Cycles: merge of cycles-x branch, a major update to the renderer

This includes much improved GPU rendering performance, viewport interactivity,
new shadow catcher, revamped sampling settings, subsurface scattering anisotropy,
new GPU volume sampling, improved PMJ sampling pattern, and more.

Some features have also been removed or changed, breaking backwards compatibility.
Including the removal of the OpenCL backend, for which alternatives are under
development.

Release notes and code docs:
https://wiki.blender.org/wiki/Reference/Release_Notes/3.0/Cycles
https://wiki.blender.org/wiki/Source/Render/Cycles

Credits:
* Sergey Sharybin
* Brecht Van Lommel
* Patrick Mours (OptiX backend)
* Christophe Hery (subsurface scattering anisotropy)
* William Leeson (PMJ sampling pattern)
* Alaska (various fixes and tweaks)
* Thomas Dinges (various fixes)

For the full commit history, see the cycles-x branch. This squashes together
all the changes since intermediate changes would often fail building or tests.

Ref T87839, T87837, T87836
Fixes T90734, T89353, T80267, T80267, T77185, T69800

1 files changed, 56 insertions, 0 deletions

diff --git a/intern/cycles/integrator/tile.h b/intern/cycles/integrator/tile.h
new file mode 100644
index 00000000000..d0824843ddb
--- /dev/null
+++ b/intern/cycles/integrator/tile.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2011-2021 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <ostream>
+
+#include "util/util_types.h"
+
+CCL_NAMESPACE_BEGIN
+
+struct TileSize {
+  TileSize() = default;
+
+  inline TileSize(int width, int height, int num_samples)
+      : width(width), height(height), num_samples(num_samples)
+  {
+  }
+
+  inline bool operator==(const TileSize &other) const
+  {
+    return width == other.width && height == other.height && num_samples == other.num_samples;
+  }
+  inline bool operator!=(const TileSize &other) const
+  {
+    return !(*this == other);
+  }
+
+  int width = 0, height = 0;
+  int num_samples = 0;
+};
+
+std::ostream &operator<<(std::ostream &os, const TileSize &tile_size);
+
+/* Calculate tile size which is best suitable for rendering image of a given size with given number
+ * of active path states.
+ * Will attempt to provide best guess to keep path tracing threads of a device as localized as
+ * possible, and have as many threads active for every tile as possible. */
+TileSize tile_calculate_best_size(const int2 &image_size,
+                                  const int num_samples,
+                                  const int max_num_path_states);
+
+CCL_NAMESPACE_END