AssetsBrowser: Add ID Properties to Asset Indexer

Object/collection asset workflow would need the bounding box for snapping.
The bounding box is stored using ID properties in the scene. Currently ID properties
aren't stored in the asset index, what would break object snapping. For this reason
Asset Indexing is turned off in mater. This patch will introduce the indexing of ID
properties what will allow the indexing to be turned on again.

## Data Mapping ##

For data mapping we store the internal structure of IDProperty to the indexer (including meta-data) to be able to deserialize it back.
```
[
  {
    "name":  ..,
    "value": ..,
    "type": ..,
    /* `subtype` and `length` are only available for IDP_ARRAYs. */
    "subtype": ..,
  },
]
```

| **DNA** | **Serialize type** | **Note** |
| IDProperty.name | StringValue| |
| IDProperty.type | StringValue| "IDP_STRING", "IDP_INT", "IDP_FLOAT", "IDP_ARRAY", "IDP_GROUP", "IDP_DOUBLE"|
| IDProperty.subtype | StringValue| "IDP_INT", "IDP_FLOAT", "IDP_GROUP", "IDP_DOUBLE" |
| IDProperty.value | StringValue | When type is IDP_STRING |
| IDProperty.value | IntValue | When type is IDP_INT |
| IDProperty.value | DoubleValue | When type is IDP_FLOAT/IDP_DOUBLE |
| IDProperty.value | ArrayValue | When type is IDP_GROUP. Recursively uses the same structure as described in this section. |
| IDProperty.value | ArrayValue | When type is IDP_ARRAY. Each element holds a single element as described in this section. |

NOTE: IDP_ID and IDP_IDARRAY aren't supported. The entry will not be added.

Example
```
[
  {
    "name": "MyIntValue,
    "type": "IDP_INT",
    "value": 6,
  },
  {
    "name": "myComplexArray",
    "type": "IDP_ARRAY",
    "subtype": "IDP_GROUP",
    "value": [
        [
          {
            "name": ..
            ....
          }
        ]
    ]
  }
]
```

## Considered alternatives ##

- Add conversion functions inside `asset_indexer`; makes generic code part of a specific solution.
- Add conversion functions inside `BLI_serialize`; would add data transformation responsibilities inside a unit that is currently only responsible for formatting.
- Use direct mapping between IDP properties and Values; leads to missing information and edge cases (empty primitive arrays) that could not be de-serialized.

Reviewed By: Severin, mont29, HooglyBoogly

Maniphest Tasks: T92306

Differential Revision: https://developer.blender.org/D12990

1 files changed, 93 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_idprop.hh b/source/blender/blenkernel/BKE_idprop.hh
new file mode 100644
index 00000000000..782fa9c7404
--- /dev/null
+++ b/source/blender/blenkernel/BKE_idprop.hh
@@ -0,0 +1,93 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#pragma once
+
+#include "BKE_idprop.h"
+
+#include "BLI_serialize.hh"
+#include "BLI_span.hh"
+
+namespace blender::bke::idprop {
+
+/**
+ * \brief Convert the given `properties` to `Value` objects for serialization.
+ *
+ * `IDP_ID` and `IDP_IDPARRAY` are not supported and will be ignored.
+ *
+ * UI data such as max/min will not be serialized.
+ */
+std::unique_ptr<io::serialize::ArrayValue> convert_to_serialize_values(
+    const IDProperty *properties);
+
+/**
+ * \brief Convert the given `value` to an `IDProperty`.
+ */
+IDProperty *convert_from_serialize_value(const blender::io::serialize::Value &value);
+
+class IDPropertyDeleter {
+ public:
+  void operator()(IDProperty *id_prop)
+  {
+    IDP_FreeProperty(id_prop);
+  }
+};
+
+/** \brief Allocate a new IDProperty of type IDP_INT, set its name and value. */
+std::unique_ptr<IDProperty, IDPropertyDeleter> create(StringRefNull prop_name, int32_t value);
+
+/** \brief Allocate a new IDProperty of type IDP_FLOAT, set its name and value. */
+std::unique_ptr<IDProperty, IDPropertyDeleter> create(StringRefNull prop_name, float value);
+
+/** \brief Allocate a new IDProperty of type IDP_DOUBLE, set its name and value. */
+std::unique_ptr<IDProperty, IDPropertyDeleter> create(StringRefNull prop_name, double value);
+
+/** \brief Allocate a new IDProperty of type IDP_STRING, set its name and value. */
+std::unique_ptr<IDProperty, IDPropertyDeleter> create(StringRefNull prop_name,
+                                                      const StringRefNull value);
+
+/**
+ * \brief Allocate a new IDProperty of type IDP_ARRAY and subtype IDP_INT.
+ *
+ * \param values: The values will be copied into the IDProperty.
+ */
+std::unique_ptr<IDProperty, IDPropertyDeleter> create(StringRefNull prop_name,
+                                                      Span<int32_t> values);
+
+/**
+ * \brief Allocate a new IDProperty of type IDP_ARRAY and subtype IDP_FLOAT.
+ *
+ * \param values: The values will be copied into the IDProperty.
+ */
+std::unique_ptr<IDProperty, IDPropertyDeleter> create(StringRefNull prop_name, Span<float> values);
+
+/**
+ * \brief Allocate a new IDProperty of type IDP_ARRAY and subtype IDP_DOUBLE.
+ *
+ * \param values: The values will be copied into the IDProperty.
+ */
+std::unique_ptr<IDProperty, IDPropertyDeleter> create(StringRefNull prop_name,
+                                                      Span<double> values);
+
+/**
+ * \brief Allocate a new IDProperty of type IDP_GROUP.
+ *
+ * \param prop_name: The name of the newly created property.
+ */
+
+std::unique_ptr<IDProperty, IDPropertyDeleter> create_group(StringRefNull prop_name);
+
+}  // namespace blender::bke::idprop