add experimental flags for present mode and fps limit

include/config/config.hpp

@@ -1,10 +1,13 @@
 #pragma once
 
-#include <atomic>
+#include <vulkan/vulkan_core.h>
+
+#include <string_view>
 #include <cstddef>
+#include <vector>
+#include <atomic>
 #include <memory>
 #include <string>
-#include <string_view>
 
 namespace Config {
 
@@ -26,6 +29,11 @@ namespace Config {
         /// Whether HDR is enabled
         bool hdr{false};
 
+        /// Experimental flag for overriding the synchronization method.
+        VkPresentModeKHR e_present;
+        /// Experimental flag for limiting the framerate of DXVK games.
+        uint32_t e_fps_limit;
+
         /// Atomic property to check if the configuration is valid or outdated.
         std::shared_ptr<std::atomic_bool> valid;
     };

src/config/config.cpp

@@ -1,6 +1,7 @@
 #include "config/config.hpp"
 #include "common/exception.hpp"
 
+#include <vulkan/vulkan_core.h>
 #include <linux/limits.h>
 #include <sys/inotify.h>
 #include <sys/poll.h>
@@ -209,7 +210,7 @@ bool Config::updateConfig(const std::string& file) {
 
     // parse global configuration
     const toml::value globalTable = toml::find_or_default<toml::table>(toml, "global");
-    const Configuration global{
+    Configuration global{
         .enable = toml::find_or(globalTable, "enable", false),
         .dll =    toml::find_or(globalTable, "dll", std::string()),
         .env =    parse_env(toml::find_or(globalTable, "env", std::string())),
@@ -217,6 +218,10 @@ bool Config::updateConfig(const std::string& file) {
         .flowScale =   toml::find_or(globalTable, "flow_scale", 1.0F),
         .performance = toml::find_or(globalTable, "performance_mode", false),
         .hdr = toml::find_or(globalTable, "hdr_mode", false),
+        .e_present =   into_present(
+            toml::find_or(globalTable, "experimental_present_mode", ""),
+            VkPresentModeKHR::VK_PRESENT_MODE_FIFO_KHR),
+        .e_fps_limit = toml::find_or(globalTable, "experimental_fps_limit", 0U),
         .valid = globalConf.valid // use the same validity flag
     };
 
@@ -249,6 +254,10 @@ bool Config::updateConfig(const std::string& file) {
             .flowScale = toml::find_or(gameTable, "flow_scale", global.flowScale),
             .performance = toml::find_or(gameTable, "performance_mode", global.performance),
             .hdr = toml::find_or(gameTable, "hdr_mode", global.hdr),
+            .e_present =   into_present(
+                toml::find_or(gameTable, "experimental_present_mode", ""),
+                global.e_present),
+            .e_fps_limit = toml::find_or(gameTable, "experimental_fps_limit", global.e_fps_limit),
             .valid = global.valid // only need a single validity flag
         };
 

src/context.cpp

@@ -51,6 +51,7 @@ LsContext::LsContext(const Hooks::DeviceInfo& info, VkSwapchainKHR swapchain,
         std::cerr << "  Flow Scale: " << conf.flowScale << '\n';
         std::cerr << "  Performance Mode: " << (conf.performance ? "Enabled" : "Disabled") << '\n';
         std::cerr << "  HDR Mode: " << (conf.hdr ? "Enabled" : "Disabled") << '\n';
+        if (conf.e_present != 2) std::cerr << "  ! Present Mode: " << conf.e_present << '\n';
     }
     // we could take the format from the swapchain,
     // but honestly this is safer.

src/hooks.cpp

@@ -107,6 +107,7 @@ namespace {
 
     std::unordered_map<VkSwapchainKHR, LsContext> swapchains;
     std::unordered_map<VkSwapchainKHR, VkDevice> swapchainToDeviceTable;
+    std::unordered_map<VkSwapchainKHR, VkPresentModeKHR> swapchainToPresent;
 
     ///
     /// Adjust swapchain creation parameters and create a swapchain context.
@@ -148,8 +149,8 @@ namespace {
         createInfo.imageUsage |= VK_IMAGE_USAGE_TRANSFER_DST_BIT;
         createInfo.imageUsage |= VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
 
-        // enforce vsync
-        createInfo.presentMode = VK_PRESENT_MODE_FIFO_KHR;
+        // enforce present mode
+        createInfo.presentMode = Config::activeConf.e_present;
 
         // retire potential old swapchain
         if (pCreateInfo->oldSwapchain) {
@@ -163,6 +164,8 @@ namespace {
             return res; // can't be caused by lsfg-vk (yet)
 
         try {
+            swapchainToPresent.emplace(*pSwapchain, createInfo.presentMode);
+
             // get all swapchain images
             uint32_t imageCount{};
             res = Layer::ovkGetSwapchainImagesKHR(device, *pSwapchain, &imageCount, nullptr);
@@ -228,7 +231,16 @@ namespace {
         }
         auto& swapchain = it3->second;
 
-        // enforce vsync | NOLINTBEGIN
+        // find present mode
+        auto it4 = swapchainToPresent.find(*pPresentInfo->pSwapchains);
+        if (it4 == swapchainToPresent.end()) {
+            Utils::logLimitN("swapMap", 5,
+                "Swapchain present mode not found in map");
+            return Layer::ovkQueuePresentKHR(queue, pPresentInfo);
+        }
+        auto& present = it4->second;
+
+        // enforce present mode | NOLINTBEGIN
         #pragma clang diagnostic push
         #pragma clang diagnostic ignored "-Wunsafe-buffer-usage"
         const VkSwapchainPresentModeInfoEXT* presentModeInfo =
@@ -237,7 +249,7 @@ namespace {
             if (presentModeInfo->sType == VK_STRUCTURE_TYPE_SWAPCHAIN_PRESENT_MODE_INFO_EXT) {
                 for (size_t i = 0; i < presentModeInfo->swapchainCount; i++)
                     const_cast<VkPresentModeKHR*>(presentModeInfo->pPresentModes)[i] =
-                        VK_PRESENT_MODE_FIFO_KHR;
+                        present;
             }
             presentModeInfo =
                 reinterpret_cast<const VkSwapchainPresentModeInfoEXT*>(presentModeInfo->pNext);
@@ -252,6 +264,10 @@ namespace {
             if (!conf.valid->load(std::memory_order_relaxed))
                 return VK_ERROR_OUT_OF_DATE_KHR;
 
+            // ensure present mode is still valid
+            if (present != conf.e_present)
+                return VK_ERROR_OUT_OF_DATE_KHR;
+
             // skip if disabled
             if (!conf.enable)
                 return Layer::ovkQueuePresentKHR(queue, pPresentInfo);
@@ -280,6 +296,7 @@ namespace {
             const VkAllocationCallbacks* pAllocator) noexcept {
         swapchains.erase(swapchain);
         swapchainToDeviceTable.erase(swapchain);
+        swapchainToPresent.erase(swapchain);
         Layer::ovkDestroySwapchainKHR(device, swapchain, pAllocator);
     }
 }

src/main.cpp

@@ -46,6 +46,15 @@ namespace {
         std::cerr << "  Flow Scale: " << conf.flowScale << '\n';
         std::cerr << "  Performance Mode: " << (conf.performance ? "Enabled" : "Disabled") << '\n';
         std::cerr << "  HDR Mode: " << (conf.hdr ? "Enabled" : "Disabled") << '\n';
+        if (conf.e_present != 2) std::cerr << "  ! Present Mode: " << conf.e_present << '\n';
+        if (conf.e_fps_limit > 0) std::cerr << "  ! FPS Limit: " << conf.e_fps_limit << '\n';
+
+        // update environment variables
+        unsetenv("MESA_VK_WSI_PRESENT_MODE"); // NOLINT
+        for (const auto& [key, value] : conf.env)
+            setenv(key.c_str(), value.c_str(), 1); // NOLINT
+        if (conf.e_fps_limit > 0)
+            setenv("DXVK_FRAME_RATE", std::to_string(conf.e_fps_limit).c_str(), 1); // NOLINT
 
         // load shaders
         try {