Shader Nodes: Add Interpolation modes to Map Range node

Modes: Linear interpolation (default), stepped linear, smoothstep and smootherstep.

This also includes an additional option for the **Clamp node** to switch between **Min Max** (default) and **Range** mode.

This was needed to allow clamping when **To Max** is less than **To Min**.

Reviewed By: JacquesLucke, brecht

Differential Revision: https://developer.blender.org/D5827

1 files changed, 8 insertions, 3 deletions

diff --git a/intern/cycles/kernel/svm/svm_clamp.h b/intern/cycles/kernel/svm/svm_clamp.h
index a45e70a3f15..a85fd82754e 100644
--- a/intern/cycles/kernel/svm/svm_clamp.h
+++ b/intern/cycles/kernel/svm/svm_clamp.h
@@ -26,8 +26,8 @@ ccl_device void svm_node_clamp(KernelGlobals *kg,
                                uint result_stack_offset,
                                int *offset)
 {
-  uint min_stack_offset, max_stack_offset;
-  svm_unpack_node_uchar2(parameters_stack_offsets, &min_stack_offset, &max_stack_offset);
+  uint min_stack_offset, max_stack_offset, type;
+  svm_unpack_node_uchar3(parameters_stack_offsets, &min_stack_offset, &max_stack_offset, &type);
 
   uint4 defaults = read_node(kg, offset);
 
@@ -35,7 +35,12 @@ ccl_device void svm_node_clamp(KernelGlobals *kg,
   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));
+  if (type == NODE_CLAMP_RANGE && (min > max)) {
+    stack_store_float(stack, result_stack_offset, clamp(value, max, min));
+  }
+  else {
+    stack_store_float(stack, result_stack_offset, clamp(value, min, max));
+  }
 }
 
 CCL_NAMESPACE_END