systemSchema.h

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//
// Copyright 2023 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
//    names, trademarks, service marks, or product names of the Licensor
//    and its affiliates, except as required to comply with Section 4(c) of
//    the License and to reproduce the content of the NOTICE file.
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//
//     http://www.apache.org/licenses/LICENSE-2.0
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/* ************************************************************************** */
/* ** This file is generated by a script.  Do not edit directly.  Edit     ** */
/* ** defs.py or the (*)Schema.template.h files to make changes.           ** */
/* ************************************************************************** */

#ifndef PXR_IMAGING_HD_SYSTEM_SCHEMA_H
#define PXR_IMAGING_HD_SYSTEM_SCHEMA_H

#include "pxr/imaging/hd/api.h"

#include "pxr/imaging/hd/schema.h" 

#include "pxr/base/tf/declarePtrs.h"

PXR_NAMESPACE_OPEN_SCOPE

//-----------------------------------------------------------------------------

#define HDSYSTEM_SCHEMA_TOKENS \
    (system) \

TF_DECLARE_PUBLIC_TOKENS(HdSystemSchemaTokens, HD_API,
    HDSYSTEM_SCHEMA_TOKENS);

//-----------------------------------------------------------------------------

TF_DECLARE_REF_PTRS(HdSceneIndexBase);

/// The HdSystemSchema specifies a container that will hold "system"
/// data.  Each piece of system data is identified by a key within the
/// container.  A piece of system data is evaluated at a given location by
/// walking up the namespace looking for a system container that contains the
/// corresponding key.
class HdSystemSchema : public HdSchema
{
public:
    HdSystemSchema(HdContainerDataSourceHandle container)
    : HdSchema(container) {}


    /// Evaluates the \p key at \p fromPath.  If \p key is found, the return
    /// value will be non-null and \p foundAtPath will contain the path at
    /// which the non-null result was found.  Otherwise, this returns null.
    ///
    /// This operation will be linear in the length of \p fromPath.
    HD_API
    static HdDataSourceBaseHandle GetFromPath(
            HdSceneIndexBaseRefPtr const &inputScene,
            SdfPath const &fromPath,
            TfToken const &key,
            SdfPath *foundAtPath);

    /// Composes the system container in at \p fromPath by walking up the
    /// prim.dataSources in \p inputScene and composing any system containers
    /// it encounters.  
    ///
    /// If no system containers were found, this returns null.
    /// Otherwise, this will return a container data source with the composed
    /// system data sources. If non-null, \p foundAtPath will be the last prim
    /// at which system data was found.
    HD_API
    static HdContainerDataSourceHandle Compose(
            HdSceneIndexBaseRefPtr const &inputScene,
            SdfPath const &fromPath,
            SdfPath *foundAtPath);

    /// Similar to `Compose` but this return value would be suitable for using
    /// with HdOverlayContainerDataSource for a prim's dataSource:
    /// ```
    /// prim.dataSource = HdOverlayContainerDataSource::New(
    ///   HdSystemSchema::ComposeAsPrimDataSource(...),
    ///   prim.dataSource);
    /// ```
    HD_API
    static HdContainerDataSourceHandle ComposeAsPrimDataSource(
            HdSceneIndexBaseRefPtr const &inputScene,
            SdfPath const &fromPath,
            SdfPath *foundAtPath);

    /// Retrieves a container data source with the schema's default name token
    /// "system" from the parent container and constructs a
    /// HdSystemSchema instance.
    /// Because the requested container data source may not exist, the result
    /// should be checked with IsDefined() or a bool comparison before use.
    HD_API
    static HdSystemSchema GetFromParent(
        const HdContainerDataSourceHandle &fromParentContainer);

    /// Returns a token where the container representing this schema is found in
    /// a container by default.
    HD_API
    static const TfToken &GetSchemaToken();

    /// Returns an HdDataSourceLocator (relative to the prim-level data source)
    /// where the container representing this schema is found by default.
    HD_API
    static const HdDataSourceLocator &GetDefaultLocator();

};

PXR_NAMESPACE_CLOSE_SCOPE

#endif