Fix T77915: Cycles OSL microfacet closure not working in custom shaders

The code to implement the newer closure in terms of the old one got lost in
the removal of our stdosl.h copy. Now implement it as a builtin closure.

2 files changed, 81 insertions, 0 deletions

diff --git a/intern/cycles/kernel/osl/osl_closures.cpp b/intern/cycles/kernel/osl/osl_closures.cpp
index 872a55143cc..7ee467a46dd 100644
--- a/intern/cycles/kernel/osl/osl_closures.cpp
+++ b/intern/cycles/kernel/osl/osl_closures.cpp
@@ -362,6 +362,9 @@ void OSLShader::register_closures(OSLShadingSystem *ss_)
                    id++,
                    closure_bsdf_transparent_params(),
                    closure_bsdf_transparent_prepare);
+
+  register_closure(
+      ss, "microfacet", id++, closure_bsdf_microfacet_params(), closure_bsdf_microfacet_prepare);
   register_closure(ss,
                    "microfacet_ggx",
                    id++,
@@ -508,6 +511,82 @@ bool CBSDFClosure::skip(const ShaderData *sd, int path_flag, int scattering)
   return false;
 }
 
+/* Standard Microfacet Closure */
+
+class MicrofacetClosure : public CBSDFClosure {
+ public:
+  MicrofacetBsdf params;
+  ustring distribution;
+  int refract;
+
+  void setup(ShaderData *sd, int path_flag, float3 weight)
+  {
+    static ustring u_ggx("ggx");
+    static ustring u_default("default");
+
+    const int label = (refract) ? LABEL_TRANSMIT : LABEL_REFLECT;
+    if (skip(sd, path_flag, LABEL_GLOSSY | label)) {
+      return;
+    }
+
+    MicrofacetBsdf *bsdf = (MicrofacetBsdf *)bsdf_alloc_osl(
+        sd, sizeof(MicrofacetBsdf), weight, &params);
+
+    if (!bsdf) {
+      return;
+    }
+
+    /* GGX */
+    if (distribution == u_ggx || distribution == u_default) {
+      if (!refract) {
+        if (params.alpha_x == params.alpha_y) {
+          /* Isotropic */
+          sd->flag |= bsdf_microfacet_ggx_isotropic_setup(bsdf);
+        }
+        else {
+          /* Anisotropic */
+          sd->flag |= bsdf_microfacet_ggx_setup(bsdf);
+        }
+      }
+      else {
+        sd->flag |= bsdf_microfacet_ggx_refraction_setup(bsdf);
+      }
+    }
+    /* Beckmann */
+    else {
+      if (!refract) {
+        if (params.alpha_x == params.alpha_y) {
+          /* Isotropic */
+          sd->flag |= bsdf_microfacet_beckmann_isotropic_setup(bsdf);
+        }
+        else {
+          /* Anisotropic */
+          sd->flag |= bsdf_microfacet_beckmann_setup(bsdf);
+        }
+      }
+      else {
+        sd->flag |= bsdf_microfacet_beckmann_refraction_setup(bsdf);
+      }
+    }
+  }
+};
+
+ClosureParam *closure_bsdf_microfacet_params()
+{
+  static ClosureParam params[] = {CLOSURE_STRING_PARAM(MicrofacetClosure, distribution),
+                                  CLOSURE_FLOAT3_PARAM(MicrofacetClosure, params.N),
+                                  CLOSURE_FLOAT3_PARAM(MicrofacetClosure, params.T),
+                                  CLOSURE_FLOAT_PARAM(MicrofacetClosure, params.alpha_x),
+                                  CLOSURE_FLOAT_PARAM(MicrofacetClosure, params.alpha_y),
+                                  CLOSURE_FLOAT_PARAM(MicrofacetClosure, params.ior),
+                                  CLOSURE_INT_PARAM(MicrofacetClosure, refract),
+                                  CLOSURE_STRING_KEYPARAM(MicrofacetClosure, label, "label"),
+                                  CLOSURE_FINISH_PARAM(MicrofacetClosure)};
+
+  return params;
+}
+CCLOSURE_PREPARE(closure_bsdf_microfacet_prepare, MicrofacetClosure)
+
 /* GGX closures with Fresnel */
 
 class MicrofacetFresnelClosure : public CBSDFClosure {
diff --git a/intern/cycles/kernel/osl/osl_closures.h b/intern/cycles/kernel/osl/osl_closures.h
index d12afdb80dd..e4058e3a746 100644
--- a/intern/cycles/kernel/osl/osl_closures.h
+++ b/intern/cycles/kernel/osl/osl_closures.h
@@ -51,6 +51,7 @@ OSL::ClosureParam *closure_bsdf_transparent_params();
 OSL::ClosureParam *closure_bssrdf_params();
 OSL::ClosureParam *closure_absorption_params();
 OSL::ClosureParam *closure_henyey_greenstein_params();
+OSL::ClosureParam *closure_bsdf_microfacet_params();
 OSL::ClosureParam *closure_bsdf_microfacet_multi_ggx_params();
 OSL::ClosureParam *closure_bsdf_microfacet_multi_ggx_glass_params();
 OSL::ClosureParam *closure_bsdf_microfacet_multi_ggx_aniso_params();
@@ -70,6 +71,7 @@ void closure_bsdf_transparent_prepare(OSL::RendererServices *, int id, void *dat
 void closure_bssrdf_prepare(OSL::RendererServices *, int id, void *data);
 void closure_absorption_prepare(OSL::RendererServices *, int id, void *data);
 void closure_henyey_greenstein_prepare(OSL::RendererServices *, int id, void *data);
+void closure_bsdf_microfacet_prepare(OSL::RendererServices *, int id, void *data);
 void closure_bsdf_microfacet_multi_ggx_prepare(OSL::RendererServices *, int id, void *data);
 void closure_bsdf_microfacet_multi_ggx_glass_prepare(OSL::RendererServices *, int id, void *data);
 void closure_bsdf_microfacet_multi_ggx_aniso_prepare(OSL::RendererServices *, int id, void *data);