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

3 files changed, 46 insertions, 0 deletions

diff --git a/intern/cycles/kernel/svm/svm.h b/intern/cycles/kernel/svm/svm.h
index e0c2c8b56dc..0d731d62e94 100644
--- a/intern/cycles/kernel/svm/svm.h
+++ b/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:
diff --git a/intern/cycles/kernel/svm/svm_clamp.h b/intern/cycles/kernel/svm/svm_clamp.h
new file mode 100644
index 00000000000..5ff4a599028
--- /dev/null
+++ b/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
diff --git a/intern/cycles/kernel/svm/svm_types.h b/intern/cycles/kernel/svm/svm_types.h
index 82e7e94d438..9a8a5401297 100644
--- a/intern/cycles/kernel/svm/svm_types.h
+++ b/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 {