Files
css-matrix-calc/js/preview.js
T

31 lines
1008 B
JavaScript

import { computeHomography } from './homography.js';
function $(id) { return document.getElementById(id); }
export function updateLivePreview(state) {
const container = $('fieldContainer');
const cw = container.clientWidth;
if (cw <= 0) return;
const scale = cw / state.fieldW;
const field = $('field');
field.style.width = state.fieldW + 'px';
field.style.height = state.fieldH + 'px';
field.style.transform = `scale(${scale})`;
container.style.height = (state.fieldH * scale) + 'px';
const widget = $('widget');
widget.style.width = state.widgetW + 'px';
widget.style.height = state.widgetH + 'px';
const H = computeHomography(state);
if (H) {
const n = v => parseFloat(v.toFixed(6));
widget.style.transform = `matrix3d(${n(H.h00)},${n(H.h10)},0,${n(H.h20)},${n(H.h01)},${n(H.h11)},0,${n(H.h21)},0,0,1,0,${n(H.h02)},${n(H.h12)},0,${n(H.h22)})`;
widget.style.opacity = '1';
} else {
widget.style.transform = 'none';
widget.style.opacity = '0.3';
}
}