[Vm-dev] simulation in BitBltSimulation

[Eliot Miranda]

On Sat, Mar 15, 2014 at 12:32 AM, Nicolas Cellier <
nicolas.cellier.aka.nice at gmail.com> wrote:

>
>
> 2014-03-15 2:44 GMT+01:00 tim Rowledge <tim at rowledge.org>:
>
>>
>>
>> On 14-03-2014, at 6:16 PM, Eliot Miranda <eliot.miranda at gmail.com> wrote:
>>
>> > Hi Tim,
>> >
>> >     I'm simulating bitblt code and have a situation where
>> >
>> > (cmShiftTable at: 0) = 4294967280
>> > (cmShiftTable at: 0) hex '16rFFFFFFF0'
>> >
>> > Clearly this should be -4.
>> >
>>
>
> I presume you mean - 2^4 (-2r1e4 or -16) ;)
>

doh!  quite :)


>
>
>> > This breaks simulation because
>> >         (sourcePixel bitAnd: (cmMaskTable at: 0)) bitShift:
>> (cmShiftTable at: 0)
>> > is trying to make a 4Gb LargePositiveInteger ;-).
>> >
>> > How can we make it so?
>>
>> Hmm, well if you need to make a 4Gb LPI I guess you'd best have plenty of
>> memory?
>>
>> Dunno; looks like cmShiftTable is supposed to use int32_t thingies in the
>> C code.
>> BitBltSimulation>loadColorMapShiftOrMaskFrom: looks like the culprit to
>> me though -  (simulated)firstIndexableField: might be not doing the right
>> thing?
>>
>> tim
>> --
>> tim Rowledge; tim at rowledge.org; http://www.rowledge.org/tim
>> Useful random insult:- Always loses battles of wits because he's unarmed.
>>
>>
>>
>
>


-- 
best,
Eliot
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