Cool. Another approach. Never thought of using assumingMemoryBound. Need to read up on that. I wonder how both versions compare from a safety/security/performance stand point.
Behold the spinning cubes… ;-) P > > On Sep 3, 2016, at 9:03 PM, Gerard Iglesias via swift-users > <swift-users@swift.org> wrote: > > This is my funny version… I succeeded and I didn’t come back to find an other > way… > > // 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().assumingMemoryBound(to: > ShadowPass.self) > shadowPtr.pointee = shadowPassData[0] > > //More Swift specific stuff - advance pointer and cast to MainPass > > //let mainPtr = UnsafeMutablePointer<MainPass>(shadowPtr.advanced(by: 1)) > let mainPtr = constantBufferForFrame.contents().advanced(by: > MemoryLayout<ShadowPass>.size).assumingMemoryBound(to: MainPass.self) > mainPtr.pointee = mainPassFrameData > > //Advance and cast to ObjectData > > //var ptr = UnsafeMutablePointer<ObjectData>(mainPtr.advanced(by: 1)) > var ptr = constantBufferForFrame.contents().advanced(by: > MemoryLayout<ShadowPass>.size + > MemoryLayout<MainPass>.size).assumingMemoryBound(to: ObjectData.self) > > >> On 3 Sep 2016, at 19:22, Patrice Kouame <pkou...@me.com >> <mailto:pkou...@me.com>> wrote: >> >> Gerard- >> >> Excellent! Looking forward to seeing your fix (hoping you get your book >> back soon ;-) ) >> >> I think Xcode/Swift gags on the last ptr advance to objectData. I recently >> tried another variant using withUnsafeMutablePointer like this: >> >> var ptr : UnsafeMutablePointer<ObjectData> = >> withUnsafeMutablePointer(to: &mainPtr) { >> $0.withMemoryRebound(to: ObjectData.self, capacity: >> objectsToRender) { >> $0.pointee = renderables[0].objectData >> } >> } >> >> ..but still crashes with no hints. >> >> My bug report also mentions that the Xcode migration/conversion tool is >> incomplete. >> It handles the “simpler" UnsafeMutableRawPointer<X> to >> UnsafeMutablePonter<Y> with bindMemory cases correctly (one still has to >> mind the capacity value though) >> In all fairness, migrating/converting automagically in these cases is always >> a little bit tricky - the proposed Xcode fixes should always be reviewed by >> a human... >> >> Patrice >> >>> On Sep 3, 2016, at 1:05 PM, Gerard Iglesias via swift-users >>> <swift-users@swift.org <mailto:swift-users@swift.org>> wrote: >>> >>> 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 >>> <mailto: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 <mailto: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 <mailto: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 >>>>>>> <mailto: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 >>>>>>> >>>>>>> <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 >>>>>>> <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 <mailto: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 <mailto:swift-users@swift.org> >>>>>>> https://lists.swift.org/mailman/listinfo/swift-users >>>>>>> <https://lists.swift.org/mailman/listinfo/swift-users> >>>>>>> >>>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> swift-users mailing list >>>>>> swift-users@swift.org <mailto:swift-users@swift.org> >>>>>> https://lists.swift.org/mailman/listinfo/swift-users >>>>>> <https://lists.swift.org/mailman/listinfo/swift-users> >>>>> _______________________________________________ >>>>> swift-users mailing list >>>>> swift-users@swift.org <mailto:swift-users@swift.org> >>>>> https://lists.swift.org/mailman/listinfo/swift-users >>>>> <https://lists.swift.org/mailman/listinfo/swift-users> >>>> >>> _______________________________________________ >>> swift-users mailing list >>> swift-users@swift.org <mailto:swift-users@swift.org> >>> https://lists.swift.org/mailman/listinfo/swift-users >>> <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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