35a58670d0b0278e3454a2cadbc0e60ee4b0d23f
8 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
35a58670d0
|
Document collision, and correct what it made false elsewhere
The new chapter 15 covers the opt-in setup, where resolution runs in the step and why it runs after the move, shapes and the z-extrusion trap, the asymmetric masks and the defaults that matter more than the mechanism, tiles as a source rather than proxies, the response hook and the three ways it is easy to write wrongly, sensors, the four queries, both partitioners, and what is still not implemented. Collision falsified claims in eight other chapters. The physics chapter said "There is no collision detection, at all" and that collide always raises AKERR_API; actors had six behaviour hooks; the heap had five pools and four non-claiming acquires; the status band held five codes; and the design philosophy had exactly two pluggable subsystems. The appendix gains a collision.h status section, the three new pool ceilings and a table of the collision constants that are deliberately not in a public header. Also fixes chapter labels the renumbering commit left pointing at their old numbers -- "18. Utilities" linked to 19-utilities.md. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01KzBDV2fqgnUAcqCKqKvc71 |
|||
|
bace818998
|
Renumber chapters 15 to 21 up by one, to open a slot for collision
A pure rename plus link rewrite and nothing else. Collision is a pluggable subsystem with two implementations, shapes, a response hook and a tile binding; that is a chapter, and burying it inside the physics chapter is the shape this manual otherwise avoids -- rendering and drawing are 8 and 9, spritesheets and characters and actors are 10, 11 and 12. Kept separate from writing the chapter because **nothing validates a cross-reference target.** The example harness reads fenced blocks; it does not follow links. A rename mixed into five hundred lines of new prose is not reviewable, and a broken link would land silently. As its own commit it is reviewable as a rename, and a grep for dangling `](NN-` targets is clean. Co-Authored-By: Claude Code <noreply@anthropic.com> Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
|||
|
fcad2822a9
|
Measure collision, and say which numbers moved for what reason
Seven new benchmark rows, budgets set from a measured full-scale run rather than guessed, and the three existing rows the work moved re-recorded from that same run. The all-pairs sweep stays and is relabelled `control:` -- it is the cost a caller paid before the library had a broad phase, measured on the same machine in the same run, which is the only honest way to read a reduction. What the numbers say: - The box fast path is two to seven times cheaper than the general solver, and the disjoint case is cheaper still because the proxies' bounds reject it before any shape arithmetic runs. 9 to 20 ns is what a tile game actually pays. - The grid beats the tree by 2.6x on the same population, which is the argument for the default measured here rather than cited from another engine. The tree also rebuilds on every move and that is not in its row, so a moving scene is worse than 2.6x. - A grid `move` that changes nothing is 11.5 ns. That is the incremental claim in one number. Two rows moved on a backend with **no collision world attached**, so no collision code runs in either, and the commit says so rather than letting the feature take credit: - akgl_Actor grew from 415 to 464 bytes -- a 40-byte shape, an override flag and a proxy pointer. The step sweeps the whole pool, so that is about 3 KB more working set per frame. The empty-pool row is unchanged at 58.7 ns, which is what identifies the cost as per live actor rather than per slot. - Reaching the collision check through CATCH cost more than the check. PASS and CATCH call akerr_valid_error_address, which walks AKERR_ARRAY_ERROR, so an early-returning function is not free when it is reached through one. The no-collision path now routes around the machinery entirely, which took the 64-actor sweep from 2,018.7 ns back to 1,588.5. AGENTS.md records that lesson for writing benchmarks; this is the same thing in production code. The remainder is the struct, and it is paid whether or not a game uses collision. Co-Authored-By: Claude Code <noreply@anthropic.com> Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
|||
|
842ef75ddf
|
Report the overlap akgl_collide_rectangles could not see
It asked whether either rectangle enclosed one of the other's four corners -- eight akgl_collide_point_rectangle calls, stopping at the first hit. That is a different question from "do these overlap", and it has the wrong answer for one arrangement: a tall thin rectangle crossing a short wide one overlaps in a plus sign with no corner of either inside the other, and all eight tests said no. A long thin platform crossing a tall thin character is exactly that shape, so this is a shape a 2D game produces, not a curiosity. util.h carried an @note describing it and docs/18-utilities.md had a diagram of it, both under the heading of a limitation rather than a defect, and there was no test for it at all -- nor for full containment, nor for a shared edge. It is four comparisons now, on both axes. `<=` rather than `<` because akgl_collide_point_rectangle is inclusive on all four edges and these two have always agreed that touching counts; a span test written with `<` would have silently changed a contract both the header and the manual state. The test was written first and failed on the cross before the fix went in. Two answers change for a caller upgrading, and both are in the header note and the chapter: - The cross reports `true`, which is the point. - The comparison is in float rather than through akgl_Point's int members, so a sub-pixel overlap is no longer truncated away. A pickup test that was accidentally forgiving by up to a pixel is no longer forgiving. Both tutorials use this for coins and hazards; both still pass. Faster as a side effect rather than a goal, and worth recording because the numbers move a documented budget: 24.9 ns -> 6.1 overlapping, 57.9 -> 6.1 disjoint, and the all-pairs sweep over 64 actors 115 us -> 12.2. The disjoint case gained most because it was the one that ran all eight tests before answering. The three moved rows are re-recorded in PERFORMANCE.md and nothing else is. akgl_rectangle_points is untouched by this change and reads 6.1 in the same run against the 4.0 recorded, so 6 ns is this run's floor and the new figure means "too cheap to measure" rather than "exactly 6.1" -- said in the prose so the next reader does not re-baseline the table around it. Co-Authored-By: Claude Code <noreply@anthropic.com> Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
|||
|
943bf4324e
|
Let a control map listen to any keyboard, and fix the dead arrow keys
The sidescroller's controls did nothing. `akgl_controller_handle_event` matched `event->key.which == curmap->kbid` exactly, with no way to say "whatever keyboard the player is typing on", so the game did the obvious thing and bound `SDL_GetKeyboards()[0]`. That cannot work. The id a key event *carries* is chosen by the video backend and is not required to be an id `SDL_GetKeyboards()` reports. On X11 without XInput2 every key event carries `SDL_GLOBAL_KEYBOARD_ID`, which is 0, while `SDL_AddKeyboard` registers the attached keyboard as `SDL_DEFAULT_KEYBOARD_ID`, which is 1; with XInput2 the events carry the physical slave device's `sourceid` while `SDL_GetKeyboards()[0]` may be the master. Either way the map matched nothing and every key press was dropped. A `kbid` or `jsid` of 0 now matches any device of that kind. 0 is safe to spend: SDL documents `which` as 0 when the source is unknown or virtual, and joystick ids start at 1, so no real device is 0. A non-zero id still matches only that device, which is what keeps two local players on two keyboards apart, and there is a test for that half too. `util/charviewer.c` already passed 0 and depended on the old behaviour by accident; it works under XInput2 now as well. Two reasons this shipped, both closed: - Every test in tests/controller.c dispatched an event whose id equalled the id the map was bound with, so none of them could see it. - The sidescroller's smoke test called the control handlers directly instead of dispatching events, so it passed against a control map that matched nothing. It now pushes synthetic events through akgl_controller_handle_event from a deliberately non-zero device id and fails if the press does not arrive. Verified by breaking the binding and watching the run exit non-zero. `test_controller_wildcard_device_ids` was written first and failed against the unfixed library with "a map bound to keyboard 0 ignored a key press from device 11", which is the whole reason to trust it now that it passes. The controls were documented, in one sentence. Chapter 19 has a proper table of them, and chapter 15 explains why not to reach for SDL_GetKeyboards(). The header said the match was exact and now says what it does. Co-Authored-By: Claude Code <noreply@anthropic.com> Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
|||
|
88aaa184e4
|
Add two tutorial games that build, run in CI, and cannot drift
examples/sidescroller and examples/jrpg are complete programs, built with the library and exercised headless by ctest. The chapters quote them with `c excerpt=examples/...` blocks rather than restating the code, so a chapter cannot drift from a program that compiles -- the excerpt check fails the moment the source moves. 34 excerpts in one chapter, 21 in the other. The two are complementary. The sidescroller is the physics tutorial: gravity, a jump, coins, hazards. The JRPG is the content-pipeline tutorial: a town map, NPCs spawned from map objects, four-way per-facing animation, a text box, a follower. Both smoke tests drive real SDL_Events through akgl_controller_handle_event and step the physics clock at a fixed 1/60s rather than sleeping, so a scripted run is deterministic and finishes in under five seconds. Writing them is what turned up most of the defects recorded in the next commit, because a game exercises paths a unit test does not. Each workaround says in the chapter which library gap forced it: - collision is written in a custom movementlogicfunc, because akgl_physics_arcade_collide raises AKERR_API and akgl_physics_simulate never calls collide at all; - the sidescroller cancels the step's own gravity when it blocks downward, because otherwise a quarter-pixel of penetration makes the *horizontal* sweep report blocked and the character walks backwards a tile at a time; - both clear movement_controls_face on every map-spawned actor, because the default facefunc leaves a stopped actor with no facing bit, no sprite, and no draw; - the JRPG's follower gets a renderfunc that nulls obj->parent for the duration of the draw, because a child's offset is counted twice. Assets are CC0 from three Kenney packs, vendored with per-pack licence text, per-file provenance, and the geometry contract in docs/tutorials/assets/README.md. CC0 specifically rather than merely free: a reader who copies a tutorial into their own game inherits no obligation. scripts/fetch_tutorial_assets.sh refreshes them in the shape mkcontrollermappings.sh was fixed into for 0.5.0 -- it checks curl's status, refuses a pack page that does not say CC0, verifies the archive and the staged dimensions, and leaves the tracked bytes untouched on any failure. Both failure paths were tested, and a no-op refresh is byte-identical. Co-Authored-By: Claude Code <noreply@anthropic.com> Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
|||
|
b938460127
|
Add the manual: nineteen chapters and a corrected README
docs/ is a narrative manual, not a second reference. Every header already carries a substantial @file/@brief block and Doxyfile sets WARN_IF_UNDOCUMENTED with WARN_AS_ERROR, so an undocumented symbol already fails CI. The gap was navigation and worked examples. Chapters teach a task and link to the Doxygen output; where a declaration or a constant table has to be in front of the reader it arrives as a `c excerpt=` block, so the text *is* the header and cannot diverge from it. That also preserves the hand-aligned bit-flag tables scripts/reindent.el goes out of its way not to destroy. The manual does not re-document its dependencies. libakerror owns the ATTEMPT/CLEANUP/PROCESS/HANDLE/FINISH protocol, SDL3 owns renderers and events, Tiled owns the map format, jansson owns json_t. A chapter that restated any of them would be wrong the day upstream changed and nothing here would notice -- the same drift this work exists to fix, arriving from a different direction. So each chapter says what libakgl adds or constrains and links out for the rest. Chapter 4 is the exception and the reason for it: libakerror documents the mechanism, but only libakgl can say which statuses its own functions raise and what they mean here, and that was written down nowhere. It carries three tables -- libakgl's five status codes, the libakerror statuses libakgl actually raises with their meaning in this library, and the exit-status trap where `exit(AKGL_ERR_SDL)` is a wait status of 0 because the band starts at 256. Every chapter was written against src/ rather than against the header comments, which is how 27 false claims in those comments came to light. Where a chapter documents a known defect rather than a design decision it says so and points at TODO.md. README.md keeps the development process and hands the reader to docs/. Its task-oriented FAQ is deleted rather than moved, because one source of truth per topic is the whole point and that FAQ's examples did not compile. Census: 39 compiled snippets, 89 verbatim header excerpts, 4 JSON documents run through the real loaders, one linked-and-executed program with its output compared byte for byte, one generated figure. 11 norun blocks, each justified. Co-Authored-By: Claude Code <noreply@anthropic.com> Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
|||
|
8ac291d2dd
|
Compile, link and run every example in the documentation
libakgl exports 157 functions and the only user-facing documentation was a FAQ in README.md whose examples did not compile: two unbalanced `PASS()` calls, a `sprite->frameids = [0, 1, 2, 3];` that is not C in any dialect, a stray `9` inside a bitmask expression, an `int screenwidth = NULL`, and -- in the first snippet a reader ever saw -- the exact `strncpy` call AGENTS.md forbids. That is not a reader routing around typos. It is what happens to samples that nothing executes. This is akbasic's documentation harness with the interpreter taken out and the ability to link and run put in. The contract is a set of fence info strings, so an example is ordinary markdown that still highlights on the forge: ```c compiled with -fsyntax-only -Wall -Werror ```c wrap=NAME the same, wrapped in tests/docs_preludes/NAME.pre/.post ```c run=NAME linked against akgl and run headless ```c excerpt=PATH must still appear verbatim in PATH ```c screenshot=NAME also the source of docs/images/NAME.png ```json kind=KIND loaded through the real akgl_*_load_json ```output the exact stdout of the runnable block above it `run=` is why this links at all: -fsyntax-only proves a call typechecks, not that the startup order works or that an ATTEMPT block gives back what it took. `json kind=` exists because the asset formats are documented in prose and read by four loaders with nothing tying the two together -- util/assets/littleguy.json is already invalid against the loader it ships with. A fence with no info string is a hard error, and so is an unknown one. The failure mode this exists to prevent is passing because it quietly ran nothing, so an unannotated block is a missing decision rather than a default. Exit status is the number of failed examples; 2 for a usage error, which is a different thing and has to be distinguishable. Proven to fail on all ten of its failure modes -- untagged fence, non-compiling snippet, stale excerpt, orphan output block, unknown info string, run= output mismatch, invalid JSON, missing figure, a -Werror warning, and a dangling preload= -- because a check that has never failed has not been tested. `-Werror` here although AKGL_WERROR stays off for the library: that option is off so a new compiler's diagnostic cannot break a consumer's build, and a doc snippet is not a consumer. A sample that warns is a sample that teaches the warning. Registered as `docs_examples` and `docs_screenshots`. No docs-path filter in CI, deliberately: documentation goes stale because the code moved, not because somebody edited a chapter. Co-Authored-By: Claude Code <noreply@anthropic.com> Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
