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Diffstat (limited to 'source/blender/io/alembic/exporter/abc_custom_props.h')
-rw-r--r-- | source/blender/io/alembic/exporter/abc_custom_props.h | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/source/blender/io/alembic/exporter/abc_custom_props.h b/source/blender/io/alembic/exporter/abc_custom_props.h new file mode 100644 index 00000000000..d3f9b2fc43c --- /dev/null +++ b/source/blender/io/alembic/exporter/abc_custom_props.h @@ -0,0 +1,96 @@ +/* + * 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. + * + * The Original Code is Copyright (C) 2020 Blender Foundation. + * All rights reserved. + */ + +/** \file + * \ingroup Alembic + */ + +#pragma once + +#include <Alembic/Abc/OArrayProperty.h> +#include <Alembic/Abc/OCompoundProperty.h> + +#include "BLI_map.hh" + +#include <memory> + +struct IDProperty; + +namespace blender::io::alembic { + +class ABCAbstractWriter; + +/* Write values of Custom Properties (a.k.a. ID Properties) to Alembic. + * + * Each Alembic Writer instance optionally has one CustomPropertiesExporter (CPE). This CPE not + * only writes the custom properties to Alembic, but also keeps references in memory so that the + * Alembic library doesn't prematurely finalize the data. */ +class CustomPropertiesExporter { + private: + /* Owner is used to get the OCompoundProperty and time sample index. The former should only be + * requested from the Alembic library when it's actually going to be used to add custom + * properties (otherwise an invalid Alembic file is written). */ + ABCAbstractWriter *owner_; + + /* The Compound Property that will contain the exported custom properties. + * + * Typically this the return value of abc_schema.getArbGeomParams() or + * abc_schema.getUserProperties(). */ + Alembic::Abc::OCompoundProperty abc_compound_prop_; + + /* Mapping from property name in Blender to property in Alembic. + * Here Blender does the same as other software (Maya, Houdini), and writes + * scalar properties as single-element arrays. */ + Map<std::string, Alembic::Abc::OArrayProperty> abc_properties_; + + public: + CustomPropertiesExporter(ABCAbstractWriter *owner); + virtual ~CustomPropertiesExporter(); + + void write_all(const IDProperty *group); + + private: + void write(const IDProperty *id_property); + void write_array(const IDProperty *id_property); + + /* IDProperty arrays are used to store arrays-of-arrays or arrays-of-strings. */ + void write_idparray(const IDProperty *idp_array); + void write_idparray_of_strings(const IDProperty *idp_array); + void write_idparray_of_numbers(const IDProperty *idp_array); + + /* Flatten an array-of-arrays into one long array, then write that. + * It is tempting to write an array of NxM numbers as a matrix, but there is + * no guarantee that the data actually represents a matrix. */ + template<typename ABCPropertyType, typename BlenderValueType> + void write_idparray_flattened_typed(const IDProperty *idp_array); + + /* Write a single scalar (i.e. non-array) property as single-value array. */ + template<typename ABCPropertyType, typename BlenderValueType> + void set_scalar_property(StringRef property_name, const BlenderValueType property_value); + + template<typename ABCPropertyType, typename BlenderValueType> + void set_array_property(StringRef property_name, + const BlenderValueType *array_values, + size_t num_array_items); + + template<typename ABCPropertyType> + Alembic::Abc::OArrayProperty create_abc_property(StringRef property_name); +}; + +} // namespace blender::io::alembic |