VideoBackends:Metal: Multi render target support

6 files changed, 82 insertions, 48 deletions

diff --git a/Source/Core/VideoBackends/Metal/MTLGfx.mm b/Source/Core/VideoBackends/Metal/MTLGfx.mm
index 1137c45e5f..cf3c134cdb 100644
--- a/Source/Core/VideoBackends/Metal/MTLGfx.mm
+++ b/Source/Core/VideoBackends/Metal/MTLGfx.mm
@@ -94,12 +94,12 @@ Metal::Gfx::CreateStagingTexture(StagingTextureType type, const TextureConfig& c
 
 std::unique_ptr<AbstractFramebuffer>
 Metal::Gfx::CreateFramebuffer(AbstractTexture* color_attachment, AbstractTexture* depth_attachment,
-                              std::vector<AbstractTexture*>)
+                              std::vector<AbstractTexture*> additional_color_attachments)
 {
   AbstractTexture* const either_attachment = color_attachment ? color_attachment : depth_attachment;
   return std::make_unique<Framebuffer>(
-      color_attachment, depth_attachment, either_attachment->GetWidth(),
-      either_attachment->GetHeight(), either_attachment->GetLayers(),
+      color_attachment, depth_attachment, std::move(additional_color_attachments),
+      either_attachment->GetWidth(), either_attachment->GetHeight(), either_attachment->GetLayers(),
       either_attachment->GetSamples());
 }
 
@@ -437,7 +437,7 @@ void Metal::Gfx::BindBackbuffer(const ClearColor& clear_color)
     CheckForSurfaceChange();
     CheckForSurfaceResize();
     m_drawable = MRCRetain([m_layer nextDrawable]);
-    m_bb_texture->SetMTLTexture(MRCRetain([m_drawable texture]));
+    m_backbuffer->UpdateBackbufferTexture([m_drawable texture]);
     SetAndClearFramebuffer(m_backbuffer.get(), clear_color);
   }
 }
@@ -460,7 +460,7 @@ void Metal::Gfx::PresentBackbuffer()
       else
         [g_state_tracker->GetRenderCmdBuf()
             addScheduledHandler:[drawable = std::move(m_drawable)](id) { [drawable present]; }];
-      m_bb_texture->SetMTLTexture(nullptr);
+      m_backbuffer->UpdateBackbufferTexture(nullptr);
       m_drawable = nullptr;
     }
     g_state_tracker->FlushEncoders();
@@ -491,8 +491,8 @@ void Metal::Gfx::SetupSurface()
   TextureConfig cfg(info.width, info.height, 1, 1, 1, info.format,
                     AbstractTextureFlag_RenderTarget);
   m_bb_texture = std::make_unique<Texture>(nullptr, cfg);
-  m_backbuffer = std::make_unique<Framebuffer>(m_bb_texture.get(), nullptr,  //
-                                               info.width, info.height, 1, 1);
+  m_backbuffer = std::make_unique<Framebuffer>(
+      m_bb_texture.get(), nullptr, std::vector<AbstractTexture*>{}, info.width, info.height, 1, 1);
 
   if (g_presenter)
     g_presenter->SetBackbuffer(info);
diff --git a/Source/Core/VideoBackends/Metal/MTLObjectCache.mm b/Source/Core/VideoBackends/Metal/MTLObjectCache.mm
index 2a9387edeb..5d29f06e88 100644
--- a/Source/Core/VideoBackends/Metal/MTLObjectCache.mm
+++ b/Source/Core/VideoBackends/Metal/MTLObjectCache.mm
@@ -313,6 +313,8 @@ public:
       framebuffer.color_texture_format = cfg.framebuffer_state.color_texture_format.Value();
       framebuffer.depth_texture_format = cfg.framebuffer_state.depth_texture_format.Value();
       framebuffer.samples = cfg.framebuffer_state.samples.Value();
+      framebuffer.additional_color_attachment_count =
+          cfg.framebuffer_state.additional_color_attachment_count.Value();
       blend.colorupdate = cfg.blending_state.colorupdate.Value();
       blend.alphaupdate = cfg.blending_state.alphaupdate.Value();
       if (cfg.blending_state.blendenable)
@@ -426,6 +428,11 @@ public:
       }
       [desc setRasterSampleCount:fs.samples];
       [color0 setPixelFormat:Util::FromAbstract(fs.color_texture_format)];
+      if (u32 cnt = fs.additional_color_attachment_count)
+      {
+        for (u32 i = 0; i < cnt; i++)
+          [[desc colorAttachments] setObject:color0 atIndexedSubscript:i + 1];
+      }
       [desc setDepthAttachmentPixelFormat:Util::FromAbstract(fs.depth_texture_format)];
       if (Util::HasStencil(fs.depth_texture_format))
         [desc setStencilAttachmentPixelFormat:Util::FromAbstract(fs.depth_texture_format)];
diff --git a/Source/Core/VideoBackends/Metal/MTLStateTracker.h b/Source/Core/VideoBackends/Metal/MTLStateTracker.h
index 54e16cac7e..f3fa306dd7 100644
--- a/Source/Core/VideoBackends/Metal/MTLStateTracker.h
+++ b/Source/Core/VideoBackends/Metal/MTLStateTracker.h
@@ -182,7 +182,6 @@ private:
   MRCOwned<id<MTLCommandBuffer>> m_last_render_cmdbuf;
   MRCOwned<id<MTLRenderCommandEncoder>> m_current_render_encoder;
   MRCOwned<id<MTLComputeCommandEncoder>> m_current_compute_encoder;
-  MRCOwned<MTLRenderPassDescriptor*> m_render_pass_desc[3];
   MRCOwned<MTLRenderPassDescriptor*> m_resolve_pass_desc;
   Framebuffer* m_current_framebuffer;
   CPUBuffer m_texture_upload_buffer;
diff --git a/Source/Core/VideoBackends/Metal/MTLStateTracker.mm b/Source/Core/VideoBackends/Metal/MTLStateTracker.mm
index f699657ade..8546744a4d 100644
--- a/Source/Core/VideoBackends/Metal/MTLStateTracker.mm
+++ b/Source/Core/VideoBackends/Metal/MTLStateTracker.mm
@@ -107,12 +107,6 @@ Metal::StateTracker::StateTracker() : m_backref(std::make_shared<Backref>(this))
 {
   m_flags.should_apply_label = true;
   m_fence = MRCTransfer([g_device newFence]);
-  for (MRCOwned<MTLRenderPassDescriptor*>& rpdesc : m_render_pass_desc)
-  {
-    rpdesc = MRCTransfer([MTLRenderPassDescriptor new]);
-    [[rpdesc depthAttachment] setStoreAction:MTLStoreActionStore];
-    [[rpdesc stencilAttachment] setStoreAction:MTLStoreActionStore];
-  }
   m_resolve_pass_desc = MRCTransfer([MTLRenderPassDescriptor new]);
   auto color0 = [[m_resolve_pass_desc colorAttachments] objectAtIndexedSubscript:0];
   [color0 setLoadAction:MTLLoadActionLoad];
@@ -299,27 +293,8 @@ void Metal::StateTracker::SetCurrentFramebuffer(Framebuffer* framebuffer)
 MTLRenderPassDescriptor* Metal::StateTracker::GetRenderPassDescriptor(Framebuffer* framebuffer,
                                                                       MTLLoadAction load_action)
 {
-  const AbstractTextureFormat depth_fmt = framebuffer->GetDepthFormat();
-  MTLRenderPassDescriptor* desc;
-  if (depth_fmt == AbstractTextureFormat::Undefined)
-    desc = m_render_pass_desc[0];
-  else if (!Util::HasStencil(depth_fmt))
-    desc = m_render_pass_desc[1];
-  else
-    desc = m_render_pass_desc[2];
-  desc.colorAttachments[0].texture = framebuffer->GetColor();
-  desc.colorAttachments[0].loadAction = load_action;
-  if (depth_fmt != AbstractTextureFormat::Undefined)
-  {
-    desc.depthAttachment.texture = framebuffer->GetDepth();
-    desc.depthAttachment.loadAction = load_action;
-    if (Util::HasStencil(depth_fmt))
-    {
-      desc.stencilAttachment.texture = framebuffer->GetDepth();
-      desc.stencilAttachment.loadAction = load_action;
-    }
-  }
-  return desc;
+  framebuffer->SetLoadAction(load_action);
+  return framebuffer->PassDesc();
 }
 
 void Metal::StateTracker::BeginClearRenderPass(MTLClearColor color, float depth)
@@ -328,11 +303,9 @@ void Metal::StateTracker::BeginClearRenderPass(MTLClearColor color, float depth)
   MTLRenderPassDescriptor* desc = GetRenderPassDescriptor(framebuffer, MTLLoadActionClear);
   desc.colorAttachments[0].clearColor = color;
   if (framebuffer->GetDepthFormat() != AbstractTextureFormat::Undefined)
-  {
     desc.depthAttachment.clearDepth = depth;
-    if (Util::HasStencil(framebuffer->GetDepthFormat()))
-      desc.stencilAttachment.clearStencil = 0;
-  }
+  for (size_t i = 0; i < framebuffer->NumAdditionalColorTextures(); i++)
+    desc.colorAttachments[i + 1].clearColor = color;
   BeginRenderPass(desc);
 }
 
diff --git a/Source/Core/VideoBackends/Metal/MTLTexture.h b/Source/Core/VideoBackends/Metal/MTLTexture.h
index 0624661414..908f281e04 100644
--- a/Source/Core/VideoBackends/Metal/MTLTexture.h
+++ b/Source/Core/VideoBackends/Metal/MTLTexture.h
@@ -29,7 +29,6 @@ public:
             u32 layer) override;
 
   id<MTLTexture> GetMTLTexture() const { return m_tex; }
-  void SetMTLTexture(MRCOwned<id<MTLTexture>> tex) { m_tex = std::move(tex); }
 
 private:
   MRCOwned<id<MTLTexture>> m_tex;
@@ -61,17 +60,30 @@ private:
 class Framebuffer final : public AbstractFramebuffer
 {
 public:
-  Framebuffer(AbstractTexture* color, AbstractTexture* depth, u32 width, u32 height, u32 layers,
-              u32 samples);
+  Framebuffer(AbstractTexture* color, AbstractTexture* depth,
+              std::vector<AbstractTexture*> additonal_color_textures,  //
+              u32 width, u32 height, u32 layers, u32 samples);
   ~Framebuffer();
 
-  id<MTLTexture> GetColor() const
+  MTLRenderPassDescriptor* PassDesc() const { return m_pass_descriptor; }
+
+  size_t NumAdditionalColorTextures() const { return m_additional_color_textures.size(); }
+
+  void SetLoadAction(MTLLoadAction action)
   {
-    return static_cast<Texture*>(GetColorAttachment())->GetMTLTexture();
+    if (m_current_load_action != action)
+      ActualSetLoadAction(action);
   }
-  id<MTLTexture> GetDepth() const
+
+  void UpdateBackbufferTexture(id<MTLTexture> tex)
   {
-    return static_cast<Texture*>(GetDepthAttachment())->GetMTLTexture();
+    [m_pass_descriptor colorAttachments][0].texture = tex;
   }
+
+private:
+  MRCOwned<MTLRenderPassDescriptor*> m_pass_descriptor;
+  std::vector<AbstractTexture*> m_additional_color_textures;
+  MTLLoadAction m_current_load_action = MTLLoadActionLoad;
+  void ActualSetLoadAction(MTLLoadAction action);
 };
 }  // namespace Metal
diff --git a/Source/Core/VideoBackends/Metal/MTLTexture.mm b/Source/Core/VideoBackends/Metal/MTLTexture.mm
index c9750eb1a5..ea4c7fb5ab 100644
--- a/Source/Core/VideoBackends/Metal/MTLTexture.mm
+++ b/Source/Core/VideoBackends/Metal/MTLTexture.mm
@@ -189,13 +189,56 @@ void Metal::StagingTexture::Flush()
   m_wait_buffer = nullptr;
 }
 
-Metal::Framebuffer::Framebuffer(AbstractTexture* color, AbstractTexture* depth,  //
+static void InitDesc(id desc, AbstractTexture* tex)
+{
+  [desc setTexture:static_cast<Metal::Texture*>(tex)->GetMTLTexture()];
+  [desc setLoadAction:MTLLoadActionLoad];
+  [desc setStoreAction:MTLStoreActionStore];
+}
+
+static void InitStencilDesc(MTLRenderPassStencilAttachmentDescriptor* desc, AbstractTexture* tex)
+{
+  InitDesc(desc, tex);
+  [desc setClearStencil:0];
+}
+
+Metal::Framebuffer::Framebuffer(AbstractTexture* color, AbstractTexture* depth,
+                                std::vector<AbstractTexture*> additonal_color_textures,  //
                                 u32 width, u32 height, u32 layers, u32 samples)
     : AbstractFramebuffer(color, depth, {},
                           color ? color->GetFormat() : AbstractTextureFormat::Undefined,  //
                           depth ? depth->GetFormat() : AbstractTextureFormat::Undefined,  //
-                          width, height, layers, samples)
+                          width, height, layers, samples),
+      m_additional_color_textures(std::move(additonal_color_textures))
 {
+  m_pass_descriptor = MRCTransfer([MTLRenderPassDescriptor new]);
+  MTLRenderPassDescriptor* desc = m_pass_descriptor;
+  if (color)
+    InitDesc(desc.colorAttachments[0], color);
+  if (depth)
+  {
+    InitDesc(desc.depthAttachment, depth);
+    if (Util::HasStencil(depth->GetFormat()))
+      InitStencilDesc(desc.stencilAttachment, depth);
+  }
+  for (size_t i = 0; i < m_additional_color_textures.size(); i++)
+    InitDesc(desc.colorAttachments[i + 1], m_additional_color_textures[i]);
 }
 
 Metal::Framebuffer::~Framebuffer() = default;
+
+void Metal::Framebuffer::ActualSetLoadAction(MTLLoadAction action)
+{
+  m_current_load_action = action;
+  AbstractTextureFormat depth_fmt = GetDepthFormat();
+  MTLRenderPassDescriptor* desc = m_pass_descriptor;
+  desc.colorAttachments[0].loadAction = action;
+  if (depth_fmt != AbstractTextureFormat::Undefined)
+  {
+    desc.depthAttachment.loadAction = action;
+    if (Util::HasStencil(depth_fmt))
+      desc.stencilAttachment.loadAction = action;
+  }
+  for (size_t i = 0; i < NumAdditionalColorTextures(); i++)
+    desc.colorAttachments[i + 1].loadAction = action;
+}