6 Commits

Author	SHA1	Message	Date
Andrew Kesterson	a9600c3fcc	Say what was hit, which way is out, and how far ... The narrowphase has been producing a contact since it went in, and the interpreter was throwing it away. `RCOLLISION(n, f)` reports it: what was hit (a sprite or a `SOLID` rectangle), which one, the contact normal, the penetration depth, the contact point, and which axis to reverse. **The normal points out of the other thing and toward this one**, so a program moves along it by the depth and is exactly clear. That sign is the one assertion in the new test that could not be caught any other way -- both parties of a sprite-against-sprite hit get their own record, each pointing the way *that* sprite has to move, and sharing one would tell both to go the same direction, which is how two things end up stuck inside each other. **Field 7 is the one that deletes the most BASIC.** It is the minimum translation axis, computed from the normal in C, and it is there because doing it in BASIC means comparing two floats -- which is exactly where this dialect's left-operand rule catches people. `BALLBRICKS`/`TESTCELL` in the artwork breakout spend six lines computing an overlap rectangle and comparing its width to its height to get this number. The record is **sticky and deepest-wins**: replaced whenever that sprite is in a contact and otherwise left alone, so `BUMP` stays the event and this stays the detail of it. Making it clear itself when nothing touches would break the pairing, because `BUMP` accumulates across steps and a once-a-frame poll would find the detail already gone. Reading `BUMP` clears both, so they cannot disagree. Deliberately narrower than `akgl_Contact`: no actor pointers, because BASIC has no actor; no tile fields, because there is no tilemap; no z, because every test is planar; and **no `dt` and no `sensor`**, which libakgl documents as filled in by the resolver. This interpreter never resolves anything, so those two come back zero and mean nothing, and an always-zero field in a reference table is a lie. Documented with the two caveats that matter: fields 2, 3 and 4 are floats and want a `%` variable, and the contact *point* is exact only for two boxes -- libakgl's solver returns a point on the portal it converged to, while the normal and depth are exact for every pair. Chapter 8's collision section stops claiming only type 1 exists, which has been false since the previous commit. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01EwxGB6TdoVvZ11KQQME9cL	2026-08-02 10:53:26 -04:00
Andrew Kesterson	802bbcc17a	Collide sprites with rectangles that are not sprites ... `SOLID id, x1, y1, x2, y2` registers static collision geometry; `SOLID id` retires one and a bare `SOLID` retires them all, the way `TRAP`, `COLLISION` and `DCLOSE` all read absence. `COLLISION 2` and `BUMP(2)` stop being refused and mean *sprite met static geometry*. **This is the thing eight sprite slots made impossible.** A wall of bricks wants sixty, so until now a program could only collide with one by doing the arithmetic itself against its own array -- which is exactly what both breakout listings do, at about two hundred lines between them. A rectangle costs no sprite slot. The id is the **program's own number**, 1 to 64, not a minted handle. That is the whole trick for "which brick did I hit": the id comes back out again, so a wall built as `SOLID I#, ...` maps onto `B#(I#)` with no lookup, and retiring a broken brick is `SOLID I#`. `COLLISION 2` was refused with "sprite-to-background collision needs the screen read back every frame", which was true of the question a C128 asks -- a sprite against the bitmap's set pixels. `SOLID` gives this interpreter a background made of rectangles instead, which is the same question in a form it can answer. Same move `SPRSAV` made when it learned to take an image path. `AKBASIC_INTERRUPT_BACKGROUND` has been sitting in the interrupt table commented "COLLISION 2 -- sprite met background; refused" the whole time. Its accumulator is separate, so a sprite hitting a wall never sets a bit in `BUMP(1)`. **There is no `akgl_CollisionWorld` here, and that is deliberate.** libakgl's uniform grid keeps its cell heads, cell size and origin in file-scope statics, so it is one index per process -- and `akgl_collision_world_init()` ends in a `reset()` that memsets those heads *and* calls `akgl_heap_init_collision_cells()`. An interpreter embedded in a game with its own collision world would have destroyed every registration that game had made, on the first `SOLID` a script ran. So the geometry is indexed by an ordinary array here and pairs go straight to `akgl_collision_test()`, which needs no world. At sixty-four rectangles that is the right answer anyway; libakgl's own numbers put a naive sweep at 0.7% of a frame at sixty-four objects. **The scan now short-circuits when nothing has moved**, and that is what makes any of it affordable. Its inputs are the sprites' boxes, which slots are collidable, and the static geometry; if none changed the answer cannot have. A frame runs one full scan and 255 cached ones. Eight sprites against sixty-four rectangles is five hundred and twelve tests -- fine once a frame, ruinous 256 times. The benchmark was rewritten to say which path it is timing, because with the cache in place a loop that only calls the scan measures the short circuit and nothing else. Breakout now costs 590.6 ns for its one full scan plus 255 cached at 40.0, which is 10.8 us against a 1.19 ms frame -- **0.91%, less than the 2.0% it cost before any of this work**, with static geometry and contacts added on top. `NEW` retires the rectangles, where it cannot undefine a sprite pattern: there *is* an entry point for this one, so leaving them would be a choice, and the wrong one -- a rectangle is invisible, so one left behind by a deleted program is an unexplainable collision in the next. `CLR` leaves them alone. `tests/sprite_verbs.c` gains the whole second path against the mock and its `COLLISION 2` case is rewritten: it pinned the refusal, and now pins that type 2 arms its own handler without disturbing type 1's. `tests/akgl_backends.c` gains the end-to-end version, including a full sixty-four-rectangle wall so the proxy budget is exercised at its ceiling and the pool has to come back intact, and the sixty-fifth refused by name. A bare `SOLID` needed `akbasic_parse_optional_arglist` rather than `akbasic_parse_arglist`, which `DCLOSE` already uses for the same shape. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01EwxGB6TdoVvZ11KQQME9cL	2026-08-02 10:25:35 -04:00
Andrew Kesterson	5c5bf63356	Draw into the whole window, not its top-left 320x200 ... The graphics verbs documented a coordinate transform that did not exist. With SCALE off a coordinate went straight to akgl_draw_* as a pixel address, so an 800x600 window drew a C128 listing into its corner and left the rest unused -- while the chapter said coordinates were 320x200 and stretching to fit was the host's business. akbasic_GraphicsBackend gains a size entry point, require_graphics() asks it before every verb that draws so a resized window is honoured between two statements, and 320x200 becomes the fallback for a backend that leaves it NULL. It is the record's one optional member, so a host written against the old header keeps the behaviour it had. SCALE now maps onto the device, and RGR(1)/RGR(2) report the drawing surface so a program can use a window whose size it did not choose. RGR(0) is BASIC 7.0's own field, the GRAPHIC mode. SCALE also mapped xmax onto the width rather than onto the last pixel, so SCALE 1, 319, 199 followed by DRAW 1, 319, 199 drew nothing at all -- one pixel past the surface. Fixed in the same line, because it is what makes "SCALE gives a C128 listing the whole window" true rather than nearly true. The akgl test renders against a 128x128 target, deliberately smaller than the old constants: a SCALE still dividing by them misses it entirely rather than landing somewhere plausible. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-08-01 07:35:20 -04:00
Andrew Kesterson	9845e77a5c	Finish the language: every remaining verb group, and the defects that blocked them ... Closes groups A, C, D, E, F, H and J of TODO.md section 4, plus RESTORE and RENUMBER, and closes section 6 -- all seventeen reference defects. Seven of those turned out to have been fixed or never ported and nobody had written it down; the audit records the evidence for each. Two of the seventeen were real. math_plus mutated its left operand when the operand was mutable, so A# + 1 could modify A#; it was gated on FOR/NEXT coverage because NEXT relied on the mutation, so tests/for_next.c came first and NEXT now writes the counter back itself. And the binary operators summed both numeric fields of their right operand, which no BASIC program can reach -- that one needed a test written against the value API. Writing the tests turned up eight defects nobody had listed. Seven are fixed: IF A = 2 THEN was a parse error; only == worked IF ... AND ... was a parse error, because a condition parsed as one relation IF A = 1 OR B = 2 THEN was silently always false, and so was IF A THEN EXIT before any NEXT restarted the program and exhausted the variable pool READ never found a DATA line above it, and swallowed the lines between PRINT 2 + 2 at the prompt was filed as program text instead of answering a short read discarded its bytes, so COPY produced empty files every verb taking an argument list said "peek() returned nil token!" on none The eighth is not fixed and cannot be quietly: a FOR whose step overshoots runs its body one extra time, and FOR I = 1 TO 1 runs it zero times. The two errors cancel for a step of 1, which is why neither was noticed. Correcting them changes the expected output of a checked-in acceptance file, and tests/reference/README.md forbids editing one to suit this interpreter. It is tests/for_semantics.c in AKBASIC_KNOWN_FAILING_TESTS, asserting the correct contract, and TODO.md items 19 and 20. Sprites are real libakgl actors with a renderfunc of their own, because akgl_actor_render draws every sprite square and an actor has no per-axis scale. Both are filed upstream. SPRSAV takes an image file, an SSHAPE handle or a 63-element integer array -- a string here cannot hold a zero byte. Verbs that need hardware that does not exist are refused by name with the reason rather than faked: SYS, HEADER, COLLECT, BACKUP, BOOT, FILTER, and DIRECTORY, which is refused for a missing libakstdlib wrapper filed upstream. 94 tests in the default build, 93 with SDL, 94 under ASan and UBSan, doxygen clean. The Go acceptance corpus stayed green throughout. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 21:50:37 -04:00
Andrew Kesterson	fca9ad4a89	Consume libakgl 0.3.0: every workaround deleted, two capabilities gained ... 0.3.0 closed all ten API gaps this port had filed. The four workarounds go with them: the CMake block that declared libakgl's vendored dependencies by hand, the akgl/actor.h include in three files, and the six vtable pointers assigned by hand in two more, now akgl_render_bind2d(). Two gaps were capabilities rather than inconveniences, and both are now real: The line editor takes the composed UTF-8 text the ring carries in preference to the keycode, so shifted characters, keyboard layouts, compose keys and dead keys all work. A double quote can be typed, which means a BASIC string literal can be typed -- the sharp end of the old limitation. Letters are no longer folded to upper case. SOUND's dir/min/step reach akgl_audio_sweep instead of being refused. dir 3 sweeps once rather than oscillating and TODO.md section 5 says so. A backend with no sweep still refuses the swept note and plays the held one. The adaptors now carry an AKGL_VERSION_AT_LEAST(0, 3, 0) floor, verified by temporarily demanding 0.4.0 and watching it fire. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 13:25:14 -04:00
Andrew Kesterson	9b9dd09c5a	Reach hardware through backend records, and take the time from the host ... Groups G, I and E are unblocked but cannot be written yet: the core library is free of SDL and builds with no libakgl present, so a graphics verb cannot call akgl_draw_* and a sound verb cannot call akgl_audio_*. This adds what they call instead. Three records of function pointers -- akbasic_GraphicsBackend, _AudioBackend and _InputBackend -- in the same shape as akbasic_TextSink, and the same shape libakgl uses for akgl_RenderBackend. akbasic_runtime_set_devices() attaches any subset; all three may be NULL and that is the standalone driver's normal state, so a runtime with no backends still comes up and still prints. A verb that needs one it was not given raises the new AKBASIC_ERR_DEVICE rather than dereferencing a NULL vtable. Two decisions worth stating. The graphics record has no circle entry point: BASIC 7.0's CIRCLE takes two radii, an arc range, a rotation and a degree increment, which makes it a polygon by definition, so it will be built from line calls rather than from akgl_draw_circle. And coordinates are double rather than an integer pixel address, because SCALE makes them fractional and rounding at each verb rather than once at the backend accumulates drift along a polyline. akbasic_runtime_settime() is how SOUND, PLAY and TEMPO get a clock without the library reading one. Section 1.6 forbids blocking or owning a loop, so the caller that owns the frame owns the time -- which is what libakgl already does, since akgl_actor_logic_changeframe takes curtimems as an argument. Left unset it is zero and every duration expires immediately: audible, but never a hang. AKBASIC_ERR_LAST is a sentinel rather than a status, so tests/error_codes.c walks every code looking for an unnamed one without anybody remembering to widen the loop when a code is added. tests/mockdevice.h records every backend call as a formatted line. The graphics and audio verbs emit nothing a golden file can compare, so that log is where their assertions have to live -- and since it needs no SDL, the whole of groups G, I and E stays testable in the default build. 62/62 ctest, clean under -Wall -Wextra, doxygen clean. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>	2026-07-31 08:07:23 -04:00