extensions/ext: Add VK_EXT_calibrated_timestamps extension

This extension can be used to correlate timestamps on the GPU timeline
(`vkCmdWriteTimestamp`, `vkCmdWriteTimestamp2KHR`) to the CPU timeline
(ie. `CLOCK_MONOTONIC` and friends).

Changelog.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Added `VK_EXT_calibrated_timestamps` device extension (#556)
 - Added `VK_KHR_get_surface_capabilities2` device extension (#530)
 
 ### Changed

ash/src/extensions/ext/calibrated_timestamps.rs

@@ -0,0 +1,65 @@
+use crate::prelude::{read_into_uninitialized_vector, VkResult};
+use crate::vk;
+use crate::{Entry, Instance};
+use std::ffi::CStr;
+use std::mem;
+
+#[derive(Clone)]
+pub struct CalibratedTimestamps {
+    handle: vk::Instance,
+    fp: vk::ExtCalibratedTimestampsFn,
+}
+
+impl CalibratedTimestamps {
+    pub fn new(entry: &Entry, instance: &Instance) -> Self {
+        let handle = instance.handle();
+        let fp = vk::ExtCalibratedTimestampsFn::load(|name| unsafe {
+            mem::transmute(entry.get_instance_proc_addr(handle, name.as_ptr()))
+        });
+        Self { handle, fp }
+    }
+
+    #[doc = "<https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/vkGetPhysicalDeviceCalibrateableTimeDomainsEXT.html>"]
+    pub unsafe fn get_physical_device_calibrateable_time_domains(
+        &self,
+        physical_device: vk::PhysicalDevice,
+    ) -> VkResult<Vec<vk::TimeDomainEXT>> {
+        read_into_uninitialized_vector(|count, data| {
+            self.fp
+                .get_physical_device_calibrateable_time_domains_ext(physical_device, count, data)
+        })
+    }
+
+    #[doc = "<https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/vkGetCalibratedTimestampsEXT.html>"]
+    ///
+    /// Returns a tuple containing `(timestamps, max_deviation)`
+    pub unsafe fn get_calibrated_timestamps(
+        &self,
+        device: vk::Device,
+        info: &[vk::CalibratedTimestampInfoEXT],
+    ) -> VkResult<(Vec<u64>, Vec<u64>)> {
+        let mut timestamps = vec![0u64; info.len()];
+        let mut max_deviation = vec![0u64; info.len()];
+        self.fp
+            .get_calibrated_timestamps_ext(
+                device,
+                info.len() as u32,
+                info.as_ptr(),
+                timestamps.as_mut_ptr(),
+                max_deviation.as_mut_ptr(),
+            )
+            .result_with_success((timestamps, max_deviation))
+    }
+
+    pub fn name() -> &'static CStr {
+        vk::ExtCalibratedTimestampsFn::name()
+    }
+
+    pub fn fp(&self) -> &vk::ExtCalibratedTimestampsFn {
+        &self.fp
+    }
+
+    pub fn instance(&self) -> vk::Instance {
+        self.handle
+    }
+}

ash/src/extensions/ext/mod.rs

@@ -1,4 +1,5 @@
 pub use self::buffer_device_address::BufferDeviceAddress;
+pub use self::calibrated_timestamps::CalibratedTimestamps;
 #[allow(deprecated)]
 pub use self::debug_marker::DebugMarker;
 #[allow(deprecated)]
@@ -11,6 +12,7 @@ pub use self::physical_device_drm::PhysicalDeviceDrm;
 pub use self::tooling_info::ToolingInfo;
 
 mod buffer_device_address;
+mod calibrated_timestamps;
 #[deprecated(note = "Please use the [DebugUtils](struct.DebugUtils.html) extension instead.")]
 mod debug_marker;
 #[deprecated(note = "Please use the [DebugUtils](struct.DebugUtils.html) extension instead.")]