HostDisplay: Add texture dumping/saving support

src/duckstation-sdl/d3d11_host_display.cpp

@@ -168,6 +168,24 @@ void D3D11HostDisplay::UpdateTexture(HostDisplayTexture* texture, u32 x, u32 y,
   }
 }
 
+bool D3D11HostDisplay::DownloadTexture(const void* texture_handle, u32 x, u32 y, u32 width, u32 height, void* out_data,
+                                       u32 out_data_stride)
+{
+  ID3D11ShaderResourceView* srv =
+    const_cast<ID3D11ShaderResourceView*>(static_cast<const ID3D11ShaderResourceView*>(texture_handle));
+  ID3D11Resource* srv_resource;
+  D3D11_SHADER_RESOURCE_VIEW_DESC srv_desc;
+  srv->GetResource(&srv_resource);
+  srv->GetDesc(&srv_desc);
+
+  if (!m_readback_staging_texture.EnsureSize(m_context.Get(), width, height, srv_desc.Format, false))
+    return false;
+
+  m_readback_staging_texture.CopyFromTexture(m_context.Get(), srv_resource, 0, x, y, 0, 0, width, height);
+  return m_readback_staging_texture.ReadPixels<u32>(m_context.Get(), 0, 0, width, height, out_data_stride / sizeof(u32),
+                                                    static_cast<u32*>(out_data));
+}
+
 void D3D11HostDisplay::SetVSync(bool enabled)
 {
   m_vsync = enabled;

src/duckstation-sdl/d3d11_host_display.h

@@ -1,5 +1,6 @@
 #pragma once
 #include "common/d3d11/stream_buffer.h"
+#include "common/d3d11/staging_texture.h"
 #include "common/d3d11/texture.h"
 #include "common/windows_headers.h"
 #include "core/host_display.h"
@@ -31,6 +32,8 @@ public:
                                                     bool dynamic) override;
   void UpdateTexture(HostDisplayTexture* texture, u32 x, u32 y, u32 width, u32 height, const void* data,
                      u32 data_stride) override;
+  bool DownloadTexture(const void* texture_handle, u32 x, u32 y, u32 width, u32 height, void* out_data,
+                       u32 out_data_stride) override;
 
   void SetVSync(bool enabled) override;
 
@@ -63,6 +66,7 @@ private:
 
   D3D11::Texture m_display_pixels_texture;
   D3D11::StreamBuffer m_display_uniform_buffer;
+  D3D11::AutoStagingTexture m_readback_staging_texture;
 
   bool m_allow_tearing_supported = false;
   bool m_vsync = true;

src/duckstation-sdl/opengl_host_display.cpp

@@ -21,7 +21,7 @@ public:
   GLuint GetGLID() const { return m_id; }
 
   static std::unique_ptr<OpenGLDisplayWidgetTexture> Create(u32 width, u32 height, const void* initial_data,
-                                                          u32 initial_data_stride)
+                                                            u32 initial_data_stride)
   {
     GLuint id;
     glGenTextures(1, &id);
@@ -129,6 +129,24 @@ void OpenGLHostDisplay::UpdateTexture(HostDisplayTexture* texture, u32 x, u32 y,
   glBindTexture(GL_TEXTURE_2D, old_texture_binding);
 }
 
+bool OpenGLHostDisplay::DownloadTexture(const void* texture_handle, u32 x, u32 y, u32 width, u32 height, void* out_data,
+                                        u32 out_data_stride)
+{
+  GLint old_alignment = 0, old_row_length = 0;
+  glGetIntegerv(GL_PACK_ALIGNMENT, &old_alignment);
+  glGetIntegerv(GL_PACK_ROW_LENGTH, &old_row_length);
+  glPixelStorei(GL_PACK_ALIGNMENT, sizeof(u32));
+  glPixelStorei(GL_PACK_ROW_LENGTH, out_data_stride / sizeof(u32));
+
+  const GLuint texture = static_cast<GLuint>(reinterpret_cast<uintptr_t>(texture_handle));
+  GL::Texture::GetTextureSubImage(texture, 0, x, y, 0, width, height, 1, GL_RGBA, GL_UNSIGNED_BYTE,
+                                  height * out_data_stride, out_data);
+
+  glPixelStorei(GL_PACK_ALIGNMENT, old_alignment);
+  glPixelStorei(GL_PACK_ROW_LENGTH, old_row_length);
+  return true;
+}
+
 void OpenGLHostDisplay::SetVSync(bool enabled)
 {
   // Window framebuffer has to be bound to call SetSwapInterval.

src/duckstation-sdl/opengl_host_display.h

@@ -3,8 +3,8 @@
 #include "common/gl/texture.h"
 #include "core/host_display.h"
 #include <SDL.h>
-#include <string>
 #include <memory>
+#include <string>
 
 class OpenGLHostDisplay final : public HostDisplay
 {
@@ -26,6 +26,8 @@ public:
                                                     bool dynamic) override;
   void UpdateTexture(HostDisplayTexture* texture, u32 x, u32 y, u32 width, u32 height, const void* data,
                      u32 data_stride) override;
+  bool DownloadTexture(const void* texture_handle, u32 x, u32 y, u32 width, u32 height, void* out_data,
+                       u32 out_data_stride) override;
 
   void SetVSync(bool enabled) override;