Question

I have 1 bitmap object witdh : 1024px and height : 768 px

I want to cut this bitmap object to 2 part like left and right but I don’t want to use DrawBitmap method in canvas because this method can use more CPU then CopyMemory.

I don’t want to use this method ( leftImg.Canvas.DrawBitmap(MainBmp, RectF(0,0, MainBmp.Width div 2, bmp.Height),
RectF(0,0, leftImg.Width, leftImg.Height), 1, True); )

MainBmp := TBitmap.Create(1024, 768);

leftImg := TBitmap.Create(MainBmp.Width div 2, MainBmp.Height);
rightImg := TBitmap.Create(MainBmp.Width div 2, MainBmp.Height);

leftBits := PAlphaColorArray(leftImg.Scanline[0]);

CopyMemory(@leftBits[0], @MainBmp.StartLine[0], (MainBmp.Width div 2) * bmp.Height);

if I am doing like this he can copy but not left part of bitmap 🙁 he copy half of top to bottom.

That drawing is exactly what I want to do.

After cut procces, i need like this without using any loop (like while or for)

Thanks

Answer 1

No can do! As you’ve found out image data is layout in the memory line by line (hence scanline). What you want could only be possible if it was column by column. Without any loops this is not possible.