import * as scrawl from '../source/scrawl.js';
import { reportSpeed, killStyle } from './utilities.js';import * as scrawl from '../source/scrawl.js';
import { reportSpeed, killStyle } from './utilities.js';const canvas = scrawl.findCanvas('mycanvas');Namespacing boilerplate
const namespace = canvas.name;
const name = (n) => `${namespace}-${n}`;Create the linear gradient - we will kill and resurrect it as the demo runs
let graddy = scrawl.makeGradient({
name: name('mygradient'),
endX: '100%',
easing: 'linear',
precision: 1,
});Test the ability to load a user-created easing algorithm into the gradient
const bespokeEasings = {
'user-steps': (val) => {
if (val < 0.2) return 0.1;
if (val < 0.4) return 0.3;
if (val < 0.6) return 0.5;
if (val < 0.8) return 0.7;
return 0.9;
},
'user-repeat': (val) => (val * 4) % 1,
};Create a block entity which will use the gradient
scrawl.makeBlock({
name: name('myblock'),
width: '90%',
height: '90%',
startX: '5%',
startY: '5%',
fillStyle: graddy,
lockFillStyleToEntity: true,
strokeStyle: 'coral',
lineWidth: 2,
method: 'fillAndDraw',
});Function to display frames-per-second data, and other information relevant to the demo
const report = reportSpeed('#reportmessage', function () {
return `
Palette - start: ${dom['paletteStart'].value}; end: ${dom['paletteEnd'].value}
Start - x: ${dom['startX'].value}%; y: ${dom['startY'].value}%
End - x: ${dom['endX'].value}%; y: ${dom['endY'].value}%
Precision: ${dom['precision'].value}`;
});Create the Display cycle animation
scrawl.makeRender({
name: name('animation'),
target: canvas,
afterShow: report,
});Setup form observer functionality. We’re doing it this way (wrapped in a function) so we can test that it can be killed, and then recreated, later
const makeObserver = () => {
return scrawl.makeUpdater({
event: ['input', 'change'],
origin: '.controlItem',
target: graddy,
useNativeListener: true,
preventDefault: true,
updates: {
paletteStart: ['paletteStart', 'int'],
paletteEnd: ['paletteEnd', 'int'],
startX: ['startX', '%'],
startY: ['startY', '%'],
endX: ['endX', '%'],
endY: ['endY', '%'],
precision: ['precision', 'int'],
cyclePalette: ['cyclePalette', 'boolean'],
colorSpace: ['colorSpace', 'raw'],
returnColorAs: ['returnColorAs', 'raw'],
},
});
}… Create the form observer
let myobserver = makeObserver();Adding and removing color stops to the gradient - we’re using updateColor and removeColor functions rather than setting them on the gradient, so need separate event listener(s) to action form changes.
const events = (e) => {
e.preventDefault();
e.returnValue = false;
};
scrawl.addNativeListener(['input', 'change'], (e) => {
events(e);
const val = parseInt(e.target.value, 10);
switch (e.target.id) {
case 'red' :
if (val) graddy.updateColor(350, 'red');
else graddy.removeColor(350);
break;
case 'blue' :
if (val) graddy.updateColor(650, 'blue');
else graddy.removeColor(650);
break;
}
}, '.colorItems');
scrawl.addNativeListener(['input', 'change'], (e) => {
events(e);
const val = e.target.value;
if (['user-steps', 'user-repeat'].includes(val)) {
graddy.set({
easing: bespokeEasings[val],
});
}
else {
graddy.set({
easing: val,
});
}
}, '#easing');Set the DOM input values
const dom = scrawl.initializeDomInputs([
['input', 'endX', '100'],
['input', 'endY', '0'],
['input', 'paletteEnd', '999'],
['input', 'paletteStart', '0'],
['input', 'precision', '1'],
['input', 'startX', '0'],
['input', 'startY', '0'],
['select', 'blue', 0],
['select', 'colorSpace', 0],
['select', 'cyclePalette', 0],
['select', 'easing', 0],
['select', 'red', 0],
['select', 'returnColorAs', 0],
]);console.log(scrawl.library);
console.log('Performing tests ...');
killStyle(scrawl, canvas, name('mygradient'), 3000, () => {Repopulate the graddy variable
/** @ts-expect-error */
graddy = scrawl.findStyles(name('mygradient'));Reset the block fillStyle to the gradient
scrawl.findEntity(name('myblock')).set({
fillStyle: name('mygradient'),
});Kill the form observer
console.log('Kill form observer');
myobserver();… and recreate it
myobserver = makeObserver();
console.log('Form observer recreated');
});