The avatar for @jonhelfman
Jonathan Helfman
Student of math, d3, svg, etc. Prototyper of visualizations for electronics design and test.
Public
Edited
Jul 3, 2023
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{
return Promise.all([promise1, promise2, promise3]).then((values) =>
getCanvas(...values, op1, op2, alpha1, alpha2)
);
Promise.all([promise1, promise2, promise3]).catch((value) => {
console.log(value);
});
}
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promise1 = promisedImage()
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promise2 = promisedImage()
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promise3 = promisedImage()
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getCanvas = (image1, image2, image3, op1, op2, alpha1 = 0.5, alpha2 = 0.5) => {
const canvas = document.createElement("canvas");
canvas.width = image1.width;
canvas.height = image1.height;
const ctx = canvas.getContext("2d");
ctx.drawImage(image1, 0, 0, image1.width, image1.height);
ctx.globalCompositeOperation = op1;
ctx.globalAlpha = alpha1;
ctx.drawImage(image2, 0, 0, image1.width, image1.height);
ctx.globalCompositeOperation = op2;
ctx.globalAlpha = alpha2;
ctx.drawImage(image3, 0, 0, image1.width, image1.height);
return canvas;
}
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promisedImage = () =>
new Promise((resolve, reject) => {
const image = new Image();
image.onload = () => resolve(image);
image.onerror = reject;
image.crossOrigin = "anonymous";
image.src = faker.image.url();
})
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