Nodes: Add Refract and Faceforward functions to Vector Maths nodes

Cycles, Eevee, OSL, Geo, Attribute

Based on outdated refract patch D6619 by @cubic_sloth

`refract` and `faceforward` are standard functions in GLSL, OSL and Godot shader languages.
Adding these functions provides Blender shader artists access to these standard functions.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D10622

3 files changed, 22 insertions, 12 deletions

diff --git a/intern/cycles/kernel/svm/svm_math.h b/intern/cycles/kernel/svm/svm_math.h
index 12a2bbdeb9b..dda2e50f916 100644
--- a/intern/cycles/kernel/svm/svm_math.h
+++ b/intern/cycles/kernel/svm/svm_math.h
@@ -44,26 +44,26 @@ ccl_device void svm_node_vector_math(KernelGlobals *kg,
                                      int *offset)
 {
   uint value_stack_offset, vector_stack_offset;
-  uint a_stack_offset, b_stack_offset, scale_stack_offset;
+  uint a_stack_offset, b_stack_offset, param1_stack_offset;
   svm_unpack_node_uchar3(
-      inputs_stack_offsets, &a_stack_offset, &b_stack_offset, &scale_stack_offset);
+      inputs_stack_offsets, &a_stack_offset, &b_stack_offset, &param1_stack_offset);
   svm_unpack_node_uchar2(outputs_stack_offsets, &value_stack_offset, &vector_stack_offset);
 
   float3 a = stack_load_float3(stack, a_stack_offset);
   float3 b = stack_load_float3(stack, b_stack_offset);
   float3 c = make_float3(0.0f, 0.0f, 0.0f);
-  float scale = stack_load_float(stack, scale_stack_offset);
+  float param1 = stack_load_float(stack, param1_stack_offset);
 
   float value;
   float3 vector;
 
   /* 3 Vector Operators */
-  if (type == NODE_VECTOR_MATH_WRAP) {
+  if (type == NODE_VECTOR_MATH_WRAP || type == NODE_VECTOR_MATH_FACEFORWARD) {
     uint4 extra_node = read_node(kg, offset);
     c = stack_load_float3(stack, extra_node.x);
   }
 
-  svm_vector_math(&value, &vector, (NodeVectorMathType)type, a, b, c, scale);
+  svm_vector_math(&value, &vector, (NodeVectorMathType)type, a, b, c, param1);
 
   if (stack_valid(value_stack_offset))
     stack_store_float(stack, value_stack_offset, value);
diff --git a/intern/cycles/kernel/svm/svm_math_util.h b/intern/cycles/kernel/svm/svm_math_util.h
index d1e1fa87e53..389c44ab1da 100644
--- a/intern/cycles/kernel/svm/svm_math_util.h
+++ b/intern/cycles/kernel/svm/svm_math_util.h
@@ -22,7 +22,7 @@ ccl_device void svm_vector_math(float *value,
                                 float3 a,
                                 float3 b,
                                 float3 c,
-                                float scale)
+                                float param1)
 {
   switch (type) {
     case NODE_VECTOR_MATH_ADD:
@@ -46,6 +46,12 @@ ccl_device void svm_vector_math(float *value,
     case NODE_VECTOR_MATH_REFLECT:
       *vector = reflect(a, b);
       break;
+    case NODE_VECTOR_MATH_REFRACT:
+      *vector = refract(a, normalize(b), param1);
+      break;
+    case NODE_VECTOR_MATH_FACEFORWARD:
+      *vector = faceforward(a, b, c);
+      break;
     case NODE_VECTOR_MATH_DOT_PRODUCT:
       *value = dot(a, b);
       break;
@@ -56,7 +62,7 @@ ccl_device void svm_vector_math(float *value,
       *value = len(a);
       break;
     case NODE_VECTOR_MATH_SCALE:
-      *vector = a * scale;
+      *vector = a * param1;
       break;
     case NODE_VECTOR_MATH_NORMALIZE:
       *vector = safe_normalize(a);
@@ -98,7 +104,7 @@ ccl_device void svm_vector_math(float *value,
       *vector = make_float3(tanf(a.x), tanf(a.y), tanf(a.z));
       break;
     default:
-      *vector = make_float3(0.0f, 0.0f, 0.0f);
+      *vector = zero_float3();
       *value = 0.0f;
   }
 }
@@ -236,10 +242,12 @@ ccl_device float3 svm_math_blackbody_color(float t)
     return make_float3(4.70366907f, 0.0f, 0.0f);
   }
 
-  int i = (t >= 6365.0f) ?
-              5 :
-              (t >= 3315.0f) ? 4 :
-                               (t >= 1902.0f) ? 3 : (t >= 1449.0f) ? 2 : (t >= 1167.0f) ? 1 : 0;
+  int i = (t >= 6365.0f) ? 5 :
+          (t >= 3315.0f) ? 4 :
+          (t >= 1902.0f) ? 3 :
+          (t >= 1449.0f) ? 2 :
+          (t >= 1167.0f) ? 1 :
+                           0;
 
   ccl_constant float *r = blackbody_table_r[i];
   ccl_constant float *g = blackbody_table_g[i];
diff --git a/intern/cycles/kernel/svm/svm_types.h b/intern/cycles/kernel/svm/svm_types.h
index 4a00afc1d7f..64a8f82a094 100644
--- a/intern/cycles/kernel/svm/svm_types.h
+++ b/intern/cycles/kernel/svm/svm_types.h
@@ -339,6 +339,8 @@ typedef enum NodeVectorMathType {
   NODE_VECTOR_MATH_SINE,
   NODE_VECTOR_MATH_COSINE,
   NODE_VECTOR_MATH_TANGENT,
+  NODE_VECTOR_MATH_REFRACT,
+  NODE_VECTOR_MATH_FACEFORWARD,
 } NodeVectorMathType;
 
 typedef enum NodeClampType {