Differential D8869 Diff 28773 source/blender/io/alembic/exporter/abc_custom_props.h

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source/blender/io/alembic/exporter/abc_custom_props.h

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				/*
				* 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