simvx.graphics.platform._sdl3

SDL3 windowing backend with multitouch support.

Module Contents

Classes

Sdl3Backend

WindowBackend implementation using SDL3.

Data

__all__
log

API

simvx.graphics.platform._sdl3.__all__

[‘Sdl3Backend’]

simvx.graphics.platform._sdl3.log

‘getLogger(…)’

class simvx.graphics.platform._sdl3.Sdl3Backend

WindowBackend implementation using SDL3.

Provides keyboard, mouse, and multitouch input. Touch events are delivered with window-relative coordinates via the touch_callback.

Initialization

supports_gamepads

True

create_window(width: int, height: int, title: str, *, visible: bool = True) → None

create_graphics_surface(instance: Any) → Any

get_required_instance_extensions() → list[str]

poll_events() → None

should_close() → bool

get_framebuffer_size() → tuple[int, int]

get_window_size() → tuple[int, int]

get_content_scale() → tuple[float, float]

set_title(title: str) → None

set_key_callback(callback: collections.abc.Callable[[int, int, int], None] | None) → None

set_mouse_button_callback(callback: collections.abc.Callable[[int, int, int], None] | None) → None

set_cursor_pos_callback(callback: collections.abc.Callable[[float, float], None] | None) → None

set_scroll_callback(callback: collections.abc.Callable[[float, float], None] | None) → None

set_char_callback(callback: collections.abc.Callable[[int], None] | None) → None

set_resize_callback(callback: collections.abc.Callable[[int, int], None] | None) → None

property paused: bool

Whether the app is paused (backgrounded on mobile).

set_lifecycle_callback(callback: collections.abc.Callable[[str], None] | None) → None

Set lifecycle event callback. Receives ‘paused’ or ‘resumed’.

set_touch_callback(callback: collections.abc.Callable[[int, int, float, float, float], None] | None) → None

Set touch event callback.

Args: callback: (finger_id, action, x, y, pressure) where action is 0=down, 1=up, 2=move. x,y are in window pixel coordinates.

get_cursor_pos() → tuple[float, float]

set_cursor_shape(shape: int) → None

Set cursor shape. 0=arrow, 1=ibeam, 2=crosshair, 3=hand, 4=hresize, 5=vresize.

set_mouse_capture(mode: int) → None

Apply a MouseCaptureMode int (0=visible, 1=hidden, 2=captured, 3=confined) to the OS cursor.

Each SDL symbol is guarded with getattr: the sdl3 binding may not expose all of them, in which case the call is skipped (debug-logged) rather than crashing.

Under CAPTURED, relative mode is enabled and poll_events integrates the per-event xrel/yrel into a virtual cursor position (self._relative), so the shared delta path tracks motion while the OS cursor is locked.

set_window_size(width: int, height: int) → None

request_close() → None

poll_gamepads() → list[tuple[int, dict[str, bool], dict[str, float]]]

Poll all connected gamepads. Returns list of (id, buttons, axes).

Each pad is opened once and its handle held until the pad goes away or the window is destroyed. Opening and closing per poll would make SDL generate a connect and a disconnect event every frame and throw both away, and it costs a device open sixty times a second per controller.

SDL reports sticks as signed 16-bit and triggers as 0..32767;

Func:

gamepad.normalise_axes maps both onto the engine’s convention.

destroy() → None