Zinc Next: window and input
zinc run app.tsx on a program that uses zinc:gfx or zinc:ui opens a window (the SDL HAL of the old runtime, targets/macos/hal_sdl.cpp) and runs
until it is closed; the same holds for programs built with zinc build. A run with ZINC_DETERMINISTIC=1, ZINC_HEADLESS=1, ZINC_RECORD or
ZINC_REPLAY, or an engine built without SDL3, uses the headless HAL: virtual clock, fixed time step of 1/60 s, no window. Tests and goldens use that one.
Both HALs are in one binary: their hal_* functions are renamed at compile time and src/host/hal_dispatch.cpp forwards to one of them when the
program starts. With a window the time step is measured (at most 0.1 s) and a frame lasts at least 8 ms; ZINC_FRAMES=n still ends a run after n frames.
Input
Every input function of zinc:gfx (pointer, buttons, wheel and trackpad scroll, pinch, touch, pen, keys, typed text, text-input requests, clipboard,
cursor, Escape) reads the HAL through host calls (Rt::HostGfx*, one table in include/zn/runtime.h). A frame starts with HostGfxPoll: input is
read, then the time step is taken, as in the old runtime’s loop.
Headless runs can be scripted with ZINC_INPUT=file, one event per line, <frame> <event>:
5 move 57 201 # pointer to (57, 201)
8 down # press the left button (also: up, right-down, right-up)
10 key Backspace # a key (names as in KeyboardEvent.key; modifiers after: shift ctrl alt meta)
12 text zinc # typed text: one word
13 text "two words" # or a whole string in quotes, spaces included (\" and \\ for a quote and a backslash, ZN-688)
15 wheel 0 -3 # scroll steps (x, y)
20 touch 7 300 200 # finger 7 lands at (300, 200), or moves there; up to 10 fingers at once, each held until its touchup
24 touchup 7 # finger 7 liftsWith windows beside the main one (ZN-663), window N sends the events after it in the same frame to window N, and close closes the window the
events go to, as its close button would.
Touch points reach touchCount, touchId, touchX and touchY in landing order, and the first finger is also the pointer, as on a touch
screen (tests/t1/input_touch.sh): a multi-touch session (two hands, pinch, rotate) is a file of such lines.
The events reach zinc:ui as a window’s would, so the whole chain is tested: tests/golden/ui/click.tsx (a button press fills a progress bar) and
type.tsx (typing and Backspace in a text field), with goldens made here and checked by eye.
Checked and not
tests/t1/input.sh (scripted pointer and keys, clipboard, the window HAL on SDL’s dummy video driver), tests/t2/input_aot.sh (the same in a
compiled program). A real window was opened and ran 180 frames at vsync speed; mouse and keyboard through the operating system were not exercised
(the scripted events take the same path from the HAL up).