Attribute Node: refactor lookup to remove duplication between engines.

Currently lookup of Object and Instancer attributes is completely
duplicated between Cycles, Eevee and Eevee Next. This is bad design,
so this patch aims to deduplicate it by introducing a common API
in blenkernel.

In case of Cycles this requires certain hacks, but according to
Brecht it is planned to be rewritten later for more direct access
to internal Blender data anyway.

Differential Revision: https://developer.blender.org/D16117

8 files changed, 143 insertions, 153 deletions

diff --git a/source/blender/blenkernel/BKE_duplilist.h b/source/blender/blenkernel/BKE_duplilist.h
index cc362495a24..79f37d2edde 100644
--- a/source/blender/blenkernel/BKE_duplilist.h
+++ b/source/blender/blenkernel/BKE_duplilist.h
@@ -64,6 +64,14 @@ typedef struct DupliObject {
   unsigned int random_id;
 } DupliObject;
 
+/** Look up the RGBA value of a uniform shader attribute.
+ *  \return true if the attribute was found; if not, r_value is also set to zero. */
+bool BKE_object_dupli_find_rgba_attribute(struct Object *ob,
+                                          struct DupliObject *dupli,
+                                          struct Object *dupli_parent,
+                                          const char *name,
+                                          float r_value[4]);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/blenkernel/intern/object_dupli.cc b/source/blender/blenkernel/intern/object_dupli.cc
index 15a4a0bbb32..b4ccef56ee3 100644
--- a/source/blender/blenkernel/intern/object_dupli.cc
+++ b/source/blender/blenkernel/intern/object_dupli.cc
@@ -58,6 +58,9 @@
 #include "BLI_hash.h"
 
 #include "NOD_geometry_nodes_log.hh"
+#include "RNA_access.h"
+#include "RNA_path.h"
+#include "RNA_types.h"
 
 using blender::Array;
 using blender::float3;
@@ -1711,3 +1714,120 @@ void free_object_duplilist(ListBase *lb)
 }
 
 /** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Uniform attribute lookup
+ * \{ */
+
+/** Lookup an arbitrary RNA property and convert it to RGBA if possible. */
+static bool find_rna_property_rgba(PointerRNA *id_ptr, const char *name, float r_data[4])
+{
+  if (id_ptr->data == nullptr) {
+    return false;
+  }
+
+  /* First, check custom properties. */
+  IDProperty *group = RNA_struct_idprops(id_ptr, false);
+  PropertyRNA *prop = nullptr;
+
+  if (group && group->type == IDP_GROUP) {
+    prop = (PropertyRNA *)IDP_GetPropertyFromGroup(group, name);
+  }
+
+  /* If not found, do full path lookup. */
+  PointerRNA ptr;
+
+  if (prop != nullptr) {
+    ptr = *id_ptr;
+  }
+  else if (!RNA_path_resolve(id_ptr, name, &ptr, &prop)) {
+    return false;
+  }
+
+  if (prop == nullptr) {
+    return false;
+  }
+
+  /* Convert the value to RGBA if possible. */
+  PropertyType type = RNA_property_type(prop);
+  int array_len = RNA_property_array_length(&ptr, prop);
+
+  if (array_len == 0) {
+    float value;
+
+    if (type == PROP_FLOAT) {
+      value = RNA_property_float_get(&ptr, prop);
+    }
+    else if (type == PROP_INT) {
+      value = static_cast<float>(RNA_property_int_get(&ptr, prop));
+    }
+    else if (type == PROP_BOOLEAN) {
+      value = RNA_property_boolean_get(&ptr, prop) ? 1.0f : 0.0f;
+    }
+    else {
+      return false;
+    }
+
+    copy_v4_fl4(r_data, value, value, value, 1);
+    return true;
+  }
+
+  if (type == PROP_FLOAT && array_len <= 4) {
+    copy_v4_fl4(r_data, 0, 0, 0, 1);
+    RNA_property_float_get_array(&ptr, prop, r_data);
+    return true;
+  }
+
+  if (type == PROP_INT && array_len <= 4) {
+    int tmp[4] = {0, 0, 0, 1};
+    RNA_property_int_get_array(&ptr, prop, tmp);
+    for (int i = 0; i < 4; i++) {
+      r_data[i] = static_cast<float>(tmp[i]);
+    }
+    return true;
+  }
+
+  return false;
+}
+
+static bool find_rna_property_rgba(ID *id, const char *name, float r_data[4])
+{
+  PointerRNA ptr;
+  RNA_id_pointer_create(id, &ptr);
+  return find_rna_property_rgba(&ptr, name, r_data);
+}
+
+bool BKE_object_dupli_find_rgba_attribute(
+    Object *ob, DupliObject *dupli, Object *dupli_parent, const char *name, float r_value[4])
+{
+  /* Check the dupli particle system. */
+  if (dupli && dupli->particle_system) {
+    ParticleSettings *settings = dupli->particle_system->part;
+
+    if (find_rna_property_rgba(&settings->id, name, r_value)) {
+      return true;
+    }
+  }
+
+  /* Check the dupli parent object. */
+  if (dupli_parent && find_rna_property_rgba(&dupli_parent->id, name, r_value)) {
+    return true;
+  }
+
+  /* Check the main object. */
+  if (ob) {
+    if (find_rna_property_rgba(&ob->id, name, r_value)) {
+      return true;
+    }
+
+    /* Check the main object data (e.g. mesh). */
+    if (ob->data && find_rna_property_rgba((ID *)ob->data, name, r_value)) {
+      return true;
+    }
+  }
+
+  copy_v4_fl(r_value, 0.0f);
+  return false;
+}
+
+/** \} */
diff --git a/source/blender/draw/intern/draw_instance_data.c b/source/blender/draw/intern/draw_instance_data.c
index 7ed5ca7c983..a56883ce304 100644
--- a/source/blender/draw/intern/draw_instance_data.c
+++ b/source/blender/draw/intern/draw_instance_data.c
@@ -585,87 +585,18 @@ static DRWUniformAttrBuf *drw_uniform_attrs_pool_ensure(GHash *table,
   return (DRWUniformAttrBuf *)*pval;
 }
 
-/* This function mirrors lookup_property in cycles/blender/blender_object.cpp */
-static bool drw_uniform_property_lookup(ID *id, const char *name, float r_data[4])
-{
-  PointerRNA ptr, id_ptr;
-  PropertyRNA *prop;
-
-  if (!id) {
-    return false;
-  }
-
-  RNA_id_pointer_create(id, &id_ptr);
-
-  if (!RNA_path_resolve(&id_ptr, name, &ptr, &prop)) {
-    return false;
-  }
-
-  if (prop == NULL) {
-    return false;
-  }
-
-  PropertyType type = RNA_property_type(prop);
-  int arraylen = RNA_property_array_length(&ptr, prop);
-
-  if (arraylen == 0) {
-    float value;
-
-    if (type == PROP_FLOAT) {
-      value = RNA_property_float_get(&ptr, prop);
-    }
-    else if (type == PROP_INT) {
-      value = RNA_property_int_get(&ptr, prop);
-    }
-    else {
-      return false;
-    }
-
-    copy_v4_fl4(r_data, value, value, value, 1);
-    return true;
-  }
-
-  if (type == PROP_FLOAT && arraylen <= 4) {
-    copy_v4_fl4(r_data, 0, 0, 0, 1);
-    RNA_property_float_get_array(&ptr, prop, r_data);
-    return true;
-  }
-
-  return false;
-}
-
-/* This function mirrors lookup_instance_property in cycles/blender/blender_object.cpp */
 static void drw_uniform_attribute_lookup(GPUUniformAttr *attr,
                                          Object *ob,
                                          Object *dupli_parent,
                                          DupliObject *dupli_source,
                                          float r_data[4])
 {
-  copy_v4_fl(r_data, 0);
-
   /* If requesting instance data, check the parent particle system and object. */
   if (attr->use_dupli) {
-    if (dupli_source && dupli_source->particle_system) {
-      ParticleSettings *settings = dupli_source->particle_system->part;
-      if (drw_uniform_property_lookup((ID *)settings, attr->name_id_prop, r_data) ||
-          drw_uniform_property_lookup((ID *)settings, attr->name, r_data)) {
-        return;
-      }
-    }
-    if (drw_uniform_property_lookup((ID *)dupli_parent, attr->name_id_prop, r_data) ||
-        drw_uniform_property_lookup((ID *)dupli_parent, attr->name, r_data)) {
-      return;
-    }
+    BKE_object_dupli_find_rgba_attribute(ob, dupli_source, dupli_parent, attr->name, r_data);
   }
-
-  /* Check the object and mesh. */
-  if (ob) {
-    if (drw_uniform_property_lookup((ID *)ob, attr->name_id_prop, r_data) ||
-        drw_uniform_property_lookup((ID *)ob, attr->name, r_data) ||
-        drw_uniform_property_lookup((ID *)ob->data, attr->name_id_prop, r_data) ||
-        drw_uniform_property_lookup((ID *)ob->data, attr->name, r_data)) {
-      return;
-    }
+  else {
+    BKE_object_dupli_find_rgba_attribute(ob, NULL, NULL, attr->name, r_data);
   }
 }
 
diff --git a/source/blender/draw/intern/draw_resource.cc b/source/blender/draw/intern/draw_resource.cc
index 689df4edb31..f57058190fb 100644
--- a/source/blender/draw/intern/draw_resource.cc
+++ b/source/blender/draw/intern/draw_resource.cc
@@ -19,58 +19,6 @@
  * \{ */
 
 /**
- * Extract object attribute from RNA property.
- * Returns true if the attribute was correctly extracted.
- * This function mirrors lookup_property in cycles/blender/blender_object.cpp
- */
-bool ObjectAttribute::id_property_lookup(ID *id, const char *name)
-{
-  PointerRNA ptr, id_ptr;
-  PropertyRNA *prop;
-
-  if (id == nullptr) {
-    return false;
-  }
-
-  RNA_id_pointer_create(id, &id_ptr);
-
-  if (!RNA_path_resolve(&id_ptr, name, &ptr, &prop)) {
-    return false;
-  }
-
-  if (prop == nullptr) {
-    return false;
-  }
-
-  PropertyType type = RNA_property_type(prop);
-  int array_len = RNA_property_array_length(&ptr, prop);
-
-  if (array_len == 0) {
-    float value;
-
-    if (type == PROP_FLOAT) {
-      value = RNA_property_float_get(&ptr, prop);
-    }
-    else if (type == PROP_INT) {
-      value = RNA_property_int_get(&ptr, prop);
-    }
-    else {
-      return false;
-    }
-
-    *reinterpret_cast<float4 *>(&data_x) = float4(value, value, value, 1.0f);
-    return true;
-  }
-
-  if (type == PROP_FLOAT && array_len <= 4) {
-    *reinterpret_cast<float4 *>(&data_x) = float4(0.0f, 0.0f, 0.0f, 1.0f);
-    RNA_property_float_get_array(&ptr, prop, &data_x);
-    return true;
-  }
-  return false;
-}
-
-/**
  * Go through all possible source of the given object uniform attribute.
  * Returns true if the attribute was correctly filled.
  * This function mirrors lookup_instance_property in cycles/blender/blender_object.cpp
@@ -81,29 +29,12 @@ bool ObjectAttribute::sync(const blender::draw::ObjectRef &ref, const GPUUniform
 
   /* If requesting instance data, check the parent particle system and object. */
   if (attr.use_dupli) {
-    if ((ref.dupli_object != nullptr) && (ref.dupli_object->particle_system != nullptr)) {
-      ParticleSettings *settings = ref.dupli_object->particle_system->part;
-      if (this->id_property_lookup((ID *)settings, attr.name_id_prop) ||
-          this->id_property_lookup((ID *)settings, attr.name)) {
-        return true;
-      }
-    }
-    if (this->id_property_lookup((ID *)ref.dupli_parent, attr.name_id_prop) ||
-        this->id_property_lookup((ID *)ref.dupli_parent, attr.name)) {
-      return true;
-    }
+    return BKE_object_dupli_find_rgba_attribute(
+        ref.object, ref.dupli_object, ref.dupli_parent, attr.name, &data_x);
   }
-
-  /* Check the object and mesh. */
-  if (ref.object != nullptr) {
-    if (this->id_property_lookup((ID *)ref.object, attr.name_id_prop) ||
-        this->id_property_lookup((ID *)ref.object, attr.name) ||
-        this->id_property_lookup((ID *)ref.object->data, attr.name_id_prop) ||
-        this->id_property_lookup((ID *)ref.object->data, attr.name)) {
-      return true;
-    }
+  else {
+    return BKE_object_dupli_find_rgba_attribute(ref.object, nullptr, nullptr, attr.name, &data_x);
   }
-  return false;
 }
 
 /** \} */
diff --git a/source/blender/draw/intern/draw_shader_shared.h b/source/blender/draw/intern/draw_shader_shared.h
index bedbedcf438..a572b9ee865 100644
--- a/source/blender/draw/intern/draw_shader_shared.h
+++ b/source/blender/draw/intern/draw_shader_shared.h
@@ -205,7 +205,6 @@ struct ObjectAttribute {
 
 #if !defined(GPU_SHADER) && defined(__cplusplus)
   bool sync(const blender::draw::ObjectRef &ref, const GPUUniformAttr &attr);
-  bool id_property_lookup(ID *id, const char *name);
 #endif
 };
 #pragma pack(pop)
diff --git a/source/blender/gpu/GPU_material.h b/source/blender/gpu/GPU_material.h
index 1c9bdc77bac..31354585308 100644
--- a/source/blender/gpu/GPU_material.h
+++ b/source/blender/gpu/GPU_material.h
@@ -335,8 +335,6 @@ typedef struct GPUUniformAttr {
 
   /* Meaningful part of the attribute set key. */
   char name[64]; /* MAX_CUSTOMDATA_LAYER_NAME */
-  /** Escaped name with [""]. */
-  char name_id_prop[64 * 2 + 4];
   /** Hash of name[64] + use_dupli. */
   uint32_t hash_code;
   bool use_dupli;
diff --git a/source/blender/gpu/intern/gpu_node_graph.c b/source/blender/gpu/intern/gpu_node_graph.c
index 510c16dfb02..e1ae731d49c 100644
--- a/source/blender/gpu/intern/gpu_node_graph.c
+++ b/source/blender/gpu/intern/gpu_node_graph.c
@@ -416,11 +416,6 @@ static GPUUniformAttr *gpu_node_graph_add_uniform_attribute(GPUNodeGraph *graph,
   if (attr == NULL && attrs->count < GPU_MAX_UNIFORM_ATTR) {
     attr = MEM_callocN(sizeof(*attr), __func__);
     STRNCPY(attr->name, name);
-    {
-      char attr_name_esc[sizeof(attr->name) * 2];
-      BLI_str_escape(attr_name_esc, attr->name, sizeof(attr_name_esc));
-      SNPRINTF(attr->name_id_prop, "[\"%s\"]", attr_name_esc);
-    }
     attr->use_dupli = use_dupli;
     attr->hash_code = BLI_ghashutil_strhash_p(attr->name) << 1 | (attr->use_dupli ? 0 : 1);
     attr->id = -1;
diff --git a/source/blender/makesrna/intern/rna_depsgraph.c b/source/blender/makesrna/intern/rna_depsgraph.c
index eb39492c7dc..db5b3c33c59 100644
--- a/source/blender/makesrna/intern/rna_depsgraph.c
+++ b/source/blender/makesrna/intern/rna_depsgraph.c
@@ -61,6 +61,14 @@ void **rna_DepsgraphIterator_instance(PointerRNA *ptr)
 }
 #  endif
 
+/* Temporary hack for Cycles until it is changed to work with the C API directly. */
+DupliObject *rna_hack_DepsgraphObjectInstance_dupli_object_get(PointerRNA *ptr)
+{
+  RNA_DepsgraphIterator *di = ptr->data;
+  DEGObjectIterData *deg_iter = (DEGObjectIterData *)di->iter.data;
+  return deg_iter->dupli_object_current;
+}
+
 static PointerRNA rna_DepsgraphObjectInstance_object_get(PointerRNA *ptr)
 {
   RNA_DepsgraphIterator *di = ptr->data;