video_core: EDEN_NX2_NO_MESH_FILE toggles task/mesh draws at run time

Skip them while the given file exists (checked every 1024 draws), to time
the same scene with and without them in one run.

1 files changed, 10 insertions, 1 deletions

diff --git a/src/video_core/renderer_vulkan/vk_rasterizer.cpp b/src/video_core/renderer_vulkan/vk_rasterizer.cpp
index 9a6feed622..91baee40e4 100644
--- a/src/video_core/renderer_vulkan/vk_rasterizer.cpp
+++ b/src/video_core/renderer_vulkan/vk_rasterizer.cpp
@@ -9,6 +9,7 @@
 #include <memory>
 #include <cstdio>
 #include <cstdlib>
+#include <filesystem>
 #include <tuple>
 #include <set>
 #include <fstream>
@@ -282,7 +283,15 @@ void RasterizerVulkan::PrepareDraw(bool is_indexed, Func&& draw_func) {
     // Task/mesh pipelines: the draw's vertex count is the number of task workgroups.
     mesh_draw = pipeline->IsMeshPipeline();
     // EDEN_NX2_NO_MESH=1: skip task/mesh draws as before they were supported (A/B comparisons).
-    static const bool no_mesh{std::getenv("EDEN_NX2_NO_MESH") != nullptr};
+    // EDEN_NX2_NO_MESH_FILE=<path>: skip them while that file exists (checked every 1024 draws),
+    // to compare the same scene with and without them in one run.
+    static const bool no_mesh_always{std::getenv("EDEN_NX2_NO_MESH") != nullptr};
+    static const char* const no_mesh_file{std::getenv("EDEN_NX2_NO_MESH_FILE")};
+    static bool no_mesh{no_mesh_always};
+    static u32 no_mesh_check{};
+    if (no_mesh_file && (no_mesh_check++ % 1024) == 0) {
+        no_mesh = std::filesystem::exists(no_mesh_file);
+    }
     if (mesh_draw && (no_mesh || !device.IsExtMeshShaderSupported())) {
         report_failure(no_mesh ? "EDEN_NX2_NO_MESH" : "no VK_EXT_mesh_shader");
         return;