Release announcement

Flecs 3.1 is out!

Release notes

This version includes the following bugfixes:

• Fixed issue with terms that had Not operator in combination with relationship traversal
• Fixed issues in C++ API where component hooks could get reregistered across DLLs
• Fixed issue in queries with shared components and change detection
• Fixed issue in queries with fixed source terms and change detection
• Fixed issue in sparse set with bulk id generation and recycling
• Fixed issues with using emplace and commands
• Fixed issue in group_by example so it always returns alive entity identifier
• Fixed issue in pipeline with no_staging system after inactive system
• Fixed issue with instanced queries and nested iter calls
• Fixed issue where using observer with multiple components would crash when setting ctx and ctx_free
• Fixed issue where ecs_ref_t would do more lookups than necessary
• Fixed C++ issue with overriding a prefab child that was associated with a type
• Fixed missing call to move hook when moving entity in table
• Fixed double free for moved-away from component
• Fixed leak where world was not destroyed when using app::run
• Fixed table lock assert when adding component in observer during merge
• Fixed crash when OnRemove observer adds component to deleted entity
• Fixed issue with using ecs_add_path when path is root
• Fixed issue with assigning the same name to an entity after reparenting
• Fixed JSON crash on union pair with invalid target
• Fixed crash where no_staging system activated at end of schedule
• Fixed leak when multithreaded pipeline rebuilt after running the last system
• Fixed issue where HTTP server would write to memory of purged connection
• Fixed issue where observer would not restore iterator state for next observer
• Fixed issues with redefining addon macro's
• Fixed issues with parsing identifiers that start with _ in ECS_STRUCT
• Fixed issues with parsing pointer types in ECS_STRUCT

This version includes the following improvements:

• [c] Added ecs_children / ecs_children_next functions for iterating an entity's children
• [c++] Added entity_view::parent function (shorthand for target(flecs::ChildOf)
• [c++] Made calling world::module in module constructor optional
• [c++] Added each/iter overloads that accept a stage
• [c++] Allow module entity to be retrieved using world::entity / world::component
• [threading] Allowed using the world (vs. stage) in single threaded system running in multi threaded apps
• [commands] Command batching, which reduces archetype moves for entities when doing deferred operations
• [entity DSL] Improved syntax
• [entity DSL] Added entity DSL examples
• [entity DSL] Added support for multiline strings
• [entity DSL] Added support for anonymous entities
• [entity DSL] Added variable support (reusable values)
• [entity DSL] Added support for using simple arithmetic expressions
• [entity DSL] Implemented a vscode extension for DSL syntax highlighting
• [os api] Added function to get OS API struct (for easier support in language bindings)
• [queries] Added ability to add user-defined context to query groups
• [queries] Added assert on invalid usage of Filter in combination with queries
• [queries] Added ecs_query_next_table for fast iteration where only tables are needed
• [queries] Improved performance/cleanup technical debt of query change detection
• [queries] Added ecs_query_get_group_info function
• [observers] Added EcsFilter/flecs::Filter term flag for terms only for filtering, not receiving events
• [observers] Added level 3 trace that shows which observers are invoked
• [pipeline] Improved detection of sync points, correctly handle wildcard queries
• [pipeline] Always insert sync point after no_staging system to ensure schedule consistency
• [stats] Added FLECS_ACCURATE_COUNTERS for tracking allocation counters in multithreaded apps
• [stats] Added new statistics for allocators, events and performance tracking
• [stats] Organized statistics into categories
• [stats] Improved system time measurement so it no longer includes merge time
• [stats] Fixed issue where measuring system time for last part of schedule could be skipped
• [stats] Use 64bit counters to reduce occurrences of stat overflows
• [stats] Ensure counter metrics are monotonically increasing in case of overflow
• [rest] Added brief descriptions to stats endpoints for improved visualization in explorer
• [http] Don't enqueue requests for connections that are no longer alive
• [http] Don't keep HTTP connection open longer than timeout
• [http] Set timeout on connection receive socket
• [http] Set SO_KEEPALIVE on connection socket so server is notified when client drops connection
• [http] Implement send queue to prevent blocking on main thread when sending reply
• [http] Fixed issue with sending replies without payload
• [ux] Throw assert when component id overlaps with reserved bits for id flags
• [ux] Added typename to invalid ctor/dtor error messages
• [ux] Added assert when attempting to use ecs_bulk_init on stage
• [internals] Reduced number of heap allocations with internals now mostly using custom allocators
• [internals] Allow for overriding of ECS_HI_COMPONENT_ID macro
• [internals] Allow for overriding of ECS_ID_CACHE_SIZE macro
• [internals] Reduced bits reserved for id flags from 8 to 4
• [internals] Improved detection of platforms where execinfo/backtrace is not available
• [internals] Improved strbuf API so it relies less on strlen
• [internals] Improved performance of flecs_sparse_clear

Known issues: https://github.com/SanderMertens/flecs/issues/765 https://github.com/SanderMertens/flecs/issues/714 https://github.com/SanderMertens/flecs/issues/620 https://github.com/SanderMertens/flecs/issues/478 https://github.com/SanderMertens/flecs/issues/314

This version includes the following bugfixes:

• Fixed issue where system created with each was not automatically instanced
• Fixed copy/paste error in term::read function that set the wrong inout kind
• Fixed issue that prevented deferring an emplace with types that had no default ctor
• Fixed issue that prevented on_add hook to be called for emplace
• Fixed issue where move_ctor wasn't called when merging deferred emplace
• Fixed issue where fps or thread count was overwritten when calling ecs_app_run
• Fixed issue where name prefix wasn't reset after bootstrap
• Fixed issue where union relationship wasn't properly initialized for prefab child
• Fixed various issues with using mingw
• Fixed wrong escaping of pipe symbol in documentation
• Fixed issues with enum reflection on clang and Windows
• Fixed issue with instantiating prefab children that are associated with root type
• Fixed issue where name lookup would fail after resetting name to NULL

This version includes the following improvements:

• Added constructor to flecs::query for creating named queries
• Rewrote outdated parts of "designing with flecs"
• Improved performance of ecs_count_id
• Improved performance of queries/observers that do relationship traversal
• Added query section to relationship manual
• Stats addon types now use customizable float type (ecs_float_t)
• Improved error message when using union relationship in C++ query signature
• Added overload for set_override where 1st element of pair is a tag
• Improved conversion logic of meta cursor API
• Improved documentation of ecs_new_id / ecs_new_low_id
• Updated outdated JSON examples
• Added entity::get_mut_second
• Improved performance of ecs_set

Known issues: https://github.com/SanderMertens/flecs/issues/765 https://github.com/SanderMertens/flecs/issues/714 https://github.com/SanderMertens/flecs/issues/620 https://github.com/SanderMertens/flecs/issues/478 https://github.com/SanderMertens/flecs/issues/314

This version includes the following bugfixes:

• Fixed bug where constructor was not called for explicitly registered component in multi world C++ application
• Fixed bug with change detection and queries with OR terms

This version includes the following improvements:

• Fixed broken links and typos in documentation
• Added links to demos and blogs to README
• Remove redundant includes
• Remove redundant assignment in sparse set code
• New group_by example

This version includes the following new features:

• Group iterators (https://github.com/SanderMertens/flecs/tree/master/examples/cpp/queries/group_iter)

Breaking changes:

• Fixed inconsistencies in naming between fields and terms: https://github.com/SanderMertens/flecs/discussions/466#discussioncomment-3381060

Known issues: https://github.com/SanderMertens/flecs/issues/765 https://github.com/SanderMertens/flecs/issues/716 https://github.com/SanderMertens/flecs/issues/714 https://github.com/SanderMertens/flecs/issues/620 https://github.com/SanderMertens/flecs/issues/478 https://github.com/SanderMertens/flecs/issues/314

This version includes the following bugfixes:

• Fixed symbol export issues when using reflection convenience macro's like ECS_STRUCT
• Fixed bug that prevented inheriting from entities with a symbol identifier
• Fixed issue that could cause crash when creating tables with OVERRIDE or TOGGLE

This version includes the following improvements:

• Improved error messages when using stage outside of readonly context
• Several improvements that enable interop between C modules and C++
• Added more prefab examples
• DontInherit property is now respected when instantiating prefab children
• Transfer ownership of world to app framework in C++ so it can be used in webasm builds

This version includes the following new features:

• Added support for prefab slots (see https://github.com/SanderMertens/flecs/tree/master/examples/cpp/prefabs/slots)

Known issues: https://github.com/SanderMertens/flecs/issues/765 https://github.com/SanderMertens/flecs/issues/716 https://github.com/SanderMertens/flecs/issues/714 https://github.com/SanderMertens/flecs/issues/620 https://github.com/SanderMertens/flecs/issues/478 https://github.com/SanderMertens/flecs/issues/314

This version includes the following bugfixes:

• Fixed issue where calling set with a new pair in a multithreaded app could assert
• Fixed issue where linking Flecs as static library would cause unresolved symbol errors
• Fixed issues in cmake files for examples

This version includes the following improvements:

• Union relationships are now serialized as regular relationships by the JSON serializer
• Added README on how to run examples

Known issues: https://github.com/SanderMertens/flecs/issues/765 https://github.com/SanderMertens/flecs/issues/716 https://github.com/SanderMertens/flecs/issues/714 https://github.com/SanderMertens/flecs/issues/620 https://github.com/SanderMertens/flecs/issues/478 https://github.com/SanderMertens/flecs/issues/314

Flecs 3 is out! 🎉

This is a major release with many new features, improvements, bugfixes and breaking changes. Enjoy!

Release Notes

See the release announcement: https://ajmmertens.medium.com/flecs-3-0-is-out-5ca1ac92e8a4

Upgrading to v3

If you are upgrading from v2.4.8, see this discussion for a list of breaking changes: https://github.com/SanderMertens/flecs/discussions/466

If you are upgrading from a later version, look for the date of your last commit, and use that as starting point in the discussion.

Known issues

https://github.com/SanderMertens/flecs/issues/776 https://github.com/SanderMertens/flecs/issues/765 https://github.com/SanderMertens/flecs/issues/716 https://github.com/SanderMertens/flecs/issues/714 https://github.com/SanderMertens/flecs/issues/620 https://github.com/SanderMertens/flecs/issues/478 https://github.com/SanderMertens/flecs/issues/314

This release will be almost functionally equivalent to the initial Flecs v3 release, but is tagged before v3 renaming (see https://github.com/SanderMertens/flecs/discussions/728).

Use this release if you want to use v3 features, but want to hold off on fixing breaking changes as a result of renaming.

If you are upgrading from an older (v2) release, see this discussion for a list of breaking changes when upgrading: https://github.com/SanderMertens/flecs/discussions/466

This version includes the following bugfixes:

• Fix index in query table cache when table is unmatched
• Fixed group_by signature

This version includes the following improvements:

• Add const variants to flecs::ref

Known issues: https://github.com/SanderMertens/flecs/issues/569 https://github.com/SanderMertens/flecs/issues/701

This version includes the following bugfixes:

• fixed issue where OnSet system would trigger for the wrong wildcard pair
• fixed issue where observer would trigger for the wrong wildcard pair
• fixed issue where observer would trigger for the wrong entity

Known issues:

• UnSet systems with wildcards only trigger for one matching component (addressed in v3)

Note that this is a v2 release that is behind master! Only use this if you cannot migrate to v3 or need API stability

This is the first v3.0 alpha release. This release gets rid of deprecated features, simplifies the API and code structure, and has a number of internal improvements. For a list of changes, see: https://github.com/SanderMertens/flecs/discussions

This is the first of a number of v3.0 alpha releases that may have breaking API changes. If you need a stable API, use the last stable 2.4 release: https://github.com/SanderMertens/flecs/releases/tag/v2.4.6

Known issues:

• cmake file for examples needs to be updated