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greyscale and invert in util

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Daniel Odendahl Jr
2017-10-13 20:55:18 +00:00
parent 1a377f55b5
commit 04668928b1
5 changed files with 31 additions and 35 deletions
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structures/Util.js
+23
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@@ -60,6 +60,29 @@ class Util {
static pad(text, prefix) {
return `${prefix.slice(text.length)}${text}`;
}
static greyscale(ctx, x, y, width, height) {
const data = ctx.getImageData(x, y, width, height);
for (let i = 0; i < data.data.length; i += 4) {
const brightness = (0.34 * data.data[i]) + (0.5 * data.data[i + 1]) + (0.16 * data.data[i + 2]);
data.data[i] = brightness;
data.data[i + 1] = brightness;
data.data[i + 2] = brightness;
}
ctx.putImageData(data, x, y);
return ctx;
}
static invert(ctx, x, y, width, height) {
const data = ctx.getImageData(x, y, width, height);
for (let i = 0; i < data.data.length; i += 4) {
data.data[i] = 255 - data.data[i];
data.data[i + 1] = 255 - data.data[i + 1];
data.data[i + 2] = 255 - data.data[i + 2];
}
ctx.putImageData(data, x, y);
return ctx;
}
}
module.exports = Util;