neco-view2d-wasm

WebAssembly bindings for neco-view2d. Exposes the View2d pan/zoom transform to JavaScript via wasm-bindgen.

JavaScript binding surface

WasmView2d mirrors the core pan, zoom, fit, and coordinate-conversion operations of neco-view2d and returns small fixed-shape arrays for JavaScript interop.

Usage

Build with wasm-pack build --target web, then import the generated package from JavaScript.

import init, { WasmView2d } from "./pkg/neco_view2d_wasm.js";

await init();

const view = new WasmView2d();

// pan (dx, dy in canvas pixels, canvas_height)
view.pan(50, 30, 600);

// zoom at canvas point (delta, cx, cy, canvas_width, canvas_height)
view.zoom_at(100, 400, 300, 800, 600);

// coordinate conversion (returns [x, y])
const [wx, wy] = view.canvas_to_world(400, 300, 800, 600);
const [cx, cy] = view.world_to_canvas(wx, wy, 800, 600);

// fit world region into canvas
view.fit(1920, 1080, 800, 600);

// get/set state: [center_x, center_y, view_size]
const [centerX, centerY, viewSize] = view.get_state();
view.set_state(0, 0, 10);

// zoom factor relative to a reference view_size
const factor = view.zoom_factor(viewSize);

API

Item	Description
`new WasmView2d()`	Create a default view -- center `(0, 0)`, view_size `1.0`
`pan(dx, dy, canvas_height)`	Translate the view by `(dx, dy)` in canvas pixels
`zoom_at(delta, cx, cy, cw, ch)`	Zoom at canvas point `(cx, cy)`; `delta > 0` zooms in
`canvas_to_world(cx, cy, cw, ch)`	Canvas coordinates to world coordinates; returns `[wx, wy]`
`world_to_canvas(wx, wy, cw, ch)`	World coordinates to canvas coordinates; returns `[cx, cy]`
`fit(ww, wh, cw, ch)`	Fit a world region into the canvas with margin
`get_state()`	Returns `[center_x, center_y, view_size]`
`set_state(cx, cy, vs)`	Set view state directly
`zoom_factor(ref_view_size)`	Current zoom relative to a reference view_size

License

MIT

neco-view2d-wasm 0.1.0

neco-view2d-wasm

JavaScript binding surface

Usage

API

License