tornavis/source/blender/blenlib/BLI_implicit_sharing.h

/* SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

#pragma once

/** \file
 * \ingroup bli
 *
 * This file only exists to forward declare `blender::ImplicitSharingInfo` in C code.
 */

#ifdef __cplusplus

namespace blender {
class ImplicitSharingInfo;
}
using ImplicitSharingInfoHandle = blender::ImplicitSharingInfo;

#else

typedef struct ImplicitSharingInfoHandle ImplicitSharingInfoHandle;

#endif
License Headers: Set copyright to "Blender Authors", add AUTHORS Listing the "Blender Foundation" as copyright holder implied the Blender Foundation holds copyright to files which may include work from many developers. While keeping copyright on headers makes sense for isolated libraries, Blender's own code may be refactored or moved between files in a way that makes the per file copyright holders less meaningful. Copyright references to the "Blender Foundation" have been replaced with "Blender Authors", with the exception of `./extern/` since these this contains libraries which are more isolated, any changed to license headers there can be handled on a case-by-case basis. Some directories in `./intern/` have also been excluded: - `./intern/cycles/` it's own `AUTHORS` file is planned. - `./intern/opensubdiv/`. An "AUTHORS" file has been added, using the chromium projects authors file as a template. Design task: #110784 Ref !110783. 2023-08-15 16:20:26 +02:00			`/* SPDX-FileCopyrightText: 2023 Blender Authors`
Cleanup: Add a copyright notice to files and use SPDX format A lot of files were missing copyright field in the header and the Blender Foundation contributed to them in a sense of bug fixing and general maintenance. This change makes it explicit that those files are at least partially copyrighted by the Blender Foundation. Note that this does not make it so the Blender Foundation is the only holder of the copyright in those files, and developers who do not have a signed contract with the foundation still hold the copyright as well. Another aspect of this change is using SPDX format for the header. We already used it for the license specification, and now we state it for the copyright as well, following the FAQ: https://reuse.software/faq/ 2023-05-31 16:19:06 +02:00			`*`
			`* SPDX-License-Identifier: GPL-2.0-or-later */`
Custom Data: support implicit sharing for custom data layers This integrates the new implicit-sharing system (from fbcddfcd68adc72f) with `CustomData`. Now the potentially long arrays referenced by custom data layers can be shared between different systems but most importantly between different geometries. This makes e.g. copying a mesh much cheaper because none of the attributes has to be copied. Only when an attribute is modified does it have to be copied. Also see the original design task: #95845. This reduces memory and improves performance by avoiding unnecessary data copies. For example, the used memory after loading a highly subdivided mesh is reduced from 2.4GB to 1.79GB. This is about 25% less which is the expected amount because in `main` there are 4 copies of the data: 1. The original data which is allocated when the file is loaded. 2. The copy for the depsgraph allocated during depsgraph evaluation. 3. The copy for the undo system allocated when the first undo step is created right after loading the file. 4. GPU buffers allocated for drawing. This patch only gets rid of copy number 2 for the depsgraph. In theory the other copies can be removed as part of follow up PRs as well though. ----- The patch has three main components: * Slightly modified `CustomData` API to make it work better with implicit sharing: * `CD_REFERENCE` and `CD_DUPLICATE` have been removed because they are meaningless when implicit-sharing is used. * `CD_ASSIGN` has been removed as well because it's not an allocation type anyway. The functionality of using existing arrays as custom data layers has not been removed though. * This can still be done with `CustomData_add_layer_with_data` which also has a new argument that allows passing in information about whether the array is shared. * `CD_FLAG_NOFREE` has been removed because it's no longer necessary. It only existed because of `CD_REFERENCE`. * `CustomData_copy` and `CustomData_merge` have been split up into a functions that do copy the actual attribute values and those that do not. The latter functions now have the `_layout` suffix (e.g. `CustomData_copy_layout`). * Changes in `customdata.cc` to make it actually use implicit-sharing. * Changes in various other files to adapt to the changes in `BKE_customdata.h`. Pull Request: https://projects.blender.org/blender/blender/pulls/106228 2023-04-13 14:57:57 +02:00
			`#pragma once`

			`/** \file`
			`* \ingroup bli`
			`*`
			* This file only exists to forward declare `blender::ImplicitSharingInfo` in C code.
			`*/`

			`#ifdef __cplusplus`

			`namespace blender {`
			`class ImplicitSharingInfo;`
			`}`
			`using ImplicitSharingInfoHandle = blender::ImplicitSharingInfo;`

			`#else`

			`typedef struct ImplicitSharingInfoHandle ImplicitSharingInfoHandle;`

			`#endif`