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, 11 insertions, 14 deletions

diff --git a/intern/cycles/kernel/closure/bsdf_hair_principled.h b/intern/cycles/kernel/closure/bsdf_hair_principled.h
index f12661b3095..bfe56e5ab0e 100644
--- a/intern/cycles/kernel/closure/bsdf_hair_principled.h
+++ b/intern/cycles/kernel/closure/bsdf_hair_principled.h
@@ -14,15 +14,14 @@
  * limitations under the License.
  */
 
+#pragma once
+
 #ifdef __KERNEL_CPU__
 #  include <fenv.h>
 #endif
 
 #include "kernel/kernel_color.h"
 
-#ifndef __BSDF_HAIR_PRINCIPLED_H__
-#  define __BSDF_HAIR_PRINCIPLED_H__
-
 CCL_NAMESPACE_BEGIN
 
 typedef ccl_addr_space struct PrincipledHairExtra {
@@ -181,12 +180,12 @@ ccl_device_inline float longitudinal_scattering(
 }
 
 /* Combine the three values using their luminances. */
-ccl_device_inline float4 combine_with_energy(KernelGlobals *kg, float3 c)
+ccl_device_inline float4 combine_with_energy(const KernelGlobals *kg, float3 c)
 {
   return make_float4(c.x, c.y, c.z, linear_rgb_to_gray(kg, c));
 }
 
-#  ifdef __HAIR__
+#ifdef __HAIR__
 /* Set up the hair closure. */
 ccl_device int bsdf_principled_hair_setup(ShaderData *sd, PrincipledHairBSDF *bsdf)
 {
@@ -226,10 +225,10 @@ ccl_device int bsdf_principled_hair_setup(ShaderData *sd, PrincipledHairBSDF *bs
   return SD_BSDF | SD_BSDF_HAS_EVAL | SD_BSDF_NEEDS_LCG;
 }
 
-#  endif /* __HAIR__ */
+#endif /* __HAIR__ */
 
 /* Given the Fresnel term and transmittance, generate the attenuation terms for each bounce. */
-ccl_device_inline void hair_attenuation(KernelGlobals *kg, float f, float3 T, float4 *Ap)
+ccl_device_inline void hair_attenuation(const KernelGlobals *kg, float f, float3 T, float4 *Ap)
 {
   /* Primary specular (R). */
   Ap[0] = make_float4(f, f, f, f);
@@ -278,7 +277,7 @@ ccl_device_inline void hair_alpha_angles(float sin_theta_i,
 }
 
 /* Evaluation function for our shader. */
-ccl_device float3 bsdf_principled_hair_eval(KernelGlobals *kg,
+ccl_device float3 bsdf_principled_hair_eval(const KernelGlobals *kg,
                                             const ShaderData *sd,
                                             const ShaderClosure *sc,
                                             const float3 omega_in,
@@ -356,7 +355,7 @@ ccl_device float3 bsdf_principled_hair_eval(KernelGlobals *kg,
 }
 
 /* Sampling function for the hair shader. */
-ccl_device int bsdf_principled_hair_sample(KernelGlobals *kg,
+ccl_device int bsdf_principled_hair_sample(const KernelGlobals *kg,
                                            const ShaderClosure *sc,
                                            ShaderData *sd,
                                            float randu,
@@ -473,11 +472,11 @@ ccl_device int bsdf_principled_hair_sample(KernelGlobals *kg,
 
   *omega_in = X * sin_theta_i + Y * cos_theta_i * cosf(phi_i) + Z * cos_theta_i * sinf(phi_i);
 
-#  ifdef __RAY_DIFFERENTIALS__
+#ifdef __RAY_DIFFERENTIALS__
   float3 N = safe_normalize(sd->I + *omega_in);
   *domega_in_dx = (2 * dot(N, sd->dI.dx)) * N - sd->dI.dx;
   *domega_in_dy = (2 * dot(N, sd->dI.dy)) * N - sd->dI.dy;
-#  endif
+#endif
 
   return LABEL_GLOSSY | ((p == 0) ? LABEL_REFLECT : LABEL_TRANSMIT);
 }
@@ -501,7 +500,7 @@ ccl_device_inline float bsdf_principled_hair_albedo_roughness_scale(
   return (((((0.245f * x) + 5.574f) * x - 10.73f) * x + 2.532f) * x - 0.215f) * x + 5.969f;
 }
 
-ccl_device float3 bsdf_principled_hair_albedo(ShaderClosure *sc)
+ccl_device float3 bsdf_principled_hair_albedo(const ShaderClosure *sc)
 {
   PrincipledHairBSDF *bsdf = (PrincipledHairBSDF *)sc;
   return exp3(-sqrt(bsdf->sigma) * bsdf_principled_hair_albedo_roughness_scale(bsdf->v));
@@ -523,5 +522,3 @@ ccl_device_inline float3 bsdf_principled_hair_sigma_from_concentration(const flo
 }
 
 CCL_NAMESPACE_END
-
-#endif /* __BSDF_HAIR_PRINCIPLED_H__ */