[PD] sending image from of / libpd

[Dan Wilcox]

On Aug 31, 2011, at 8:45 AM, Peter Brinkmann wrote:

> 
> On Wed, Aug 31, 2011 at 6:25 AM, Dan Wilcox <danomatika at gmail.com> wrote:
> I think it's much simpler to just add a call to get/set the message limit, say:
> 
> int libpd_max_message_length();
> void libpd_set_max_message_length(int length);
> 
> This doesn't break any current code.
> 
> Having to set a custom limit each time is far more tedious then just setting it at startup.
> 
> Actually, breakage of current code is a feature as far as I am concerned because it makes people aware of the change, and it should be harmless because it's easy to fix.  The language bindings for Java and Objective-C actually became simpler when I updated them for the new version.
> 
> I don't think the new signature of libpd_start_message is tedious, really.  Essentially, I see two use cases: Either you know an a-priori limit on your message length, in which case there's the tiny extra effort of passing in the limit every time you start a message, or you don't have an a-priori limit, in which case you need to check the length before assembling a message anyway.
> 
> Another aspect is API design.  One feature of a good API is that it's difficult to use incorrectly.  With a separate call for setting the message limit, people will forget that the limit is a consideration.  With the current solution, people will briefly contemplate the length of each message they start, which is a good thing.

... but you can simply return an error or print a message complaining when the message is too long. My whole point is that most people won't bother changing the limit and those that do will just pick a larger size with plenty of space anyway. It's too much work to bother setting it EACH and EVERY time. It's far LESS elegant, and dare I say intuitive. It seems like an unnecessary step. [eople that have problems will only run into this once, increase the max size, and then be fine. Why force them to compute a size manually each time when they could just be happily adding objects ... ?

In case, my wrapper will include max message size get/set functions and complain to cout when something is out of bounds.

> Cheers,
>      Peter
> 
>  
> 
> On Aug 30, 2011, at 5:47 PM, Peter Brinkmann wrote:
> 
>> 
>> 
>> On Tue, Aug 30, 2011 at 3:44 PM, Mathieu Bouchard <matju at artengine.ca> wrote:
>> On Tue, 30 Aug 2011, Peter Brinkmann wrote:
>> 
>> For the time being, I have something much simpler in mind: Just take the current call "int libpd_start_message(void)", which returns the current limit, and replace it with "int libpd_start_message(int length)", which takes a parameter indicating the length of the message and returns a nonzero error code if the length is too big.
>> 
>> But this means that new libpd-using apps won't compile with old versions of libpd AND vice-versa.
>> 
>> Well, the vast majority of users won't notice any difference at all because they're using the Android or iOS branch, which I'm updating as I go along.  The only people who are affected by this are those who are using the C library directly, and I hope that they'll either be willing to update their code (which should be no more than a two-line change in most cases) or just stick to the current version, which will remain available via git.
>> 
>> In any case, I think everybody understands that this is still a young library that needs to adapt as we gain a better understanding of how people are using it, and the cost of making a small incompatible change is a lot lower than choosing a suboptimal solution for compatibility with an earlier version.  This period of youthful innocence is coming to an end, though; the API has been quite stable for quite a while now, and I believe that it'll soon be time to declare it finished.  I want to take a critical look at every piece before we officially lock the API, and I won't be afraid to cut things that may turn out to be a burden in the long run.  (That's why I floated the idea of getting rid of the simple message assembly mechanism, but it looks like that's here to stay.)
>> Cheers,
>>      Peter
>> 
> 
> --------
> Dan Wilcox
> danomatika.com
> robotcowboy.com
> 
> 
> 
> 
> 

--------
Dan Wilcox
danomatika.com
robotcowboy.com




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