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OpenSpace/include/openspace/scene/asset.h

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/*****************************************************************************************
* *
* OpenSpace *
* *
* Copyright (c) 2014-2024 *
* *
* Permission is hereby granted, free of charge, to any person obtaining a copy of this *
* software and associated documentation files (the "Software"), to deal in the Software *
* without restriction, including without limitation the rights to use, copy, modify, *
* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to *
* permit persons to whom the Software is furnished to do so, subject to the following *
* conditions: *
* *
* The above copyright notice and this permission notice shall be included in all copies *
* or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, *
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A *
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT *
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF *
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE *
* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
****************************************************************************************/
#ifndef __OPENSPACE_CORE___ASSET___H__
#define __OPENSPACE_CORE___ASSET___H__
#include <openspace/util/resourcesynchronization.h>
#include <filesystem>
#include <optional>
namespace openspace {
class AssetManager;
/**
* This class represents a successfully loaded Asset. Each Lua asset file results in
* exactly one instance of this class unless it contains a syntax error or some other
* error occurred while loading. Each Asset can have 0-* number of resource
* synchronizations that were requested through the `syncedResource` function in Lua and
* 0-* number of other Assets that this Asset requires (through the `require` function in
* Lua. There also is a list of requiring assets that contain all assets which require
* this asset.
*
* An asset goes through three external states. Starting out as unloaded when the instance
* is newly created but the file has not been processed. In this case the #isLoaded,
* #isSynchronized and the #isInitialized functions all return `false`. After the asset
* has been loaded it is in the `Loaded` state (#isLoaded = true, #isSynchronized = false,
* #isInitialized = false). After all registered synchronizations finish successfully, the
* Asset transitions into the Synchronized state (#isLoaded = true,
* #isSynchronized = true, #isInitialized = false) and after the final initialization
* step, the asset is initialized (#isLoaded = true, #isSynchronized = true and
* #isInitialized = true)
*/
class Asset {
public:
/// This struct contains all the meta information about this asset
struct MetaInformation {
/// The name of the asset
std::string name;
/// The version number of the asset. This is only a string representation and does
/// not have to follow SemVer (even though it is advised)
std::string version;
/// A user-facing description of the asset contents
std::string description;
/// The author of the asset
std::string author;
/// A URL where a consumer of the asset might find additional information about,
/// for example, the author or the used dataset(s)
std::string url;
/// The license under which this asset has been provided
std::string license;
/// A list of all scene graph nodes that have been created in this asset
std::vector<std::string> identifiers;
};
/**
* Creates a new Asset that is backed by the provided \p assetPath. The \p manager is
* the AssetManager instance that is responsible for loading this and all the other
* required Assets.
*
* \param manager The AssetManager that is responsible for loading this Asset and all
* of its dependencies
* \param assetPath The file path that will be used to load this Asset
* \param explicitEnabled If the contents of this asset should start their life as
* being enabled or not
*
* \pre The \p assetPath must not be empty and must be an existing file
*/
Asset(AssetManager& manager, std::filesystem::path assetPath,
std::optional<bool> explicitEnabled);
/**
* Returns the path to the file that was used to initialize this Asset.
*
* \return The path to the file that was used to initialize this Asset
*/
std::filesystem::path path() const;
/**
* Adds a new dependent ResourceSynchronization object to this Asset.
*
* \param synchronization The resource synchronization object that is bound to this
* Asset
* \pre \p synchronization must not be nullptr
* \pre \p synchronization must not have been added to this Asset before
*/
void addSynchronization(ResourceSynchronization* synchronization);
/**
* Updates the state of this Asset based on the latest synchronization being
* successfully resolved. Depending on the sum state of all registered
* synchronizations this Asset's state changes to successfully Synchronized, or
* Failed.
*/
void setSynchronizationStateResolved();
/**
* Updates the state of this Asset based on the latest synchronization being rejected.
* Depending on the sum state of all registered synchronizations this Asset's state
* changes to successfully Synchronized, or Failed.
*/
void setSynchronizationStateRejected();
/**
* Register a SceneGraphNodeIdentifier with the asset (used to associate Nodes with
* asset meta).
*/
void addIdentifier(std::string identifier);
/**
* If the asset has not yet been loaded, this function loads the asset and returns the
* success state. If the loading succeeded, the Asset transitions into the `Loaded`
* state. The \p parent that is provided is the Asset that caused this load operation
* to be triggered and might be `nullptr` if this asset does not have any parents. If
* this Asset has been previously loaded (even with a different \p parent), this
* function does nothing.
*
* \param parent The parent asset (or `nullptr`) that triggered this loading
*/
void load(Asset* parent);
/**
* Returns `true` if this Asset has at least one parent that is in the Loaded state.
*
* \return `true` if this Asset has at least one parent that is in the Loaded state
*/
bool hasLoadedParent();
/**
* Returns `true` if this Asset has been successfully #load ed.
*
* /return `true` if this Asset has been successfully loaded
*/
bool isLoaded() const;
/**
* Unloads this Asset and unrequires all of its required assets, potentially causing
* a cascading effect of further #unload calls if this asset was those required assets
* only parent. After this call, this Asset will be in the Unloaded state. If this
* Asset has already been unloaded (or has not yet been loaded), this function does
* nothing.
*/
void unload();
/**
* Starts the registered synchronizations of this asset and returns `true` if all its
* synchronizations and required assets' synchronizations could start. When all
* synchronizations have completed successfully, this Asset transitions into the
* Synchronized state.
*
* \pre This Asset must have been Loaded before
*/
void startSynchronizations();
/**
* Returns `true` if this Asset's synchronizations (if any) have completed
* successfully.
*
* \return `true` if this Asset is in the Synchronized or Initialized state
*/
bool isSynchronized() const;
/**
* Initializes this asset and returns `true` if the initialized succeeded, i.e. if
* this and all required assets initialized without errors. After this call, if it has
* been successful, this Asset is in the Initialized state. If the Asset has already
* been initialized, calling this function does nothing.
*/
void initialize();
/**
* Returns `true` if this Asset has been #initialize d successfully.
*
* \return `true` if this Asset has been #initialize d successfully. It returns
* `false` both if this initialization failed as well as if thie #initialize
* function has not been called on this Asset
*/
bool isInitialized() const;
/**
* Returns whether any of the parents of this Asset is currently in an initialized
* state, meaning that any parent is still interested in this Asset at all.
*
* \return `true` if there is at least one initialized parent, `false` otherwise
*/
bool hasInitializedParent() const;
/**
* Deinitializes this Asset and recursively deinitializes the required assets if this
* Asset was their ownly initialized parent. If the Asset was already deinitialized,
* calling this function does nothing.
*/
void deinitialize();
/**
* Marks the passed \p dependency as being required by this Asset. If the
* \p dependency is already required by this asset, this function does nothing.
*
* \param dependency The asset that is required by this asset
*
* \pre \p dependency must not be nullptr
*/
void require(Asset* dependency);
/**
* Returns `true` if the loading of the Asset has failed in any way so that
* recovering from the error is impossible.
*
* \return `true` if the Asset handling failed in any way, `false` otherwise
*/
bool isFailed() const;
/**
* Returns the state of whether this asset was loaded with an explicit enable/disable
* or not. If it was specified, the optional will have a value and the value is
* whether the original `require` call asked for a true/false. If no such parameter
* was used, the optional will not contain a value.
*
* \return Whether the asset was loaded with an explicit enable or not
*/
std::optional<bool> explicitEnabled() const;
/**
* Returns the asset that has first loaded this asset or nullptr if that has not been
* determined yet.
*
* \return The asset that has first loaded this asset
*/
Asset* firstParent() const;
/**
* Sets the provided \p metaInformation as the meta information struct for this asset.
* If previous information existed, it will be silently overwritten.
*
* \param metaInformation The meta information about this asset
*/
void setMetaInformation(MetaInformation metaInformation);
/**
* Returns the meta information of this asset back to the caller. If no such
* information exists, a `std::nullopt` will be returned.
*
* \return The MetaInformation about this asset or `std::nullopt`
*/
std::optional<MetaInformation> metaInformation() const;
private:
/// All of the (internal) states that the Asset can move through. The externally
/// visible states (Loaded, Synchronized, Initialized) are a subset of these states
enum class State {
/// The asset is created, but the Lua file has not been executed yet
Unloaded,
/// The execution of the asset file as Lua failed with some error
LoadingFailed,
/// The loading of the asset file succeeded
Loaded,
/// The Asset is currently synchronizing its ResourceSynchronizations and waiting
/// for them to finish
Synchronizing,
/// All registered synchronizations have completed successfully
Synchronized,
/// At least one of the registered synchronizations failed to synchronize
SyncRejected,
/// The onInitialize method (if the asset has one) was executed successfully
Initialized,
/// The execution of the onInitialize method (if existing) resulted in a Lua error
InitializationFailed
};
/**
* Sets the \p state of this Asset to the new state. Depending on the current state of
* this Asset, if \p state is a state related to the synchronization, it will
* potentially propagate to this Asset's parents and cause them to be set to be
* successfully synchronized or faild.
*
* \param state The new State that this Asset is set to
*/
void setState(State state);
/**
* Returns whether the Asset is synchronizing or has successfully synchronized.
*/
bool isSyncingOrResolved() const;
/**
* Returns whether the Asset has been successfully synchronized, meaning that both its
* own resource synchronizations are finished as well as all requiered assets are
* finished synchronizing.
*/
bool isSyncResolveReady() const;
/// The state that this Asset is currently in
std::atomic<State> _state = State::Unloaded;
/// Reference to the manager that is responsible for loading and unloading this asset
AssetManager& _manager;
/// Absolute path to asset file
std::filesystem::path _assetPath;
/// Additional information about this asset, such as its name, author, license, etc
std::optional<MetaInformation> _metaInformation;
/// Assets that are required by this asset
std::vector<Asset*> _requiredAssets;
/// Assets that refers to this asset as a required asset
std::vector<Asset*> _parentAssets;
/// Synchronizations that were requested by this asset
std::vector<ResourceSynchronization*> _synchronizations;
/// The parameter that was passed into the original `require` call whether the
/// contents of this asset should be enabled or disabled
std::optional<bool> _explicitEnabled = std::nullopt;
};
} // namespace openspace
#endif // __OPENSPACE_CORE___ASSET___H__