adaptivegrain/vapoursynth/src/plugins/frame_context.rs
2019-05-30 11:06:53 +00:00

41 lines
1.1 KiB
Rust

use std::marker::PhantomData;
use std::ptr::NonNull;
use vapoursynth_sys as ffi;
use api::API;
/// A frame context used in filters.
#[derive(Debug, Clone, Copy)]
pub struct FrameContext<'a> {
handle: NonNull<ffi::VSFrameContext>,
_owner: PhantomData<&'a ()>,
}
impl<'a> FrameContext<'a> {
/// Wraps `handle` in a `FrameContext`.
///
/// # Safety
/// The caller must ensure `handle` is valid and API is cached.
#[inline]
pub(crate) unsafe fn from_ptr(handle: *mut ffi::VSFrameContext) -> Self {
Self {
handle: NonNull::new_unchecked(handle),
_owner: PhantomData,
}
}
/// Returns the underlying pointer.
#[inline]
pub(crate) fn ptr(self) -> *mut ffi::VSFrameContext {
self.handle.as_ptr()
}
/// Returns the index of the node from which the frame is being requested.
#[inline]
pub fn output_index(self) -> usize {
let index = unsafe { API::get_cached().get_output_index(self.handle.as_ptr()) };
debug_assert!(index >= 0);
index as _
}
}