Hello.

My application works extensively with png images. So Image based PNGReadWriter speed not enough for me.
I have C library dll which has function "byte* readPNG(filename)". It returns buffer (pointer address) with same structure as Form Bitmap has.

I use FFI to call this function. And I have very naive converter of returned buffer to Form:

buffer := self primReadImageBytesFrom: imagePath.
buffer getHandle asInteger == 0 ifTrue: [self error: 'bad image: ', imagePath ].��
��
form := Form extent: width @ height depth: 32.

��

x:= 0. y:=0.
[y <=� height ] whileTrue: [
x :=0.
[x <= width] whileTrue: [

�� offset� := x * 4 + (y * width * 4) + 1 + 8.
�� value := buffer getHandle integerAt: offset size: 4 signed: false. ��
�� form pixelValueAt: x@y put: value.
�� x := x + 1.
].
y := y + 1.
].
^form

It's work and it is improve that buffer format similar to Form bits format. But such algorithm very slow.
So my question is: How efficiently convert external byte array from FFI call to internal ByteArray (Bitmap, Form).

I know about BitBlt class and

�� blt := (BitBlt current
�� toForm: f)
�� sourceForm: source.
�� blt combinationRule: Form over. "store"
�� blt sourceX: 0;
�� sourceY: 0;
�� height: height;
�� width: width.
�� blt destX: 0;
�� destY: 0.
�� blt copyBits.

And it works very fast. I try create source Form by

source := Form extent: width@height depth: 32.
source bits: buffer getHandle

But BitBlt raise error for such form. #copyBits primitive failed and method execution continue with attempt to unhibernate given forms.

Any ideas?