ezEngine  Milestone 9
ezResourceLoaderFromMemory Class Reference

A resource loader that is mainly used to update a resource on the fly with custom data, e.g. in an editor. More...

#include <ResourceTypeLoader.h>

Inheritance diagram for ezResourceLoaderFromMemory:

Public Member Functions

virtual ezResourceLoadData OpenDataStream (const ezResource *pResource) override
 Override this function to implement the resource loading. More...
 
virtual void CloseDataStream (const ezResource *pResource, const ezResourceLoadData &LoaderData) override
 This function is called when the resource has been updated with the data from the resource loader and the loader can deallocate any temporary memory.
 
virtual bool IsResourceOutdated (const ezResource *pResource) const override
 If this function returns true, a resource is unloaded and loaded again to update its content. More...
 

Public Attributes

ezString m_sResourceDescription
 
ezTimestamp m_ModificationTimestamp
 
ezMemoryStreamStorage m_CustomData
 

Detailed Description

A resource loader that is mainly used to update a resource on the fly with custom data, e.g. in an editor.

Use like this: Allocate a ezResourceLoaderFromMemory instance on the heap, using EZ_DEFAULT_NEW and store the result in a ezUniquePtr<ezResourceTypeLoader>. Then set the description, the modification time (simply use ezTimestamp::CurrentTimestamp()), and the custom data. Use a ezMemoryStreamWriter to write your custom data. Make sure to write EXACTLY the same format that the targeted resource type would read, including all data that would typically be written by outside code, e.g. the default ezResourceLoaderFromFile additionally writes the path to the resource at the start of the stream. If such data is usually present in the stream, you must write this yourself. Then call ezResourceManager::UpdateResourceWithCustomLoader(), specify the target resource and std::move your created loader in there.

Member Function Documentation

◆ IsResourceOutdated()

bool ezResourceLoaderFromMemory::IsResourceOutdated ( const ezResource pResource) const
overridevirtual

If this function returns true, a resource is unloaded and loaded again to update its content.

Call ezResource::GetLoadedFileModificationTime() to query the file modification time that was returned through ezResourceLoadData::m_LoadedFileModificationDate.

Reimplemented from ezResourceTypeLoader.

◆ OpenDataStream()

ezResourceLoadData ezResourceLoaderFromMemory::OpenDataStream ( const ezResource pResource)
overridevirtual

Override this function to implement the resource loading.

This function should take the information from pResource, e.g. which file to load, and do the loading work. It should allocate temporary storage for the loaded data and encode it in a memory stream, such that the resource can read all necessary information from the stream.

See also
ezResourceLoadData

Implements ezResourceTypeLoader.


The documentation for this class was generated from the following files: