• GHOST Rust bindings
  • Layout
  • Notes
  • Implementation
    • Implemented C compatable ABI
    • Native Rust API
      • Overview
      • Handles
        • Example
      • Error handling

GHOST Rust bindings

Rust bindings and interop for GHOST.

Layout

ABI-compatable types and functions are all prefixed with `GHOST_` and are exported in the `c` module (TODO). I've attempted to provide more Rust-idiomatic API variants as well, which have non-prefixed names.

Notes

Eventually I intend to have most (if not all) C compatable types either reimplemented or aliased to non-prefixed Rust types. At present though this is not the case, and prefixed names that can double as ergonomic Rust types are not aliased to them, so you'll have to use both often. The reimplementation is undergoing, the aliasing not yet.

I've elected to leave out implementing Copy for most FFI types, because I think the ownership model will work well here. This may be changed in the future, as (virtually) all implement Clone anyway. I did this basically just because I want people to think about it when and why they copy something, instead of it being default behaviour.

Implementation

Implemented C compatable ABI

Note: List is in-progress and doesn't show everything

• `GHOST_Types.h`

  • Handles

    • GHOST_SystemHandle
    • GHOST_TimerTaskHandle
    • GHOST_WindowHandle
    • GHOST_EventHandle
    • GHOST_RectangleHandle
    • GHOST_EventConsumerHandle
    • GHOST_ContextHandle
    • GHOST_XrContextHandle

  • Primitives (ones that begin with T I count as `primitive')

    • GHOST_TInt8
    • GHOST_TUns8
    • GHOST_Tint16
    • GHOST_TUns16
    • GHOST_Tint32
    • GHOST_TUns32
    • GHOST_TInt64
    • GHOST_TUns64
    • GHOST_TUserDataPtr
    • GHOST_TSuccess
    • GHOST_TTabletMode
    • GHOST_TTabletAPI
    • GHOST_TVisibility
    • GHOST_TFireTimeConstant
    • GHOST_TModifierKeyMask
    • GHOST_TWindowState
    • GHOST_TWindowOrder
    • GHOST_TDrawingContextType
    • GHOST_TButtonMask
    • GHOST_TEventType
    • GHOST_TStandardCursor
    • GHOST_TKey

  • Structures

    • GHOST_GLSettings
    • GHOST_GLFlags
    • GHOST_DialogOptions
    • GHOST_TabletData

  • Constants

    • GHOST_TABLET_DATA_NONE (reimpl as const fn GHOST_TabletData::none())

Native Rust API

I provide more Rust idiomatic API for some things. They may or may not share ABI, if they do they will have type aliases to the corresponding GHOST_ identifier, so always use those when ABI compatability is desired.

Overview

List and implementation status of features

• Types

  • /flanchan/ghost-rust/src/commit/f486c061ed1064aa0cfa03d947e8752981966acf/Handles: handle.rs
  • /flanchan/ghost-rust/src/commit/f486c061ed1064aa0cfa03d947e8752981966acf/Error%20handling: error.rs
  • Events: event.rs

Handles

Handles keep the C ABI, but are re-wrtten with traits to be more idiomatic.

The trait GhostHandle is provided, which should be implemented on a structure that is not intended to be instantiated, but instead used as a `marker' for `Handle<T>'. These types are ABI equivalent, and are present (with their corresponding GHOST_ alias in handle.rs) Since handles are just types pointers, they are only ever used as such and shouldn't exist themselves.

Example

  extern "C" {fn some_internal_call(window: GHOST_WindowHandle) -> GHOST_TSuccess;}

  fn do_something_to_window(window: &mut Handle<Window>) -> GhostResult<()>
  {
      some_internal_call(window as GHOST_WindowHandle).into()
  }

Error handling

I have provided an idiomatic Rust error handling module, with conversion and interop between the C ABI GHOST_TSuccess and the Rust error::GhostError. There is also the type alias GhostResult provided.

On nightly Rust versions, values of type GHOST_TSuccess can be propagated directly with ?, but on stable they must be propagated through GhostResult:

extern "C" {fn returns_tsuccess() -> GHOST_TSuccess;}

fn try_things_internal() -> GhostResult // On nightly, we can propagage `GHOST_TSuccess` directly here, but it's still more desireable for us to have a `Result<T,E>` instead of an integer in Rust, so this is still preferrable.
{
 returns_tsuccess()?;

 Ok(())
}

fn caller()
{
 match try_things_internal() {
     Ok(_) => println!("Yay!"),
     Err(_) => panic!("Fug"),
 }
}

Keeping such a style is usually preferred, anyhow.

See error.rs for more details.