On 22 November 2013 01:23, Sean P. DeNigris <s...@clipperadams.com> wrote:
> Igor Stasenko wrote > >> err.. again, you must pass an address where value will be stored, > > hee hee... sorry... I don't understand enough of what's going on behind the > scenes to adapt well. I reasoned that since last time, the signature was > "Whatever**" and you said to make it "NBExternalAddress*", that therefore > "Whatever*" (one less *) would be "NBExternalAddress" (also one less *). > > While we're here, I'll ask my other questions... > > 1. What's the differenct between <primitive: #primitiveNativeCall module: > #NativeBoostPlugin> and the variant with error:? What does the second one > buy you? > > Historically, NB was first running on Squeak VM, which has no support for primitive error. Using extra #error: keyword in primitive is HIGHLY recommended, unless you want to deal with some quite rare (but possible and thus very hard to track down) wrong error reporting. > 2. instead of returning useful objects, FMOD returns error codes and you > pass a pointer to receive the object. > > - The first consequence is that I have to wrap all the calls e.g. "self > processErrorCode: self primCreate." where > processErrorCode: anInteger > anInteger = 0 ifFalse: [ self error: 'FMOD returned error code ', > anInteger > asString ]. > Is there a more graceful way to do that? > > i doubt so.. since it is library API which dictates you to use it in certain way. The proper error handling never hurts (except from causing extra code bloat, of course :) > - The second issue is how to create a Smalltalk object from the pointer. > What I've been doing is: > | soundHandle | > soundHandle := NBExternalAddress new. > self processErrorCode: (self primCreate: soundHandle on: system > handle > fromFile: file fullName). > sound := FmodSystemSound on: soundHandle. > Again, is there a better way? I thought to subclass NBExternalAddress, but > evaluating "sound := FmodSystemSound new" to pass to the callout seemed a > bit dirty i.e. it is not a invalid instance until initialized by the > callout. I also played around with NBExternalObject, but couldn't get that > to work either... > > The better way is to subclass from NBExternalObject then which made exactly for such purposes, by holding an opaque handle to something (you don't care what is inside), and simplifies a lot of things. > Thanks for all the support. This is fun!! > > You are very welcome. > > > ----- > Cheers, > Sean > -- > View this message in context: > http://forum.world.st/NativeBoost-Questions-while-wrapping-FMOD-tp4724116p4724158.html > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. > > -- Best regards, Igor Stasenko.
