XRay Unreal Engine 4.5 source code

http://www.codergears.com/Blog/?p=965

by cppdesign • 12 years ago

63 13 12 years ago

maccard• 12 years ago

Although this article points out that UE4 doesn't use synamic_cast, Unreal implements a full reflection system and uses it instead. Similarly, if you searched for uses of stl, you'd be is appointed because everything is reimplemented as TArray, TPair, TMap, etc.

RCL• 12 years ago

Not "full", just UObject and such, so much more lightweight.

desdiv• 12 years ago

if you searched for uses of stl, you'd be is appointed because everything is reimplemented as TArray, TPair, TMap, etc.

In case anyone else is wondering "why didn't they just use STL?", here's an answer from an Unreal employee: https://answers.unrealengine.com/questions/2695/rocket-and-t...

illicium• 12 years ago

⁎((uint32⁎)3) = ExceptionCode

Is this just a way to force a segfault, or clever sorcery? What is significant about the pointer 3?

omnigoat• 12 years ago

They're calling the Int 3 debugger instruction, I believe:

http://en.wikipedia.org/wiki/INT_%28x86_instruction%29

I'd prefer to see this either with inline assembly, or using __debugbreak() (and variants for other compilers). I'd say it's a deref because many compilers don't generate inline-asm for 64-bit skus. This makes the instruction always emitted, and then 64-bit platforms ignore it. But not always (recent claims say it works: http://stackoverflow.com/questions/3634124/where-did-int-3-g...).

pandaman4• 12 years ago

Int3 is a one byte instruction, how do you imagine this code could possibly compile into one byte? This will compile into several moves/stores. Not to mention the code is not x86 specific at all.

It's a forced memory access violation and the 3 is used to distinguish it from a natural one: when you hit this you will see an immediate 3 load nearby and that's a constant that is rarely seen in code normally.

XRay Unreal Engine 4.5 source code

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