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

9 files changed, 169 insertions, 0 deletions

diff --git a/intern/cycles/blender/blender_shader.cpp b/intern/cycles/blender/blender_shader.cpp
index f952b3025f0..dc0563c3bb8 100644
--- a/intern/cycles/blender/blender_shader.cpp
+++ b/intern/cycles/blender/blender_shader.cpp
@@ -315,6 +315,9 @@ static ShaderNode *add_node(Scene *scene,
   else if (b_node.is_a(&RNA_ShaderNodeRGBToBW)) {
     node = new RGBToBWNode();
   }
+  else if (b_node.is_a(&RNA_ShaderNodeMapRange)) {
+    node = new MapRangeNode();
+  }
   else if (b_node.is_a(&RNA_ShaderNodeMath)) {
     BL::ShaderNodeMath b_math_node(b_node);
     MathNode *math = new MathNode();
diff --git a/intern/cycles/kernel/CMakeLists.txt b/intern/cycles/kernel/CMakeLists.txt
index a8b5b077ece..2078b1a8f4e 100644
--- a/intern/cycles/kernel/CMakeLists.txt
+++ b/intern/cycles/kernel/CMakeLists.txt
@@ -198,6 +198,7 @@ set(SRC_SVM_HEADERS
   svm/svm_invert.h
   svm/svm_light_path.h
   svm/svm_magic.h
+  svm/svm_map_range.h
   svm/svm_mapping.h
   svm/svm_math.h
   svm/svm_math_util.h
diff --git a/intern/cycles/kernel/shaders/CMakeLists.txt b/intern/cycles/kernel/shaders/CMakeLists.txt
index b42b9b2fe64..2a84d89f9be 100644
--- a/intern/cycles/kernel/shaders/CMakeLists.txt
+++ b/intern/cycles/kernel/shaders/CMakeLists.txt
@@ -46,6 +46,7 @@ set(SRC_OSL
   node_light_falloff.osl
   node_light_path.osl
   node_magic_texture.osl
+  node_map_range.osl
   node_mapping.osl
   node_math.osl
   node_mix.osl
diff --git a/intern/cycles/kernel/shaders/node_map_range.osl b/intern/cycles/kernel/shaders/node_map_range.osl
new file mode 100644
index 00000000000..417d2ae50a8
--- /dev/null
+++ b/intern/cycles/kernel/shaders/node_map_range.osl
@@ -0,0 +1,25 @@
+/*
+ * 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.
+ */
+
+#include "stdosl.h"
+
+shader node_map_range(float Value = 1.0, float FromMin = 0.0, float FromMax = 1.0,
+                      float ToMin = 0.0, float ToMax = 1.0, output float Result = 0.0)
+{
+  if (FromMax != FromMin) {
+    Result = ToMin + ((Value - FromMin) / (FromMax - FromMin)) * (ToMax - ToMin);
+  }
+}
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 {
diff --git a/intern/cycles/render/nodes.cpp b/intern/cycles/render/nodes.cpp
index 8e7969cfbaf..0f054b42088 100644
--- a/intern/cycles/render/nodes.cpp
+++ b/intern/cycles/render/nodes.cpp
@@ -5259,6 +5259,75 @@ void OutputNode::compile(OSLCompiler &compiler)
     compiler.add(this, "node_output_displacement");
 }
 
+/* Map Range Node */
+
+NODE_DEFINE(MapRangeNode)
+{
+  NodeType *type = NodeType::add("map_range", create, NodeType::SHADER);
+
+  SOCKET_IN_FLOAT(value, "Value", 1.0f);
+  SOCKET_IN_FLOAT(from_min, "From Min", 0.0f);
+  SOCKET_IN_FLOAT(from_max, "From Max", 1.0f);
+  SOCKET_IN_FLOAT(to_min, "To Min", 0.0f);
+  SOCKET_IN_FLOAT(to_max, "To Max", 1.0f);
+
+  SOCKET_OUT_FLOAT(result, "Result");
+
+  return type;
+}
+
+MapRangeNode::MapRangeNode() : ShaderNode(node_type)
+{
+}
+
+void MapRangeNode::constant_fold(const ConstantFolder &folder)
+{
+  if (folder.all_inputs_constant()) {
+    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;
+    }
+    folder.make_constant(result);
+  }
+}
+
+void MapRangeNode::compile(SVMCompiler &compiler)
+{
+  ShaderInput *value_in = input("Value");
+  ShaderInput *from_min_in = input("From Min");
+  ShaderInput *from_max_in = input("From Max");
+  ShaderInput *to_min_in = input("To Min");
+  ShaderInput *to_max_in = input("To Max");
+  ShaderOutput *result_out = output("Result");
+
+  int value_stack_offset = compiler.stack_assign(value_in);
+  int from_min_stack_offset = compiler.stack_assign_if_linked(from_min_in);
+  int from_max_stack_offset = compiler.stack_assign_if_linked(from_max_in);
+  int to_min_stack_offset = compiler.stack_assign_if_linked(to_min_in);
+  int to_max_stack_offset = compiler.stack_assign_if_linked(to_max_in);
+  int result_stack_offset = compiler.stack_assign(result_out);
+
+  compiler.add_node(
+      NODE_MAP_RANGE,
+      value_stack_offset,
+      compiler.encode_uchar4(
+          from_min_stack_offset, from_max_stack_offset, to_min_stack_offset, to_max_stack_offset),
+      result_stack_offset);
+
+  compiler.add_node(__float_as_int(from_min),
+                    __float_as_int(from_max),
+                    __float_as_int(to_min),
+                    __float_as_int(to_max));
+}
+
+void MapRangeNode::compile(OSLCompiler &compiler)
+{
+  compiler.add(this, "node_map_range");
+}
+
 /* Math */
 
 NODE_DEFINE(MathNode)
diff --git a/intern/cycles/render/nodes.h b/intern/cycles/render/nodes.h
index 6b21be88663..13c096a00c2 100644
--- a/intern/cycles/render/nodes.h
+++ b/intern/cycles/render/nodes.h
@@ -1228,6 +1228,17 @@ class BlackbodyNode : public ShaderNode {
   float temperature;
 };
 
+class MapRangeNode : public ShaderNode {
+ public:
+  SHADER_NODE_CLASS(MapRangeNode)
+  void constant_fold(const ConstantFolder &folder);
+  virtual int get_group()
+  {
+    return NODE_GROUP_LEVEL_3;
+  }
+  float value, from_min, from_max, to_min, to_max;
+};
+
 class MathNode : public ShaderNode {
  public:
   SHADER_NODE_CLASS(MathNode)