1 files changed, 49 insertions, 0 deletions
diff --git a/src/device_clock.hh b/src/device_clock.hh
new file mode 100644
index 0000000..a52c59c
--- /dev/null
+++ b/src/device_clock.hh
@@ -0,0 +1,49 @@
+#ifndef CLOCK_HH_
+#define CLOCK_HH_
+
+#include <chrono>
+
+// This header provides a DeviceClock that abstracts away the Vulkan details of
+// comparing CPU and GPU times.
+
+namespace low_latency {
+
+class DeviceContext;
+
+class DeviceClock final {
+  public:
+    // FIXME this is bad, see now().
+    using time_point_t = std::chrono::time_point<std::chrono::steady_clock,
+                                                 std::chrono::nanoseconds>;
+    const DeviceContext& device;
+
+  public:
+    std::uint64_t host_ns;
+    std::uint64_t error_bound;
+    std::uint64_t device_ticks;
+
+  public:
+    DeviceClock(const DeviceContext& device);
+    DeviceClock(const DeviceClock&) = delete;
+    DeviceClock(DeviceClock&&) = delete;
+    DeviceClock operator=(const DeviceClock&) = delete;
+    DeviceClock operator=(DeviceClock&&) = delete;
+    ~DeviceClock();
+
+  public:
+    // WARNING: This *MUST* be used over std::chrono::steady_clock::now if
+    // you're planning on comparing it to a device's clock. If it isn't, the
+    // timestamps might from different domains and will be completely
+    // nonsensical.
+    // FIXME we should be able to fix this with a tiny wrapper class of
+    // time_point_t that enforces typesafety.
+    static time_point_t now();
+
+  public:
+    void calibrate();
+    time_point_t ticks_to_time(const std::uint64_t& ticks) const;
+};
+
+} // namespace low_latency
+
+#endif
+\ No newline at end of file