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import {GUI} from '../../examples/jsm/libs/lil-gui.module.min.js';
{
function outlineText(ctx, msg, x, y) {
ctx.strokeText(msg, x, y);
ctx.fillText(msg, x, y);
}
function arrow(ctx, x1, y1, x2, y2, start, end, size) {
size = size || 1;
const dx = x1 - x2;
const dy = y1 - y2;
const rot = -Math.atan2(dx, dy);
const len = Math.sqrt(dx * dx + dy * dy);
ctx.save();
{
ctx.translate(x1, y1);
ctx.rotate(rot);
ctx.beginPath();
ctx.moveTo(0, 0);
ctx.lineTo(0, -(len - 10 * size));
ctx.stroke();
}
ctx.restore();
if (start) {
arrowHead(ctx, x1, y1, rot, size);
}
if (end) {
arrowHead(ctx, x2, y2, rot + Math.PI, size);
}
}
function arrowHead(ctx, x, y, rot, size) {
ctx.save();
{
ctx.translate(x, y);
ctx.rotate(rot);
ctx.scale(size, size);
ctx.translate(0, -10);
ctx.beginPath();
ctx.moveTo(0, 0);
ctx.lineTo(-5, -2);
ctx.lineTo(0, 10);
ctx.lineTo(5, -2);
ctx.closePath();
ctx.fill();
}
ctx.restore();
}
const THREE = {
MathUtils: {
radToDeg(rad) {
return rad * 180 / Math.PI;
},
degToRad(deg) {
return deg * Math.PI / 180;
},
},
};
class DegRadHelper {
constructor(obj, prop) {
this.obj = obj;
this.prop = prop;
}
get value() {
return THREE.MathUtils.radToDeg(this.obj[this.prop]);
}
set value(v) {
this.obj[this.prop] = THREE.MathUtils.degToRad(v);
}
}
function dot(x1, y1, x2, y2) {
return x1 * x2 + y1 * y2;
}
function distance(x1, y1, x2, y2) {
const dx = x1 - x2;
const dy = y1 - y2;
return Math.sqrt(dx * dx + dy * dy);
}
function normalize(x, y) {
const l = distance(0, 0, x, y);
if (l > 0.00001) {
return [x / l, y / l];
} else {
return [0, 0];
}
}
function resizeCanvasToDisplaySize(canvas, pixelRatio = 1) {
const width = canvas.clientWidth * pixelRatio | 0;
const height = canvas.clientHeight * pixelRatio | 0;
const needResize = canvas.width !== width || canvas.height !== height;
if (needResize) {
canvas.width = width;
canvas.height = height;
}
return needResize;
}
const diagrams = {
dotProduct: {
create(info) {
const {elem} = info;
const div = document.createElement('div');
div.style.position = 'relative';
div.style.width = '100%';
div.style.height = '100%';
elem.appendChild(div);
const ctx = document.createElement('canvas').getContext('2d');
div.appendChild(ctx.canvas);
const settings = {
rotation: 0.3,
};
const gui = new GUI({autoPlace: false});
gui.add(new DegRadHelper(settings, 'rotation'), 'value', -180, 180).name('rotation').onChange(render);
gui.domElement.style.position = 'absolute';
gui.domElement.style.top = '0';
gui.domElement.style.right = '0';
div.appendChild(gui.domElement);
const darkColors = {
globe: 'green',
camera: '#AAA',
base: '#DDD',
label: '#0FF',
};
const lightColors = {
globe: '#0C0',
camera: 'black',
base: '#000',
label: 'blue',
};
const darkMatcher = window.matchMedia('(prefers-color-scheme: dark)');
darkMatcher.addEventListener('change', render);
function render() {
const {rotation} = settings;
const isDarkMode = darkMatcher.matches;
const colors = isDarkMode ? darkColors : lightColors;
const pixelRatio = window.devicePixelRatio;
resizeCanvasToDisplaySize(ctx.canvas, pixelRatio);
ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
ctx.save();
{
const width = ctx.canvas.width / pixelRatio;
const height = ctx.canvas.height / pixelRatio;
const min = Math.min(width, height);
const half = min / 2;
const r = half * 0.4;
const x = r * Math.sin(-rotation);
const y = r * Math.cos(-rotation);
const camDX = x - 0;
const camDY = y - (half - 40);
const labelDir = normalize(x, y);
const camToLabelDir = normalize(camDX, camDY);
const dp = dot(...camToLabelDir, ...labelDir);
ctx.scale(pixelRatio, pixelRatio);
ctx.save();
{
{
ctx.translate(width / 2, height / 2);
ctx.beginPath();
ctx.arc(0, 0, half * 0.4, 0, Math.PI * 2);
ctx.fillStyle = colors.globe;
ctx.fill();
ctx.save();
{
ctx.fillStyle = colors.camera;
ctx.translate(0, half);
ctx.fillRect(-15, -30, 30, 30);
ctx.beginPath();
ctx.moveTo(0, -25);
ctx.lineTo(-25, -50);
ctx.lineTo( 25, -50);
ctx.closePath();
ctx.fill();
}
ctx.restore();
ctx.save();
{
ctx.lineWidth = 4;
ctx.strokeStyle = colors.camera;
ctx.fillStyle = colors.camera;
arrow(ctx, 0, half - 40, x, y, false, true, 2);
ctx.save();
{
ctx.strokeStyle = colors.label;
ctx.fillStyle = colors.label;
arrow(ctx, 0, 0, x, y, false, true, 2);
}
ctx.restore();
{
ctx.lineWidth = 3;
ctx.strokeStyle = 'black';
ctx.fillStyle = dp < 0 ? 'white' : 'red';
ctx.font = '20px sans-serif';
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';
outlineText(ctx, 'label', x, y);
}
}
ctx.restore();
}
ctx.restore();
}
ctx.lineWidth = 3;
ctx.font = '24px sans-serif';
ctx.strokeStyle = 'black';
ctx.textAlign = 'left';
ctx.textBaseline = 'middle';
ctx.save();
{
ctx.translate(width / 4, 80);
const textColor = dp < 0 ? colors.base : 'red';
advanceText(ctx, textColor, 'dot( ');
ctx.save();
{
ctx.fillStyle = colors.camera;
ctx.strokeStyle = colors.camera;
ctx.rotate(Math.atan2(camDY, camDX));
arrow(ctx, -8, 0, 8, 0, false, true, 1);
}
ctx.restore();
advanceText(ctx, textColor, ' , ');
ctx.save();
{
ctx.fillStyle = colors.label;
ctx.strokeStyle = colors.label;
ctx.rotate(rotation + Math.PI * 0.5);
arrow(ctx, -8, 0, 8, 0, false, true, 1);
}
ctx.restore();
advanceText(ctx, textColor, ` ) = ${dp.toFixed(2)}`);
}
ctx.restore();
}
ctx.restore();
}
render();
window.addEventListener('resize', render);
},
},
};
function advanceText(ctx, color, str) {
ctx.fillStyle = color;
ctx.fillText(str, 0, 0);
ctx.translate(ctx.measureText(str).width, 0);
}
[...document.querySelectorAll('[data-diagram]')].forEach(createDiagram);
function createDiagram(base) {
const name = base.dataset.diagram;
const info = diagrams[name];
if (!info) {
throw new Error(`no diagram ${name}`);
}
info.create({elem:base});
}
}