speice.io/posts/2023/06/flam3/3c-logarithmic.ts

34 lines
1.1 KiB
TypeScript

import { RenderParams, histIndex, imageIndex } from "./0-utility.js";
import { transformAllPost } from "./2b-post.js";
import { transformFinal } from "./2c-final.js";
import { RendererHistogram } from "./3a-binary.js";
export class RendererLogarithmic extends RendererHistogram {
render(image: ImageData): void {
// Because log(0) is -Infinity, all the math actually works out.
const histogramLog = this.histogram.map(Math.log);
const histogramLogMax = histogramLog.reduce(
(max, v) => Math.max(max, v),
-Infinity
);
for (var x = 0; x < this.size; x++) {
for (var y = 0; y < this.size; y++) {
const hIndex = histIndex(x, y, this.size);
const iIndex = imageIndex(x, y, this.size);
image.data[iIndex + 0] = 0;
image.data[iIndex + 1] = 0;
image.data[iIndex + 2] = 0;
image.data[iIndex + 3] =
(histogramLog[hIndex] / histogramLogMax) * 0xff;
}
}
}
}
export const paramsLogarithmic: RenderParams = {
quality: 10,
renderer: (size) =>
new RendererLogarithmic(size, transformAllPost, transformFinal),
};