diff options
Diffstat (limited to 'third_party/rust/d3d12/src/com.rs')
| -rw-r--r-- | third_party/rust/d3d12/src/com.rs | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/third_party/rust/d3d12/src/com.rs b/third_party/rust/d3d12/src/com.rs new file mode 100644 index 0000000000..f3a85789ce --- /dev/null +++ b/third_party/rust/d3d12/src/com.rs @@ -0,0 +1,263 @@ +use crate::D3DResult; +use std::{ + fmt, + hash::{Hash, Hasher}, + ops::Deref, + ptr, +}; +use winapi::{ctypes::c_void, um::unknwnbase::IUnknown, Interface}; + +#[repr(transparent)] +pub struct WeakPtr<T>(*mut T); + +impl<T> WeakPtr<T> { + pub fn null() -> Self { + WeakPtr(ptr::null_mut()) + } + + pub unsafe fn from_raw(raw: *mut T) -> Self { + WeakPtr(raw) + } + + pub fn is_null(&self) -> bool { + self.0.is_null() + } + + pub fn as_ptr(&self) -> *const T { + self.0 + } + + pub fn as_mut_ptr(&self) -> *mut T { + self.0 + } + + pub fn mut_void(&mut self) -> *mut *mut c_void { + &mut self.0 as *mut *mut _ as *mut *mut _ + } + + pub fn mut_self(&mut self) -> *mut *mut T { + &mut self.0 as *mut *mut _ + } +} + +impl<T: Interface> WeakPtr<T> { + pub unsafe fn as_unknown(&self) -> &IUnknown { + debug_assert!(!self.is_null()); + &*(self.0 as *mut IUnknown) + } + + // Cast creates a new WeakPtr requiring explicit destroy call. + pub unsafe fn cast<U>(&self) -> D3DResult<WeakPtr<U>> + where + U: Interface, + { + let mut obj = WeakPtr::<U>::null(); + let hr = self + .as_unknown() + .QueryInterface(&U::uuidof(), obj.mut_void()); + (obj, hr) + } + + // Destroying one instance of the WeakPtr will invalidate all + // copies and clones. + pub unsafe fn destroy(&self) { + self.as_unknown().Release(); + } +} + +impl<T> Clone for WeakPtr<T> { + fn clone(&self) -> Self { + WeakPtr(self.0) + } +} + +impl<T> Copy for WeakPtr<T> {} + +impl<T> Deref for WeakPtr<T> { + type Target = T; + fn deref(&self) -> &T { + debug_assert!(!self.is_null()); + unsafe { &*self.0 } + } +} + +impl<T> fmt::Debug for WeakPtr<T> { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + write!(f, "WeakPtr( ptr: {:?} )", self.0) + } +} + +impl<T> PartialEq<*mut T> for WeakPtr<T> { + fn eq(&self, other: &*mut T) -> bool { + self.0 == *other + } +} + +impl<T> PartialEq for WeakPtr<T> { + fn eq(&self, other: &Self) -> bool { + self.0 == other.0 + } +} + +impl<T> Hash for WeakPtr<T> { + fn hash<H: Hasher>(&self, state: &mut H) { + self.0.hash(state); + } +} + +/// Macro that allows generation of an easy to use enum for dealing with many different possible versions of a COM object. +/// +/// Give the variants so that parents come before children. This often manifests as going up in order (1 -> 2 -> 3). This is vital for safety. +/// +/// Three function names need to be attached to each variant. The examples are given for the MyComObject1 variant below: +/// - the from function (`WeakPtr<actual::ComObject1> -> Self`) +/// - the as function (`&self -> Option<WeakPtr<actual::ComObject1>>`) +/// - the unwrap function (`&self -> WeakPtr<actual::ComObject1>` panicing on failure to cast) +/// +/// ```rust +/// # pub use d3d12::weak_com_inheritance_chain; +/// # mod actual { +/// # pub struct ComObject; impl winapi::Interface for ComObject { fn uuidof() -> winapi::shared::guiddef::GUID { todo!() } } +/// # pub struct ComObject1; impl winapi::Interface for ComObject1 { fn uuidof() -> winapi::shared::guiddef::GUID { todo!() } } +/// # pub struct ComObject2; impl winapi::Interface for ComObject2 { fn uuidof() -> winapi::shared::guiddef::GUID { todo!() } } +/// # } +/// weak_com_inheritance_chain! { +/// pub enum MyComObject { +/// MyComObject(actual::ComObject), from_my_com_object, as_my_com_object, my_com_object; // First variant doesn't use "unwrap" as it can never fail +/// MyComObject1(actual::ComObject1), from_my_com_object1, as_my_com_object1, unwrap_my_com_object1; +/// MyComObject2(actual::ComObject2), from_my_com_object2, as_my_com_object2, unwrap_my_com_object2; +/// } +/// } +/// ``` +#[macro_export] +macro_rules! weak_com_inheritance_chain { + // We first match a human readable enum style, before going into the recursive section. + // + // Internal calls to the macro have either the prefix + // - @recursion_logic for the recursion and termination + // - @render_members for the actual call to fill in the members. + ( + $(#[$meta:meta])* + $vis:vis enum $name:ident { + $first_variant:ident($first_type:ty), $first_from_name:ident, $first_as_name:ident, $first_unwrap_name:ident $(;)? + $($variant:ident($type:ty), $from_name:ident, $as_name:ident, $unwrap_name:ident);* $(;)? + } + ) => { + $(#[$meta])* + $vis enum $name { + $first_variant($crate::WeakPtr<$first_type>), + $( + $variant($crate::WeakPtr<$type>) + ),+ + } + impl $name { + $vis unsafe fn destroy(&self) { + match *self { + Self::$first_variant(v) => v.destroy(), + $( + Self::$variant(v) => v.destroy(), + )* + } + } + + $crate::weak_com_inheritance_chain! { + @recursion_logic, + $vis, + ; + $first_variant($first_type), $first_from_name, $first_as_name, $first_unwrap_name; + $($variant($type), $from_name, $as_name, $unwrap_name);* + } + } + + impl std::ops::Deref for $name { + type Target = $crate::WeakPtr<$first_type>; + fn deref(&self) -> &Self::Target { + self.$first_unwrap_name() + } + } + }; + + // This is the iteration case of the recursion. We instantiate the member functions for the variant we + // are currently at, recursing on ourself for the next variant. Note we only keep track of the previous + // variant name, not the functions names, as those are not needed. + ( + @recursion_logic, + $vis:vis, + $(,)? $($prev_variant:ident),* $(,)?; + $this_variant:ident($this_type:ty), $this_from_name:ident, $this_as_name:ident, $this_unwrap_name:ident $(;)? + $($next_variant:ident($next_type:ty), $next_from_name:ident, $next_as_name:ident, $next_unwrap_name:ident);* + ) => { + // Actually generate the members for this variant. Needs the previous and future variant names. + $crate::weak_com_inheritance_chain! { + @render_members, + $vis, + $this_from_name, $this_as_name, $this_unwrap_name; + $($prev_variant),*; + $this_variant($this_type); + $($next_variant),*; + } + + // Recurse on ourselves. If there is no future variants left, we'll hit the base case as the final expansion returns no tokens. + $crate::weak_com_inheritance_chain! { + @recursion_logic, + $vis, + $($prev_variant),* , $this_variant; + $($next_variant($next_type), $next_from_name, $next_as_name, $next_unwrap_name);* + } + }; + // Base case for recursion. There are no more variants left + ( + @recursion_logic, + $vis:vis, + $($prev_variant:ident),*; + ) => {}; + + + // This is where we generate the members using the given names. + ( + @render_members, + $vis:vis, + $from_name:ident, $as_name:ident, $unwrap_name:ident; + $($prev_variant:ident),*; + $variant:ident($type:ty); + $($next_variant:ident),*; + ) => { + // Construct this enum from weak pointer to this interface. For best usability, always use the highest constructor you can. This doesn't try to upcast. + $vis unsafe fn $from_name(value: $crate::WeakPtr<$type>) -> Self { + Self::$variant(value) + } + + // Returns Some if the value implements the interface otherwise returns None. + $vis fn $as_name(&self) -> Option<&$crate::WeakPtr<$type>> { + match *self { + $( + Self::$prev_variant(_) => None, + )* + Self::$variant(ref v) => Some(v), + $( + Self::$next_variant(ref v) => { + // v is &WeakPtr<NextType> and se cast to &WeakPtr<Type> + Some(unsafe { std::mem::transmute(v) }) + } + )* + } + } + + // Returns the interface if the value implements it, otherwise panics. + #[track_caller] + $vis fn $unwrap_name(&self) -> &$crate::WeakPtr<$type> { + match *self { + $( + Self::$prev_variant(_) => panic!(concat!("Tried to unwrap a ", stringify!($prev_variant), " as a ", stringify!($variant))), + )* + Self::$variant(ref v) => &*v, + $( + Self::$next_variant(ref v) => { + // v is &WeakPtr<NextType> and se cast to &WeakPtr<Type> + unsafe { std::mem::transmute(v) } + } + )* + } + } + }; +} |