1 files changed, 54 insertions, 0 deletions

diff --git a/intern/cycles/device/device_multi.cpp b/intern/cycles/device/device_multi.cpp
index 624260a81c8..bc505b676fc 100644
--- a/intern/cycles/device/device_multi.cpp
+++ b/intern/cycles/device/device_multi.cpp
@@ -299,6 +299,60 @@ public:
 		return -1;
 	}
 
+	void map_neighbor_tiles(Device *sub_device, RenderTile *tiles)
+	{
+		for(int i = 0; i < 9; i++) {
+			if(!tiles[i].buffers) {
+				continue;
+			}
+			/* If the tile was rendered on another device, copy its memory to
+			 * to the current device now, for the duration of the denoising task.
+			 * Note that this temporarily modifies the RenderBuffers and calls
+			 * the device, so this function is not thread safe. */
+			if(tiles[i].buffers->device != sub_device) {
+				device_vector<float> &mem = tiles[i].buffers->buffer;
+
+				tiles[i].buffers->copy_from_device();
+				device_ptr original_ptr = mem.device_pointer;
+				mem.device_pointer = 0;
+				sub_device->mem_alloc("Temporary memory for neighboring tile", mem, MEM_READ_WRITE);
+				sub_device->mem_copy_to(mem);
+				tiles[i].buffer = mem.device_pointer;
+				mem.device_pointer = original_ptr;
+			}
+		}
+	}
+
+	void unmap_neighbor_tiles(Device * sub_device, RenderTile * tiles)
+	{
+		for(int i = 0; i < 9; i++) {
+			if(!tiles[i].buffers) {
+				continue;
+			}
+			if(tiles[i].buffers->device != sub_device) {
+				device_vector<float> &mem = tiles[i].buffers->buffer;
+
+				device_ptr original_ptr = mem.device_pointer;
+				mem.device_pointer = tiles[i].buffer;
+
+				/* Copy denoised tile to the host. */
+				if(i == 4) {
+					tiles[i].buffers->copy_from_device(sub_device);
+				}
+
+				size_t mem_size = mem.device_size;
+				sub_device->mem_free(mem);
+				mem.device_pointer = original_ptr;
+				mem.device_size = mem_size;
+
+				/* Copy denoised tile to the original device. */
+				if(i == 4) {
+					tiles[i].buffers->device->mem_copy_to(mem);
+				}
+			}
+		}
+	}
+
 	int get_split_task_count(DeviceTask& task)
 	{
 		int total_tasks = 0;