Shading: Add Map Range node to Cycles and EEVEE.

This patch adds a new Map Range node that linearly remaps an input
value from a range to another. This node is similar to the compositor's
Map Range node.

Reviewers: brecht, JacquesLucke

Differential Revision: https://developer.blender.org/D5471

3 files changed, 59 insertions, 0 deletions

diff --git a/intern/cycles/kernel/svm/svm.h b/intern/cycles/kernel/svm/svm.h
index 4a386afa5de..e0c2c8b56dc 100644
--- a/intern/cycles/kernel/svm/svm.h
+++ b/intern/cycles/kernel/svm/svm.h
@@ -192,6 +192,7 @@ CCL_NAMESPACE_END
 #include "kernel/svm/svm_vector_transform.h"
 #include "kernel/svm/svm_voxel.h"
 #include "kernel/svm/svm_bump.h"
+#include "kernel/svm/svm_map_range.h"
 
 #ifdef __SHADER_RAYTRACE__
 #  include "kernel/svm/svm_ao.h"
@@ -486,6 +487,9 @@ ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg,
       case NODE_BLACKBODY:
         svm_node_blackbody(kg, sd, stack, node.y, node.z);
         break;
+      case NODE_MAP_RANGE:
+        svm_node_map_range(kg, sd, stack, node.y, node.z, node.w, &offset);
+        break;
 #  endif /* __EXTRA_NODES__ */
 #  if NODES_FEATURE(NODE_FEATURE_VOLUME)
       case NODE_TEX_VOXEL:
diff --git a/intern/cycles/kernel/svm/svm_map_range.h b/intern/cycles/kernel/svm/svm_map_range.h
new file mode 100644
index 00000000000..5d542e959d1
--- /dev/null
+++ b/intern/cycles/kernel/svm/svm_map_range.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2011-2013 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+CCL_NAMESPACE_BEGIN
+
+/* Map Range Node */
+
+ccl_device void svm_node_map_range(KernelGlobals *kg,
+                                   ShaderData *sd,
+                                   float *stack,
+                                   uint value_stack_offset,
+                                   uint parameters_stack_offsets,
+                                   uint result_stack_offset,
+                                   int *offset)
+{
+  uint from_min_stack_offset, from_max_stack_offset, to_min_stack_offset, to_max_stack_offset;
+  decode_node_uchar4(parameters_stack_offsets,
+                     &from_min_stack_offset,
+                     &from_max_stack_offset,
+                     &to_min_stack_offset,
+                     &to_max_stack_offset);
+
+  uint4 defaults = read_node(kg, offset);
+
+  float value = stack_load_float(stack, value_stack_offset);
+  float from_min = stack_load_float_default(stack, from_min_stack_offset, defaults.x);
+  float from_max = stack_load_float_default(stack, from_max_stack_offset, defaults.y);
+  float to_min = stack_load_float_default(stack, to_min_stack_offset, defaults.z);
+  float to_max = stack_load_float_default(stack, to_max_stack_offset, defaults.w);
+
+  float result;
+  if (from_max != from_min) {
+    result = to_min + ((value - from_min) / (from_max - from_min)) * (to_max - to_min);
+  }
+  else {
+    result = 0.0f;
+  }
+  stack_store_float(stack, result_stack_offset, result);
+}
+
+CCL_NAMESPACE_END
diff --git a/intern/cycles/kernel/svm/svm_types.h b/intern/cycles/kernel/svm/svm_types.h
index ea92fd7ce59..82e7e94d438 100644
--- a/intern/cycles/kernel/svm/svm_types.h
+++ b/intern/cycles/kernel/svm/svm_types.h
@@ -138,6 +138,7 @@ typedef enum ShaderNodeType {
   NODE_VECTOR_DISPLACEMENT,
   NODE_PRINCIPLED_VOLUME,
   NODE_IES,
+  NODE_MAP_RANGE,
 } ShaderNodeType;
 
 typedef enum NodeAttributeType {