Queues and refresh rate adjustments

src/common/settings.cpp

@@ -380,6 +380,43 @@ void UpdateRescalingInfo() {
     TranslateResolutionInfo(setup, info);
 }
 
+u32 FrameGenMultiplierCeiling() {
+    const u32 configured = values.frame_gen_multiplier.GetValue();
+    if (configured == AUTO_FRAME_GEN_MULTIPLIER) {
+        return MAX_FRAME_GEN_MULTIPLIER;
+    }
+    return std::clamp(configured, MIN_FRAME_GEN_MULTIPLIER, MAX_FRAME_GEN_MULTIPLIER);
+}
+
+u32 FrameGenMultiplier() {
+    const u32 ceiling = FrameGenMultiplierCeiling();
+
+    const float refresh = values.display_refresh_rate;
+    if (refresh <= 1.0f) {
+        return ceiling;
+    }
+
+    constexpr float UNMEASURED_GUEST_FRAME_RATE = 60.0f;
+    float base = values.guest_frame_rate > 1.0f ? values.guest_frame_rate
+                                                : UNMEASURED_GUEST_FRAME_RATE;
+    if (values.use_speed_limit.GetValue()) {
+        const u16 limit = std::min<u16>(SpeedLimit(), 100);
+        if (limit > 0) {
+            base *= static_cast<float>(limit) / 100.0f;
+        }
+    }
+
+    const u32 presentable = static_cast<u32>(refresh / std::max(base, 1.0f));
+    return std::min(ceiling, std::max(presentable, 1u));
+}
+
+size_t FrameGenGenerations() {
+    if (!values.frame_gen.GetValue()) {
+        return 0;
+    }
+    return FrameGenMultiplier() - 1;
+}
+
 void RestoreGlobalState(bool is_powered_on) {
     // If a game is running, DO NOT restore the global settings state
     if (is_powered_on) {

src/common/settings.h

@@ -392,8 +392,8 @@ struct Values {
                                       Specialization::Default, true, false};
 
     SwitchableSetting<u32, true> frame_gen_multiplier{linkage,
-                                                      2,
-                                                      2,
+                                                      0,
+                                                      0,
                                                       4,
                                                       "frame_gen_multiplier",
                                                       Category::Renderer,
@@ -414,6 +414,17 @@ struct Values {
                                                       true,
                                                       &frame_gen};
 
+    SwitchableSetting<u32, true> frame_gen_queue_target{linkage,
+                                                        1,
+                                                        0,
+                                                        2,
+                                                        "frame_gen_queue_target",
+                                                        Category::Renderer,
+                                                        Specialization::Countable,
+                                                        true,
+                                                        false,
+                                                        &frame_gen};
+
     SwitchableSetting<bool> frame_gen_fp16{linkage,      true,  "frame_gen_fp16", Category::Renderer,
                                            Specialization::Default, true, false, &frame_gen};
 
@@ -902,10 +913,24 @@ struct Values {
 
     // Per-game overrides
     bool use_squashed_iterated_blend;
+
+    // Rates published by the frontend, in hertz. Zero means not measured yet.
+    float display_refresh_rate;
+    float guest_frame_rate;
 };
 
 extern Values values;
 
+constexpr u32 AUTO_FRAME_GEN_MULTIPLIER = 0;
+constexpr u32 MIN_FRAME_GEN_MULTIPLIER = 2;
+constexpr u32 MAX_FRAME_GEN_MULTIPLIER = 4;
+
+[[nodiscard]] u32 FrameGenMultiplierCeiling();
+
+[[nodiscard]] u32 FrameGenMultiplier();
+
+[[nodiscard]] size_t FrameGenGenerations();
+
 bool getDebugKnobAt(u8 i);
 
 void UpdateGPUAccuracy();