Flecs v3.1.4

Highlights

• Performance improvements for many core ECS operations! 🎉 (see below)
• A new benchmark suite with more than 100 tests: https://github.com/SanderMertens/ecs_benchmark
• Changes made to an existing component with a deferred get_mut are now immediately visible to systems & other get_mut calls (#466 (comment))

Performance improved in this release for 116 in a total of 120 benchmarks! Here are a few of the most significant improvements between v3.0.0 and v3.1.4 (which also includes improvements from command batching & the observer cache):

Benchmark	v3.0.0	v3.1.4	Difference
has_id	8.92ns	4.38ns	+50.90%
get_id	7.18ns	3.69ns	+48.61%
get_mut_id	12.22ns	7.35ns	+39.85%
set_id	29.13ns	11.85ns	+59.32%
add_remove_1_tag	20.43ns	17.63ns	+13.71%
add_remove_cmd_16_tags	40.40ns	17.55ns	+56.56% (command batching)
get_mut_cmd_16	47.17ns	18.65ns	+60.46% (command batching)
create_delete_tree_depth_10	19.27us	8.24us	+57.25%
emit_propagate_depth_10	1.52us	194.33ns	+87.25% (observer cache)
query_iter_16_tags_4_terms	56.39ns	26.15ns	+53.63%

Release notes

This version includes the following bugfixes:

• Ensure HAVE_EXECINFO is defined on all platforms
• Fix compilation issue on clang 16 (thanks @gorilux!)
• Add missing flecs_cpp.c to the meson build file
• Fix issue where non-instanced query with multiple traversal terms did not match entities
• Fix broken links in documentation
• Remove <strong></strong> from documentation markdown headers
• Fix issue where atomic id generation was used without threading
• Fix issue where flecs::ref would store stage instead of world
• Fix assert in observer cache after deleting parent with relationship to child
• Fix issue with passing string to ecs_set_name that overlaps with current name
• Fix compile error when passing existing object to set<R, T>
• Fix memory corruption when using ecs_bulk_init with existing table
• Fix command batching issue with adding ChildOf pair while removing name

This version includes the following improvements:

• [core] Require entities to be alive for ECS operations
• [core] Deferred ecs_get_mut_id now returns reference to actual component if it exists (thanks @dmlary!)
• [c] Add matching *_DECLARE convenience macro's for each *_DEFINE macro
• [cpp] Add world::get_ref
• [docs] Lots of small improvements to documentation (thanks @copygirl!)
• [docs] Move build instructions from README to Quickstart
• [docs] Improve build instructions for gcc/clang on Windows
• [ux] Add example for entity::emplace
• [internals] Faster map implementation that no longer stores a variable size payload
• [internals] Use array vs. sparse set to lookup id records with low ids
• [internals] Replace usage of ecs_vector_t in sparse set with faster ecs_vec_t
• [internals] Add new/faster sparse set operations that assume id is alive
• [internals] Cleanup sparse set API
• [internals] Replace code of ecs_has_id with faster implementation
• [internals] Remove redundant code from table graph operations
• [internals] Improve performance of defer/suspend mechanism
• [internals] Improve performance of pipelines queries by adding self flag to System term

Breaking Changes:

• Entities now must be alive before using with ECS operations (#466 (comment))
• Deferred get_mut now returns pointer to existing component (#466 (comment))

Known issues:
#844
#765
#714
#620
#478
#314

New Contributors

• @copygirl made their first contribution in #902
• @gorilux made their first contribution in #906
• @dmlary made their first contribution in #908

Full Changelog: v3.1.3...v3.1.4