Ok
For the record I succeeded this transformation phase last week
I remember the tedious stuff to advance pointer from one struct to the other
kind of struct... it worked
But I don't have my MacBook with me, only the phone, the six :)
Gérard
> Le 3 sept. 2016 à 18:22, Patrice Kouame <pkou...@me.com> a écrit :
>
> Indeed. There is a difference between stride and size, but I interpreted
> capacity incorrectly for my purposes. It should indicate the number of <T>
> elements (not their size - right?) and the snippets below should work.
>
> Still, compiler crashes and Xcode IDE is left in inconsistent state. So I
> filed this Apple radar against Developer Tools.
>
> 28150447 - Swift 3 UnsafeMutablePointer conversion crashes the compiler
> and IDE
> Should I file a Swift bug too? Would that be helpful?
>
> Regards, Patrice
>
>> On Sep 3, 2016, at 11:39 AM, Gerard Iglesias via swift-users
>> <swift-users@swift.org> wrote:
>>
>> Hello,
>>
>> I think that it is more secure to use stride in place of size, sometimes it
>> is not the same value.
>>
>> I use it in my own use of raw bindings
>>
>> Regards
>>
>> Gérard
>>
>>> Le 3 sept. 2016 à 10:03, Patrice Kouame via swift-users
>>> <swift-users@swift.org> a écrit :
>>>
>>> Hi Jacob -
>>>
>>> I think you’re right. “capacity” should be the count of type T elements in
>>> my buffer. So in my case that line should read
>>>
>>> let shadowPtr = constantBufferForFrame.contents().bindMemory(to:
>>> ShadowPass.self, capacity: shadowPassData.count)
>>>
>>> The withMemoryRebound calls need similar adjustments. The pointer to
>>> MainPass is actually a single structure to it should be safe to do this
>>>
>>> let mainPtr : UnsafeMutablePointer<MainPass> =
>>> shadowPtr.advanced(by: 1).withMemoryRebound(to: MainPass.self, capacity: 1)
>>> {
>>> $0.pointee = mainPassFrameData
>>> }
>>>
>>> Whereas the unsafe pointer to <ObjectData> is actually a buffer of
>>> renderable objects, so this should work:
>>>
>>> var ptr : UnsafeMutablePointer<ObjectData> = mainPtr.advanced(by:
>>> 1).withMemoryRebound(to: ObjectData.self, capacity: objectsToRender) {_ in
>>> }
>>>
>>> There are surely ways to refactor and simplify this, but I’m trying to
>>> retain as much of the original sample code approach as possible.
>>>
>>> However, the compiler still segs badly.
>>> Xcode also borks an internal error often. Only cleaning or restarting the
>>> project can clear up that state.
>>> Compilers (or Playgrounds for that matter) should never crash, and I’m not
>>> sure where to file this bug : Swift or Apple radar against Xcode or both? I
>>> now Xcode 8 is beta but…it’s been doing this for quite a while now...
>>>
>>> In both our “close to the metal” (no pun intended) cases, it seems like a
>>> lot of churning for very little gain. Don’t you think? The easier, but
>>> “unsafe” casting afforded previously did the trick with the normal caveats.
>>> Don’t get me wrong, I love Swift and “get" all the neat type safety
>>> features. Guess we can’t have our cake and eat it too, especially when
>>> interfacing with “unsafe” C APIs.
>>>
>>> Anyway, back to rtfm … maybe some of the Swift Gods can chime in? ;-)
>>>
>>> I must be doing something stupid...Patrice
>>>
>>>> On Sep 3, 2016, at 2:32 AM, Jacob Bandes-Storch <jtban...@gmail.com> wrote:
>>>>
>>>> Hi Patrice,
>>>> I don't have a solution for you, but I just wanted to point out what I
>>>> think may be an error with your use of the new UnsafeRawPointer APIs:
>>>>
>>>> constantBufferForFrame.contents().bindMemory(to: ShadowPass.self,
>>>> capacity: MemoryLayout<ShadowPass>.size)
>>>>
>>>> I believe the `capacity` should actually be the number of ShadowPass
>>>> elements in the buffer, not the size of each element. Using
>>>> `bindMemory(to: ShadowPass.self` already implies that
>>>> MemoryLayout<ShadowPass>.size is the size of each element.
>>>>
>>>> More info at
>>>> https://developer.apple.com/reference/swift/unsaferawpointer/2428875-bindmemory
>>>>
>>>> I just updated a small Metal project of mine to Swift 3. I ran into some
>>>> compiler (playground) crashes, but it does seem to work most of the time.
>>>> Although I only have 1 buffer :-)
>>>> https://github.com/jtbandes/Metalbrot.playground
>>>>
>>>> Jacob
>>>>
>>>>> On Fri, Sep 2, 2016 at 11:00 AM, Patrice Kouame via swift-users
>>>>> <swift-users@swift.org> wrote:
>>>>> Hi all -
>>>>>
>>>>> I’m converting Apple’s Swift Sample "Adopting Metal II: Designing and
>>>>> Implementing a Real-World Metal Renderer” in Xcode 8 beta6 to the latest
>>>>> UnsafeMutablePointer API for untyped memory access.
>>>>> Changes are necessary in MetalView.swift (Apple hasn’t updated their
>>>>> sample code for the latest beta yet…)
>>>>> The Swift Compiler crashes (Segmentation Fault: 11) on the attempt:
>>>>>
>>>>> // Grab a pointer to the constant buffer's data store
>>>>> // Since we are using Swift, it is easier to cast the pointer to
>>>>> the ShadowPass type to fill the constant buffer
>>>>> // We need to make a copy of these so the block captures the
>>>>> correct data
>>>>>
>>>>> // let shadowPtr =
>>>>> UnsafeMutablePointer<ShadowPass>(constantBufferForFrame.contents())
>>>>> let shadowPtr = constantBufferForFrame.contents().bindMemory(to:
>>>>> ShadowPass.self, capacity: MemoryLayout<ShadowPass>.size)
>>>>> shadowPtr.pointee = shadowPassData[0]
>>>>>
>>>>> //More Swift specific stuff - advance pointer and cast to MainPass
>>>>>
>>>>> // let mainPtr =
>>>>> UnsafeMutablePointer<MainPass>(shadowPtr.advanced(by: 1))
>>>>> // mainPtr.pointee = mainPassFrameData
>>>>> let mainPtr : UnsafeMutablePointer<MainPass> =
>>>>> shadowPtr.advanced(by: 1).withMemoryRebound(to: MainPass.self, capacity:
>>>>> MemoryLayout<MainPass>.size) {
>>>>> $0.pointee = mainPassFrameData
>>>>> }
>>>>>
>>>>> //Advance and cast to ObjectData
>>>>>
>>>>> // var ptr = UnsafeMutablePointer<ObjectData>(mainPtr.advanced(by:
>>>>> 1))
>>>>> var ptr : UnsafeMutablePointer<ObjectData> = mainPtr.advanced(by:
>>>>> 1).withMemoryRebound(to: ObjectData.self, capacity:
>>>>> MemoryLayout<ObjectData>.size) {_ in
>>>>> }
>>>>>
>>>>> let shadowOffset = 0
>>>>> let mainPassOffset = MemoryLayout<ShadowPass>.size + shadowOffset
>>>>> let objectDataOffset = MemoryLayout<MainPass>.size +
>>>>> mainPassOffset
>>>>>
>>>>> // Update position of all the objects
>>>>> if multithreadedUpdate {
>>>>> DispatchQueue.concurrentPerform(iterations: objectsToRender)
>>>>> { i in
>>>>> let thisPtr = ptr.advanced(by: i)
>>>>> _ = self.renderables[i].UpdateData(ptr, deltaTime:
>>>>> 1.0/60.0)
>>>>> }
>>>>> }
>>>>> else {
>>>>> for index in 0..<objectsToRender {
>>>>> ptr = renderables[index].UpdateData(ptr, deltaTime:
>>>>> 1.0/60.0)
>>>>> }
>>>>> }
>>>>>
>>>>> ptr = ptr.advanced(by: objectsToRender)
>>>>>
>>>>> _ = groundPlane!.UpdateData(ptr, deltaTime: 1.0/60.0)
>>>>>
>>>>> Any help is appreciated. I have the latest Xcode log handy if necessary.
>>>>> Here’s a clip of the stack trace.
>>>>>
>>>>> 0 swift 0x000000010714a99d
>>>>> PrintStackTraceSignalHandler(void*) + 45
>>>>> 1 swift 0x000000010714a3e6 SignalHandler(int) + 470
>>>>> 2 libsystem_platform.dylib 0x00007fff91461bba _sigtramp + 26
>>>>> 3 libsystem_platform.dylib 000000000000000000 _sigtramp + 1857676384
>>>>> 4 swift 0x00000001047207b3 (anonymous
>>>>> namespace)::SILGenApply::visitExpr(swift::Expr*) + 51
>>>>> 5 swift 0x0000000104723ace (anonymous
>>>>> namespace)::SILGenApply::visitApplyExpr(swift::ApplyExpr*) + 5182
>>>>> 6 swift 0x0000000104711cc1
>>>>> prepareApplyExpr(swift::Lowering::SILGenFunction&, swift::Expr*) + 273
>>>>> 7 swift 0x00000001047624e7
>>>>> swift::ASTVisitor<(anonymous namespace)::RValueEmitter,
>>>>> swift::Lowering::RValue, void, void, void, void, void,
>>>>> swift::Lowering::SGFContext>::visit(swift::Expr*,
>>>>> swift::Lowering::SGFContext) + 103
>>>>> 8 swift 0x0000000104762313
>>>>> swift::Lowering::SILGenFunction::emitExprInto(swift::Expr*,
>>>>> swift::Lowering::Initialization*) + 195
>>>>> 9 swift 0x000000010474fbc3
>>>>> swift::Lowering::SILGenFunction::emitPatternBinding(swift::PatternBindingDecl*,
>>>>> unsigned int) + 195
>>>>> 10 swift 0x00000001047077bd
>>>>> swift::ASTVisitor<swift::Lowering::SILGenFunction, void, void, void,
>>>>> void, void, void>::visit(swift::Decl*) + 125
>>>>> 11 swift 0x00000001047c0019
>>>>> swift::ASTVisitor<(anonymous namespace)::StmtEmitter, void, void, void,
>>>>> void, void, void>::visit(swift::Stmt*) + 4169
>>>>> 12 swift 0x00000001047809ba
>>>>> swift::Lowering::SILGenFunction::emitFunction(swift::FuncDecl*) + 314
>>>>> 13 swift 0x00000001046fd775
>>>>> swift::Lowering::SILGenModule::emitFunction(swift::FuncDecl*)::$_1::operator()(swift::SILFunction*)
>>>>> const + 1877
>>>>> 14 swift 0x00000001046fc322
>>>>> swift::Lowering::SILGenModule::emitFunction(swift::FuncDecl*) + 626
>>>>> 15 swift 0x00000001047c7007 (anonymous
>>>>> namespace)::SILGenType::emitType() + 1271
>>>>> 16 swift 0x00000001047c6a9e
>>>>> swift::Lowering::SILGenModule::visitNominalTypeDecl(swift::NominalTypeDecl*)
>>>>> + 30
>>>>> 17 swift 0x0000000104709093
>>>>> swift::Lowering::SILGenModule::emitSourceFile(swift::SourceFile*,
>>>>> unsigned int) + 1795
>>>>> 18 swift 0x000000010470ad4d
>>>>> swift::SILModule::constructSIL(swift::ModuleDecl*, swift::SILOptions&,
>>>>> swift::FileUnit*, llvm::Optional<unsigned int>, bool, bool) + 1629
>>>>> 19 swift 0x00000001045621bf
>>>>> performCompile(swift::CompilerInstance&, swift::CompilerInvocation&,
>>>>> llvm::ArrayRef<char const*>, int&, swift::FrontendObserver*) + 19487
>>>>> 20 swift 0x000000010455b2c5
>>>>> swift::performFrontend(llvm::ArrayRef<char const*>, char const*, void*,
>>>>> swift::FrontendObserver*) + 17029
>>>>> 21 swift 0x000000010451888d main + 8685
>>>>> 22 libdyld.dylib 0x00007fff91255255 start + 1
>>>>>
>>>>>
>>>>> Patrice
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> swift-users mailing list
>>>>> swift-users@swift.org
>>>>> https://lists.swift.org/mailman/listinfo/swift-users
>>>>>
>>>>
>>>
>>> _______________________________________________
>>> swift-users mailing list
>>> swift-users@swift.org
>>> https://lists.swift.org/mailman/listinfo/swift-users
>> _______________________________________________
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>
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