1 files changed, 59 insertions, 2 deletions

diff --git a/src/device_context.cc b/src/device_context.cc
index 5f5c1f7..4b39210 100644
--- a/src/device_context.cc
+++ b/src/device_context.cc
@@ -6,11 +6,12 @@
 namespace low_latency {
 
 DeviceContext::DeviceContext(InstanceContext& parent_instance,
+                             PhysicalDeviceContext& parent_physical_device,
                              const VkDevice& device,
                              const PFN_vkSetDeviceLoaderData& sdld,
                              VkuDeviceDispatchTable&& vtable)
-    : instance(parent_instance), device(device), sdld(sdld),
-      vtable(std::move(vtable)) {}
+    : instance(parent_instance), physical_device(parent_physical_device),
+      device(device), sdld(sdld), vtable(std::move(vtable)), clock(*this) {}
 
 DeviceContext::~DeviceContext() {
     // We will let the destructor handle clearing here, but they should be
@@ -20,4 +21,60 @@ DeviceContext::~DeviceContext() {
     }
 }
 
+void DeviceContext::notify_acquire(const VkSwapchainKHR& swapchain,
+                                   const std::uint32_t& image_index,
+                                   const VkSemaphore& signal_semaphore) {
+
+    const auto it = this->swapchain_signals.try_emplace(swapchain).first;
+
+    // Doesn't matter if it was already there, overwrite it.
+    it->second.insert_or_assign(image_index, signal_semaphore);
+}
+
+DeviceContext::Clock::Clock(const DeviceContext& context) {
+
+    const auto infos = std::vector<VkCalibratedTimestampInfoKHR>{
+        {VK_STRUCTURE_TYPE_CALIBRATED_TIMESTAMP_INFO_EXT, nullptr,
+         VK_TIME_DOMAIN_DEVICE_EXT},
+        {VK_STRUCTURE_TYPE_CALIBRATED_TIMESTAMP_INFO_EXT, nullptr,
+         VK_TIME_DOMAIN_CLOCK_MONOTONIC_EXT}};
+
+    auto device_host = std::array<std::uint64_t, 2>{};
+
+    const auto steady_before = std::chrono::steady_clock::now();
+    context.vtable.GetCalibratedTimestampsKHR(
+        context.device, 2, std::data(infos), std::data(device_host),
+        &this->error_bound);
+    const auto steady_after = std::chrono::steady_clock::now();
+
+    this->cpu_time = steady_before + (steady_after - steady_before) / 2;
+    this->device_ticks = device_host[0];
+    this->host_ns = device_host[1];
+
+    // Might need to get physical limits again?
+    this->ticks_per_ns =
+        context.physical_device.properties->limits.timestampPeriod;
+}
+
+DeviceContext::Clock::time_point_t
+DeviceContext::Clock::ticks_to_time(const std::uint64_t& ticks) const {
+    /*
+    struct timespec tv;
+    clock_gettime(CLOCK_MONOTONIC, &tv);
+    return tv.tv_nsec + tv.tv_sec*1000000000ull;
+    */
+
+    auto a = this->device_ticks;
+    auto b = ticks;
+
+    const auto was_before = a > b;
+    if (was_before) { // it's happened before
+        std::swap(a, b);
+    }
+    const auto nsec = std::chrono::nanoseconds((b - a) * this->ticks_per_ns);
+    return this->cpu_time + (was_before ? -nsec : nsec);
+}
+
+void DeviceContext::calibrate_timestamps() { this->clock = Clock{*this}; }
+
 } // namespace low_latency
\ No newline at end of file