Fix broken Cycles rendering with recent OSL versions

Commit c8dd33f5a37b6a6db0b6950d24f9a7cff5ceb799 in OSL
changed behavior of shader parameters that reference each other
and are also overwritten with an instance value.
This is causing the "NormalIn" parameter of a few OSL nodes in
Cycles to be set to zero somehow, which should instead have
received the value from a "node_geometry" node Cycles generates
and connects automatically. I am not entirely sure why that is
happening, but these parameters are superfluous anyway, since
OSL already provides the necessary data in the global variable "N".
So this patch simply removes those parameters (which mimics
SVM, where these parameters do not exist either), which also
fixes the rendering artifacts that occured with recent OSL.

Maniphest Tasks: T101222

Differential Revision: https://developer.blender.org/D16470

intern/cycles/kernel/osl/services_gpu.h

@@ -419,6 +419,8 @@ ccl_device_extern bool osl_transformc(ccl_private ShaderGlobals *sg,
       c_out[i] = rgb;
     }
   }
+
+  return true;
 }
 
 /* Matrix Utilities */

intern/cycles/kernel/osl/shaders/node_geometry.osl

@@ -3,8 +3,7 @@
 
 #include "stdcycles.h"
 
-shader node_geometry(normal NormalIn = N,
-                     string bump_offset = "center",
+shader node_geometry(string bump_offset = "center",
 
                      output point Position = point(0.0, 0.0, 0.0),
                      output normal Normal = normal(0.0, 0.0, 0.0),
@@ -17,7 +16,7 @@ shader node_geometry(normal NormalIn = N,
                      output float RandomPerIsland = 0.0)
 {
   Position = P;
-  Normal = NormalIn;
+  Normal = N;
   TrueNormal = Ng;
   Incoming = I;
   Parametric = point(1.0 - u - v, u, 0.0);

intern/cycles/kernel/osl/shaders/node_normal_map.osl

@@ -3,13 +3,12 @@
 
 #include "stdcycles.h"
 
-shader node_normal_map(normal NormalIn = N,
-                       float Strength = 1.0,
+shader node_normal_map(float Strength = 1.0,
                        color Color = color(0.5, 0.5, 1.0),
                        string space = "tangent",
                        string attr_name = "geom:tangent",
                        string attr_sign_name = "geom:tangent_sign",
-                       output normal Normal = NormalIn)
+                       output normal Normal = N)
 {
   color mcolor = 2.0 * color(Color[0] - 0.5, Color[1] - 0.5, Color[2] - 0.5);
   int is_backfacing = backfacing();
@@ -71,5 +70,5 @@ shader node_normal_map(normal NormalIn = N,
   }
 
   if (Strength != 1.0)
-    Normal = normalize(NormalIn + (Normal - NormalIn) * max(Strength, 0.0));
+    Normal = normalize(N + (Normal - N) * max(Strength, 0.0));
 }

intern/cycles/kernel/osl/shaders/node_tangent.osl

@@ -3,8 +3,7 @@
 
 #include "stdcycles.h"
 
-shader node_tangent(normal NormalIn = N,
-                    string attr_name = "geom:tangent",
+shader node_tangent(string attr_name = "geom:tangent",
                     string direction_type = "radial",
                     string axis = "z",
                     output normal Tangent = normalize(dPdu))
@@ -29,5 +28,5 @@ shader node_tangent(normal NormalIn = N,
   }
 
   T = transform("object", "world", T);
-  Tangent = cross(NormalIn, normalize(cross(T, NormalIn)));
+  Tangent = cross(N, normalize(cross(T, N)));
 }

intern/cycles/kernel/osl/shaders/node_texture_coordinate.osl

@@ -4,7 +4,6 @@
 #include "stdcycles.h"
 
 shader node_texture_coordinate(
-    normal NormalIn = N,
     int is_background = 0,
     int is_volume = 0,
     int from_dupli = 0,
@@ -27,7 +26,7 @@ shader node_texture_coordinate(
     point Pcam = transform("camera", "world", point(0, 0, 0));
     Camera = transform("camera", P + Pcam);
     getattribute("NDC", Window);
-    Normal = NormalIn;
+    Normal = N;
     Reflection = I;
   }
   else {
@@ -59,8 +58,8 @@ shader node_texture_coordinate(
     }
     Camera = transform("camera", P);
     Window = transform("NDC", P);
-    Normal = transform("world", "object", NormalIn);
-    Reflection = -reflect(I, NormalIn);
+    Normal = transform("world", "object", N);
+    Reflection = -reflect(I, N);
   }
 
   if (bump_offset == "dx") {

intern/cycles/scene/shader_nodes.cpp

@@ -3677,9 +3677,6 @@ NODE_DEFINE(GeometryNode)
 {
   NodeType *type = NodeType::add("geometry", create, NodeType::SHADER);
 
-  SOCKET_IN_NORMAL(
-      normal_osl, "NormalIn", zero_float3(), SocketType::LINK_NORMAL | SocketType::OSL_INTERNAL);
-
   SOCKET_OUT_POINT(position, "Position");
   SOCKET_OUT_NORMAL(normal, "Normal");
   SOCKET_OUT_NORMAL(tangent, "Tangent");
@@ -3812,9 +3809,6 @@ NODE_DEFINE(TextureCoordinateNode)
   SOCKET_BOOLEAN(use_transform, "Use Transform", false);
   SOCKET_TRANSFORM(ob_tfm, "Object Transform", transform_identity());
 
-  SOCKET_IN_NORMAL(
-      normal_osl, "NormalIn", zero_float3(), SocketType::LINK_NORMAL | SocketType::OSL_INTERNAL);
-
   SOCKET_OUT_POINT(generated, "Generated");
   SOCKET_OUT_NORMAL(normal, "Normal");
   SOCKET_OUT_POINT(UV, "UV");
@@ -7305,8 +7299,6 @@ NODE_DEFINE(NormalMapNode)
 
   SOCKET_STRING(attribute, "Attribute", ustring());
 
-  SOCKET_IN_NORMAL(
-      normal_osl, "NormalIn", zero_float3(), SocketType::LINK_NORMAL | SocketType::OSL_INTERNAL);
   SOCKET_IN_FLOAT(strength, "Strength", 1.0f);
   SOCKET_IN_COLOR(color, "Color", make_float3(0.5f, 0.5f, 1.0f));
 
@@ -7400,8 +7392,6 @@ NODE_DEFINE(TangentNode)
 
   SOCKET_STRING(attribute, "Attribute", ustring());
 
-  SOCKET_IN_NORMAL(
-      normal_osl, "NormalIn", zero_float3(), SocketType::LINK_NORMAL | SocketType::OSL_INTERNAL);
   SOCKET_OUT_NORMAL(tangent, "Tangent");
 
   return type;

intern/cycles/scene/shader_nodes.h

@@ -907,8 +907,6 @@ class GeometryNode : public ShaderNode {
     return true;
   }
   int get_group();
-
-  NODE_SOCKET_API(float3, normal_osl)
 };
 
 class TextureCoordinateNode : public ShaderNode {
@@ -924,7 +922,6 @@ class TextureCoordinateNode : public ShaderNode {
     return true;
   }
 
-  NODE_SOCKET_API(float3, normal_osl)
   NODE_SOCKET_API(bool, from_dupli)
   NODE_SOCKET_API(bool, use_transform)
   NODE_SOCKET_API(Transform, ob_tfm)
@@ -1573,7 +1570,6 @@ class NormalMapNode : public ShaderNode {
   NODE_SOCKET_API(ustring, attribute)
   NODE_SOCKET_API(float, strength)
   NODE_SOCKET_API(float3, color)
-  NODE_SOCKET_API(float3, normal_osl)
 };
 
 class TangentNode : public ShaderNode {
@@ -1592,7 +1588,6 @@ class TangentNode : public ShaderNode {
   NODE_SOCKET_API(NodeTangentDirectionType, direction_type)
   NODE_SOCKET_API(NodeTangentAxis, axis)
   NODE_SOCKET_API(ustring, attribute)
-  NODE_SOCKET_API(float3, normal_osl)
 };
 
 class BevelNode : public ShaderNode {