Re: Defining ConstraintSet and the constrainable algorithm in terms of it

Not quite.  The problem is that a constraint may have the side effect of 
constraining a property other than the one it explicitly mentions.  
aspectRatio is one example, but a more common one may be ones due to 
resource limitations.  On a certain machine it may be impossible to have 
both foo and bar set to 'high', while on another, less resource 
constrained one, it may be fine.  I think we need a concept like 
"effective Capability", which is the range that the machine is actually 
able to support, given the circumstances and the other constraints that 
are in effect.  The setting has to be in the intersection of the 
effective Capability and the range specified by the constraint.

- Jim
On 2/7/2014 12:30 PM, Martin Thomson wrote:
> On 6 February 2014 20:28, Harald Alvestrand <harald@alvestrand.no> wrote:
>> You're right. The "intersection" has to be in terms of what's possible given
>> the already-satisfied constraints, not just what that particular constraint
>> has been constrained to.
> You mean that for constraints from a set of sources S, the constraint
> is the intersection of the set formed from the present constraints and
> the constraints already set by {S - S[current]}.
>

-- 
Jim Barnett
Genesys

Received on Friday, 7 February 2014 17:58:11 UTC