Merge pull request #4282 from zhaowenlan1779/frame-advance

core, citra_qt: add frame advancing to framelimiter

src/core/perf_stats.cpp

@@ -74,6 +74,13 @@ double PerfStats::GetLastFrameTimeScale() {
 }
 
 void FrameLimiter::DoFrameLimiting(microseconds current_system_time_us) {
+    if (frame_advancing_enabled) {
+        // Frame advancing is enabled: wait on event instead of doing framelimiting
+        frame_advance_event.Wait();
+        frame_advance_event.Reset();
+        return;
+    }
+
     if (!Settings::values.use_frame_limit) {
         return;
     }
@@ -104,4 +111,20 @@ void FrameLimiter::DoFrameLimiting(microseconds current_system_time_us) {
     previous_walltime = now;
 }
 
+void FrameLimiter::SetFrameAdvancing(bool value) {
+    const bool was_enabled = frame_advancing_enabled.exchange(value);
+    if (was_enabled && !value) {
+        // Set the event to let emulation continue
+        frame_advance_event.Set();
+    }
+}
+
+void FrameLimiter::AdvanceFrame() {
+    if (!frame_advancing_enabled) {
+        // Start frame advancing
+        frame_advancing_enabled = true;
+    }
+    frame_advance_event.Set();
+}
+
 } // namespace Core

src/core/perf_stats.h

@@ -4,9 +4,11 @@
 
 #pragma once
 
+#include <atomic>
 #include <chrono>
 #include <mutex>
 #include "common/common_types.h"
+#include "common/thread.h"
 
 namespace Core {
 
@@ -70,6 +72,14 @@ public:
 
     void DoFrameLimiting(std::chrono::microseconds current_system_time_us);
 
+    /**
+     * Sets whether frame advancing is enabled or not.
+     * Note: The frontend must cancel frame advancing before shutting down in order
+     *       to resume the emu_thread.
+     */
+    void SetFrameAdvancing(bool value);
+    void AdvanceFrame();
+
 private:
     /// Emulated system time (in microseconds) at the last limiter invocation
     std::chrono::microseconds previous_system_time_us{0};
@@ -78,6 +88,12 @@ private:
 
     /// Accumulated difference between walltime and emulated time
     std::chrono::microseconds frame_limiting_delta_err{0};
+
+    /// Whether to use frame advancing (i.e. frame by frame)
+    std::atomic_bool frame_advancing_enabled;
+
+    /// Event to advance the frame when frame advancing is enabled
+    Common::Event frame_advance_event;
 };
 
 } // namespace Core