Fix T83494: Eevee clamp node incorrect when min > max.

In glsl the clamp function has undefined behavior when min > max. For
the clamp node this resulted in differences between cycles and eevee.
This patch adds the expected implementation for minmax.

The old clamp function is still used in cases where we know for certain
that the input values are correct (math node clamp option). GPU uses
optimized code and silicon in these cases.

1 files changed, 3 insertions, 2 deletions

diff --git a/source/blender/nodes/shader/nodes/node_shader_clamp.cc b/source/blender/nodes/shader/nodes/node_shader_clamp.cc
index d3a893e1d76..4f77421cfe0 100644
--- a/source/blender/nodes/shader/nodes/node_shader_clamp.cc
+++ b/source/blender/nodes/shader/nodes/node_shader_clamp.cc
@@ -46,8 +46,9 @@ static int gpu_shader_clamp(GPUMaterial *mat,
                             GPUNodeStack *in,
                             GPUNodeStack *out)
 {
-  return (node->custom1 == NODE_CLAMP_MINMAX) ? GPU_stack_link(mat, node, "clamp_value", in, out) :
-                                                GPU_stack_link(mat, node, "clamp_range", in, out);
+  return (node->custom1 == NODE_CLAMP_MINMAX) ?
+             GPU_stack_link(mat, node, "clamp_minmax", in, out) :
+             GPU_stack_link(mat, node, "clamp_range", in, out);
 }
 
 static void sh_node_clamp_expand_in_mf_network(blender::nodes::NodeMFNetworkBuilder &builder)