sceneIndexPluginRegistry.h

//
// Copyright 2021 Pixar
//
// Licensed under the terms set forth in the LICENSE.txt file available at
// https://openusd.org/license.
//
#ifndef PXR_IMAGING_HD_SCENE_INDEX_PLUGIN_REGISTRY_H
#define PXR_IMAGING_HD_SCENE_INDEX_PLUGIN_REGISTRY_H
 
#include "pxr/pxr.h"
#include "pxr/base/tf/singleton.h"
#include "pxr/base/tf/staticTokens.h"
#include "pxr/imaging/hf/pluginRegistry.h"
#include "pxr/imaging/hd/api.h"
#include "pxr/imaging/hd/sceneIndex.h"
 
PXR_NAMESPACE_OPEN_SCOPE
 
#define HDSCENEINDEXPLUGINREGISTRY_TOKENS \
    ((rendererDisplayName, "__rendererDisplayName")) \
 
 
TF_DECLARE_PUBLIC_TOKENS(HdSceneIndexPluginRegistryTokens, HD_API,
    HDSCENEINDEXPLUGINREGISTRY_TOKENS);
 
 
 
class HdSceneIndexPlugin;
 
class HdSceneIndexPluginRegistry final  : public HfPluginRegistry
{
public:
    HD_API
    static HdSceneIndexPluginRegistry &GetInstance();
 
    template<typename T, typename... Bases>
    static void Define();
 
    HD_API
    HdSceneIndexBaseRefPtr AppendSceneIndex(
        const TfToken &sceneIndexPluginId,
        const HdSceneIndexBaseRefPtr &inputScene,
        const HdContainerDataSourceHandle &inputArgs,
        const std::string &renderInstanceId=std::string());
 
    HD_API
    HdSceneIndexBaseRefPtr AppendSceneIndicesForRenderer(
        const std::string &rendererDisplayName,
        const HdSceneIndexBaseRefPtr &inputScene,
        const std::string &renderInstanceId=std::string(),
        const std::string &appName=std::string());
 
    enum InsertionOrder
    {
        InsertionOrderAtStart,
        InsertionOrderAtEnd,
    };
 
    using InsertionPhase = int;
 
    HD_API
    void RegisterSceneIndexForRenderer(
        const std::string &rendererDisplayName,
        const TfToken &sceneIndexPluginId,
        const HdContainerDataSourceHandle &inputArgs,
        InsertionPhase insertionPhase,
        InsertionOrder insertionOrder);
 
 
    using SceneIndexAppendCallback = 
        std::function<
            HdSceneIndexBaseRefPtr(
                const std::string &renderInstanceId,
                const HdSceneIndexBaseRefPtr &inputScene,
                const HdContainerDataSourceHandle &inputArgs)>;
 
    HD_API
    void RegisterSceneIndexForRenderer(
        const std::string &rendererDisplayName,
        SceneIndexAppendCallback callback,
        const HdContainerDataSourceHandle &inputArgs,
        InsertionPhase insertionPhase,
        InsertionOrder insertionOrder);
 
    HD_API
    std::vector<TfToken> LoadAndGetSceneIndexPluginIds(
        const std::string& rendererDisplayName,
        const std::string& appName);
 
protected:
 
     void _CollectAdditionalMetadata(
        const PlugRegistry &plugRegistry, const TfType &pluginType) override;
 
private:
    friend class TfSingleton<HdSceneIndexPluginRegistry>;
    
    // Singleton gets private constructed
    HdSceneIndexPluginRegistry();
    ~HdSceneIndexPluginRegistry() override;
 
    void _LoadPluginsForRenderer(
        const std::string &rendererDisplayName,
        const std::string &appName);
 
    HdSceneIndexPlugin *_GetSceneIndexPlugin(const TfToken &pluginId);
 
    struct _Entry
    {
        _Entry(const TfToken &sceneIndexPluginId,
                const HdContainerDataSourceHandle &args)
        : sceneIndexPluginId(sceneIndexPluginId)
        , args(args)
        {}
 
        _Entry(SceneIndexAppendCallback callback,
                const HdContainerDataSourceHandle &args)
        : args(args)
        , callback(callback)
        {}
 
        TfToken sceneIndexPluginId;
        HdContainerDataSourceHandle args;
        SceneIndexAppendCallback callback;
    };
 
    using _EntryList = std::vector<_Entry>;
    using _EntriesByPhasesMap = std::map<InsertionPhase, _EntryList>;
    using _RendererEntries
        = std::map<std::pair<InsertionPhase, InsertionOrder>, _EntryList>;
 
    using _RenderersMap = std::map<std::string, _RendererEntries>;
 
    static _EntriesByPhasesMap
    _RendererEntriesToPhaseMap(const _RendererEntries& rendererEntries);
 
    _EntriesByPhasesMap
    _ComputeEntriesByPhasesMap(const std::string& rendererDisplayName) const;
 
    HdSceneIndexBaseRefPtr _AppendForPhases(
        const HdSceneIndexBaseRefPtr &inputScene,
        const _EntriesByPhasesMap &entriesByPhases,
        const HdContainerDataSourceHandle &argsUnderlay,
        const std::string &renderInstanceId);
 
    _RenderersMap _sceneIndicesForRenderers;
 
    // Used to track plugins whose plugInfo entries contain "loadWithRenderer"
    // values to load when the specified renderer or renderers are used.
    // Loading the plug-in allows for further registration code to run when
    // a plug-in wouldn't be loaded elsewhere.
    using _PreloadMap = std::map<std::string, TfTokenVector>;
    _PreloadMap _preloadsForRenderer;
 
    // Used to track app-name-based filtering for plugin loading. If a plugin
    // declares "preloadInApps" in its plugInfo, the plugin will appear in this
    // map. When a plugin is in this map, its library will only be loaded if
    // the appName provided to AppendSceneIndexes is in the list of
    // preloadInApps for the plugin.
    using _EnabledAppsMap = std::map<TfToken, std::set<std::string>>;
    _EnabledAppsMap _preloadAppsForPlugins;
};
 
template<typename T, typename... Bases>
void HdSceneIndexPluginRegistry::Define()
{
    HfPluginRegistry::Define<T, HdSceneIndexPlugin, Bases...>();
}
 
PXR_NAMESPACE_CLOSE_SCOPE
 
#endif // PXR_IMAGING_HD_SCENE_INDEX_PLUGIN_REGISTRY_H