Highlights

• Small release to fix a few bugs that got identified shortly after releasing 4.1.3

Release notes

This version includes the following bugfixes:

• [core] Revert change for supporting types with destructive move semantics (caused crash)
• [core] Fix issues with ordered children trait and nested prefabs
• [core] Fix issues with ordered children trait and prefab slots
• [core] Fix assert when reclaiming component record (using world.shrink()) for large component id

This version includes the following improvements:

• [core] Add ecs_get_version() function (thanks @tabdroid-1!)
• [docs] Correct bazel test example in building flecs manual
• [docs] Fix documentation for ECS_QUERY, ECS_QUERY_DEFINE and ecs_query macros

New Contributors

• @tabdroid-1 made their first contribution in #1891

Full Changelog: v4.1.3...v4.1.4

Highlights

• Improved RAM utilization (create fewer component records, reclaim more data from component vectors, smaller entity administration)
• A new Building Flecs manual!

Release notes

This version includes the following bugfixes:

• [core] Fix issue with reparenting named ordered children
• [core] Fix issue with ecs_ref_get and ecs_shrink
• [core] Fix issue where order or instantiated prefab children could be wrong
• [core] Fix assert for DontFragment relationship during world cleanup
• [core] Fix issue with how dtors get called for types that don't support non-destructive moves (thanks @Watermelon914!)
• [os_api] Add missing WIN32_LEAN_AND_MEAN before new windows.h include
• [queries] Fix assert when using set_varfor query with one cascad term
• [meta] Fix corruption with deserializing into enum with non-32 bits underlying type

This version includes the following improvements:

• [cpp] Allow set_ptr to be used for pairs (thanks @Reddy-dev!)
• [cpp] Add owns_second() and auto_override_second() methods (thanks @Reddy-dev!)
• [core] Don't always create (T, *), (*, T) component records (only create when used)
• [core] Don't create component record when registering trait
• [core] Don't create component record for ChildOf
• [core] Prevent creation of (*, 0) component record
• [core] Reclaim component vectors to actual count instead of power of 2
• [core] Reclaim memory from map data structures on world.shrink()
• [core] Reclaim memory from empty component records during world.shrink()
• [core] Remove redundant component record lookup in observable code
• [core] Add convenience macro's for iterating component records and queries
• [core] Remve redundant ecs_map_params_t type and functions
• [core] Remove redundant if (table) check in table cache
• [core] Remove redundant check on cache initialized in ecs_table_cache_get
• [core] Remove ecs_record_t::cr field
• [core] Increase the maximum size of error strings
• [core] Prevent modifications to map while iterating
• [core] Don't call flecs_notify_on_add when creating entity in root table
• [core] Add ecs_is_defer_suspended() function
• [observers] Remove redundant check in flecs_emit
• [queries] Add traversal tests for (ChildOf, _)
• [queries] Add performance tracing to ecs_query_init
• [os_api] Use ecs_os_free() instead of free() in flecs_dump_backtrace()
• [stats] Track memory of new locked components map
• [docs] Add Rescue Ops: Wildfire to README
• [docs] Rename custom_runner examples to run_callback
• [docs] Remove outdated references to .singleton() API
• [docs] Add new "Building Flecs" manual (previously on quickstart)

Breaking changes:

• None

New Contributors

• @Watermelon914 made their first contribution in #1874

Full Changelog: v4.1.2...v4.1.3

Highlights

• The C++ API now needs to be compiled as C++17!
• Lots of bugfixes for the new DontFragment storage
• New API and explorer dashboard for detailed memory statistics

• New endpoints and explorer pages for inspecting tables, components and queries

Release notes

This version includes the following bugfixes:

• [cpp] Fix assert when using ecs_query_next in system.run callback
• [cpp] Fix issue with setting term flags with flecs::term::flags() method
• [cpp] Fix compiler error when using set/assign with non-copyable type
• [core] Fix issue where ecs_ref_t could point to incorrect ecs_record_t after shrink
• [core] Fix issue with remove_all() and query rematching
• [core] Fix issue where enqueueing command in on_add hook didn't work when bulk creating
• [core] Fix memory leak for error message when FLECS_SOFT_ASSERT is defined
• [core] Fix memory corruption when overriding components with on_set hooks
• [core] Fix issue where on_set hook could be called multiple times for same component on override
• [core] Fix issue where ECS_ON_ADD, ECS_ON_SET, ECS_ON_REMOVE macros could provide bad address when bulk creating
• [core] Fix issue where get_alive() could return current generation of not-alive entity
• [core] Fix issue where on_add hooks could get incorrectly invoked during delete_empty_tables()
• [core] Fix assert when empty table is cleared with hooks registered
• [core] Fix issue with flecs_sparse_ensure and recycled entity ids
• [core] Fix issue where table edges for DontFragment relationships weren't cleaned up
• [core] Fix issue with deleting parent with DontFragment relationship to child
• [core] Fix issue with cleaning up DontFragment components during bulk deletion
• [core] Fix issue where component record for not-alive id would be created in table graph code
• [core] Fix issue where sometimes the wrong entity was removed from a DontFragment sparse set
• [core] Fix issue with instantiating component with (With, DontFragmentComponent)
• [core] Fix issue where DontFragment component was removed before calling regular component observer
• [core] Fix issue with DontFragment tags and clone()
• [os-api] Fix dbghelp casing for MinGW cross compilation (thanks @thomashodgkinson1987!)
• [queries] Fix issue where query flags weren't properly set for query with singleton terms
• [queries] Fix assert where depth calculation for cascade query sees not alive entity
• [observers] Fix issue where single-term observers didn't set the field size
• [observers] Fix issue where observer would provide incorrect field sizes
• [json] Fix issue where a serialization error in an inherited component would return invalid JSON
• [json] Fix assert with serializing sparse tag to JSON with type_info=true
• [json] Fix issue with skipping pretty printed objects in JSON parser
• [json] Fix issue with deserializing entity alias (thanks @degustaf!)
• [rest] Fix escaping for /tables endpoint

This version includes the following improvements:

• [cpp] Update to C++17
• [cpp] Add world() method to flecs::untyped_ref
• [cpp] Use faster compile time alternative to std::conditional (thanks @dementive!)
• [cpp] Add C++ API for singleton enum constants
• [core] Remove unused block allocators
• [core] Remove unused deser_stack allocator
• [core] Add error messages when adding traits after creating queries
• [core] Improve accuracy of frame pacing
• [core] Add compiler flags to build info type
• [core] Don't use private allocator in hashmap data structure
• [core] Add support for using children() with sparse relationships
• [core] Add Singleton trait to module entities
• [os-api] Add Windows implementation for flecs_dump_backtrace()
• [queries] Make terms with Any wildcard cacheable
• [queries] Improve performance of toggle queries
• [observers] Remove ecs_observer_desc_t::observable field
• [meta] Parent anonymous as_types to opaque type to avoid anonymous types in root scope
• [meta] Implement lax member checks when deserializing
• [meta] Add support for character literals (thanks @degustaf!)
• [meta] Add filter callback to serializer that allows for blacklisting components
• [stats] Implement new API for getting detailed memory statistics
• [stats] Store pointer to ecs_world_stats_t in EcsWorldStats to improve memory utilization
• [stats] Fix isue with setting command count in WorldSummary component
• [stats] Add more statistics to WorldSummary component
• [rest] Add action endpoint with method to shrink memory
• [rest] Add /components REST endpoint
• [rest] Add /queries REST endpoint
• [rest] Improve statistics of /tables endpoint
• [docs] Fix issues with on_replace documentation
• [docs] Fix issues in doc examples (thanks @Indra-db!)
• [docs] Fix incorrect ecs_merge() docs and improve error message when used incorrectly
• [docs] Remove outdated references to $ singleton notation
• [docs] Add example that shows how to serialize std::optional (thanks @degustaf!)
• [docs] Add links to new Godot projects
• [ci] Update macOS 13 runners to 14

Breaking changes:

• The C++ API must now be compiled as C++17 (#466 (comment))

New Contributors

• @degustaf made their first contribution in #1791
• @dementive made their first contribution in #1788
• @thomashodgkinson1987 made their first contribution in #1813
• @Real-Septicake made their first contribution in #1834

Full Changelog: v4.1.1...v4.1.2

Highlights

• 2x faster trivial set() calls (no hooks, observers or change detection)
• 5x faster trivial modified() calls (no hooks, observers or change detection)
• 3x faster prefab instantiation due to new component overriding design
• Lots of reflection improvements for arrays, vectors and enums with custom underlying types
• Lots of explorer improvements (better autocomplete, drag-to-change values in inspector, pane resizing, script saving and more!)
• New script features that introduce more flexible ways to refer to entities:

// Create anonymous entity that is referred to later (previously impossible)
const alice: new {
  Position: {10, 20}
}
bob {
  // Alice variable can now be used without $ prefix
  (Likes, alice)
}
for i in 0..10 {
  "spaceship_{i}" { }
  "shuttle_{i}" {
    // Interpolated strings can now also be used in component/pair expressions
    (DockedTo, "spaceship_{i}")
  }
}

Release notes

This version includes the following bugfixes:

• [cpp] Don't move lvalue during component assignment (thanks @ColoredCarrot!)
• [cpp] Fix issue where flecs::Script component couldn't be used when defining FLECS_CPP_NO_AUTO_REGISTRATION
• [core] Fix issue where component hooks were not correctly called on world.shrink()
• [core] Fix fatal assert with OrderedChildren test in release mode
• [core] Fix issue where .get<Rel>(Wildcard) did not work for sparse components
• [core] Fix issue where children weren't correctly populated for instance of prefab with OrderedChildren
• [observers] Fix issue where ecs_field_is_set didn't work for single term observers
• [queries] Fix issue where queries sometimes returned entities with NotQueryable tag
• [meta] Fix issues with deserializing inline arrays and vectors
• [meta] Fix issue in cursor API where it assumed int32_t for underlying enum type
• [meta] Fix issues with serializing enums with custom underlying type
• [rest] Fix issue where REST API would not restore correct log function after endpoint
• [script] Fix crashes when using script annotations for invalid targets
• [script] Fix "can't serialize" errors when serializing script AST
• [script] Fix issue where value of script variable was incorrectly cached
• [script] Fix incorrect type check for component expressions used in initializer

This version includes the following improvements:

• [cpp] Implement type traits in library to support older versions of gcc (thanks @AnonimiAngels!)
• [cpp] Implement world::id_if_registered method
• [cpp] Implement world::type_info()
• [cpp] Remove redundant FLECS_META check for to_constant()
• [cpp] Make world::to_json() methods const
• [cpp] Allow using APIs that accept enum constants in builds with FLECS_CPP_NO_ENUM_REFLECTION
• [core] Implement ecs_table_has_traversable() function
• [core] Implement on_replace hook
• [core] Don't emit OnSet events for operations when there are no hooks/observers
• [core] Improve performance of set/ensure/emplace
• [core] Remove redundant cr field from command struct
• [core] Improve error messages
• [core] Add checks that prevent making invalid modifications to core entities
• [core] Change table_record_t.hdr.cache type to ecs_component_record_t
• [core] Improve performance of component overriding
• [core] Remove redundant New command
• [core] Add new size argument to ecs_emplace_id and ecs_ensure_id
• [core] Implement new Singleton trait
• [core] Add more ecs_ref_t tests
• [core] Turn setting both FLECS_DEBUG/NDEBUG error into warning
• [core] Assert when passing alive ids to .entities member of ecs_bulk_desc_t
• [meta] Split up push serializer operation into struct, array, vector
• [meta] Split up opaque type serializer operation into value, struct, array, vector
• [meta] Add underlying_kind field to serializer operation for serializing enums
• [meta] Add constants field to serializer operation for serializing enums/bitmasks
• [meta] Change meaning of ecs_member_t::count so that it's interpreted as inline array when >= 0
• [meta] Split off constants member from EcsEnum/EcsBitmask into separate EcsConstants component
• [meta] Split up meta addon code into smaller files
• [json] Don't serialize schema to JSON for none fields
• [script] Add script tests for CRLF line endings
• [script] Don't reset script code for managed scripts after error
• [script] Store errors on managed script
• [script] Implement new expressions
• [script] Implement exported variables
• [script] Allow for using variable names without $ prefix as components, relationships and targets
• [script] Allow for using interpolated string expressions as components
• [script] Inheritance statements now require a scope
• [rest] Allow managed scripts to be saved from the REST API/explorer
• [rest] Always store build info on world so it is available for the explorer
• [cmake] Bump cmake_minimum_required_version (thanks @niceEli!)
• [docs] Fix issues in script examples
• [docs] Remove outdated section on pipelines from system manual
• [docs] Add Gloam vault to README
• [docs] Fix source documentation for is_alive()/is_valid()
• [docs] Fix query section in design with flecs manual
• [docs] Fix broken link in quickstart (thanks @ZaddikDev!)
• [docs] Add custom_serializer example
• [docs] Fix issues in queries and prefab manual (thanks @Chetco!)
• [docs] Fix outdated examples in change detection section of query manual
• [docs] Update incorrect is_enabled to enabled in manuals (thanks @ericjeker!)
• [docs] Add hooks section to entities and components manual

Breaking changes:

• ecs_emplace_id and ecs_ensure_id now accept an additional size argument: #466 (comment)
• The singleton API has been changed to use a component trait: #466 (comment)
• Script evaluation APIs now have a result argument for capturing errors: #466 (comment)
• Inheritance statements in flecs script now require a scope: #466 (comment)
• The serializer data structures have been updated to allow for vector deserialization, enums with underlying types and more: #466 (comment) and #466 (comment)

New Contributors

• @AnonimiAngels made their first contribution in #1714
• @niceEli made their first contribution in #1731
• @ZaddikDev made their first contribution in #1734
• @ColoredCarrot made their first contribution in #1715
• @Chetco made their first contribution in #1754
• @ericjeker made their first contribution in #1768

Full Changelog: v4.1.0...v4.1.1

Release announcement

https://ajmmertens.medium.com/flecs-4-1-is-out-fab4f32e36f6

Release notes

This version includes the following bugfixes:

• [core] Add missing FLECS_API to ecs_get_path_w_sep_buf
• [core] Fix issue with component toggling in multithreaded apps
• [core] Fix issue where not having a default ctor would mark copy/move ctor as invalid
• [core] Fix issue where component_record::keep_alive refcount was incorrectly updated by observers (thanks @garrett-is-a-swann!)
• [core] Fix misaligned addresses in sanitized mode
• [queries] Fix issue with change detection after early outing from iterator
• [queries] Fix issue where query incorrectly flagged itself as MatchOnlySelf
• [observers] Don't assert on invalid observer creation
• [observers] Fix uninitialized value in multi-component OnSet observer when overriding
• [json] Fix crash when escaping null character in JSON serializer
• [script] Fix issue in script template instantiation where children vector was deleted while iterating
• [script] Fix script assert when adding component as tag without default ctor
• [script] Fix issue where token buffer was incorrectly used for interpolated strings
• [script] Fix assert when parsing incorrect syntax for interpolated strings
• [http] Fix buffer overflow in ecs_http_server_request function
• [rest] Fix serialization of pipeline statistics to JSON
• [os] Fix bug where a condition variable was not correctly freed on Windows (thanks @kagetu!)

This version includes the following improvements:

• [cpp] Change flecs::entity::parent() to use ecs_get_parent
• [cpp] Add size(), entities(), clear_entities(), column_size(), depth(), records(), id(), lock(), unlock(), has_flags() methods to C++ table API
• [cpp] Run system queries entirely in C++ to avoid function pointer overhead
• [cpp] Change return type of get() to const T&
• [cpp] Change return type of get_mut() to T&
• [cpp] Add new try_get() with const T* return type
• [cpp] Add new try_get_mut() with T* return type
• [cpp] Add entity_view::get_constant() for fetching constant from enum relationship
• [cpp] Add entity::child() method for spawning a child of an existing entity
• [cpp] Remove redundant set functions
• [cpp] Implement entity::assign() method
• [c] Add ecs_singleton_get_mut, ecs_singleton_ensure
• [core] Remove redundant ecs_header_t::magic field
• [core] Reduce large initial size of table edge diff builder vectors
• [core] Reduce page size of entity index
• [core] Shrink world after bootstrap when FLECS_LOW_FOOTPRINT is defined
• [core] Allocate stack allocator page on first use, not when initializing the allocator
• [core] Bypass ecs_allocator_t when using FLECS_USE_OS_ALLOC
• [core] Reclaim memory from stages when calling shrink()
• [core] Improve performnace of ecs_ref_get
• [core] Implement support for non-fragmenting components
• [core] Cleanup sparse set functions
• [core] Implement world exclusive access feature
• [core] Remove redundant entity count arguments from internal functions
• [core] Improve organization and documentation of core code
• [core] Implement OrderedChildren storage
• [core] Remove redundant fields from ecs_iter_t
• [core] Make sure ecs_vec_reclaim frees memory when FLECS_USE_OS_ALLOC is defined
• [core] Remove support for creating entity ids in multithreaded mode
• [core] Remove support for Union relationships (replaced by DontFragment, Exclusive)
• [core] Move core tags out of low id range
• [queries] Improve detection of trivial queries
• [queries] Don't use large static arrays in query struct
• [queries] Reduce size of ecs_query_op_ctx_t
• [queries] Default to uncached queries when FLECS_LOW_FOOTPRINT is defined
• [queries] Speed up query evaluation with bloom filter
• [queries] Remove redundant table_id field from query cache element
• [queries] Reduce query cache footprint by removing dependency on ecs_table_cache_t
• [queries] Add trivial query cache iterator
• [queries] Speed up change detection for trivial queries
• [queries] Remove now redundant query notification mechanism
• [queries] Use smaller query cache element for trivial queries
• [queries] Use array to store query cache elements instead of a linked list
• [queries] Cache column pointers on query cache elements
• [queries] Allow using trivial query cache for queries with not/optional operators
• [queries] Treat !(R, *) terms as cacheable
• [queries] Prevent rematching when creating/deleting targets of traversable relationships
• [queries] Change argument of ecs_iter_get_group to const ecs_iter_t* (thanks @Indra-db!)
• [observers] Support single-term observers without query
• [systems] Improve performace of running systems by using more efficient iteration function
• [timer] Replace AddTickSource system with With pair
• [pipeline] Improve performance of running systems in pipeline
• [meta] Implement ordered enum/bitmask constants (thanks @Bonkt!)
• [script] Add flecs::entity::lookup() method to script
• [build] Add Android support to cmake build (thanks @jiannanya!)
• [docs] Fix C# filter example in observer manual
• [docs] Add clojure binding to quickstart guide (thanks @pfeodrippe!)
• [docs] Remove unmaintained Rust binding from README (thanks @Indra-db!)
• [docs] Add new jellycacke videos on observers and singletons
• [docs] Add link to ECS survivors to docs
• [docs] Update change tracking examples
• [docs] Add FEAST game to README
• [docs] Remove Hytale game to README
• [docs] Remove outdated references to instancing in query manual
• [docs] Improve monitor example in observer manual
• [docs] Fix incorrect location of lookup variable section in query manual
• [docs] Add ECS Survivors, Ascendant to README

Breaking changes:

• Change detection now has to be explicitly enabled on queries (#466 (comment))
• It is no longer possible to pass 0 to the size argument of ecs_field_w_size (#466 (comment))
• It is no longer allowed to create entities in multithreaded systems (#466 (comment))
• get/get_mut now return references instead of pointers (#466 (comment))
• get no longer returns the enumeration constant when used with enum relationship (#466 (comment))
• Union relationships are no longer supported (#466 (comment))

New Contributors

• @sean-reed made their first contribution in #1612
• @Bonkt made their first contribution in #1619
• @jiannanya made their first contribution in #1646

Full Changelog: v4.0.5...v4.1.0

Happy GDC! 👾

Highlights

• Many changes that reduce memory utilization and binary footprint!
• Flecs now has more than 10.000 tests ran on every commit ✅
• 30-50% performance improvement for get/get_mut/has/owns on clang & gcc when using LTO 🚀
• New APIs to work directly with internal data structures for building fast custom ECS operations

Release notes

This version includes the following bugfixes:

• [cpp] Fix issue with assigning flecs::Component to implicitly registered tags and prefabs
• [cpp] Fix query copy ctor/assign for default constructed queries (thanks @Thinkofname!)
• [cpp] Fix ambiguous methods for enum types (thanks @Reddy-dev!)
• [cpp] Use correct world in term_builder_i::singleton() (thanks @BeanCheeseBurrito!)
• [cpp] Fix issue with using .field_at when using .with<T>() where T is sparse
• [cpp] Fix assert in ecs_cpp_trim_module when component name overlaps with module
• [cpp] Fix issue where entity::remove could not be used to remove enum components
• [cpp] Fix race condition in enum reflection code
• [core] Fix issue with batched set commands and inherited components
• [core] Fix compilation error with stray FLECS_API annotations in source files
• [core] Fix issue with instantiating prefab with union relationship while deferring is suspended
• [core] Fix shift overflow for events with large (>64) numbers of components
• [core] Fix issue with command queue that contains both recycled id and old id
• [core] Fix use after free when FLECS_USE_OS_ALLOC is defined
• [core] Fix invalid read for table with many flag/pair ids
• [core] Fix memory leak in the entity index (thanks @jpeletier!)
• [core] Fix ubsan error where offset was applied to NULL
• [queries] Fix issue with queries matching (ChildOf, 0) when iterating component ids
• [queries] Fix issue with cached queries and up traversal
• [queries] Fix crash when using iter::get_var on chained iterators
• [observers] Fix issue in observer event forwarding code where source was incorrectly set
• [observers] Fix issue when using LOG_LEVEL_3 in release mode
• [observers] Fix issue with observers that have a fixed entity source
• [observers] Fix issue with two observers with run actions where one could prevent the other from running (thanks @Thinkofname!)
• [observers] Fix issue where observers could get registered multiple times for same event
• [observers] Fix issue with observers that have terms with a variable source
• [pipelines] Fix issue where sync point wasn't inserted for InOutNone terms
• [meta] Fix issue where member with _ name was not created in struct (thanks @GsLogiMaker!)
• [json] Fix issue in JSON deserializer when skipping missing component
• [meson] Add missing addons/app.c to meson.build (thanks @justinian!)

This version includes the following improvements:

• [cpp] Add flecs::ref::component() method
• [cpp] Fix warning in enum.hpp (thanks @jpeletier!)
• [cpp] Allow specifying underlying type for constants with template parameter (thanks @Reddy-dev!)
• [cpp] Support using enum reflection without requiring FLECS_META addon
• [cpp] Add FLECS_CPP_NO_ENUM_REFLECTION flag
• [cpp] Add path separator argument to flecs::entity constructor
• [cpp] Reduce memory footprint of component registration
• [cpp] Add support for type checked .term_at<T> and .term_at<T>(i) (thanks @deathbeam!)
• [cpp] Add support for untyped references (thanks @jpeletier!)
• [cpp] Use low ids for untyped components (thanks @Reddy-dev!)
• [core] Improve performance of ecs_ref_get / flecs::entity::get_ref
• [core] Improve performance of ecs_delete_empty_tables
• [core] Make functions to suspend/resume readonly mode public again for language bindings
• [core] Add fields to support debug (natvis) visualization
• [core] Remove redundant component record flags
• [core] Add new Inheritable trait to indicate in advance a component will be inherited from
• [core] Store entities without components in root table
• [core] Don't retain large allocations in block allocator
• [core] Remove entry_allocator field from maps
• [core] Pack ecs_map_t fields to reduce footprint
• [core] Reduce footprint of ecs_id_record_t, ecs_table_t
• [core] Simplify command batching logic by removing redundant guarantee
• [core] Implement ecs_shrink/world::shrink method that frees unused memory
• [core] Add always_inline annotation to performance critical functions
• [core] Expose internal APIs to work with ecs_component_record_t and ecs_table_record_t
• [queries] Reduce number of block allocators for cached queries
• [queries] Change default cache policy to cached when query has cascade term
• [queries] Add compiler flag to change default query caching policy to uncached
• [meta] Implement equals/compare type hooks (thanks @jpeletier!)
• [meta] Add opaque serializer callbacks for members and elements (thanks @jpeletier!)
• [script] Split off parser and query DSL code from FLECS_SCRIPT addon
• [script] Add support for parsing binary and hex base numbers
• [allocators] Remove redundant block_tail member from block allocator
• [os api] Add support for cosmo compiler (thanks @bnjmnjrk!)
• [docs] Add links to new jellycake youtube tutorials
• [docs] Remove outdated emplace documentation from C++ API
• [docs] Add SDL3 example project to documentation page
• [docs] Update link to Zig binding in README
• [docs] Bazel docs update that reflects improvements in renovate (thanks @reutermj!)
• [docs] Remove incorrect statement about Final trait from component traits manual
• [docs] Improve API documentation for binding support functions
• [docs] Fix formatting of code segment in quickstart (thanks @theaveasso!)
• [ci] Fix typo in Allocator.c
• [ci] Add missing enum tests to cpp/project.json (thanks @BeanCheeseBurrito!)
• [ci] Add missing reference tests to cpp/project.json (thanks @jpeletier!)
• [ci] Remove clang-13 from CI builds
• [ci] Add emscripten build to CI (thanks @zelosleone!)

Breaking changes:

• flecs.meta.constant has moved to flecs.core (#466 (comment))
• Entities without components are now stored in a table (#466 (comment))
• Specifying a component with query_builder::with now uses InOutDefault (previously InOutNone, #466 (comment))
• flecs::entity::remove has changed to enable removing enum components (#466 (comment))

New Contributors

• @justinian made their first contribution in #1514
• @bnjmnjrk made their first contribution in #1548
• @Reddy-dev made their first contribution in #1551
• @GsLogiMaker made their first contribution in #1568
• @zelosleone made their first contribution in #1579
• @KenthJohan made their first contribution in #1605
• @theaveasso made their first contribution in #1610

Full Changelog: v4.0.4...v4.0.5

Happy new year! 🥂 🎉

Highlights

• Component ids no longer need to match between worlds, which means Flecs worlds are now truly independent!
• Enums with custom underlying types are now properly supported by the core and meta addon
• The script and query implementations have been fuzzed, which lead to lots of gnarly bugs being found 🐛
• A big flecs script refactor improved performance 50x (!) over 4.0.3, and 6x over 3.2.12
• Many, many new flecs script features which means much more complex scenes can now be built:

Procedural scene constructed from primitive shapes with flecs script

Release notes

This version includes the following bugfixes:

• [cpp] Fix ubsan error in free_obj<T> (thanks @jspohr!)
• [cpp] Fix issue with registering hooks after component registration (thanks @jpeletier!)
• [cpp] Fix issue where calling set_group/set_var on const query objects was not possible
• [cpp] Fix crash when iterating components of entity with an empty type
• [cpp] Fix issue with nested observers and implicit namespaced component registration
• [cpp] Fix issue with reregistering component symbol after deletion
• [cpp] Fix issue where shared fields could not be accessed with field/field_at in each callback
• [cpp] Fix issue with enum_data::index_by_value
• [cpp] Fix crash in C++ addon logging
• [cpp] Fix issue in C++ API when iterating a large number of sparse components
• [core] Fix issue where batched commands for implicitly registered component could crash
• [core] Fix issue with registration of traits for builtin entities
• [core] Fix issue with using ecs_entity_desc_t::set while deferring is suspended
• [core] Fix illegal memory access in ecs_add_path_w_sep
• [core] Fix write to invalid memory in flecs_path_append
• [core] Fix issue with name lookups that have multiple consecutive separator characters
• [core] Fix issue with attempting to lookup #id's with value larger than UINT32_MAX
• [core] Fix leaks when using FLECS_USE_OS_ALLOC
• [core] Fix issues where code was accessing world flags on stage object
• [core] Fix access to uninitialized ecs_cmd_t::id field
• [core] Fix leak when deferring a batched set for a large non-trivial component
• [core] Fix issue where second element of pair could not be a sparse component
• [core] Fix command batching issue where component is added in two stages
• [observers] Fix issue where observers could be triggered multiple times for the same event
• [observers] Fix issue where event was incorrectly propagated for masked component
• [observers] Fix issue where observer with multiple up() terms could get duplicate events
• [observers] Fix issue where OnTableCreate observer did not trigger in deferred mode
• [queries] Fix crash when sorted query with MatchEmptyTables only matches empty tables
• [queries] Fix issue where up traversal with inheritance could return duplicate results
• [queries] Fix issue where IsA was incorrectly traversed for non-inheritable components
• [queries] Fix issue with using query.find(flecs::entity, ...) and EcsQueryMatchEmptyTables
• [queries] Fix issue where queries would return inconsistent component id for *From operator fields
• [queries] Fix assert that happens while reporting a query error
• [queries] Fix assert when query has unbalanced {} scopes
• [queries] Fix issue where query incorrectly treated this entity reference as variable
• [queries] Fix issue with queries that have mixed cached fields and shared fields
• [queries] Fix issue with queries created in stage, change detection and shared fields
• [meta] Fix memory leaks in cursor string conversions
• [json] Fix issue where override components would show up as inheritable in serialized JSON
• [script] Fix issue where script AST would incorrectly cache ids of entities created by template
• [script] Fix issue with parsing opaque primitive components
• [script] Fix issue with using pair components in templates
• [rest] Fix issue with reporting errors that contain formatting characters
• [misc] Fix file handle leak when file fails to load (thanks @peter15914!)

This version includes the following improvements:

• [cpp] Prevent recycled entity ids when reparenting C++ module
• [cpp] Add to_json() method to flecs::query_base
• [cpp] Allow for X_TO_JSON_INIT macros to be used in C++
• [cpp] Fix warning for incorrect type in static_cast for inout & operator kinds
• [cpp] Implement world local component ids
• [cpp] Enums with custom underlying types are now supported
• [core] Reduce overhead of monitors by not creating observers for optional terms
• [core] Add assert to prevent entity ids from overflowing the 32 bit range (thanks @Ukendio!)
• [core] Implement type info flags for detecting invalid component lifecycle (thanks @jpeletier!)
• [core] Reduce page size of non-entity sparse sets (Reduce memory footprint)
• [core] Use map instead of sparse set for type_info (Reduce memory footprint)
• [core] Remove unnecessary observer sparse set (Reduce memory footprint)
• [core] Reduce size of low id record array (reduces RAM)
• [core] Change flecs.core.Disabled to (OnInstantiate, Override) (from Inherit)
• [core] Allow for infinitely nested observer calls
• [core] Add cycle detection in observer code to prevent stack overflows
• [core] Add error message when invalid path is passed to ecs_add_path_w_sep
• [core] Remove propagation of empty state for tables
• [core] Change ecs_delete_empty_tables API by changing its parameters to a desc struct
• [queries] Add ecs_query_get to get ecs_query_t* object from entity
• [queries] Add more validator tests for !(ChildOf, _) queries
• [systems] Add system disabling test
• [script] Flecs script expression refactor
• [script] Add support for function arguments to flecs script
• [script] Add math functions to flecs script in a new FLECS_SCRIPT_MATH addon
• [script] Add ability to specify variables when running a script
• [script] Add support for multiple template instances per entity
• [script] Improve detection of invalid statements in with scopes
• [script] Add ability to define world-scoped script variables (like PI)
• [script] Add support for string interpolation to expression parser
• [script] Add support for entity name expressions (like"e_$i" { })
• [script] Implement support for for var in x..y loops
• [script] Add divide by zero checks so runtime doesn't crash but reports error
• [script] Add more builtin script functions for doc addon and testing for components
• [script] Implement random number generator for flecs script
• [script] Bulk-add components in entity scope to improve script performance
• [script] Add support for else if
• [script] Add support for match expressions
• [script] Add support for using add assign and multiply assign in initializers
• [script] Empty scopes now create an anonymous entity
• [script] Allow referring to variables without $
• [script] Variables now need to use const x: value notation when using implicit type
• [script] Props can now have implicit types
• [http] Allow HTTP server to be created without threading support (thanks @basicer!)
• [http] Allow for script code to be provided in body of /script request
• [http] Increase size of HTTP receive buffer, throw warning if request exceeds it
• [http] Add body parameter to ecs_http_server_request
• [docs] Add system & query examples for each and run callback variants
• [docs] Add example that shows how to iterate multiple queries in a system
• [docs] Add Unreal-Flecs link to documentation page
• [docs] Fix issue with query_to_custom_json example
• [docs] Fix ecs/world typo in system manual (thanks @iHR4K!)
• [docs] Add Resistance is Brutal to README
• [docs] Improvements to migration guide (thanks @999pingGG!)
• [docs] Add flecs tutorial links to documentation page
• [ci] Fix warnings in tests (thanks @jpeletier!)
• [ci] Silence clang warning about missing default case
• [ci] Fix CI bazel job to work with new bazel version

Breaking changes

• Flecs script API functions have been renamed: #466 (comment)
• flecs::reset() no longer exists: #466 (comment)
• Events for communicating empty table state no longer exist: #466 (comment)
• The signature of ecs_http_server_request has changed: #466 (comment)
• The const var = value script syntax has been deprecated: #466 (comment)
• Empty script scopes now create anonymous entities: #466 (comment)
• Not strictly a breaking change, but the order in which nested observers are evaluated has changed, which may break code that relied on observer ordering (which is undefined).

New Contributors

• @jspohr made their first contribution in #1436
• @Ukendio made their first contribution in #1435
• @basicer made their first contribution in #1462
• @iHR4K made their first contribution in #1457...

Highlights

• None, just a lot of small improvements and bugfixes 🐛

Release notes

This version includes the following bugfixes:

• [cpp] Fix issue with modified<R, T> where first type is a tag
• [cpp] Fix conflicting identifier between flecs and magic_enum library
• [cpp] Fix issue with reparenting module that is in root namespace
• [cpp] Disable incorrect msvc warning on enum reflection code
• [core] Remove FLECS_API in block_allocator.c which was causing linker errors (thanks @Indra-db!)
• [core] Fix crash if component and entity w/component are deleted in same cleanup operation
• [core] Fix linked list corruption in supporting data structure for Union relationships
• [core] Fix issue where union relationships weren't copied from prefab to prefab instance
• [core] Fix bug with component overriding for prefabs with union pairs
• [core] Avoid size integer overflow of command buffer vector during world cleanup (thanks @jpeletier!)
• [queries] Fix issue with queries that match empty tables and iterate individual entities
• [queries] Fix issue with evaluating queries with any wildcards that match multiple tables
• [queries] Fix issue where offset could be applied to NULL address
• [observers] Fix issue with yield_existing observers and not terms
• [observers] Fix issue with getting field in OnSet observer after removing override
• [observers] Fix issue where (OnInstantiate, Override) would not trigger OnSet observers
• [expr] Fix memory leak after failed multiline string assignment
• [json] Fix JSON serialization for auto_override/toggle components
• [json] Fix issue with serializing type info to JSON for sparse components
• [log] Fix issue where ecs_log_set_level returns wrong value
• [stats] Fix issue in flecs::stats module when global MatchEmptyTables flag is set
• [alerts] Fix broken FLECS_NO_ALERTS macro (thanks @pfeodrippe!)

This version includes the following improvements:

• [cpp] Implement iter::targets for easy iteration of relationship targets for a field
• [cpp] Remove redundant call to strcpy in ecs_cpp_get_symbol_name
• [cpp] Enforce correct type when using *_second operations in entity, entity_view and entity_builder
• [queries] Return wildcard table records in ecs_iter_t::trs for any wildcard terms
• [queries] Report errors for invalid usage of cascade and desc modifiers
• [observers] Add yield_existing flags for customizing observer create/delete behavior
• [observers] Trigger events for optional observer terms
• [core] Add ecs_world_get_flags function
• [core] Escape separator characters in entity name when using ecs_get_path
• [core] Add option to escape characters for serialization in entity path
• [core] Implement ecs_table_clear_entities (thanks @gsnook!)
• [meta] Emit OnSet after modifying EcsEnum component (thanks @jpeletier!)
• [json] Fix issue with serializing queries that have large numbers of fields
• [json] Don't serialize base DontInherit components to JSON
• [rest] Include query plan used to populate cache in REST reply
• [http] Automatically test port range when creating HTTP server for multi-application support
• [doc] Add UUID to doc addon
• [docs] Add link to flecs raylib starter kit to documents
• [docs] Add Hyperion to README
• [docs] Add Age of Respair to README
• [docs] Fix incomplete sentence in query manual
• [docs] Fix find/replace errors in query manual
• [docs] Show how to use lookup functions in hierarchy examples
• [docs] Fix disabling typo in entity manual
• [docs] Fix TermAt indexing in C# docs (thanks @deathbeam!)
• [docs] Rename Routine to System in C# docs (thanks @deathbeam)
• [docs] Fix comment typo in prefab example (thanks @Indra-db)
• [docs] Fix broken link in relationship manual
• [docs] Add note to prefab manual on how prefabs are only ignored for entities matched on $this
• [docs] Add missing , in migration guide
• [docs] Fix typo in scopes section of query manual
• [tests] Fix duplicate test case
• [build] Remove unnecessary version attribute from flecs bazel model definition (thanks @reutermj!)
• [ci] macOS CI improvements (thanks @waywardmonkeys!)

Breaking changes

• ecs_get_path_w_sep_buf now has an additional escape argument (#466 (comment))

New Contributors

• @deathbeam made their first contribution in #1395

Full Changelog: v4.0.2...v4.0.3

Highlights

• New blog: Building an ECS #3: Storage in pictures
• Runtime types now automatically generate hooks that cleanup resources (thanks @jpeletier!)
• New OS API hooks that enable integration with tracy-style profilers!

Release notes

This version includes the following bugfixes:

• [cpp] Fix spurious entities that are created when renaming C++ module
• [cpp] Fix issue with non-$this fields in query iteration (thanks @Gaspard--!)
• [cpp] Fix issue with computing component name from multiple threads/worlds
• [cpp] Fix issue where C++ world object would sometimes not get freed (thanks @jpeletier!)
• [cpp] Fix issue with observers and up traversal
• [cpp] Fix clang 20 compiler error in enum reflection code
• [core] Fix issue with using sparse components and ecs_new_w_table
• [core] Fix issue with ecs_new_w_table and overriding components
• [core] Fix issue with creating queries inside of hooks
• [core] Fix issue with testing tables for wildcard pair ids
• [core] Fix potential leak in ecs_clone due to double constructor call (thanks @jpeletier!)
• [core] Fix issues with simple observers/queries for sparse components
• [core] Fix issues with hooks for sparse components
• [core] Fix issue with batched OnAdd + OnRemove observers
• [queries] Fix issue with matching IsA -> IsA -> ChildOf up traversal
• [queries] Fix issue with matching prefab/disabled entities for queries that start with not term
• [systems] Fix issue with setting rate filter on system without tick source
• [systems] Fix issue with cleaning up iterator resources for systems that match nothing
• [json] Fix crash when serializing query plan for trivial query
• [json] Fix issue where conflicting alerts member could serialize to invalid JSON
• [script] Fix issue where script visitor function wasn't restored after parsing template
• [stats] Fix issue where units module was not always imported by stats (thanks @domdom!)
• [stats] Fix crash when fetching WorldSummary by REST API before it's initialized
• [explorer] Fix issue with entity names that have contain / characters

This version includes the following improvements:

• [cpp] Add flecs::ref::has
• [cpp] Add missing overload for query_builder::with(const char*, id_t)
• [cpp] Add flecs::iter::other_table()
• [c] Remove const from ecs_ref_get
• [core] Implement fine-grained feature tracking for add/remove operations
• [core] Add performance tracing hooks to OS API
• [core] Add perf trace when sleeping due to target_fps (thanks @waywardmonkeys!)
• [core] Add support for AUTO_OVERRIDE to prefab children
• [core] Implement deterministic ids for prefab children
• [core] Use __alignof__ on clang
• [core] Allow for restoring ranges with ecs_set_entity_range
• [core] Add compile time flag to disable statistics counters
• [core] Fix thread sanitizer warnings
• [core] Prevent calling ecs_run_post_frame outside of frame
• [core] Add ecs_id_from_str
• [core] Allow for suspending readonly mode outside of multithreaded systems
• [queries] Remove redundant query instruction constants
• [queries] Allow (IsA, tgt|self) queries to be cached
• [queries] Don't automatically cache queries with only not/optional terms
• [observers] Add yield_existing support to OnRemove observers
• [meta] Support calling ecs_meta_get_string on opaque string types
• [meta] Make flaky alert tests not flaky (thanks @jpeletier!)
• [meta] Add a const_string opaque type (thanks @jpeletier!)
• [meta] Auto-generate lifecycle hooks for reflection-only types
• [stats] Add counter for tracking component monitor evaluations
• [units] Remove unused symbols from units addons
• [docs] Fix typos in documentation on how to run tests (thanks @jpeletier!)
• [docs] Add Meta copyright notice to LICENSE (has no impact on license which is still MIT!)
• [docs] Fix typos (thanks @waywardmonkeys!)
• [docs] Fix emit/event typo in observer manual (thanks @awest03!)
• [docs] Add missing access modifier section to query language manual
• [docs] Add link to storage in pictures to docs
• [docs] Fix broken links in design guide
• [build] Move flecs.c and flecs.h files to distr folder
• [build] Migrate bazel build to bzlmod (thanks @reutermj!)
• [build] Add bazel build definitions for examples and add bazel build/test to CI
• [ci] Add spell check to CI (thanks @Georgiy-Tugai!)

Breaking changes

• The flecs.c and flecs.h have moved to distr (#466)

New Contributors

• @domdom made their first contribution in #1312
• @reutermj made their first contribution in #1301
• @Gaspard-- made their first contribution in #1327
• @awest03 made their first contribution in #1344
• @Georgiy-Tugai made their first contribution in #1353

Full Changelog: v4.0.1...v4.0.2

Highlights

Lots of performance improvements! 🚀

• Queries for sparse components are up to 20x faster
• get, get_mut, has and owns are 1.5-3x faster
• Cached queries are 5x faster to create, and match 1.5x faster with new tables
• Simple uncached queries are up to 2x faster than v4.0.0 (5x faster than v3.2.12)

Release notes

This version includes the following bugfixes:

• [cpp] Fix crash when copying world object during shutdown (thanks @jpeletier!)
• [cpp] Call populate_self recursively for simple query results (thanks @Indra-db!)
• [core] Fix assert when toggling component from stage
• [core] Fix command batching issue that could prevent query rematching
• [core] Fix issues with commands for sparse components
• [core] Fix issue with cloning named entities
• [core] Fix assert when calling emplace after remove while deferred
• [queries] Fix issue with not operator, traversal and wildcards
• [queries] Fix issue with toggleable components and terms with #0 source
• [queries] Fix issue with up traversal and (re)matching empty tables
• [observers] Fix issue with updating observers to different callback kind
• [observers] Fix issue with observer for sparse component (thanks @Megafunk!)
• [systems] Fix issue with updating system to different callback kind
• [script] Fix issue where anonymous entities wouldn't clear after script update
• [script] Fix syntax error for scripts with only a using statement
• [script] Fix issue where unresolved component in template didn't throw an error
• [script] Fix issue with anonymous template instance creation
• [script] Fix issues with partial component assignments
• [script] Fix issues with assigning non-trivial components
• [json] Fix issues in new deserializer, serialize full paths by default
• [json] Fix issue with serializing entity to JSON from stage
• [json] Fix issues with serializing sparse components
• [json] Fix issue with serializing inherited components without reflection data
• [rest] Ensure REST HTTP server always has valid delta_time value
• [rest] Only enable time measurements when OS time API is initialized

This version includes the following improvements:

• [cpp] Add flecs::ref<T> constructor that just takes an entity (thanks @RoyAwesome!)
• [cpp] Add support for iterating sparse component queries with run callback
• [core] Remove id and size fields from ecs_column_t
• [core] Use one size/count member for all table columns
• [core] Add component_map to tables to improve get/get_mut/has/owns performance
• [core] Improve performance of ecs_table_get_*_index functions
• [queries] Add dedicated iterator mode for queries that are fully cached
• [queries] Add dedicated iterator mode for queries that are fully trivial
• [queries] Don't evaluate first term of uncached queries twice
• [queries] Reduce branching in trivial iterator code
• [queries] Remove iterator mode that returned entities one by one
• [queries] Replace ecs_iter_t::columns with table records array
• [queries] Remove ecs_iter_t::ptrs
• [queries] Reduce number of observers created per query
• [queries] Reuse static sources/ids arrays for cached results where possible
• [queries] Don't generate query plan for trivial queries
• [queries] Implement fast query validation for simple queries
• [meta] Add option to provide 0 offset without triggering automatic offset computation (thanks @Indra-db!)
• [script] Suppress variable shadowing warning for parser on msvc
• [json] Remove legacy (v3) deserializer
• [log] Fix incorrect log color comparison (thanks @kagetu!)
• [docs] Replace no_readonly with immediate in system manual
• [docs] Fix link to migration guide
• [docs] Fix grammar in Rust query examples (thanks @waywardmonkeys!)
• [docs] Fix find/replace typos (thanks @waywardmonkeys!)
• [docs] Remove references to EcsIteratble (thanks @waywardmonkeys!)
• [misc] Create .gitattributes to preserve line endings on Windows (thanks @epreston!)
• [ci] Prevent running workflows concurrently for same branch

Benchmark results
https://github.com/SanderMertens/ecs_benchmark/tree/bda57ec04f1cb9ebeacab8a17cf9a0c3353d267b

Breaking changes

• Query results with inherited components now must be explicitly handled in C API (#466 (comment))
• Sparse components must now be obtained with ecs_field_at (#466 (comment))
• The columns/ptrs members got removed from iterators (#466 (comment))
• Member target query results have changed (#466 (comment))

New Contributors

• @epreston made their first contribution in #1294
• @Megafunk made their first contribution in #1299

Full Changelog: v4.0.0...v4.0.1