Cycles: refactor API for GPU display

* Split GPUDisplay into two classes. PathTraceDisplay to implement the Cycles side,
  and DisplayDriver to implement the host application side. The DisplayDriver is now
  a fully abstract base class, embedded in the PathTraceDisplay.
* Move copy_pixels_to_texture implementation out of the host side into the Cycles side,
  since it can be implemented in terms of the texture buffer mapping.
* Move definition of DeviceGraphicsInteropDestination into display driver header, so
  that we do not need to expose private device headers in the public API.
* Add more detailed comments about how the DisplayDriver should be implemented.

The "driver" terminology might not be obvious, but is also used in other renderers.

Differential Revision: https://developer.blender.org/D12626

2 files changed, 9 insertions, 8 deletions

diff --git a/intern/cycles/device/cuda/graphics_interop.cpp b/intern/cycles/device/cuda/graphics_interop.cpp
index e8ca8b90eae..30efefd9b6b 100644
--- a/intern/cycles/device/cuda/graphics_interop.cpp
+++ b/intern/cycles/device/cuda/graphics_interop.cpp
@@ -37,14 +37,15 @@ CUDADeviceGraphicsInterop::~CUDADeviceGraphicsInterop()
   }
 }
 
-void CUDADeviceGraphicsInterop::set_destination(
-    const DeviceGraphicsInteropDestination &destination)
+void CUDADeviceGraphicsInterop::set_display_interop(
+    const DisplayDriver::GraphicsInterop &display_interop)
 {
-  const int64_t new_buffer_area = int64_t(destination.buffer_width) * destination.buffer_height;
+  const int64_t new_buffer_area = int64_t(display_interop.buffer_width) *
+                                  display_interop.buffer_height;
 
-  need_clear_ = destination.need_clear;
+  need_clear_ = display_interop.need_clear;
 
-  if (opengl_pbo_id_ == destination.opengl_pbo_id && buffer_area_ == new_buffer_area) {
+  if (opengl_pbo_id_ == display_interop.opengl_pbo_id && buffer_area_ == new_buffer_area) {
     return;
   }
 
@@ -55,12 +56,12 @@ void CUDADeviceGraphicsInterop::set_destination(
   }
 
   const CUresult result = cuGraphicsGLRegisterBuffer(
-      &cu_graphics_resource_, destination.opengl_pbo_id, CU_GRAPHICS_MAP_RESOURCE_FLAGS_NONE);
+      &cu_graphics_resource_, display_interop.opengl_pbo_id, CU_GRAPHICS_MAP_RESOURCE_FLAGS_NONE);
   if (result != CUDA_SUCCESS) {
     LOG(ERROR) << "Error registering OpenGL buffer: " << cuewErrorString(result);
   }
 
-  opengl_pbo_id_ = destination.opengl_pbo_id;
+  opengl_pbo_id_ = display_interop.opengl_pbo_id;
   buffer_area_ = new_buffer_area;
 }
 
diff --git a/intern/cycles/device/cuda/graphics_interop.h b/intern/cycles/device/cuda/graphics_interop.h
index 8a70c8aa71d..ec480f20c86 100644
--- a/intern/cycles/device/cuda/graphics_interop.h
+++ b/intern/cycles/device/cuda/graphics_interop.h
@@ -41,7 +41,7 @@ class CUDADeviceGraphicsInterop : public DeviceGraphicsInterop {
   CUDADeviceGraphicsInterop &operator=(const CUDADeviceGraphicsInterop &other) = delete;
   CUDADeviceGraphicsInterop &operator=(CUDADeviceGraphicsInterop &&other) = delete;
 
-  virtual void set_destination(const DeviceGraphicsInteropDestination &destination) override;
+  virtual void set_display_interop(const DisplayDriver::GraphicsInterop &display_interop) override;
 
   virtual device_ptr map() override;
   virtual void unmap() override;