Shading: Add Clamp node to Cycles and EEVEE.

This patch adds a new node that clamps a value between a maximum and
a minimum values.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D5476

intern/cycles/blender/blender_shader.cpp

@@ -318,6 +318,9 @@ static ShaderNode *add_node(Scene *scene,
   else if (b_node.is_a(&RNA_ShaderNodeMapRange)) {
     node = new MapRangeNode();
   }
+  else if (b_node.is_a(&RNA_ShaderNodeClamp)) {
+    node = new ClampNode();
+  }
   else if (b_node.is_a(&RNA_ShaderNodeMath)) {
     BL::ShaderNodeMath b_math_node(b_node);
     MathNode *math = new MathNode();

intern/cycles/kernel/CMakeLists.txt

@@ -179,6 +179,7 @@ set(SRC_SVM_HEADERS
   svm/svm_blackbody.h
   svm/svm_bump.h
   svm/svm_camera.h
+  svm/svm_clamp.h
   svm/svm_closure.h
   svm/svm_convert.h
   svm/svm_checker.h

intern/cycles/kernel/shaders/CMakeLists.txt

@@ -13,6 +13,7 @@ set(SRC_OSL
   node_bump.osl
   node_camera.osl
   node_checker_texture.osl
+  node_clamp.osl
   node_combine_rgb.osl
   node_combine_hsv.osl
   node_combine_xyz.osl

intern/cycles/kernel/shaders/node_clamp.osl

@@ -0,0 +1,23 @@
+/*
+ * 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_clamp(float Value = 1.0, float Min = 0.0, float Max = 1.0,
+                  output float Result = 0.0)
+{
+    Result = clamp(Value, Min, Max);
+}

intern/cycles/kernel/svm/svm.h

@@ -193,6 +193,7 @@ CCL_NAMESPACE_END
 #include "kernel/svm/svm_voxel.h"
 #include "kernel/svm/svm_bump.h"
 #include "kernel/svm/svm_map_range.h"
+#include "kernel/svm/svm_clamp.h"
 
 #ifdef __SHADER_RAYTRACE__
 #  include "kernel/svm/svm_ao.h"
@@ -490,6 +491,9 @@ ccl_device_noinline void svm_eval_nodes(KernelGlobals *kg,
       case NODE_MAP_RANGE:
         svm_node_map_range(kg, sd, stack, node.y, node.z, node.w, &offset);
         break;
+      case NODE_CLAMP:
+        svm_node_clamp(kg, sd, stack, node.y, node.z, node.w, &offset);
+        break;
 #  endif /* __EXTRA_NODES__ */
 #  if NODES_FEATURE(NODE_FEATURE_VOLUME)
       case NODE_TEX_VOXEL:

intern/cycles/kernel/svm/svm_clamp.h

@@ -0,0 +1,41 @@
+/*
+ * 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
+
+/* Clamp Node */
+
+ccl_device void svm_node_clamp(KernelGlobals *kg,
+                               ShaderData *sd,
+                               float *stack,
+                               uint value_stack_offset,
+                               uint parameters_stack_offsets,
+                               uint result_stack_offset,
+                               int *offset)
+{
+  uint min_stack_offset, max_stack_offset;
+  decode_node_uchar4(parameters_stack_offsets, &min_stack_offset, &max_stack_offset, NULL, NULL);
+
+  uint4 defaults = read_node(kg, offset);
+
+  float value = stack_load_float(stack, value_stack_offset);
+  float min = stack_load_float_default(stack, min_stack_offset, defaults.x);
+  float max = stack_load_float_default(stack, max_stack_offset, defaults.y);
+
+  stack_store_float(stack, result_stack_offset, clamp(value, min, max));
+}
+
+CCL_NAMESPACE_END

intern/cycles/kernel/svm/svm_types.h

@@ -139,6 +139,7 @@ typedef enum ShaderNodeType {
   NODE_PRINCIPLED_VOLUME,
   NODE_IES,
   NODE_MAP_RANGE,
+  NODE_CLAMP,
 } ShaderNodeType;
 
 typedef enum NodeAttributeType {

intern/cycles/render/nodes.cpp

@@ -5328,6 +5328,56 @@ void MapRangeNode::compile(OSLCompiler &compiler)
   compiler.add(this, "node_map_range");
 }
 
+/* Clamp Node */
+
+NODE_DEFINE(ClampNode)
+{
+  NodeType *type = NodeType::add("clamp", create, NodeType::SHADER);
+
+  SOCKET_IN_FLOAT(value, "Value", 1.0f);
+  SOCKET_IN_FLOAT(min, "Min", 0.0f);
+  SOCKET_IN_FLOAT(max, "Max", 1.0f);
+
+  SOCKET_OUT_FLOAT(result, "Result");
+
+  return type;
+}
+
+ClampNode::ClampNode() : ShaderNode(node_type)
+{
+}
+
+void ClampNode::constant_fold(const ConstantFolder &folder)
+{
+  if (folder.all_inputs_constant()) {
+    folder.make_constant(clamp(value, min, max));
+  }
+}
+
+void ClampNode::compile(SVMCompiler &compiler)
+{
+  ShaderInput *value_in = input("Value");
+  ShaderInput *min_in = input("Min");
+  ShaderInput *max_in = input("Max");
+  ShaderOutput *result_out = output("Result");
+
+  int value_stack_offset = compiler.stack_assign(value_in);
+  int min_stack_offset = compiler.stack_assign(min_in);
+  int max_stack_offset = compiler.stack_assign(max_in);
+  int result_stack_offset = compiler.stack_assign(result_out);
+
+  compiler.add_node(NODE_CLAMP,
+                    value_stack_offset,
+                    compiler.encode_uchar4(min_stack_offset, max_stack_offset),
+                    result_stack_offset);
+  compiler.add_node(__float_as_int(min), __float_as_int(max));
+}
+
+void ClampNode::compile(OSLCompiler &compiler)
+{
+  compiler.add(this, "node_clamp");
+}
+
 /* Math */
 
 NODE_DEFINE(MathNode)

intern/cycles/render/nodes.h

@@ -1239,6 +1239,17 @@ class MapRangeNode : public ShaderNode {
   float value, from_min, from_max, to_min, to_max;
 };
 
+class ClampNode : public ShaderNode {
+ public:
+  SHADER_NODE_CLASS(ClampNode)
+  void constant_fold(const ConstantFolder &folder);
+  virtual int get_group()
+  {
+    return NODE_GROUP_LEVEL_3;
+  }
+  float value, min, max;
+};
+
 class MathNode : public ShaderNode {
  public:
   SHADER_NODE_CLASS(MathNode)

release/scripts/startup/nodeitems_builtins.py

@@ -259,6 +259,7 @@ shader_node_categories = [
     ]),
     ShaderNodeCategory("SH_NEW_CONVERTOR", "Converter", items=[
         NodeItem("ShaderNodeMapRange"),
+        NodeItem("ShaderNodeClamp"),
         NodeItem("ShaderNodeMath"),
         NodeItem("ShaderNodeValToRGB"),
         NodeItem("ShaderNodeRGBToBW"),

source/blender/blenkernel/BKE_node.h

@@ -977,6 +977,7 @@ void BKE_nodetree_remove_layer_n(struct bNodeTree *ntree,
 /* 201..700 occupied by other node types, continue from 701 */
 #define SH_NODE_BSDF_HAIR_PRINCIPLED 701
 #define SH_NODE_MAP_RANGE 702
+#define SH_NODE_CLAMP 703
 
 /* custom defines options for Material node */
 #define SH_NODE_MAT_DIFF 1

source/blender/blenkernel/intern/node.c

@@ -3857,6 +3857,7 @@ static void registerShaderNodes(void)
   register_node_type_sh_curve_vec();
   register_node_type_sh_curve_rgb();
   register_node_type_sh_map_range();
+  register_node_type_sh_clamp();
   register_node_type_sh_math();
   register_node_type_sh_vect_math();
   register_node_type_sh_vect_transform();

source/blender/gpu/shaders/gpu_shader_material.glsl

@@ -971,9 +971,9 @@ void clamp_vec3(vec3 vec, vec3 min, vec3 max, out vec3 out_vec)
   out_vec = clamp(vec, min, max);
 }
 
-void clamp_val(float value, float min, float max, out float out_value)
+void clamp_value(float value, float min, float max, out float result)
 {
-  out_value = clamp(value, min, max);
+  result = clamp(value, min, max);
 }
 
 void hue_sat(float hue, float sat, float value, float fac, vec4 col, out vec4 outcol)

source/blender/nodes/CMakeLists.txt

@@ -147,6 +147,7 @@ set(SRC
   shader/nodes/node_shader_bsdf_velvet.c
   shader/nodes/node_shader_bump.c
   shader/nodes/node_shader_camera.c
+  shader/nodes/node_shader_clamp.c
   shader/nodes/node_shader_common.c
   shader/nodes/node_shader_curves.c
   shader/nodes/node_shader_displacement.c

source/blender/nodes/NOD_shader.h

@@ -49,6 +49,7 @@ void register_node_type_sh_mapping(void);
 void register_node_type_sh_curve_vec(void);
 void register_node_type_sh_curve_rgb(void);
 void register_node_type_sh_map_range(void);
+void register_node_type_sh_clamp(void);
 void register_node_type_sh_math(void);
 void register_node_type_sh_vect_math(void);
 void register_node_type_sh_squeeze(void);

source/blender/nodes/NOD_static_types.h

@@ -51,6 +51,7 @@ DefNode(ShaderNode,     SH_NODE_CURVE_VEC,       def_vector_curve,       "CURVE_
 DefNode(ShaderNode,     SH_NODE_CURVE_RGB,       def_rgb_curve,          "CURVE_RGB",      RGBCurve,         "RGB Curves",        ""              )
 DefNode(ShaderNode,     SH_NODE_CAMERA,          0,                      "CAMERA",         CameraData,       "Camera Data",       ""              )
 DefNode(ShaderNode,     SH_NODE_MAP_RANGE,       0,                      "MAP_RANGE",      MapRange,         "Map Range",         ""              )
+DefNode(ShaderNode,     SH_NODE_CLAMP,           0,                      "CLAMP",          Clamp,            "Clamp",             ""              )
 DefNode(ShaderNode,     SH_NODE_MATH,            def_math,               "MATH",           Math,             "Math",              ""              )
 DefNode(ShaderNode,     SH_NODE_VECT_MATH,       def_vector_math,        "VECT_MATH",      VectorMath,       "Vector Math",       ""              )
 DefNode(ShaderNode,     SH_NODE_SQUEEZE,         0,                      "SQUEEZE",        Squeeze,          "Squeeze Value",     ""              )

source/blender/nodes/shader/nodes/node_shader_clamp.c

@@ -0,0 +1,56 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2005 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup shdnodes
+ */
+
+#include "node_shader_util.h"
+
+/* **************** Clamp ******************** */
+static bNodeSocketTemplate sh_node_clamp_in[] = {
+    {SOCK_FLOAT, 1, N_("Value"), 1.0f, 1.0f, 1.0f, 1.0f, 0.0f, 1.0f, PROP_NONE},
+    {SOCK_FLOAT, 1, N_("Min"), 0.0f, 1.0f, 1.0f, 1.0f, -10000.0f, 10000.0f, PROP_NONE},
+    {SOCK_FLOAT, 1, N_("Max"), 1.0f, 1.0f, 1.0f, 1.0f, -10000.0f, 10000.0f, PROP_NONE},
+    {-1, 0, ""},
+};
+static bNodeSocketTemplate sh_node_clamp_out[] = {
+    {SOCK_FLOAT, 0, N_("Result")},
+    {-1, 0, ""},
+};
+
+static int gpu_shader_clamp(GPUMaterial *mat,
+                            bNode *node,
+                            bNodeExecData *UNUSED(execdata),
+                            GPUNodeStack *in,
+                            GPUNodeStack *out)
+{
+  return GPU_stack_link(mat, node, "clamp_value", in, out);
+}
+
+void register_node_type_sh_clamp(void)
+{
+  static bNodeType ntype;
+
+  sh_node_type_base(&ntype, SH_NODE_CLAMP, "Clamp", NODE_CLASS_CONVERTOR, 0);
+  node_type_socket_templates(&ntype, sh_node_clamp_in, sh_node_clamp_out);
+  node_type_gpu(&ntype, gpu_shader_clamp);
+
+  nodeRegisterType(&ntype);
+}

source/blender/nodes/shader/nodes/node_shader_math.c

@@ -360,7 +360,7 @@ static int gpu_shader_math(GPUMaterial *mat,
   if (node->custom2 & SHD_MATH_CLAMP) {
     float min[3] = {0.0f, 0.0f, 0.0f};
     float max[3] = {1.0f, 1.0f, 1.0f};
-    GPU_link(mat, "clamp_val", out[0].link, GPU_constant(min), GPU_constant(max), &out[0].link);
+    GPU_link(mat, "clamp_value", out[0].link, GPU_constant(min), GPU_constant(max), &out[0].link);
   }
 
   return 1;