[Cuis-dev] BMP Reader broken

lewis at mail.msen.com lewis at mail.msen.com
Sat Mar 16 14:22:49 PDT 2024

Hi Hilaire,

I compared the behavior in Squeak with both opensmalltalk-vm and with V3 
interpreter VM.

In Squeak:
ImageReadWriter formFromFileNamed: 'splash.bmp'. "==> Form(400x300x32)"

In Cuis (with the same VM):
ImageReadWriter formFromFileEntry: 'splash.bmp' asFileEntry. "==> Error"

I see two possible issues here.
1) The call to #primitiveRead24BmpLine is failing in both Squeak and 
Cuis. This may be a problem in the VM plugin (or maybe it is expected in 
this case, I am not sure).

2) In the primitive fallback code in method 
#read24BmpLine:into:startingAt:width: the error happens at the "formBits 
at: (bitsIndex := bitsIndex+1) put: rgb". The formBits is a BitMap, so 
maybe the some difference between Squeak and Cuis here.

I also tried Squeak with a V3 image and interpreter VM, and the results 
are the same as with opensmalltalk-vm. The form is created successfully, 
and the #primitiveRead24BmpLine call fails and goes to the fallback 

At this point I cannot say if there primitive failure is a problem in 
the VM plugin, or if the primitive failure is normal and expected for 
this particular case. But I can say that the actual Error in Cuis must 
be something related to the fallback code when it updates the formBits 


On 2024-03-16 18:47, Hilaire Fernandes via Cuis-dev wrote:

> Hi folks,
> It looks like the BMP reader is broken.
> ImageReadWriter formFromFileEntry: 'splash.bmp'.
> Could it be a VM issue? Seem to occure in a plugin. I am not forwarding 
> to VM mailing list for now, waiting for more advices.
> See screen capture and bmp example known to load previously.
> --
> GNU Dr. Geo
> http://gnu.org/s/dr-geo/
> http://gnu-drgeo.blogspot.com/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.cuis.st/mailman/archives/cuis-dev/attachments/20240316/3b7909d3/attachment.htm>

More information about the Cuis-dev mailing list