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, 9 insertions, 4 deletions

diff --git a/source/blender/windowmanager/intern/wm_window.c b/source/blender/windowmanager/intern/wm_window.c
index 887aed7ffc7..8baf4a0e013 100644
--- a/source/blender/windowmanager/intern/wm_window.c
+++ b/source/blender/windowmanager/intern/wm_window.c
@@ -2426,10 +2426,15 @@ void wm_window_IME_end(wmWindow *win)
 
 void *WM_opengl_context_create(void)
 {
-  /* On Windows there is a problem creating contexts that share lists
-   * from one context that is current in another thread.
-   * So we should call this function only on the main thread.
-   */
+  /* On Windows there is a problem creating contexts that share resources (almost any object,
+   * including legacy display lists, but also textures) with a context which is current in another
+   * thread. This is a documented and behavior of both `::wglCreateContextAttribsARB()` and
+   * `::wglShareLists()`.
+   *
+   * Other platforms might successfully share resources from context which is active somewhere
+   * else, but to keep our code behave the same on all platform we expect contexts to only be
+   * created from the main thread. */
+
   BLI_assert(BLI_thread_is_main());
   BLI_assert(GPU_framebuffer_active_get() == GPU_framebuffer_back_get());