The other half of the hybrid decision: an application that wants a dialog
box, a score counter or a main menu gets each in one call, without touching a
CLAY() macro -- and an application that outgrows them still has clay's whole
DSL, because the widgets are nothing but functions that declare the same
elements between the same frame bracket.
akgl_ui_dialog is the JRPG textbox in one line: bottom panel spanning the
layout, AKGL_UI_DIALOG_HEIGHT tall, one-pixel border, wrapped text. The NULL
style *is* the textbox palette -- near-black fill, parchment edge and ink,
8px padding -- deliberately, so the widget and the 125-line hand-rolled panel
it stands beside in the comparison chapter produce the same picture. Showing
and hiding is the frame's business: call it while somebody is talking, don't
while nobody is; a declarative frame is the visible flag.
akgl_ui_label pins a fit-sized text chip to a corner or the centre, inset by
the style's padding. akgl_ui_menu declares a centred vertical menu from a
caller-owned struct (no heap layer: it owns no texture, no font, no registry
entry), with the selected row drawn inverted, hover moving the selection and
the frame-latched press edge activating it. akgl_ui_menu_handle_event drives
the same struct from Up/Down/Return and D-pad/South with wrapping, slotting
into the event chain after akgl_ui_handle_event; routing events to a menu is
the application's focus model, stated rather than invented.
Tests cover the dialog's geometry and palette by pixel, label anchoring by
quadrant, menu validation, the inverted highlight, keyboard and gamepad
wrap/activate/pass-through, and the full two-frame mouse protocol -- click
aimed at the second row's real box via Clay_GetElementData, seen by the next
frame's declaration as selection plus activation.
Co-Authored-By: Claude Code (Claude Fable 5, claude-fable-5) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KzBDV2fqgnUAcqCKqKvc71
akgl_ui_handle_event is the mouse half of the input story -- keyboard and
gamepad stay with the control maps, because keyboard focus is something an
application declares rather than something a pointer position implies. It
handles motion, left-button presses and releases, the wheel and window
resizes; everything else, and everything while the subsystem is inert,
reports consumed=false and succeeds, the same pass-everything contract
akgl_controller_handle_event already has. The documented call order is UI
first, control maps second, skipping on consumed.
A press, release or wheel is consumed when the pointer is over any UI
element. The hit test asks clay against the layout the previous frame
retained -- this frame's does not exist while events are polled, and one
frame of staleness is the standard model's accepted cost -- with clay's
internal full-screen Clay__RootContainer excluded, because being inside the
window is not being over the interface (unexcluded, every click anywhere was
consumed; the test that pins this caught it).
Pointer state is fed to clay per event, as clay documents; the press edge is
latched once per frame_begin for the widgets to come, rather than trusting
Clay_PointerData's per-SetPointerState edge, which advances per mouse event.
frame_begin also drives Clay_UpdateScrollContainers from the accumulated
wheel (32 pixels per notch) and a wall-clock dt.
Tests pin the whole contract: pass-through before init, no consumption
before any layout exists, press/release inside vs beside a panel, right
button ignored, motion never consumed, wheel consumed only over the UI,
resize reaching the layout engine, and key events left alone.
Co-Authored-By: Claude Code (Claude Fable 5, claude-fable-5) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KzBDV2fqgnUAcqCKqKvc71
The UI subsystem now draws. akgl_ui_frame_begin/frame_end bracket one frame's
CLAY() declarations: begin clears the error stash and starts the clay layout,
end computes it and walks the render commands through a backend -- RECTANGLE
as (rounded) fills, BORDER as radius-shortened edge fills plus corner arcs,
TEXT through akgl_text_rendertextat one wrapped line per command, IMAGE as an
akgl_Sprite's first frame stretched to the bounding box, and the SCISSOR pair
through akgl_draw_set_clip, cleared again on any exit so a failed frame
cannot leave the world clipped.
akgl_ui_font_register maps registry font names onto clay's uint16_t fontIds.
The table keeps the *name* and resolves it per use -- fonts are not reference
counted, and a cached TTF_Font* would dangle where a name reports "gone"
honestly. Clay_TextElementConfig.fontSize is deliberately ignored: libakgl
bakes the size into the handle at load, so one face at two sizes is two ids.
The measure bridge passes clay's non-NUL-terminated slices straight to
SDL_ttf's explicit-length TTF_GetStringSize -- no copy, no scratch. Its
signature has no error channel, so failures report zero-by-zero and stash a
message that frame_end raises, the same route clay's own void error handler
uses; layout errors take precedence over drawing and one bad frame leaves the
next one clean.
Tests drive real CLAY() layouts through the software renderer and read pixels
back: fill placement, border edges with an empty middle, a child clipped by
its container, text landing in its colour, slice-vs-whole measurement
agreement, fontId table dedupe/refusal/exhaustion, and the bracket's
begin/begin, end-without-begin and failure-recovery contracts.
Co-Authored-By: Claude Code (Claude Fable 5, claude-fable-5) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KzBDV2fqgnUAcqCKqKvc71
clay v0.14 (deps/clay, zlib licence) supplies the layout engine for the new
akgl_ui subsystem. Sources-listed rather than add_subdirectory()'d, on the
semver/libccd precedent: clay's CMakeLists declares no library target, builds
its examples by default, and requires CMake 3.27 against this project's 3.10.
src/ui_clay.c is the one CLAY_IMPLEMENTATION translation unit, compiled -w on
the vendored-code terms but with clay's symbols deliberately exported --
consumers' CLAY() macros resolve against libakgl.so, and akgl/ui.h warns them
never to link a second clay.
The subsystem is runtime-optional the way collision is: always compiled in,
inert until akgl_ui_init(), which bounds clay to the overridable AKGL_UI_*
ceilings, checks Clay_MinMemorySize() against a static BSS arena (no malloc),
and refuses with both numbers in the message when it does not fit. Measured:
812544 bytes at the default 1024 elements / 4096 measured words, against a
1 MiB arena. clay's void-callback layout errors are logged as they happen and
the first is stashed for the error protocol to raise later.
AKGL_ERR_UI joins the status band before AKGL_ERR_LIMIT, named in
akgl_error_init. New `ui` test suite covers validation, the init/shutdown
lifecycle, and arena exhaustion via the akgl_ui_arena_limit test hook (same
contract as akgl_ccd_arena_set_limit). clay.h is installed beside semver.h,
its licence beside libccd's, and the headers suite proves akgl/ui.h
self-contained -- clay.h compiles clean under -Wall.
Co-Authored-By: Claude Code (Claude Fable 5, claude-fable-5) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KzBDV2fqgnUAcqCKqKvc71
