HostDisplay: Add method to render screenshots at window size

src/core/host_display.cpp

@@ -613,3 +613,40 @@ bool HostDisplay::WriteDisplayTextureToBuffer(std::vector<u32>* buffer, u32 resi
 
   return true;
 }
+
+bool HostDisplay::WriteScreenshotToFile(std::string filename, bool compress_on_thread /*= false*/)
+{
+  const u32 width = m_window_info.surface_width;
+  const u32 height = m_window_info.surface_height;
+  if (width == 0 || height == 0)
+    return false;
+
+  std::vector<u32> pixels;
+  u32 pixels_stride;
+  HostDisplayPixelFormat pixels_format;
+  if (!RenderScreenshot(width, height, &pixels, &pixels_stride, &pixels_format))
+  {
+    Log_ErrorPrintf("Failed to render %ux%u screenshot", width, height);
+    return false;
+  }
+
+  auto fp = FileSystem::OpenManagedCFile(filename.c_str(), "wb");
+  if (!fp)
+  {
+    Log_ErrorPrintf("Can't open file '%s': errno %d", filename.c_str(), errno);
+    return false;
+  }
+
+  const RenderAPI api = GetRenderAPI();
+  const bool flip_y = (api == RenderAPI::OpenGL || api == RenderAPI::OpenGLES);
+  if (!compress_on_thread)
+  {
+    return CompressAndWriteTextureToFile(width, height, std::move(filename), std::move(fp), true, flip_y, width, height,
+                                         std::move(pixels), pixels_stride, pixels_format);
+  }
+
+  std::thread compress_thread(CompressAndWriteTextureToFile, width, height, std::move(filename), std::move(fp), true,
+                              flip_y, width, height, std::move(pixels), pixels_stride, pixels_format);
+  compress_thread.detach();
+  return true;
+}

src/core/host_display.h

@@ -115,6 +115,10 @@ public:
   /// Returns false if the window was completely occluded.
   virtual bool Render() = 0;
 
+  /// Renders the display with postprocessing to the specified image.
+  virtual bool RenderScreenshot(u32 width, u32 height, std::vector<u32>* out_pixels, u32* out_stride,
+                                HostDisplayPixelFormat* out_format) = 0;
+
   virtual void SetVSync(bool enabled) = 0;
 
 #ifdef WITH_IMGUI
@@ -232,6 +236,9 @@ public:
   bool WriteDisplayTextureToBuffer(std::vector<u32>* buffer, u32 resize_width = 0, u32 resize_height = 0,
                                    bool clear_alpha = true);
 
+  /// Helper function to save screenshot to PNG.
+  bool WriteScreenshotToFile(std::string filename, bool compress_on_thread = false);
+
 protected:
   ALWAYS_INLINE bool HasSoftwareCursor() const { return static_cast<bool>(m_cursor_texture); }
   ALWAYS_INLINE bool HasDisplayTexture() const { return (m_display_texture_handle != nullptr); }

src/frontend-common/d3d11_host_display.cpp

@@ -709,6 +709,59 @@ bool D3D11HostDisplay::Render()
   return true;
 }
 
+bool D3D11HostDisplay::RenderScreenshot(u32 width, u32 height, std::vector<u32>* out_pixels, u32* out_stride,
+                                        HostDisplayPixelFormat* out_format)
+{
+  static constexpr DXGI_FORMAT format = DXGI_FORMAT_R8G8B8A8_UNORM;
+  static constexpr HostDisplayPixelFormat hdformat = HostDisplayPixelFormat::RGBA8;
+
+  D3D11::Texture render_texture;
+  if (!render_texture.Create(m_device.Get(), width, height, 1, 1, format, D3D11_BIND_RENDER_TARGET) ||
+      !m_readback_staging_texture.EnsureSize(m_context.Get(), width, height, format, false))
+  {
+    return false;
+  }
+
+  static constexpr std::array<float, 4> clear_color = {};
+  m_context->ClearRenderTargetView(render_texture.GetD3DRTV(), clear_color.data());
+  m_context->OMSetRenderTargets(1, render_texture.GetD3DRTVArray(), nullptr);
+
+  if (HasDisplayTexture())
+  {
+    const auto [left, top, draw_width, draw_height] = CalculateDrawRect(width, height, 0);
+
+    if (!m_post_processing_chain.IsEmpty())
+    {
+      ApplyPostProcessingChain(render_texture.GetD3DRTV(), left, top, draw_width, draw_height, m_display_texture_handle,
+                               m_display_texture_width, m_display_texture_height, m_display_texture_view_x,
+                               m_display_texture_view_y, m_display_texture_view_width, m_display_texture_view_height,
+                               width, height);
+    }
+    else
+    {
+      RenderDisplay(left, top, draw_width, draw_height, m_display_texture_handle, m_display_texture_width,
+                    m_display_texture_height, m_display_texture_view_x, m_display_texture_view_y,
+                    m_display_texture_view_width, m_display_texture_view_height, m_display_linear_filtering);
+    }
+  }
+
+  m_context->OMSetRenderTargets(0, nullptr, nullptr);
+
+  m_readback_staging_texture.CopyFromTexture(m_context.Get(), render_texture, 0, 0, 0, 0, 0, width, height);
+
+  if (!m_readback_staging_texture.Map(m_context.Get(), false))
+    return false;
+
+  const u32 stride = sizeof(u32) * width;
+  out_pixels->resize(width * height);
+  *out_stride = stride;
+  *out_format = hdformat;
+
+  m_readback_staging_texture.ReadPixels<u32>(0, 0, width, height, stride, out_pixels->data());
+  m_readback_staging_texture.Unmap(m_context.Get());
+  return true;
+}
+
 void D3D11HostDisplay::RenderImGui()
 {
   ImGui::Render();
@@ -726,7 +779,8 @@ void D3D11HostDisplay::RenderDisplay()
   {
     ApplyPostProcessingChain(m_swap_chain_rtv.Get(), left, top, width, height, m_display_texture_handle,
                              m_display_texture_width, m_display_texture_height, m_display_texture_view_x,
-                             m_display_texture_view_y, m_display_texture_view_width, m_display_texture_view_height);
+                             m_display_texture_view_y, m_display_texture_view_width, m_display_texture_view_height,
+                             GetWindowWidth(), GetWindowHeight());
     return;
   }
 
@@ -971,11 +1025,12 @@ bool D3D11HostDisplay::CheckPostProcessingRenderTargets(u32 target_width, u32 ta
 void D3D11HostDisplay::ApplyPostProcessingChain(ID3D11RenderTargetView* final_target, s32 final_left, s32 final_top,
                                                 s32 final_width, s32 final_height, void* texture_handle,
                                                 u32 texture_width, s32 texture_height, s32 texture_view_x,
-                                                s32 texture_view_y, s32 texture_view_width, s32 texture_view_height)
+                                                s32 texture_view_y, s32 texture_view_width, s32 texture_view_height,
+                                                u32 target_width, u32 target_height)
 {
   static constexpr std::array<float, 4> clear_color = {0.0f, 0.0f, 0.0f, 1.0f};
 
-  if (!CheckPostProcessingRenderTargets(GetWindowWidth(), GetWindowHeight()))
+  if (!CheckPostProcessingRenderTargets(target_width, target_height))
   {
     RenderDisplay(final_left, final_top, final_width, final_height, texture_handle, texture_width, texture_height,
                   texture_view_x, texture_view_y, texture_view_width, texture_view_height, m_display_linear_filtering);

src/frontend-common/d3d11_host_display.h

@@ -68,6 +68,8 @@ public:
   virtual void SetVSync(bool enabled) override;
 
   virtual bool Render() override;
+  virtual bool RenderScreenshot(u32 width, u32 height, std::vector<u32>* out_pixels, u32* out_stride,
+                                HostDisplayPixelFormat* out_format) override;
 
   static AdapterAndModeList StaticGetAdapterAndModeList();
 
@@ -107,7 +109,7 @@ protected:
   void ApplyPostProcessingChain(ID3D11RenderTargetView* final_target, s32 final_left, s32 final_top, s32 final_width,
                                 s32 final_height, void* texture_handle, u32 texture_width, s32 texture_height,
                                 s32 texture_view_x, s32 texture_view_y, s32 texture_view_width,
-                                s32 texture_view_height);
+                                s32 texture_view_height, u32 target_width, u32 target_height);
 
   ComPtr<ID3D11Device> m_device;
   ComPtr<ID3D11DeviceContext> m_context;

src/frontend-common/opengl_host_display.cpp

@@ -749,7 +749,6 @@ bool OpenGLHostDisplay::Render()
     return false;
   }
 
-  glDisable(GL_SCISSOR_TEST);
   glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
   glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
   glClear(GL_COLOR_BUFFER_BIT);
@@ -765,6 +764,46 @@ bool OpenGLHostDisplay::Render()
   return true;
 }
 
+bool OpenGLHostDisplay::RenderScreenshot(u32 width, u32 height, std::vector<u32>* out_pixels, u32* out_stride,
+                                         HostDisplayPixelFormat* out_format)
+{
+  GL::Texture texture;
+  if (!texture.Create(width, height, 1, GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE, nullptr) || !texture.CreateFramebuffer())
+    return false;
+
+  texture.BindFramebuffer(GL_FRAMEBUFFER);
+  glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+  glClear(GL_COLOR_BUFFER_BIT);
+
+  if (HasDisplayTexture())
+  {
+    const auto [left, top, draw_width, draw_height] = CalculateDrawRect(width, height, 0);
+
+    if (!m_post_processing_chain.IsEmpty())
+    {
+      ApplyPostProcessingChain(texture.GetGLFramebufferID(), left, height - top - draw_height, draw_width, draw_height,
+                               m_display_texture_handle, m_display_texture_width, m_display_texture_height,
+                               m_display_texture_view_x, m_display_texture_view_y, m_display_texture_view_width,
+                               m_display_texture_view_height, width, height);
+    }
+    else
+    {
+      RenderDisplay(left, height - top - draw_height, draw_width, draw_height, m_display_texture_handle,
+                    m_display_texture_width, m_display_texture_height, m_display_texture_view_x,
+                    m_display_texture_view_y, m_display_texture_view_width, m_display_texture_view_height,
+                    m_display_linear_filtering);
+    }
+  }
+
+  out_pixels->resize(width * height);
+  *out_stride = sizeof(u32) * width;
+  *out_format = HostDisplayPixelFormat::RGBA8;
+  glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, out_pixels->data());
+  glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+  return true;
+}
+
 void OpenGLHostDisplay::RenderImGui()
 {
   ImGui::Render();
@@ -783,7 +822,8 @@ void OpenGLHostDisplay::RenderDisplay()
   {
     ApplyPostProcessingChain(0, left, GetWindowHeight() - top - height, width, height, m_display_texture_handle,
                              m_display_texture_width, m_display_texture_height, m_display_texture_view_x,
-                             m_display_texture_view_y, m_display_texture_view_width, m_display_texture_view_height);
+                             m_display_texture_view_y, m_display_texture_view_width, m_display_texture_view_height,
+                             GetWindowWidth(), GetWindowHeight());
     return;
   }
 
@@ -995,11 +1035,12 @@ bool OpenGLHostDisplay::CheckPostProcessingRenderTargets(u32 target_width, u32 t
 void OpenGLHostDisplay::ApplyPostProcessingChain(GLuint final_target, s32 final_left, s32 final_top, s32 final_width,
                                                  s32 final_height, void* texture_handle, u32 texture_width,
                                                  s32 texture_height, s32 texture_view_x, s32 texture_view_y,
-                                                 s32 texture_view_width, s32 texture_view_height)
+                                                 s32 texture_view_width, s32 texture_view_height, u32 target_width,
+                                                 u32 target_height)
 {
-  if (!CheckPostProcessingRenderTargets(GetWindowWidth(), GetWindowHeight()))
+  if (!CheckPostProcessingRenderTargets(target_width, target_height))
   {
-    RenderDisplay(final_left, GetWindowHeight() - final_top - final_height, final_width, final_height, texture_handle,
+    RenderDisplay(final_left, target_height - final_top - final_height, final_width, final_height, texture_handle,
                   texture_width, texture_height, texture_view_x, texture_view_y, texture_view_width,
                   texture_view_height, m_display_linear_filtering);
     return;
@@ -1008,7 +1049,7 @@ void OpenGLHostDisplay::ApplyPostProcessingChain(GLuint final_target, s32 final_
   // downsample/upsample - use same viewport for remainder
   m_post_processing_input_texture.BindFramebuffer(GL_DRAW_FRAMEBUFFER);
   glClear(GL_COLOR_BUFFER_BIT);
-  RenderDisplay(final_left, GetWindowHeight() - final_top - final_height, final_width, final_height, texture_handle,
+  RenderDisplay(final_left, target_height - final_top - final_height, final_width, final_height, texture_handle,
                 texture_width, texture_height, texture_view_x, texture_view_y, texture_view_width, texture_view_height,
                 m_display_linear_filtering);
 

src/frontend-common/opengl_host_display.h

@@ -32,8 +32,10 @@ public:
   virtual bool HasRenderDevice() const override;
   virtual bool HasRenderSurface() const override;
 
-  virtual bool CreateRenderDevice(const WindowInfo& wi, std::string_view adapter_name, bool debug_device, bool threaded_presentation) override;
-  virtual bool InitializeRenderDevice(std::string_view shader_cache_directory, bool debug_device, bool threaded_presentation) override;
+  virtual bool CreateRenderDevice(const WindowInfo& wi, std::string_view adapter_name, bool debug_device,
+                                  bool threaded_presentation) override;
+  virtual bool InitializeRenderDevice(std::string_view shader_cache_directory, bool debug_device,
+                                      bool threaded_presentation) override;
   virtual void DestroyRenderDevice() override;
 
   virtual bool MakeRenderContextCurrent() override;
@@ -65,6 +67,8 @@ public:
   virtual void SetVSync(bool enabled) override;
 
   virtual bool Render() override;
+  virtual bool RenderScreenshot(u32 width, u32 height, std::vector<u32>* out_pixels, u32* out_stride,
+                                HostDisplayPixelFormat* out_format) override;
 
 protected:
   const char* GetGLSLVersionString() const;
@@ -99,7 +103,8 @@ protected:
   bool CheckPostProcessingRenderTargets(u32 target_width, u32 target_height);
   void ApplyPostProcessingChain(GLuint final_target, s32 final_left, s32 final_top, s32 final_width, s32 final_height,
                                 void* texture_handle, u32 texture_width, s32 texture_height, s32 texture_view_x,
-                                s32 texture_view_y, s32 texture_view_width, s32 texture_view_height);
+                                s32 texture_view_y, s32 texture_view_width, s32 texture_view_height, u32 target_width,
+                                u32 target_height);
 
   std::unique_ptr<GL::Context> m_gl_context;
 

src/frontend-common/vulkan_host_display.cpp

@@ -640,14 +640,107 @@ bool VulkanHostDisplay::Render()
   return true;
 }
 
-void VulkanHostDisplay::BeginSwapChainRenderPass(VkFramebuffer framebuffer)
+bool VulkanHostDisplay::RenderScreenshot(u32 width, u32 height, std::vector<u32>* out_pixels, u32* out_stride,
+                                         HostDisplayPixelFormat* out_format)
+{
+  // in theory we could do this without a swap chain, but postprocessing assumes it for now...
+  if (!m_swap_chain)
+    return false;
+
+  const VkFormat format = m_swap_chain ? m_swap_chain->GetTextureFormat() : VK_FORMAT_R8G8B8A8_UNORM;
+  switch (format)
+  {
+    case VK_FORMAT_R8G8B8A8_UNORM:
+    case VK_FORMAT_R8G8B8A8_SRGB:
+      *out_format = HostDisplayPixelFormat::RGBA8;
+      *out_stride = sizeof(u32) * width;
+      out_pixels->resize(width * height);
+      break;
+
+    case VK_FORMAT_B8G8R8A8_UNORM:
+    case VK_FORMAT_B8G8R8A8_SRGB:
+      *out_format = HostDisplayPixelFormat::BGRA8;
+      *out_stride = sizeof(u32) * width;
+      out_pixels->resize(width * height);
+      break;
+
+    case VK_FORMAT_A1R5G5B5_UNORM_PACK16:
+      *out_format = HostDisplayPixelFormat::RGBA5551;
+      *out_stride = sizeof(u16) * width;
+      out_pixels->resize(((width * height) + 1) / 2);
+      break;
+
+    case VK_FORMAT_R5G6B5_UNORM_PACK16:
+      *out_format = HostDisplayPixelFormat::RGB565;
+      *out_stride = sizeof(u16) * width;
+      out_pixels->resize(((width * height) + 1) / 2);
+      break;
+
+    default:
+      Log_ErrorPrintf("Unhandled swap chain pixel format %u", static_cast<unsigned>(format));
+      break;
+  }
+
+  Vulkan::Texture tex;
+  Vulkan::StagingTexture staging_tex;
+  if (!tex.Create(width, height, 1, 1, format, VK_SAMPLE_COUNT_1_BIT, VK_IMAGE_VIEW_TYPE_2D, VK_IMAGE_TILING_OPTIMAL,
+                  VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_TRANSFER_SRC_BIT) ||
+      !staging_tex.Create(Vulkan::StagingBuffer::Type::Readback, format, width, height))
+  {
+    return false;
+  }
+
+  const VkRenderPass rp =
+    m_swap_chain ?
+      m_swap_chain->GetClearRenderPass() :
+      g_vulkan_context->GetRenderPass(format, VK_FORMAT_UNDEFINED, VK_SAMPLE_COUNT_1_BIT, VK_ATTACHMENT_LOAD_OP_CLEAR);
+  if (!rp)
+    return false;
+
+  const VkFramebuffer fb = tex.CreateFramebuffer(rp);
+  if (!fb)
+    return false;
+
+  tex.TransitionToLayout(g_vulkan_context->GetCurrentCommandBuffer(), VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);
+
+  const auto [left, top, draw_width, draw_height] =
+    CalculateDrawRect(GetWindowWidth(), GetWindowHeight(), m_display_top_margin);
+
+  if (!m_post_processing_chain.IsEmpty())
+  {
+    ApplyPostProcessingChain(fb, left, top, draw_width, draw_height, m_display_texture_handle, m_display_texture_width,
+                             m_display_texture_height, m_display_texture_view_x, m_display_texture_view_y,
+                             m_display_texture_view_width, m_display_texture_view_height, width, height);
+  }
+  else
+  {
+    BeginSwapChainRenderPass(fb, width, height);
+    RenderDisplay(left, top, draw_width, draw_height, m_display_texture_handle, m_display_texture_width,
+                  m_display_texture_height, m_display_texture_view_x, m_display_texture_view_y,
+                  m_display_texture_view_width, m_display_texture_view_height, m_display_linear_filtering);
+  }
+
+  vkCmdEndRenderPass(g_vulkan_context->GetCurrentCommandBuffer());
+  tex.TransitionToLayout(g_vulkan_context->GetCurrentCommandBuffer(), VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL);
+  staging_tex.CopyFromTexture(tex, 0, 0, 0, 0, 0, 0, width, height);
+  staging_tex.ReadTexels(0, 0, width, height, out_pixels->data(), *out_stride);
+
+  // destroying these immediately should be safe since nothing's going to access them, and it's not part of the command
+  // stream
+  vkDestroyFramebuffer(g_vulkan_context->GetDevice(), fb, nullptr);
+  staging_tex.Destroy(false);
+  tex.Destroy(false);
+  return true;
+}
+
+void VulkanHostDisplay::BeginSwapChainRenderPass(VkFramebuffer framebuffer, u32 width, u32 height)
 {
   const VkClearValue clear_value = {{{0.0f, 0.0f, 0.0f, 1.0f}}};
   const VkRenderPassBeginInfo rp = {VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO,
                                     nullptr,
                                     m_swap_chain->GetClearRenderPass(),
                                     framebuffer,
-                                    {{0, 0}, {m_swap_chain->GetWidth(), m_swap_chain->GetHeight()}},
+                                    {{0, 0}, {width, height}},
                                     1u,
                                     &clear_value};
   vkCmdBeginRenderPass(g_vulkan_context->GetCurrentCommandBuffer(), &rp, VK_SUBPASS_CONTENTS_INLINE);
@@ -657,7 +750,8 @@ void VulkanHostDisplay::RenderDisplay()
 {
   if (!HasDisplayTexture())
   {
-    BeginSwapChainRenderPass(m_swap_chain->GetCurrentFramebuffer());
+    BeginSwapChainRenderPass(m_swap_chain->GetCurrentFramebuffer(), m_swap_chain->GetWidth(),
+                             m_swap_chain->GetHeight());
     return;
   }
 
@@ -665,13 +759,14 @@ void VulkanHostDisplay::RenderDisplay()
 
   if (!m_post_processing_chain.IsEmpty())
   {
-    ApplyPostProcessingChain(left, top, width, height, m_display_texture_handle, m_display_texture_width,
-                             m_display_texture_height, m_display_texture_view_x, m_display_texture_view_y,
-                             m_display_texture_view_width, m_display_texture_view_height);
+    ApplyPostProcessingChain(m_swap_chain->GetCurrentFramebuffer(), left, top, width, height, m_display_texture_handle,
+                             m_display_texture_width, m_display_texture_height, m_display_texture_view_x,
+                             m_display_texture_view_y, m_display_texture_view_width, m_display_texture_view_height,
+                             m_swap_chain->GetWidth(), m_swap_chain->GetHeight());
     return;
   }
 
-  BeginSwapChainRenderPass(m_swap_chain->GetCurrentFramebuffer());
+  BeginSwapChainRenderPass(m_swap_chain->GetCurrentFramebuffer(), m_swap_chain->GetWidth(), m_swap_chain->GetHeight());
   RenderDisplay(left, top, width, height, m_display_texture_handle, m_display_texture_width, m_display_texture_height,
                 m_display_texture_view_x, m_display_texture_view_y, m_display_texture_view_width,
                 m_display_texture_view_height, m_display_linear_filtering);
@@ -946,14 +1041,15 @@ bool VulkanHostDisplay::CheckPostProcessingRenderTargets(u32 target_width, u32 t
   return true;
 }
 
-void VulkanHostDisplay::ApplyPostProcessingChain(s32 final_left, s32 final_top, s32 final_width, s32 final_height,
-                                                 void* texture_handle, u32 texture_width, s32 texture_height,
-                                                 s32 texture_view_x, s32 texture_view_y, s32 texture_view_width,
-                                                 s32 texture_view_height)
+void VulkanHostDisplay::ApplyPostProcessingChain(VkFramebuffer target_fb, s32 final_left, s32 final_top,
+                                                 s32 final_width, s32 final_height, void* texture_handle,
+                                                 u32 texture_width, s32 texture_height, s32 texture_view_x,
+                                                 s32 texture_view_y, s32 texture_view_width, s32 texture_view_height,
+                                                 u32 target_width, u32 target_height)
 {
-  if (!CheckPostProcessingRenderTargets(m_swap_chain->GetWidth(), m_swap_chain->GetHeight()))
+  if (!CheckPostProcessingRenderTargets(target_width, target_height))
   {
-    BeginSwapChainRenderPass(m_swap_chain->GetCurrentFramebuffer());
+    BeginSwapChainRenderPass(target_fb, target_width, target_height);
     RenderDisplay(final_left, final_top, final_width, final_height, texture_handle, texture_width, texture_height,
                   texture_view_x, texture_view_y, texture_view_width, texture_view_height, m_display_linear_filtering);
     return;
@@ -962,7 +1058,7 @@ void VulkanHostDisplay::ApplyPostProcessingChain(s32 final_left, s32 final_top,
   // downsample/upsample - use same viewport for remainder
   VkCommandBuffer cmdbuffer = g_vulkan_context->GetCurrentCommandBuffer();
   m_post_processing_input_texture.TransitionToLayout(cmdbuffer, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);
-  BeginSwapChainRenderPass(m_post_processing_input_framebuffer);
+  BeginSwapChainRenderPass(m_post_processing_input_framebuffer, target_width, target_height);
   RenderDisplay(final_left, final_top, final_width, final_height, texture_handle, texture_width, texture_height,
                 texture_view_x, texture_view_y, texture_view_width, texture_view_height, m_display_linear_filtering);
   vkCmdEndRenderPass(cmdbuffer);
@@ -983,11 +1079,11 @@ void VulkanHostDisplay::ApplyPostProcessingChain(s32 final_left, s32 final_top,
     if (i != final_stage)
     {
       pps.output_texture.TransitionToLayout(cmdbuffer, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);
-      BeginSwapChainRenderPass(pps.output_framebuffer);
+      BeginSwapChainRenderPass(pps.output_framebuffer, target_width, target_height);
     }
     else
     {
-      BeginSwapChainRenderPass(m_swap_chain->GetCurrentFramebuffer());
+      BeginSwapChainRenderPass(target_fb, target_width, target_height);
     }
 
     const bool use_push_constants = m_post_processing_chain.GetShaderStage(i).UsePushConstants();

src/frontend-common/vulkan_host_display.h

@@ -64,6 +64,8 @@ public:
   virtual void SetVSync(bool enabled) override;
 
   virtual bool Render() override;
+  virtual bool RenderScreenshot(u32 width, u32 height, std::vector<u32>* out_pixels, u32* out_stride,
+                                HostDisplayPixelFormat* out_format) override;
 
   static AdapterAndModeList StaticGetAdapterAndModeList(const WindowInfo* wi);
 
@@ -89,9 +91,10 @@ protected:
   };
 
   bool CheckPostProcessingRenderTargets(u32 target_width, u32 target_height);
-  void ApplyPostProcessingChain(s32 final_left, s32 final_top, s32 final_width, s32 final_height, void* texture_handle,
-                                u32 texture_width, s32 texture_height, s32 texture_view_x, s32 texture_view_y,
-                                s32 texture_view_width, s32 texture_view_height);
+  void ApplyPostProcessingChain(VkFramebuffer target_fb, s32 final_left, s32 final_top, s32 final_width,
+                                s32 final_height, void* texture_handle, u32 texture_width, s32 texture_height,
+                                s32 texture_view_x, s32 texture_view_y, s32 texture_view_width, s32 texture_view_height,
+                                u32 target_width, u32 target_height);
 
   // Can be overridden by frontends.
   virtual VkRenderPass GetRenderPassForDisplay() const;
@@ -103,7 +106,7 @@ protected:
   virtual void DestroyImGuiContext() override;
   virtual bool UpdateImGuiFontTexture() override;
 
-  void BeginSwapChainRenderPass(VkFramebuffer framebuffer);
+  void BeginSwapChainRenderPass(VkFramebuffer framebuffer, u32 width, u32 height);
   void RenderDisplay();
   void RenderImGui();
   void RenderSoftwareCursor();