Shading: Add a clamp option to the Map Range node.

If the option is enabled, the output is clamped to the target range.
The target range is [To Min, To Max]. The option is enabled by default.

The clamp option is implemented in EEVEE by linking to the `clamp_value`
GLSL function. And it is implemented in Cycles using a graph expand
function.

Reviewers: brecht, JacquesLucke

Differential Revision: https://developer.blender.org/D5477

1 files changed, 8 insertions, 0 deletions

diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index b63f0daaa0d..704d878e620 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -249,6 +249,11 @@ static void node_buts_texture(uiLayout *layout, bContext *UNUSED(C), PointerRNA
   }
 }
 
+static void node_buts_map_range(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
+{
+  uiItemR(layout, ptr, "clamp", 0, NULL, ICON_NONE);
+}
+
 static void node_buts_math(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
 {
   uiItemR(layout, ptr, "operation", 0, "", ICON_NONE);
@@ -1209,6 +1214,9 @@ static void node_shader_set_butfunc(bNodeType *ntype)
     case SH_NODE_VALTORGB:
       ntype->draw_buttons = node_buts_colorramp;
       break;
+    case SH_NODE_MAP_RANGE:
+      ntype->draw_buttons = node_buts_map_range;
+      break;
     case SH_NODE_MATH:
       ntype->draw_buttons = node_buts_math;
       break;