April 2016 - Pharo-users - lists.pharo.org

New project: AR.Drone communication API in Pharo

by Carolina HernÃ¡ndez

Hi, my name is Carolina Hernandez and I'm a Computer Engineering student at the University of Chile. As part of my final degree project, I'm creating a communication API for controlling the Parrot AR.Drone 2.0 from Pharo. I've just released an early version. The code is hosted in Smalltalkhub: http://smalltalkhub.com/#!/~CaroHernandez/ArDronePharo I also made a video of a test flight, where the AR.Drone is controlled using the API and keyboard: https://www.youtube.com/watch?v=d8rERiBoD0o I couldn't find any direct way to use a joystick in Pharo, if someone knows about one, I'd like to integrate it to my code. Development and tests have been done in Pharo 4.0 and ubuntu 12.04 Comments are welcome! Caro

April 9, 2016

Re: [Pharo-users] Nesting Builders in Roassal

by Evan Donahue

Hello, I got that working, and a bit more besides, and things are starting to look pretty good. However, I've run into another issue I'm not sure how to resolve. Recognizing that, as you mentioned, nested builders are something of a bleeding edge feature, I'm happy to try to contribute code if what I'm trying to do isn't already implemented. My question now is how to adjust the size and shape of the nested, builder-produced elements. In the example code you posted, is it possible to 1) remove the square borders from the pie graphs, and 2) make the pie graphs different sizes based on, for instance, the size of the array they represent? This second question is also relevant for sizing the pie graphs in proportion to other elements such as labels. Witness the uneven proportions between the pie charts and a label added to the display: v := RTView new. data := #((1) (2) (1 2)). es := data collect: [ :d | b := RTPieBuilder new. b interaction popupText. b objects: d. b slice: #value. b build. b view asElement. ]. v add: (RTLabel new elementOn: 'label'). v addAll: es. RTCellLayout new lineItemsCount: 3; on: es. RTMetricNormalizer new view: v; elements: v elements; distinctColor. v Normally, I gather, this is done by adding size and shape info to the element factory before it produces its elements. Since the builders do not appear to have been intended to fill this role initially, however, I can't seem to find any corresponding inputs for size or shape of their generated elements as nested in another builder's view. Cheers, Evan -- View this message in context: http://forum.world.st/Nesting-Builders-in-Roassal-tp4885185p4889195.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

April 9, 2016

Re: [Pharo-users] FFI return by reference

by Esteban Lorenzano

> On 08 Apr 2016, at 11:34, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: > > >> On 07 Apr 2016, at 14:15, Damien Pollet <damien.pollet+pharo(a)gmail.com <mailto:damien.pollet+pharo@gmail.com>> wrote: >> >> I think in that case you need to pass an instance of FFIExternalValueHolder. > > yes. > you can take the test FFIExternalValueHolderTests>>testCall as an example. > > But since it uses anonymous classes it might require a better explanation, there is the class comment, but basically, you do this: > > 1) Declare a class variable > > MyClass class>>initialize > INT_PTR := FFIExternalValueHolder ofType: âintâ. as a larger explanation, this will create an anonymous subclass to keep âintâ values, than later you can use as a type in your function call. Some people would call this obscure, but is a good way of solving this problem (I adopted it from old NB). If you want to have a named class instead an anonymous class, you can just subclass FFIExternalValueHolder: FFIExternalValueHolder subclass: #MyIntPtr and then implement typeDecl class method MyIntPtr class>>typeDecl ^ âint' and this will work as the anonymous class > > 2) Replace "int *â in your function calls with your new type: > > glGetAttribute: attr into: value > ^ self ffiCall: #( int SDL_GL_GetAttribute(SDL_GLattr attr, INT_PTR value) ) > > 3) pass an instance of INT_PTR to get the value: > > | ptr value | > > ptr := INT_PTR new. > self glGetAttribute: anAttributeIDontKnow into: ptr. > > value := ptr value. > > Esteban > > >> >> On 7 April 2016 at 17:42, Thibault Raffaillac <thibault.raffaillac(a)inria.fr <mailto:thibault.raffaillac@inria.fr>> wrote: >> Hi again, >> >> Does anyone know what is the state of return by reference in FFI? >> Example: >> glGetAttribute: attr into: value >> <primitive: #primitiveNativeCall module: #NativeBoostPlugin error: errorCode> >> ^ self nbCall: #( int SDL_GL_GetAttribute(SDL_GLattr attr, int *value) ) >> >> On my image (50666) it does nothing on value yet (if nil, remains nil, if SmallInteger 0, remains 0). >> (SDL2 glGetAttribute: 6 into: value) should return 16. >> I've seen NBOpenGL put "out" before value in method header, should it matter? (does not make it work though) >> Last but not least, should we attach '*' to the type or variable for FFI to understand it is a pointer? >> >> Cheers, >> Thibault Raffaillac >> >> >

April 8, 2016

Re: [Pharo-users] FFI return by reference

by Esteban Lorenzano

> On 07 Apr 2016, at 14:15, Damien Pollet <damien.pollet+pharo(a)gmail.com> wrote: > > I think in that case you need to pass an instance of FFIExternalValueHolder. yes. you can take the test FFIExternalValueHolderTests>>testCall as an example. But since it uses anonymous classes it might require a better explanation, there is the class comment, but basically, you do this: 1) Declare a class variable MyClass class>>initialize INT_PTR := FFIExternalValueHolder ofType: âintâ. 2) Replace "int *â in your function calls with your new type: glGetAttribute: attr into: value ^ self ffiCall: #( int SDL_GL_GetAttribute(SDL_GLattr attr, INT_PTR value) ) 3) pass an instance of INT_PTR to get the value: | ptr value | ptr := INT_PTR new. self glGetAttribute: anAttributeIDontKnow into: ptr. value := ptr value. Esteban > > On 7 April 2016 at 17:42, Thibault Raffaillac <thibault.raffaillac(a)inria.fr <mailto:thibault.raffaillac@inria.fr>> wrote: > Hi again, > > Does anyone know what is the state of return by reference in FFI? > Example: > glGetAttribute: attr into: value > <primitive: #primitiveNativeCall module: #NativeBoostPlugin error: errorCode> > ^ self nbCall: #( int SDL_GL_GetAttribute(SDL_GLattr attr, int *value) ) > > On my image (50666) it does nothing on value yet (if nil, remains nil, if SmallInteger 0, remains 0). > (SDL2 glGetAttribute: 6 into: value) should return 16. > I've seen NBOpenGL put "out" before value in method header, should it matter? (does not make it work though) > Last but not least, should we attach '*' to the type or variable for FFI to understand it is a pointer? > > Cheers, > Thibault Raffaillac > >

April 8, 2016

Re: [Pharo-users] Passing nil with FFI

by Esteban Lorenzano

Hi, marshalling in UFFI is complex and sometimes not worthy, so we do not do auto-conversion between nil in smalltalk o zero to NULL (yes, I know NULL=0, but not for UFFI who is waiting a object type). In this case (since it expects a kind of external object) you have to do: SDL2 glCreateContext: FFIExternalObject null. Esteban > On 07 Apr 2016, at 12:06, Thibault Raffaillac <thibault.raffaillac(a)inria.fr> wrote: > > Hi, > > I am having trouble passing nil to a function with FFI (i.e. NULL, i.e. 0). > For example: SDL2 glCreateContext: nil. > The function expects a subclass of FFIExternalObject, so calls instVarAt: 1 but nil has no such field! > Am I missing something? (like a special nil instance of FFIExternalObject) > Note however that putting nil works when FFI expects a String. > > Cheers, > Thibault Raffaillac >

April 8, 2016

Re: [Pharo-users] FFI return by reference

by Thibault Raffaillac

Is there something like a generic int value holder then? > > I think in that case you need to pass an instance of FFIExternalValueHolder. > > > Hi again, > > > > Does anyone know what is the state of return by reference in FFI? > > Example: > > glGetAttribute: attr into: value > > <primitive: #primitiveNativeCall module: #NativeBoostPlugin error: > > errorCode> > > ^ self nbCall: #( int SDL_GL_GetAttribute(SDL_GLattr attr, int > > *value) ) > > > > On my image (50666) it does nothing on value yet (if nil, remains nil, if > > SmallInteger 0, remains 0). > > (SDL2 glGetAttribute: 6 into: value) should return 16. > > I've seen NBOpenGL put "out" before value in method header, should it > > matter? (does not make it work though) > > Last but not least, should we attach '*' to the type or variable for FFI > > to understand it is a pointer? > > > > Cheers, > > Thibault Raffaillac

April 8, 2016

Re: [Pharo-users] Debugger in 4.0

by Hilaire

I open a bug ticket, it is important https://pharo.fogbugz.com/f/cases/17961/Evaluating-instance-and-method-vari… -- Dr. Geo http://drgeo.eu

April 8, 2016

Re: [Pharo-users] Pharo-users Question about the symbols

by Cyril Ferlicot Delbecque

On 08/04/2016 09:05, Henrik Nergaard wrote: > | s1 s2 | > > s1 := 1234 asString. > s2 := 1234 asString. > > s1 = s2. "true" > s1 == s2. "false" > > s1 asSymbol = s2 asSymbol. "true" > s1 asSymbol == s2 asSymbol. "true" > > (s1 class allInstances select: [:s | s = s1 ]) size. "2" > (s1 asSymbol class allInstances select: [:s | s = s1 asSymbol ]) size. "1" > > [ #stringA = #stringB ] bench. "26,812,864 per second" > [ 'StringA' = 'StringB' ] bench. "3,492,987 per second" > > Best regards, > Henrik Hi Henrik, The class comment of Symbol is really not enough. It need improvement. I think it would be good to add your examples at least in the class comment. -- Cyril Ferlicot http://www.synectique.eu 165 Avenue Bretagne Lille 59000 France

April 8, 2016

Re: [Pharo-users] Pharo-users Question about the symbols

by stepharo

+1 >> | s1 s2 | >> >> s1 := 1234 asString. >> s2 := 1234 asString. >> >> s1 = s2. "true" >> s1 == s2. "false" >> >> s1 asSymbol = s2 asSymbol. "true" >> s1 asSymbol == s2 asSymbol. "true" >> >> (s1 class allInstances select: [:s | s = s1 ]) size. "2" >> (s1 asSymbol class allInstances select: [:s | s = s1 asSymbol ]) size. "1" >> >> [ #stringA = #stringB ] bench. "26,812,864 per second" >> [ 'StringA' = 'StringB' ] bench. "3,492,987 per second" > very very nice summary. >

April 8, 2016

Re: [Pharo-users] Pharo-users Question about the symbols

by Sven Van Caekenberghe

> On 08 Apr 2016, at 09:19, Damien Cassou <damien.cassou(a)inria.fr> wrote: > > Henrik Nergaard <henrik.nergaard(a)uia.no> writes: > >> | s1 s2 | >> >> s1 := 1234 asString. >> s2 := 1234 asString. >> >> s1 = s2. "true" >> s1 == s2. "false" >> >> s1 asSymbol = s2 asSymbol. "true" >> s1 asSymbol == s2 asSymbol. "true" >> >> (s1 class allInstances select: [:s | s = s1 ]) size. "2" >> (s1 asSymbol class allInstances select: [:s | s = s1 asSymbol ]) size. "1" >> >> [ #stringA = #stringB ] bench. "26,812,864 per second" >> [ 'StringA' = 'StringB' ] bench. "3,492,987 per second" > > very very nice summary. YES! > -- > Damien Cassou > http://damiencassou.seasidehosting.st > > "Success is the ability to go from one failure to another without > losing enthusiasm." --Winston Churchill

April 8, 2016