Node: Mix node

This patch is a response to T92588 and is implemented
as a Function/Shader node.

This node has support for Float, Vector and Color data types.

For Vector it supports uniform and non-uniform mixing.

For Color it now has the option to remove factor clamping.

It replaces the Mix RGB for Shader and Geometry node trees.

As discussed in T96219, this patch converts existing nodes
in .blend files. The old node is still available in the
Python API but hidden from the menus.

Reviewed By: HooglyBoogly, JacquesLucke, simonthommes, brecht

Maniphest Tasks: T92588

Differential Revision: https://developer.blender.org/D13749

5 files changed, 110 insertions, 6 deletions

diff --git a/intern/cycles/kernel/svm/color_util.h b/intern/cycles/kernel/svm/color_util.h
index 41f44378ff0..96adb6fd64c 100644
--- a/intern/cycles/kernel/svm/color_util.h
+++ b/intern/cycles/kernel/svm/color_util.h
@@ -247,10 +247,8 @@ ccl_device float3 svm_mix_clamp(float3 col)
   return saturate(col);
 }
 
-ccl_device_noinline_cpu float3 svm_mix(NodeMix type, float fac, float3 c1, float3 c2)
+ccl_device_noinline_cpu float3 svm_mix(NodeMix type, float t, float3 c1, float3 c2)
 {
-  float t = saturatef(fac);
-
   switch (type) {
     case NODE_MIX_BLEND:
       return svm_mix_blend(t, c1, c2);
@@ -282,7 +280,7 @@ ccl_device_noinline_cpu float3 svm_mix(NodeMix type, float fac, float3 c1, float
       return svm_mix_sat(t, c1, c2);
     case NODE_MIX_VAL:
       return svm_mix_val(t, c1, c2);
-    case NODE_MIX_COLOR:
+    case NODE_MIX_COL:
       return svm_mix_color(t, c1, c2);
     case NODE_MIX_SOFT:
       return svm_mix_soft(t, c1, c2);
@@ -295,6 +293,12 @@ ccl_device_noinline_cpu float3 svm_mix(NodeMix type, float fac, float3 c1, float
   return make_float3(0.0f, 0.0f, 0.0f);
 }
 
+ccl_device_noinline_cpu float3 svm_mix_clamped_factor(NodeMix type, float t, float3 c1, float3 c2)
+{
+  float fac = saturatef(t);
+  return svm_mix(type, fac, c1, c2);
+}
+
 ccl_device_inline float3 svm_brightness_contrast(float3 color, float brightness, float contrast)
 {
   float a = 1.0f + contrast;
diff --git a/intern/cycles/kernel/svm/mix.h b/intern/cycles/kernel/svm/mix.h
index a9796096410..ead2fc44685 100644
--- a/intern/cycles/kernel/svm/mix.h
+++ b/intern/cycles/kernel/svm/mix.h
@@ -21,10 +21,94 @@ ccl_device_noinline int svm_node_mix(KernelGlobals kg,
   float fac = stack_load_float(stack, fac_offset);
   float3 c1 = stack_load_float3(stack, c1_offset);
   float3 c2 = stack_load_float3(stack, c2_offset);
-  float3 result = svm_mix((NodeMix)node1.y, fac, c1, c2);
+  float3 result = svm_mix_clamped_factor((NodeMix)node1.y, fac, c1, c2);
 
   stack_store_float3(stack, node1.z, result);
   return offset;
 }
 
+ccl_device_noinline void svm_node_mix_color(ccl_private ShaderData *sd,
+                                            ccl_private float *stack,
+                                            uint options,
+                                            uint input_offset,
+                                            uint result_offset)
+{
+  uint use_clamp, blend_type, use_clamp_result;
+  uint fac_in_stack_offset, a_in_stack_offset, b_in_stack_offset;
+  svm_unpack_node_uchar3(options, &use_clamp, &blend_type, &use_clamp_result);
+  svm_unpack_node_uchar3(
+      input_offset, &fac_in_stack_offset, &a_in_stack_offset, &b_in_stack_offset);
+
+  float t = stack_load_float(stack, fac_in_stack_offset);
+  if (use_clamp > 0) {
+    t = saturatef(t);
+  }
+  float3 a = stack_load_float3(stack, a_in_stack_offset);
+  float3 b = stack_load_float3(stack, b_in_stack_offset);
+  float3 result = svm_mix((NodeMix)blend_type, t, a, b);
+  if (use_clamp_result) {
+    result = saturate(result);
+  }
+  stack_store_float3(stack, result_offset, result);
+}
+
+ccl_device_noinline void svm_node_mix_float(ccl_private ShaderData *sd,
+                                            ccl_private float *stack,
+                                            uint use_clamp,
+                                            uint input_offset,
+                                            uint result_offset)
+{
+  uint fac_in_stack_offset, a_in_stack_offset, b_in_stack_offset;
+  svm_unpack_node_uchar3(
+      input_offset, &fac_in_stack_offset, &a_in_stack_offset, &b_in_stack_offset);
+
+  float t = stack_load_float(stack, fac_in_stack_offset);
+  if (use_clamp > 0) {
+    t = saturatef(t);
+  }
+  float a = stack_load_float(stack, a_in_stack_offset);
+  float b = stack_load_float(stack, b_in_stack_offset);
+  float result = a * (1 - t) + b * t;
+
+  stack_store_float(stack, result_offset, result);
+}
+
+ccl_device_noinline void svm_node_mix_vector(ccl_private ShaderData *sd,
+                                             ccl_private float *stack,
+                                             uint input_offset,
+                                             uint result_offset)
+{
+  uint use_clamp, fac_in_stack_offset, a_in_stack_offset, b_in_stack_offset;
+  svm_unpack_node_uchar4(
+      input_offset, &use_clamp, &fac_in_stack_offset, &a_in_stack_offset, &b_in_stack_offset);
+
+  float t = stack_load_float(stack, fac_in_stack_offset);
+  if (use_clamp > 0) {
+    t = saturatef(t);
+  }
+  float3 a = stack_load_float3(stack, a_in_stack_offset);
+  float3 b = stack_load_float3(stack, b_in_stack_offset);
+  float3 result = a * (one_float3() - t) + b * t;
+  stack_store_float3(stack, result_offset, result);
+}
+
+ccl_device_noinline void svm_node_mix_vector_non_uniform(ccl_private ShaderData *sd,
+                                                         ccl_private float *stack,
+                                                         uint input_offset,
+                                                         uint result_offset)
+{
+  uint use_clamp, fac_in_stack_offset, a_in_stack_offset, b_in_stack_offset;
+  svm_unpack_node_uchar4(
+      input_offset, &use_clamp, &fac_in_stack_offset, &a_in_stack_offset, &b_in_stack_offset);
+
+  float3 t = stack_load_float3(stack, fac_in_stack_offset);
+  if (use_clamp > 0) {
+    t = saturate(t);
+  }
+  float3 a = stack_load_float3(stack, a_in_stack_offset);
+  float3 b = stack_load_float3(stack, b_in_stack_offset);
+  float3 result = a * (one_float3() - t) + b * t;
+  stack_store_float3(stack, result_offset, result);
+}
+
 CCL_NAMESPACE_END
diff --git a/intern/cycles/kernel/svm/node_types_template.h b/intern/cycles/kernel/svm/node_types_template.h
index 39d279be4cb..aab9b9f1158 100644
--- a/intern/cycles/kernel/svm/node_types_template.h
+++ b/intern/cycles/kernel/svm/node_types_template.h
@@ -103,6 +103,10 @@ SHADER_NODE_TYPE(NODE_AOV_START)
 SHADER_NODE_TYPE(NODE_AOV_COLOR)
 SHADER_NODE_TYPE(NODE_AOV_VALUE)
 SHADER_NODE_TYPE(NODE_FLOAT_CURVE)
+SHADER_NODE_TYPE(NODE_MIX_COLOR)
+SHADER_NODE_TYPE(NODE_MIX_FLOAT)
+SHADER_NODE_TYPE(NODE_MIX_VECTOR)
+SHADER_NODE_TYPE(NODE_MIX_VECTOR_NON_UNIFORM)
 
 /* Padding for struct alignment. */
 SHADER_NODE_TYPE(NODE_PAD1)
diff --git a/intern/cycles/kernel/svm/svm.h b/intern/cycles/kernel/svm/svm.h
index 9d6d3e9222c..3ca632c5f0b 100644
--- a/intern/cycles/kernel/svm/svm.h
+++ b/intern/cycles/kernel/svm/svm.h
@@ -585,6 +585,18 @@ ccl_device void svm_eval_nodes(KernelGlobals kg,
       SVM_CASE(NODE_AOV_VALUE)
       svm_node_aov_value<node_feature_mask>(kg, state, sd, stack, node, render_buffer);
       break;
+      SVM_CASE(NODE_MIX_COLOR)
+      svm_node_mix_color(sd, stack, node.y, node.z, node.w);
+      break;
+      SVM_CASE(NODE_MIX_FLOAT)
+      svm_node_mix_float(sd, stack, node.y, node.z, node.w);
+      break;
+      SVM_CASE(NODE_MIX_VECTOR)
+      svm_node_mix_vector(sd, stack, node.y, node.z);
+      break;
+      SVM_CASE(NODE_MIX_VECTOR_NON_UNIFORM)
+      svm_node_mix_vector_non_uniform(sd, stack, node.y, node.z);
+      break;
       default:
         kernel_assert(!"Unknown node type was passed to the SVM machine");
         return;
diff --git a/intern/cycles/kernel/svm/types.h b/intern/cycles/kernel/svm/types.h
index 98dfe6a4375..9dd8f196e0f 100644
--- a/intern/cycles/kernel/svm/types.h
+++ b/intern/cycles/kernel/svm/types.h
@@ -133,7 +133,7 @@ typedef enum NodeMix {
   NODE_MIX_HUE,
   NODE_MIX_SAT,
   NODE_MIX_VAL,
-  NODE_MIX_COLOR,
+  NODE_MIX_COL,
   NODE_MIX_SOFT,
   NODE_MIX_LINEAR,
   NODE_MIX_CLAMP /* used for the clamp UI option */