dtourolle
dc1add9dbb
The Android develop view reads its frame back through memory (TD-1) because wgpu's Vulkan swapchain never pre-rotates, and a portrait window on this tablet's landscape panel then tears. The fix is a small patch to each of these two crates, and this commit is only the ground it lands on: both are byte-for-byte the crates.io sources the lockfile already resolved, so the commits that follow are the patch and nothing else. third_party/ is excluded from the workspace, or every path dependency under the root would become a member and `--workspace` would test and lint upstream code as ours. The README says how to carry the patches across a Slint or wgpu bump, which matters because a stale version here does not fail the build — cargo just warns and uses the unpatched crate.
39 lines
1005 B
Rust
39 lines
1005 B
Rust
//! Handling of global timestamps.
|
|
|
|
#[repr(C)]
|
|
#[derive(Debug)]
|
|
struct MachTimebaseInfo {
|
|
numerator: u32,
|
|
denominator: u32,
|
|
}
|
|
extern "C" {
|
|
fn mach_timebase_info(out: *mut MachTimebaseInfo) -> u32;
|
|
fn mach_absolute_time() -> u64;
|
|
}
|
|
|
|
/// A timer which uses mach_absolute_time to get its time. This is what the metal callbacks use.
|
|
#[derive(Debug)]
|
|
pub struct PresentationTimer {
|
|
scale: MachTimebaseInfo,
|
|
}
|
|
impl PresentationTimer {
|
|
/// Generates a new timer.
|
|
pub fn new() -> Self {
|
|
// Default to 1 / 1 in case the call to timebase_info fails.
|
|
let mut scale = MachTimebaseInfo {
|
|
numerator: 1,
|
|
denominator: 1,
|
|
};
|
|
unsafe { mach_timebase_info(&mut scale) };
|
|
|
|
Self { scale }
|
|
}
|
|
|
|
/// Gets the current time in nanoseconds.
|
|
pub fn get_timestamp_ns(&self) -> u128 {
|
|
let time = unsafe { mach_absolute_time() };
|
|
|
|
(time as u128 * self.scale.numerator as u128) / self.scale.denominator as u128
|
|
}
|
|
}
|