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, 15 insertions, 10 deletions

diff --git a/intern/cycles/kernel/kernel_light_background.h b/intern/cycles/kernel/kernel_light_background.h
index f0f64ce8704..493ed560bc6 100644
--- a/intern/cycles/kernel/kernel_light_background.h
+++ b/intern/cycles/kernel/kernel_light_background.h
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#pragma once
+
 #include "kernel_light_common.h"
 
 CCL_NAMESPACE_BEGIN
@@ -22,7 +24,10 @@ CCL_NAMESPACE_BEGIN
 
 #ifdef __BACKGROUND_MIS__
 
-ccl_device float3 background_map_sample(KernelGlobals *kg, float randu, float randv, float *pdf)
+ccl_device float3 background_map_sample(const KernelGlobals *kg,
+                                        float randu,
+                                        float randv,
+                                        float *pdf)
 {
   /* for the following, the CDF values are actually a pair of floats, with the
    * function value as X and the actual CDF as Y.  The last entry's function
@@ -104,7 +109,7 @@ ccl_device float3 background_map_sample(KernelGlobals *kg, float randu, float ra
 /* TODO(sergey): Same as above, after the release we should consider using
  * 'noinline' for all devices.
  */
-ccl_device float background_map_pdf(KernelGlobals *kg, float3 direction)
+ccl_device float background_map_pdf(const KernelGlobals *kg, float3 direction)
 {
   float2 uv = direction_to_equirectangular(direction);
   int res_x = kernel_data.background.map_res_x;
@@ -138,7 +143,7 @@ ccl_device float background_map_pdf(KernelGlobals *kg, float3 direction)
 }
 
 ccl_device_inline bool background_portal_data_fetch_and_check_side(
-    KernelGlobals *kg, float3 P, int index, float3 *lightpos, float3 *dir)
+    const KernelGlobals *kg, float3 P, int index, float3 *lightpos, float3 *dir)
 {
   int portal = kernel_data.background.portal_offset + index;
   const ccl_global KernelLight *klight = &kernel_tex_fetch(__lights, portal);
@@ -154,7 +159,7 @@ ccl_device_inline bool background_portal_data_fetch_and_check_side(
 }
 
 ccl_device_inline float background_portal_pdf(
-    KernelGlobals *kg, float3 P, float3 direction, int ignore_portal, bool *is_possible)
+    const KernelGlobals *kg, float3 P, float3 direction, int ignore_portal, bool *is_possible)
 {
   float portal_pdf = 0.0f;
 
@@ -214,7 +219,7 @@ ccl_device_inline float background_portal_pdf(
   return (num_possible > 0) ? portal_pdf / num_possible : 0.0f;
 }
 
-ccl_device int background_num_possible_portals(KernelGlobals *kg, float3 P)
+ccl_device int background_num_possible_portals(const KernelGlobals *kg, float3 P)
 {
   int num_possible_portals = 0;
   for (int p = 0; p < kernel_data.background.num_portals; p++) {
@@ -225,7 +230,7 @@ ccl_device int background_num_possible_portals(KernelGlobals *kg, float3 P)
   return num_possible_portals;
 }
 
-ccl_device float3 background_portal_sample(KernelGlobals *kg,
+ccl_device float3 background_portal_sample(const KernelGlobals *kg,
                                            float3 P,
                                            float randu,
                                            float randv,
@@ -280,7 +285,7 @@ ccl_device float3 background_portal_sample(KernelGlobals *kg,
   return zero_float3();
 }
 
-ccl_device_inline float3 background_sun_sample(KernelGlobals *kg,
+ccl_device_inline float3 background_sun_sample(const KernelGlobals *kg,
                                                float randu,
                                                float randv,
                                                float *pdf)
@@ -292,7 +297,7 @@ ccl_device_inline float3 background_sun_sample(KernelGlobals *kg,
   return D;
 }
 
-ccl_device_inline float background_sun_pdf(KernelGlobals *kg, float3 D)
+ccl_device_inline float background_sun_pdf(const KernelGlobals *kg, float3 D)
 {
   const float3 N = float4_to_float3(kernel_data.background.sun);
   const float angle = kernel_data.background.sun.w;
@@ -300,7 +305,7 @@ ccl_device_inline float background_sun_pdf(KernelGlobals *kg, float3 D)
 }
 
 ccl_device_inline float3
-background_light_sample(KernelGlobals *kg, float3 P, float randu, float randv, float *pdf)
+background_light_sample(const KernelGlobals *kg, float3 P, float randu, float randv, float *pdf)
 {
   float portal_method_pdf = kernel_data.background.portal_weight;
   float sun_method_pdf = kernel_data.background.sun_weight;
@@ -400,7 +405,7 @@ background_light_sample(KernelGlobals *kg, float3 P, float randu, float randv, f
   return D;
 }
 
-ccl_device float background_light_pdf(KernelGlobals *kg, float3 P, float3 direction)
+ccl_device float background_light_pdf(const KernelGlobals *kg, float3 P, float3 direction)
 {
   float portal_method_pdf = kernel_data.background.portal_weight;
   float sun_method_pdf = kernel_data.background.sun_weight;