From 2d5b13383369fb9972d686506c797e84a89e534c Mon Sep 17 00:00:00 2001
From: Nico de Poel <ndepoel@gmail.com>
Date: Mon, 10 Mar 2025 16:05:36 +0100
Subject: [PATCH] Implemented thread-safe allocation/freeing of feature slots,
 plus decoding of texture userdata

---
 FSR3UnityPlugin.cpp | 53 ++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 45 insertions(+), 8 deletions(-)

diff --git a/FSR3UnityPlugin.cpp b/FSR3UnityPlugin.cpp
index 89ecd97..fc04a0a 100644
--- a/FSR3UnityPlugin.cpp
+++ b/FSR3UnityPlugin.cpp
@@ -1,5 +1,9 @@
 #include <stdint.h>
 
+#include <vector>
+#include <queue>
+#include <mutex>
+
 #include "UnityPluginAPI/IUnityInterface.h"
 #include "UnityPluginAPI/IUnityLog.h"
 #include "UnityPluginAPI/IUnityGraphics.h"
@@ -19,6 +23,15 @@ static void UNITY_INTERFACE_API OnGraphicsDeviceEvent(UnityGfxDeviceEventType ev
 static void UNITY_INTERFACE_API OnRenderEventAndData(int eventID, void* data);
 static void UNITY_INTERFACE_API OnSetTextureEvent(int eventID, void* data);
 
+struct FSR3Context
+{
+    // TODO: contains FSR3 context object + related metadata (texture table etc)
+};
+
+static std::vector<FSR3Context> s_Contexts;
+static std::queue<uint32_t> s_FeatureSlots;
+static std::mutex s_FeatureMutex;
+
 // Unity plugin load event
 extern "C" void UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API UnityPluginLoad(IUnityInterfaces* unityInterfaces)
 {
@@ -68,6 +81,32 @@ static void UNITY_INTERFACE_API OnGraphicsDeviceEvent(UnityGfxDeviceEventType ev
     };
 }
 
+// Thread-safe allocation of FSR3 Context feature slot
+static uint32_t AllocateFeatureSlot()
+{
+    std::lock_guard<std::mutex> lock(s_FeatureMutex);
+
+    if (s_FeatureSlots.empty())
+    {
+        uint32_t featureSlot = (uint32_t)s_Contexts.size();
+        s_Contexts.push_back(std::move(FSR3Context()));
+        return featureSlot;
+    }
+
+    uint32_t featureSlot = s_FeatureSlots.front();
+    s_FeatureSlots.pop();
+    return featureSlot;
+}
+
+// Thread-safe freeing and clearing of FSR3 Context feature slot
+static void FreeFeatureSlot(uint32_t featureSlot)
+{
+    std::lock_guard<std::mutex> lock(s_FeatureMutex);
+
+    s_FeatureSlots.push(featureSlot);
+    memset(&s_Contexts[featureSlot], 0, sizeof(FSR3Context));
+}
+
 extern "C" bool UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API AMDUP_InitApi()
 {
     // TODO: implement
@@ -96,18 +135,15 @@ extern "C" UnityRenderingEventAndData UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API
 
 extern "C" uint32_t UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API AMDUP_CreateFeatureSlot()
 {
-    // TODO: thread-safe allocation of slot
-    return 0u;
+    return AllocateFeatureSlot();
 }
 
-// TODO: use FSR2Quality enum for qualityMode
 extern "C" bool UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API AMDUP_GetRenderResolutionFromQualityMode(FSR3Quality qualityMode, uint32_t displayWidth, uint32_t displayHeight, uint32_t* renderWidth, uint32_t* renderHeight)
 {
     // TODO: implement
     return false;
 }
 
-// TODO: use FSR2Quality enum for qualityMode
 extern "C" float UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API AMDUP_GetUpscaleRatioFromQualityMode(FSR3Quality qualityMode)
 {
     // TODO: implement
@@ -127,8 +163,9 @@ static void UNITY_INTERFACE_API OnRenderEventAndData(int eventID, void* data)
     {
     case BaseEventId + FSR3PluginEvent::eDestroyFeature:
     {
-        // TODO: thread-safe freeing of slot (data = feature slot int64_t, cast as pointer)
         uint32_t featureSlot = (uint32_t)(int64_t)data;
+        // TODO: destroy FSR3Context at feature slot index
+        FreeFeatureSlot(featureSlot);
         break;
     }
     case BaseEventId + FSR3PluginEvent::eExecute:
@@ -151,11 +188,11 @@ static void UNITY_INTERFACE_API OnRenderEventAndData(int eventID, void* data)
 
 static void UNITY_INTERFACE_API OnSetTextureEvent(int eventID, void* data)
 {
-    // TODO userData field in UnityRenderingExtTextureUpdateParamsV2 is an encoded value: (featureId & (int) ushort.MaxValue) << 16 | (textureSlot & (int) short.MaxValue) << 1 | (clearTextureTable ? 1 : 0);
     auto* params = (UnityRenderingExtTextureUpdateParamsV2*)data;
 
-    // TODO: featureId => featureSlot
-    // TODO: textureSlot => FSR3Textures enum (could just use as numeric index to calculate a pointer offset)
+    uint32_t featureSlot = (params->userData >> 16) & 0xFFFF;
+    uint32_t textureSlot = (params->userData >> 1) & 0x7FFF;    // TODO: could just use as numeric index to calculate a pointer offset
+    uint32_t clearTextureTable = params->userData & 0x1;
 
     // User rendering code
     switch (eventID)