Re:[SOLVED] with CAUTION - I need a pointer for asm.
lazarus / 39-Graphics

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RWC · 2015-10-23 15:06

To access a TBGRABitmap in ASM use a PBGRAPixel pointer:
Var PMyBGRA: PBGRAPixel;..
PMyBGRA := MYBGRAImage.Data; //writes upwards from bottom line.
ASM... mov edi/esi,PMyBGRA... End;

Which is the same as:
Var PMyBGRA: PBGRAPixel;...
PMyBGRA := MYBGRAImage.Scanline[MYBGRAImage.height-1]; //so Delphi
compatible.
ASM...mov edi/esi,PMyBGRA...End;

BUT CAUTION -> PMyBGRA := MYBGRAImage.Scanline[0]; //is top line
writing upwards so don't write more than the Image.Width!!

To access a TLazIntfImage in ASM use a PByteArray pointer:
Var PMyLazIntf: PByteArray;...
PMyLazIntf := MyIntfImage.GetDataLineStart(0); //top line and writes
downwards.
ASM...mov edi/esi,PMyLazIntf...End;

Credit goes to GetMem - and of course the Lazarus Team - Best to all -
RWC.

Create TBGRABitmap:    http://wiki.freepascal.org/BGRABitmap_tutorial
Create TLazIntfImage: 
http://wiki.lazarus.freepascal.org/Fast_direct_pixel_access