get address of the contents of the array
             mov ecx,dword ptr (ecx+ebx*4);
             // get the address of a row of pixels

             mov b2,ebx; // temperarily store the value of ebx

             mov edx,x;
             @startloop: // loop through x-coordinates
                        mov ebx,edx;
                        imul ebx,eax; // eax's value is based on the frame number
                        // this is what causes the colour for each frame to be different
                        mov dword ptr (ecx+edx*4),ebx; // set the pixel
                  dec edx;
                  cmp edx,0;
                  jg @startloop;

             mov ebx,b2; // restore the value of ebx to the y-coordniate

          dec ebx;
          cmp ebx,0;
          jg @bigstart;
        mov ebx,b; // restore the value of ebx to its original value
       end;
       canvas.draw(0,0,bit); // draw the frame on the form
       // this draw sometimes is almost as time consuming as creating the frame
     end;
     ti:=gettickcount-ti; // get the number of miliseconds since the beginning of the animation
     canvas.draw(0,0,bit);
     caption:='animation took '+inttostr(ti)+'ms, height='+inttostr(bit.height)+
     ', width='+inttostr(bit.width)+', '+floattostr(ti/(bit.width*bit.height*z)*1000000)+'ns/pixel';
     panel1.Visible:=true;
end;

Ive been able to create some pretty nice stuff so far. Thank you again you were a big help