[hud] Add frame latency item

src/dxvk/hud/dxvk_hud_item.cpp

@@ -1596,4 +1596,76 @@ namespace dxvk::hud {
          / (uint32_t(m_tasksTotal - m_offset));
   }
 
+
+
+  HudLatencyItem::HudLatencyItem() {
+
+  }
+
+
+  HudLatencyItem::~HudLatencyItem() {
+
+  }
+
+
+  void HudLatencyItem::accumulateStats(const DxvkLatencyStats& stats) {
+    std::lock_guard lock(m_mutex);
+
+    if (stats.frameLatency.count()) {
+      m_accumStats.frameLatency += stats.frameLatency;
+      m_accumStats.sleepDuration += stats.sleepDuration;
+
+      m_accumFrames += 1u;
+    } else {
+      m_accumStats = { };
+      m_accumFrames = 0u;
+    }
+  }
+
+
+  void HudLatencyItem::update(dxvk::high_resolution_clock::time_point time) {
+    uint64_t ticks = std::chrono::duration_cast<std::chrono::microseconds>(time - m_lastUpdate).count();
+
+    if (ticks >= UpdateInterval) {
+      std::lock_guard lock(m_mutex);
+
+      if (m_accumFrames) {
+        uint32_t latency = (m_accumStats.frameLatency / m_accumFrames).count() / 100u;
+        uint32_t sleep = (m_accumStats.sleepDuration / m_accumFrames).count() / 100u;
+
+        m_latencyString = str::format(latency / 10, ".", latency % 10, " ms");
+        m_sleepString = str::format(sleep / 10, ".", sleep % 10, " ms");
+
+        m_accumStats = { };
+        m_accumFrames = 0u;
+      } else {
+        m_latencyString = "--";
+        m_sleepString = "--";
+      }
+
+      m_lastUpdate = time;
+    }
+  }
+
+
+  HudPos HudLatencyItem::render(
+    const DxvkContextObjects& ctx,
+    const HudPipelineKey&     key,
+    const HudOptions&         options,
+          HudRenderer&        renderer,
+          HudPos              position) {
+    position.y += 16;
+
+    renderer.drawText(16, position, 0xffff60a0u, "Latency: ");
+    renderer.drawText(16, { position.x + 108, position.y }, 0xffffffffu, m_latencyString);
+
+    position.y += 20;
+
+    renderer.drawText(16, position, 0xffff60a0u, "Sleep: ");
+    renderer.drawText(16, { position.x + 108, position.y }, 0xffffffffu, m_sleepString);
+
+    position.y += 8;
+    return position;
+  }
+
 }

src/dxvk/hud/dxvk_hud_item.h

@@ -734,4 +734,42 @@ namespace dxvk::hud {
 
   };
 
+
+  /**
+   * \brief Frame latency item
+   */
+  class HudLatencyItem : public HudItem {
+    constexpr static int64_t UpdateInterval = 500'000;
+  public:
+
+    HudLatencyItem();
+
+    ~HudLatencyItem();
+
+    void accumulateStats(const DxvkLatencyStats& stats);
+
+    void update(dxvk::high_resolution_clock::time_point time);
+
+    HudPos render(
+      const DxvkContextObjects& ctx,
+      const HudPipelineKey&     key,
+      const HudOptions&         options,
+            HudRenderer&        renderer,
+            HudPos              position);
+
+  private:
+
+    sync::Spinlock      m_mutex;
+
+    DxvkLatencyStats    m_accumStats = { };
+    uint32_t            m_accumFrames = 0u;
+
+    std::string         m_latencyString;
+    std::string         m_sleepString;
+
+    dxvk::high_resolution_clock::time_point m_lastUpdate
+      = dxvk::high_resolution_clock::now();
+
+  };
+
 }