From c5a62cfa1d2b3b95dfb8fdeb6afeeacbe2f7ecaf Mon Sep 17 00:00:00 2001 From: Brion Vibber Date: Sat, 7 Jan 2023 21:19:40 -0800 Subject: [PATCH] wip --- fixed.js | 13 +++++++----- sim.html | 22 +++++++++++++++++++ sim.js | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 95 insertions(+), 5 deletions(-) create mode 100644 sim.html create mode 100644 sim.js diff --git a/fixed.js b/fixed.js index 397de0f..b1d671d 100644 --- a/fixed.js +++ b/fixed.js @@ -17,11 +17,11 @@ let bytes = Math.ceil(bits / 8) * entries; let epsilonBits = 1 ; let epsilon = 2 ** epsilonBits; -function toFixed(float) { +export function toFixed(float) { return Math.round(float * base); } -function toFloat(fixed) { +export function toFloat(fixed) { return fixed / base; } @@ -48,12 +48,12 @@ for (let i = 0; i < entries * 2; i++) { // returns fixed point -function log2(fixed) { +export function log2(fixed) { return enloggen[toIndex(fixed)]; } // returns rounded integer -function pow2(fixed) { +export function pow2(fixed) { let n = toIndex(fixed); if (n > empower.length) { n = empower.length - 1; @@ -61,7 +61,7 @@ function pow2(fixed) { return empower[entries + n]; } -function mul(a, b) { +export function mul(a, b) { if (a == 0) return 0; if (b == 0) return 0; let la = log2(a)|0; @@ -93,6 +93,7 @@ for (let i = 0; i < powEntries; i++) { } */ +/* // now just try multipling numbers let deltas = 0; let deltaAvg = 0; @@ -153,3 +154,5 @@ for (let i = 0; i < enloggen.length; i++) { m = Math.max(m, enloggen[i]); } console.log(`max enloggen entry is ${m}`); + +*/ \ No newline at end of file diff --git a/sim.html b/sim.html new file mode 100644 index 0000000..61689cb --- /dev/null +++ b/sim.html @@ -0,0 +1,22 @@ + + + + Mandelbrot fixed-point test + + +

Mandelbrot fixed-point test

+ +

Float

+ + +

Fixed-point imul

+ + +

Fixed-point log

+ + + + + \ No newline at end of file diff --git a/sim.js b/sim.js new file mode 100644 index 0000000..4f819f0 --- /dev/null +++ b/sim.js @@ -0,0 +1,65 @@ +import {toFixed, toFloat, mul} from './fixed.js'; + +let max = 256; +let width = 256; +let height = 256; +let zoom = 1; + +let black = 0xff000000; +let tricolor = [ + 0xffff0000, + 0xff00ff00, + 0xff0000ff, +]; + +let palette = new Uint32Array(256); +palette[0] = black; +for (let i = 0; i < 255; i++) { + palette[i + 1] = tricolor[i % 3]; +} +function nap() { + return new Promise((resolve) => setTimeout(() => resolve())); +} + +async function setup(id, iterfunc) { + let canvas = document.getElementById(id); + let ctx = canvas.getContext('2d'); + let imageData = ctx.createImageData(width, height); + let rgba = new Uint32Array(imageData.data.buffer); + for (let y = 0; y < height; y++) { + let cy = (y * 2 - height) / (height / 2); + for (let x = 0; x < width; x++) { + let cx = (x * 2 - width) / (width / 2); + let i = iterfunc(cx, cy); + let color = palette[i]; + rgba[y * width + x] = color; + rgba[(256 - y) * width + x] = color; + + if (x % 16 == 15) { + ctx.putImageData(imageData, 0, 0); + await nap(); + } + } + } +} + +setup('float', (cx, cy) => { + let zx = 0; + let zy = 0; + let zx_2 = 0; + let zy_2 = 0; + let zx_zy = 0; + for (let i = 1; i < max; i++) { + zx = zx_2 - zy_2 + cx; + zy = zx_zy + zx_zy + cy; + zx_2 = zx * zx; + zy_2 = zy * zy; + zx_zy = zx * zy; + if (zx_2 >= 4 || zy_2 >= 4 || zx_2 + zy_2 >= 4) { + return i; + } + } + return 0; +}).then(() => { + console.log('done'); +}) \ No newline at end of file