metal: do not begin render pass if already active

src/video_core/renderer_metal/mtl_command_recorder.cpp

@@ -10,11 +10,14 @@ CommandRecorder::CommandRecorder(const Device& device_) : device(device_) {}
 
 CommandRecorder::~CommandRecorder() = default;
 
-void CommandRecorder::BeginRenderPass(MTL::RenderPassDescriptor* render_pass) {
-    RequireCommandBuffer();
-    EndEncoding();
-    encoder = command_buffer->renderCommandEncoder(render_pass);
-    encoder_type = EncoderType::Render;
+void CommandRecorder::BeginOrContinueRenderPass(MTL::RenderPassDescriptor* render_pass) {
+    if (render_pass != bound_render_pass) {
+        RequireCommandBuffer();
+        EndEncoding();
+        encoder = command_buffer->renderCommandEncoder(render_pass);
+        encoder_type = EncoderType::Render;
+        bound_render_pass = render_pass;
+    }
 }
 
 void CommandRecorder::RequireComputeEncoder() {
@@ -40,6 +43,7 @@ void CommandRecorder::EndEncoding() {
         encoder->endEncoding();
         //[encoder release];
         encoder = nullptr;
+        bound_render_pass = nullptr;
     }
 }
 

src/video_core/renderer_metal/mtl_command_recorder.h

@@ -20,7 +20,7 @@ public:
     CommandRecorder(const Device& device_);
     ~CommandRecorder();
 
-    void BeginRenderPass(MTL::RenderPassDescriptor* render_pass);
+    void BeginOrContinueRenderPass(MTL::RenderPassDescriptor* render_pass);
 
     void CheckIfRenderPassIsActive() {
         if (!encoder || encoder_type != EncoderType::Render) {
@@ -66,11 +66,14 @@ private:
 
     // HACK: Command buffers and encoders currently aren't released every frame due to Xcode
     // crashing in Debug mode. This leads to memory leaks
-    MTL::CommandBuffer* command_buffer = nil;
-    MTL::CommandEncoder* encoder = nil;
+    MTL::CommandBuffer* command_buffer{nullptr};
+    MTL::CommandEncoder* encoder{nullptr};
 
     EncoderType encoder_type;
 
+    // Keep track of last bound render pass
+    MTL::RenderPassDescriptor* bound_render_pass{nullptr};
+
     void RequireCommandBuffer();
 };
 

src/video_core/renderer_metal/mtl_rasterizer.cpp

@@ -96,7 +96,7 @@ void RasterizerMetal::Clear(u32 layer_count) {
     }
 
     // Begin render pass
-    command_recorder.BeginRenderPass(framebuffer->GetHandle());
+    command_recorder.BeginOrContinueRenderPass(framebuffer->GetHandle());
 }
 
 void RasterizerMetal::DispatchCompute() {

src/video_core/renderer_metal/renderer_metal.cpp

@@ -14,8 +14,8 @@ namespace Metal {
 RendererMetal::RendererMetal(Core::Frontend::EmuWindow& emu_window,
                              Tegra::MaxwellDeviceMemoryManager& device_memory_, Tegra::GPU& gpu_,
                              std::unique_ptr<Core::Frontend::GraphicsContext> context_)
-    : RendererBase(emu_window, std::move(context_)),
-      device_memory{device_memory_}, gpu{gpu_}, device{}, command_recorder(device),
+    : RendererBase(emu_window, std::move(context_)), device_memory{device_memory_}, gpu{gpu_},
+      device{}, command_recorder(device),
       swap_chain(device, command_recorder,
                  static_cast<CA::MetalLayer*>(render_window.GetWindowInfo().render_surface)),
       rasterizer(gpu_, device_memory, device, command_recorder, swap_chain) {
@@ -42,7 +42,7 @@ void RendererMetal::Composite(std::span<const Tegra::FramebufferConfig> framebuf
     render_pass_descriptor->colorAttachments()->object(0)->setTexture(
         swap_chain.GetDrawableTexture());
 
-    command_recorder.BeginRenderPass(render_pass_descriptor);
+    command_recorder.BeginOrContinueRenderPass(render_pass_descriptor);
 
     // Blit the framebuffer to the drawable texture
     // TODO: acquire the texture from @ref framebuffers