Proprosed break in libGL / DRI driver ABI

Brian Paul brian.paul at tungstengraphics.com
Wed Apr 6 21:02:04 PDT 2005


Roland Mainz wrote:
> Brian Paul wrote:
> [snip]
> 
>>>What about making MAX_WIDTH and MAX_HEIGHT runtime-configurable - would
>>>that be possible (for stack allocations the Mesa code then has to depend
>>>on |alloca()|) ?
>>
>>Probably do-able, but a lot of work.
> 
> 
> Depends... if |alloca()| can safely be used on all platforms supported
> by Mesa then this should be no problem to implement. Alternatively the
> code could simply assume that the C compiler supports the C++ feature
> (BTW: Is this supported in C99, too ?) that an array can be dynamically
> sized at declaration (however that's less portable).

I don't want to create a dependency on C99's variable length arrays.
I'm also leary of alloca() since it's not in POSIX.

"grep MAX_WIDTH src/mesa/*/*.[ch] | wc" shows there's about 160 
occurances of MAX_WIDTH that would have to be changed for dynamic 
allocation.  A lot of work.

-Brian


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