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<!doctype html><html lang=en dir=ltr class="blog-wrapper blog-post-page plugin-blog plugin-id-default" data-has-hydrated=false><meta charset=UTF-8><meta name=generator content="Docusaurus v3.6.1"><title data-rh=true>Playing with fire: Tone mapping and color | The Old Speice Guy</title><meta data-rh=true name=viewport content="width=device-width,initial-scale=1.0"><meta data-rh=true name=twitter:card content=summary_large_image><meta data-rh=true property=og:url content=https://speice.io/2024/11/playing-with-fire-log-density><meta data-rh=true property=og:locale content=en><meta data-rh=true name=docusaurus_locale content=en><meta data-rh=true name=docusaurus_tag content=default><meta data-rh=true name=docsearch:language content=en><meta data-rh=true name=docsearch:docusaurus_tag content=default><meta data-rh=true property=og:title content="Playing with fire: Tone mapping and color | The Old Speice Guy"><meta data-rh=true name=description content="So far, our plot() function has been fairly simple: map a fractal flame coordinate to a specific pixel,"><meta data-rh=true property=og:description content="So far, our plot() function has been fairly simple: map a fractal flame coordinate to a specific pixel,"><meta data-rh=true property=og:type content=article><meta data-rh=true property=article:published_time content=2024-12-16T21:32:00.000Z><link data-rh=true rel=icon href=/img/favicon.ico><link data-rh=true rel=canonical href=https://speice.io/2024/11/playing-with-fire-log-density><link data-rh=true rel=alternate href=https://speice.io/2024/11/playing-with-fire-log-density hreflang=en><link data-rh=true rel=alternate href=https://speice.io/2024/11/playing-with-fire-log-density hreflang=x-default><script data-rh=true type=application/ld+json>{"@context":"https://schema.org","@id":"https://speice.io/2024/11/playing-with-fire-log-density","@type":"BlogPosting","author":{"@type":"Person","name":"Bradlee Speice"},"dateModified":"2024-12-17T02:30:05.000Z","datePublished":"2024-12-16T21:32:00.000Z","description":"So far, our plot() function has been fairly simple: map a fractal flame coordinate to a specific pixel,","headline":"Playing with fire: Tone mapping and color","isPartOf":{"@id":"https://speice.io/","@type":"Blog","name":"Blog"},"keywords":[],"mainEntityOfPage":"https://speice.io/2024/11/playing-with-fire-log-density","name":"Playing with fire: Tone mapping and color","url":"https://speice.io/2024/11/playing-with-fire-log-density"}</script><link rel=alternate type=application/rss+xml href=/rss.xml title="The Old Speice Guy RSS Feed"><link rel=alternate type=application/atom+xml href=/atom.xml title="The Old Speice Guy Atom Feed"><link rel=stylesheet href=/katex/katex.min.css><link rel=stylesheet href=/assets/css/styles.16c3428d.css><script src=/assets/js/runtime~main.29a27dcf.js defer></script><script src=/assets/js/main.d461af80.js defer></script><body class=navigation-with-keyboard><script>!function(){var t,e=function(){try{return new URLSearchParams(window.location.search).get("docusaurus-theme")}catch(t){}}()||function(){try{return window.localStorage.getItem("theme")}catch(t){}}();t=null!==e?e:"light",document.documentElement.setAttribute("data-theme",t)}(),function(){try{for(var[t,e]of new URLSearchParams(window.location.search).entries())if(t.startsWith("docusaurus-data-")){var a=t.replace("docusaurus-data-","data-");document.documentElement.setAttribute(a,e)}}catch(t){}}()</script><div id=__docusaurus><div role=region aria-label="Skip to main content"><a class=skipToContent_fXgn href=#__docusaurus_skipToContent_fallback>Skip to main content</a></div><nav aria-label=Main class="navbar navbar--fixed-top"><div class=navbar__inner><div class=navbar__items><button aria-label="Toggle navigation bar" aria-expanded=false class="navbar__toggle clean-btn" type=button><svg width=30 height=30 viewBox="0 0 30 30" aria-hidden=true><path stroke=currentColor stroke-linecap=round stroke-miterlimit=10 stroke-width=2 d="M4 7h22M4 15h22M4 23h22"/></svg></button><a class=navbar__brand href=/><div class=navbar__logo><img src=/img/logo
and color in that pixel. This works well for simple function systems (like Sierpinski's Gasket),
but more complex systems (like the reference parameters) produce grainy images.</p>
<p>In this post, we'll refine the image quality and add color to really make things shine.</p>
<h2 class="anchor anchorWithStickyNavbar_LWe7" id=image-histograms>Image histograms<a href=#image-histograms class=hash-link aria-label="Direct link to Image histograms" title="Direct link to Image histograms"></a></h2>
<div class="theme-admonition theme-admonition-note admonition_xJq3 alert alert--secondary"><div class=admonitionHeading_Gvgb><span class=admonitionIcon_Rf37><svg viewBox="0 0 14 16"><path fill-rule=evenodd d="M6.3 5.69a.942.942 0 0 1-.28-.7c0-.28.09-.52.28-.7.19-.18.42-.28.7-.28.28 0 .52.09.7.28.18.19.28.42.28.7 0 .28-.09.52-.28.7a1 1 0 0 1-.7.3c-.28 0-.52-.11-.7-.3zM8 7.99c-.02-.25-.11-.48-.31-.69-.2-.19-.42-.3-.69-.31H6c-.27.02-.48.13-.69.31-.2.2-.3.44-.31.69h1v3c.02.27.11.5.31.69.2.2.42.31.69.31h1c.27 0 .48-.11.69-.31.2-.19.3-.42.31-.69H8V7.98v.01zM7 2.3c-3.14 0-5.7 2.54-5.7 5.68 0 3.14 2.56 5.7 5.7 5.7s5.7-2.55 5.7-5.7c0-3.15-2.56-5.69-5.7-5.69v.01zM7 .98c3.86 0 7 3.14 7 7s-3.14 7-7 7-7-3.12-7-7 3.14-7 7-7z"/></svg></span>note</div><div class=admonitionContent_BuS1><p>This post covers sections 4 and 5 of the Fractal Flame Algorithm paper</div></div>
<p>One problem with the current chaos game algorithm is that we waste work
because pixels are either "on" (opaque) or "off" (transparent).
If the chaos game encounters the same pixel twice, nothing changes.</p>
<p>To demonstrate how much work is wasted, we'll count each time the chaos game
visits a pixel while iterating. This gives us a kind of image "histogram":</p>
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<div class="language-typescript codeBlockContainer_Ckt0 theme-code-block" style="--prism-background-color:hsl(230, 1%, 98%);--prism-color:hsl(230, 8%, 24%)"><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-typescript codeBlock_bY9V thin-scrollbar" style="background-color:hsl(230, 1%, 98%);color:hsl(230, 8%, 24%)"><code class=codeBlockLines_e6Vv><span class="token-line code-block-hidden" style="color:hsl(230, 8%, 24%)"><span class="token keyword" style="color:hsl(301, 63%, 40%)">import</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"> randomBiUnit </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">}</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">from</span><span class="token plain"> </span><span class="token string" style="color:hsl(119, 34%, 47%)">"../src/randomBiUnit"</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class="token-line code-block-hidden" style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token keyword" style="color:hsl(301, 63%, 40%)">import</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"> randomChoice </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">}</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">from</span><span class="token plain"> </span><span class="token string" style="color:hsl(119, 34%, 47%)">"../src/randomChoice"</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class="token-line code-block-hidden" style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token keyword" style="color:hsl(301, 63%, 40%)">import</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"> Props </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">as</span><span class="token plain"> ChaosGameFinalProps </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">}</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">from</span><span class="token plain"> </span><span class="token string" style="color:hsl(119, 34%, 47%)">"../2-transforms/chaosGameFinal"</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class="token-line code-block-hidden" style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token keyword" style="color:hsl(301, 63%, 40%)">import</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"> camera</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"> histIndex </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">}</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">from</span><span class="token plain"> </span><span class="token string" style="color:hsl(119, 34%, 47%)">"../src/camera"</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class="token-line code-block-hidden" style="color:hsl(230, 8%, 24%)"><span class="token plain" style=display:inline-block></span><br></span><span class="token-line code-block-hidden" style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token keyword" style="color:hsl(301, 63%, 40%)">const</span><span class="token plain"> quality </span><span class="token operator" style="color:hsl(221, 87%, 60%)">=</span><span class="token plain"> </span><span class="token number" style=
<p>When the chaos game finishes, we find the pixel encountered most often.
Finally, we "paint" the image by setting each pixel's alpha (transparency) value
to the ratio of times visited divided by the maximum:</p>
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<div class="language-typescript codeBlockContainer_Ckt0 theme-code-block" style="--prism-background-color:hsl(230, 1%, 98%);--prism-color:hsl(230, 8%, 24%)"><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-typescript codeBlock_bY9V thin-scrollbar" style="background-color:hsl(230, 1%, 98%);color:hsl(230, 8%, 24%)"><code class=codeBlockLines_e6Vv><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token keyword" style="color:hsl(301, 63%, 40%)">export</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">function</span><span class="token plain"> </span><span class="token function" style="color:hsl(221, 87%, 60%)">paintLinear</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">(</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  width</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  height</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  hist</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">[</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">]</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">const</span><span class="token plain"> img </span><span class="token operator" style="color:hsl(221, 87%, 60%)">=</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">    </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">new</span><span class="token plain"> </span><span class="token class-name" style="color:hsl(35, 99%, 36%)">ImageData</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">(</span><span class="token plain">width</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"> height</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">)</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain" style=display:inline-block></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">let</span><span class="token plain"> hMax </span><span class="token operator" style="color:hsl(221, 87%, 60%)">=</span><span class="token plain"> </span><span class="token number" style="color:hsl(35, 99%, 36%)">0</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token pla
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<center><center><div style=width:75%;aspect-ratio:1/1></div></center></center>
<h2 class="anchor anchorWithStickyNavbar_LWe7" id=tone-mapping>Tone mapping<a href=#tone-mapping class=hash-link aria-label="Direct link to Tone mapping" title="Direct link to Tone mapping"></a></h2>
<p>While using a histogram reduces the "graining," it also leads to some parts vanishing entirely.
In the reference parameters, the outer circle is still there, but the interior is gone!</p>
<p>To fix this, we'll introduce the second major innovation of the fractal flame algorithm: <a href=https://en.wikipedia.org/wiki/Tone_mapping target=_blank rel="noopener noreferrer">tone mapping</a>.
This is a technique used in computer graphics to compensate for differences in how
computers represent brightness, and how people actually see brightness.</p>
<p>As a concrete example, high-dynamic-range (HDR) photography uses this technique to capture
scenes with a wide range of brightnesses. To take a picture of something dark,
you need a long exposure time. However, long exposures lead to "hot spots" (sections that are pure white).
By taking multiple pictures with different exposure times, we can combine them to create
a final image where everything is visible.</p>
<p>In fractal flames, this "tone map" is accomplished by scaling brightness according to the <em>logarithm</em>
of how many times we encounter a pixel. This way, "cold spots" (pixels the chaos game visits infrequently)
are still visible, and "hot spots" (pixels the chaos game visits frequently) won't wash out.</p>
<details class="details_lb9f alert alert--info details_b_Ee" data-collapsed=true><summary>Log-scale vibrancy also explains fractal flames appear to be 3D...</summary><div><div class=collapsibleContent_i85q><p>As mentioned in the paper:<blockquote>
<p>Where one branch of the fractal crosses another, one may appear to occlude the other
if their densities are different enough because the lesser density is inconsequential in sum.
For example, branches of densities 1000 and 100 might have brightnesses of 30 and 20.
Where they cross the density is 1100, whose brightness is 30.4, which is
hardly distinguishable from 30.</p>
</blockquote></div></div></details>
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<div class="language-typescript codeBlockContainer_Ckt0 theme-code-block" style="--prism-background-color:hsl(230, 1%, 98%);--prism-color:hsl(230, 8%, 24%)"><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-typescript codeBlock_bY9V thin-scrollbar" style="background-color:hsl(230, 1%, 98%);color:hsl(230, 8%, 24%)"><code class=codeBlockLines_e6Vv><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token keyword" style="color:hsl(301, 63%, 40%)">export</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">function</span><span class="token plain"> </span><span class="token function" style="color:hsl(221, 87%, 60%)">paintLogarithmic</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">(</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  width</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  height</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  hist</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">[</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">]</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">const</span><span class="token plain"> img </span><span class="token operator" style="color:hsl(221, 87%, 60%)">=</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">    </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">new</span><span class="token plain"> </span><span class="token class-name" style="color:hsl(35, 99%, 36%)">ImageData</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">(</span><span class="token plain">width</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"> height</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">)</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain" style=display:inline-block></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">const</span><span class="token plain"> histLog </span><span class="token operator" style="color:hsl(221, 87%, 60%)">=</span><span class="token plain"> hist</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">.</span><span class="token function" style="color:hsl(221, 87%, 60%)">map</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">(</span><span class="token plain">Mat
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<center><center><div style=width:75%;aspect-ratio:1/1></div></center></center>
<h2 class="anchor anchorWithStickyNavbar_LWe7" id=color>Color<a href=#color class=hash-link aria-label="Direct link to Color" title="Direct link to Color"></a></h2>
<p>Now we'll introduce the last innovation of the fractal flame algorithm: color.
By including a third coordinate (<span class=katex><span class=katex-mathml><math><semantics><mrow><mi>c</mi></mrow><annotation encoding=application/x-tex>c</annotation></semantics></math></span><span class=katex-html aria-hidden=true><span class=base><span class=strut style=height:0.4306em></span><span class="mord mathnormal">c</span></span></span></span>) in the chaos game, we can illustrate the transforms
responsible for the image.</p>
<h3 class="anchor anchorWithStickyNavbar_LWe7" id=color-coordinate>Color coordinate<a href=#color-coordinate class=hash-link aria-label="Direct link to Color coordinate" title="Direct link to Color coordinate"></a></h3>
<p>Color in a fractal flame is continuous on the range <span class=katex><span class=katex-mathml><math><semantics><mrow><mo stretchy=false>[</mo><mn>0</mn><mo separator=true>,</mo><mn>1</mn><mo stretchy=false>]</mo></mrow><annotation encoding=application/x-tex>[0, 1]</annotation></semantics></math></span><span class=katex-html aria-hidden=true><span class=base><span class=strut style=height:1em;vertical-align:-0.25em></span><span class=mopen>[</span><span class=mord>0</span><span class=mpunct>,</span><span class=mspace style=margin-right:0.1667em></span><span class=mord>1</span><span class=mclose>]</span></span></span></span>. This is important for two reasons:</p>
<ul>
<li>It helps blend colors together in the final image. Slight changes in the color value lead to
slight changes in the actual color</li>
<li>It allows us to swap in new color palettes easily. We're free to choose what actual colors
each value represents</li>
</ul>
<p>We'll give each transform a color value (<span class=katex><span class=katex-mathml><math><semantics><mrow><msub><mi>c</mi><mi>i</mi></msub></mrow><annotation encoding=application/x-tex>c_i</annotation></semantics></math></span><span class=katex-html aria-hidden=true><span class=base><span class=strut style=height:0.5806em;vertical-align:-0.15em></span><span class=mord><span class="mord mathnormal">c</span><span class=msupsub><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:0.3117em><span style=top:-2.55em;margin-left:0em;margin-right:0.05em><span class=pstrut style=height:2.7em></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">i</span></span></span></span><span class=vlist-s></span></span><span class=vlist-r><span class=vlist style=height:0.15em><span></span></span></span></span></span></span></span></span></span>) in the <span class=katex><span class=katex-mathml><math><semantics><mrow><mo stretchy=false>[</mo><mn>0</mn><mo separator=true>,</mo><mn>1</mn><mo stretchy=false>]</mo></mrow><annotation encoding=application/x-tex>[0, 1]</annotation></semantics></math></span><span class=katex-html aria-hidden=true><span class=base><span class=strut style=height:1em;vertical-align:-0.25em></span><span class=mopen>[</span><span class=mord>0</span><span class=mpunct>,</span><span class=mspace style=margin-right:0.1667em></span><span class=mord>1</span><span class=mclose>]</span></span></span></span> range.
The final transform gets a value too (<span class=katex><span class=katex-mathml><math><semantics><mrow><msub><mi>c</mi><mi>f</mi></msub></mrow><annotation encoding=application/x-tex>c_f</annotation></semantics></math></span><span class=katex-html aria-hidden=true><span class=base><span class=strut style=height:0.7167em;vertical-align:-0.2861em></span><span class=mord><span class="mord mathnormal">c</span><span class=msupsub><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:0.3361em><span style=top:-2.55em;margin-left:0em;margin-right:0.05em><span class=pstrut style=height:2.7em></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style=margin-right:0.10764em>f</span></span></span></span><span class=vlist-s></span></span><span class=vlist-r><span class=vlist style=height:0.2861em><span></span></span></span></span></span></span></span></span></span>).
Then, at each step in the chaos game, we'll set the current color
by blending it with the previous color:</p>
<span class=katex-display><span class=katex><span class=katex-mathml><math display=block><semantics><mtable rowspacing=0.25em columnalign="right left" columnspacing=0em><mtr><mtd><mstyle scriptlevel=0 displaystyle=true><mrow/></mstyle></mtd><mtd><mstyle scriptlevel=0 displaystyle=true><mrow><mrow/><mo stretchy=false>(</mo><mi>x</mi><mo separator=true>,</mo><mi>y</mi><mo stretchy=false>)</mo><mo>=</mo><mtext>random point in the bi-unit square</mtext></mrow></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel=0 displaystyle=true><mrow/></mstyle></mtd><mtd><mstyle scriptlevel=0 displaystyle=true><mrow><mrow/><mi>c</mi><mo>=</mo><mtext>random point from [0,1]</mtext></mrow></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel=0 displaystyle=true><mrow/></mstyle></mtd><mtd><mstyle scriptlevel=0 displaystyle=true><mrow><mrow/><mtext>iterate </mtext><mo stretchy=false>{</mo></mrow></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel=0 displaystyle=true><mrow/></mstyle></mtd><mtd><mstyle scriptlevel=0 displaystyle=true><mrow><mrow/><mspace width=2.8453em /><mi>i</mi><mo>=</mo><mtext>random integer from 0 to </mtext><mi>n</mi><mo>−</mo><mn>1</mn></mrow></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel=0 displaystyle=true><mrow/></mstyle></mtd><mtd><mstyle scriptlevel=0 displaystyle=true><mrow><mrow/><mspace width=2.8453em /><mo stretchy=false>(</mo><mi>x</mi><mo separator=true>,</mo><mi>y</mi><mo stretchy=false>)</mo><mo>=</mo><msub><mi>F</mi><mi>i</mi></msub><mo stretchy=false>(</mo><mi>x</mi><mo separator=true>,</mo><mi>y</mi><mo stretchy=false>)</mo></mrow></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel=0 displaystyle=true><mrow/></mstyle></mtd><mtd><mstyle scriptlevel=0 displaystyle=true><mrow><mrow/><mspace width=2.8453em /><mo stretchy=false>(</mo><msub><mi>x</mi><mi>f</mi></msub><mo separator=true>,</mo><msub><mi>y</mi><mi>f</mi></msub><mo stretchy=false>)</mo><mo>=</mo><msub><mi>F</mi><mrow><mi>f</mi><mi>i</mi><mi>n</mi><mi>a</mi><mi>l</mi></mrow></msub><mo stretchy=false>(</mo><mi>x</mi><mo separator=true>,</mo><mi>y</mi><mo stretchy=false>)</mo></mrow></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel=0 displaystyle=true><mrow/></mstyle></mtd><mtd><mstyle scriptlevel=0 displaystyle=true><mrow><mrow/><mspace width=2.8453em /><mi>c</mi><mo>=</mo><mo stretchy=false>(</mo><mi>c</mi><mo>+</mo><msub><mi>c</mi><mi>i</mi></msub><mo stretchy=false>)</mo><mi mathvariant=normal>/</mi><mn>2</mn></mrow></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel=0 displaystyle=true><mrow/></mstyle></mtd><mtd><mstyle scriptlevel=0 displaystyle=true><mrow><mrow/><mspace width=2.8453em /><mtext>plot</mtext><mo stretchy=false>(</mo><msub><mi>x</mi><mi>f</mi></msub><mo separator=true>,</mo><msub><mi>y</mi><mi>f</mi></msub><mo separator=true>,</mo><msub><mi>c</mi><mi>f</mi></msub><mo stretchy=false>)</mo><mtext> if iterations</mtext><mo>></mo><mn>20</mn></mrow></mstyle></mtd></mtr><mtr><mtd><mstyle scriptlevel=0 displaystyle=true><mo stretchy=false lspace=0em rspace=0em>}</mo></mstyle></mtd></mtr></mtable><annotation encoding=application/x-tex>\begin{align*}
&(x, y) = \text{random point in the bi-unit square} \\
&c = \text{random point from [0,1]} \\
&\text{iterate } \{ \\
&\hspace{1cm} i = \text{random integer from 0 to } n - 1 \\
&\hspace{1cm} (x,y) = F_i(x,y) \\
&\hspace{1cm} (x_f,y_f) = F_{final}(x,y) \\
&\hspace{1cm} c = (c + c_i) / 2 \\
&\hspace{1cm} \text{plot}(x_f,y_f,c_f) \text{ if iterations} > 20 \\
\}
\end{align*}</annotation></semantics></math></span><span class=katex-html aria-hidden=true><span class=base><span class=strut style=height:13.5em;vertical-align:-6.5em></span><span class=mord><span class=mtable><span class=col-align-r><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:7em><span style=top:-9.16em><span class=pstrut style=height:3em></span><span class=mord></span></span><span style=top:-7.66em><span class=pstrut style=height:3em></span><span class=mord></span></span><span style=top:-6.16em><span class=pstrut style=height:3em></span><span class=mord></span></span><span style=top:-4.66em><span class=pstrut style=height:3em></span><span class=mord></span></span><span style=top:-3.16em><span class=pstrut style=height:3em></span><span class=mord></span></span><span style=top:-1.66em><span class=pstrut style=height:3em></span><span class=mord></span></span><span style=top:-0.16em><span class=pstrut style=height:3em></span><span class=mord></span></span><span style=top:1.34em><span class=pstrut style=height:3em></span><span class=mord></span></span><span style=top:2.84em><span class=pstrut style=height:3em></span><span class=mord><span class=mclose>}</span></span></span></span><span class=vlist-s></span></span><span class=vlist-r><span class=vlist style=height:6.5em><span></span></span></span></span></span><span class=col-align-l><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:7em><span style=top:-9.16em><span class=pstrut style=height:3em></span><span class=mord><span class=mord></span><span class=mopen>(</span><span class="mord mathnormal">x</span><span class=mpunct>,</span><span class=mspace style=margin-right:0.1667em></span><span class="mord mathnormal" style=margin-right:0.03588em>y</span><span class=mclose>)</span><span class=mspace style=margin-right:0.2778em></span><span class=mrel>=</span><span class=mspace style=margin-right:0.2778em></span><span class="mord text"><span class=mord>random point in the bi-unit square</span></span></span></span><span style=top:-7.66em><span class=pstrut style=height:3em></span><span class=mord><span class=mord></span><span class="mord mathnormal">c</span><span class=mspace style=margin-right:0.2778em></span><span class=mrel>=</span><span class=mspace style=margin-right:0.2778em></span><span class="mord text"><span class=mord>random point from [0,1]</span></span></span></span><span style=top:-6.16em><span class=pstrut style=height:3em></span><span class=mord><span class=mord></span><span class="mord text"><span class=mord>iterate </span></span><span class=mopen>{</span></span></span><span style=top:-4.66em><span class=pstrut style=height:3em></span><span class=mord><span class=mord></span><span class=mspace style=margin-right:2.8453em></span><span class="mord mathnormal">i</span><span class=mspace style=margin-right:0.2778em></span><span class=mrel>=</span><span class=mspace style=margin-right:0.2778em></span><span class="mord text"><span class=mord>random integer from 0 to </span></span><span class="mord mathnormal">n</span><span class=mspace style=margin-right:0.2222em></span><span class=mbin>−</span><span class=mspace style=margin-right:0.2222em></span><span class=mord>1</span></span></span><span style=top:-3.16em><span class=pstrut style=height:3em></span><span class=mord><span class=mord></span><span class=mspace style=margin-right:2.8453em></span><span class=mopen>(</span><span class="mord mathnormal">x</span><span class=mpunct>,</span><span class=mspace style=margin-right:0.1667em></span><span class="mord mathnormal" style=margin-right:0.03588em>y</span><span class=mclose>)</span><span class=mspace style=margin-right:0.2778em></span><span class=mrel>=</span><span class=mspace style=margin-right:0.2778em></span><span class=mord><span class="mord mathnormal" style=margin-right:0.13889em>F</span><span class=msupsub><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:0.3117em><span style=top:-2.55em;margin-left:-0.1389em;margin-right:0.05em><span class=pstr
<h3 class="anchor anchorWithStickyNavbar_LWe7" id=color-speed>Color speed<a href=#color-speed class=hash-link aria-label="Direct link to Color speed" title="Direct link to Color speed"></a></h3>
<div class="theme-admonition theme-admonition-warning admonition_xJq3 alert alert--warning"><div class=admonitionHeading_Gvgb><span class=admonitionIcon_Rf37><svg viewBox="0 0 16 16"><path fill-rule=evenodd d="M8.893 1.5c-.183-.31-.52-.5-.887-.5s-.703.19-.886.5L.138 13.499a.98.98 0 0 0 0 1.001c.193.31.53.501.886.501h13.964c.367 0 .704-.19.877-.5a1.03 1.03 0 0 0 .01-1.002L8.893 1.5zm.133 11.497H6.987v-2.003h2.039v2.003zm0-3.004H6.987V5.987h2.039v4.006z"/></svg></span>warning</div><div class=admonitionContent_BuS1><p>Color speed isn't introduced in the Fractal Flame Algorithm paper.<p>It is included here because <a href=https://github.com/scottdraves/flam3/blob/7fb50c82e90e051f00efcc3123d0e06de26594b2/variations.c#L2140 target=_blank rel="noopener noreferrer"><code>flam3</code> implements it</a>,
and because it's fun to play with.</div></div>
<p>Next, we'll add a parameter to each transform that controls how much it changes the current color.
This is known as the "color speed" (<span class=katex><span class=katex-mathml><math><semantics><mrow><msub><mi>s</mi><mi>i</mi></msub></mrow><annotation encoding=application/x-tex>s_i</annotation></semantics></math></span><span class=katex-html aria-hidden=true><span class=base><span class=strut style=height:0.5806em;vertical-align:-0.15em></span><span class=mord><span class="mord mathnormal">s</span><span class=msupsub><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:0.3117em><span style=top:-2.55em;margin-left:0em;margin-right:0.05em><span class=pstrut style=height:2.7em></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">i</span></span></span></span><span class=vlist-s></span></span><span class=vlist-r><span class=vlist style=height:0.15em><span></span></span></span></span></span></span></span></span></span>):</p>
<span class=katex-display><span class=katex><span class=katex-mathml><math display=block><semantics><mrow><mi>c</mi><mo>=</mo><mi>c</mi><mo>⋅</mo><mo stretchy=false>(</mo><mn>1</mn><mo>−</mo><msub><mi>s</mi><mi>i</mi></msub><mo stretchy=false>)</mo><mo>+</mo><msub><mi>c</mi><mi>i</mi></msub><mo>⋅</mo><msub><mi>s</mi><mi>i</mi></msub></mrow><annotation encoding=application/x-tex>c = c \cdot (1 - s_i) + c_i \cdot s_i</annotation></semantics></math></span><span class=katex-html aria-hidden=true><span class=base><span class=strut style=height:0.4306em></span><span class="mord mathnormal">c</span><span class=mspace style=margin-right:0.2778em></span><span class=mrel>=</span><span class=mspace style=margin-right:0.2778em></span></span><span class=base><span class=strut style=height:0.4445em></span><span class="mord mathnormal">c</span><span class=mspace style=margin-right:0.2222em></span><span class=mbin>⋅</span><span class=mspace style=margin-right:0.2222em></span></span><span class=base><span class=strut style=height:1em;vertical-align:-0.25em></span><span class=mopen>(</span><span class=mord>1</span><span class=mspace style=margin-right:0.2222em></span><span class=mbin>−</span><span class=mspace style=margin-right:0.2222em></span></span><span class=base><span class=strut style=height:1em;vertical-align:-0.25em></span><span class=mord><span class="mord mathnormal">s</span><span class=msupsub><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:0.3117em><span style=top:-2.55em;margin-left:0em;margin-right:0.05em><span class=pstrut style=height:2.7em></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">i</span></span></span></span><span class=vlist-s></span></span><span class=vlist-r><span class=vlist style=height:0.15em><span></span></span></span></span></span></span><span class=mclose>)</span><span class=mspace style=margin-right:0.2222em></span><span class=mbin>+</span><span class=mspace style=margin-right:0.2222em></span></span><span class=base><span class=strut style=height:0.5945em;vertical-align:-0.15em></span><span class=mord><span class="mord mathnormal">c</span><span class=msupsub><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:0.3117em><span style=top:-2.55em;margin-left:0em;margin-right:0.05em><span class=pstrut style=height:2.7em></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">i</span></span></span></span><span class=vlist-s></span></span><span class=vlist-r><span class=vlist style=height:0.15em><span></span></span></span></span></span></span><span class=mspace style=margin-right:0.2222em></span><span class=mbin>⋅</span><span class=mspace style=margin-right:0.2222em></span></span><span class=base><span class=strut style=height:0.5806em;vertical-align:-0.15em></span><span class=mord><span class="mord mathnormal">s</span><span class=msupsub><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:0.3117em><span style=top:-2.55em;margin-left:0em;margin-right:0.05em><span class=pstrut style=height:2.7em></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">i</span></span></span></span><span class=vlist-s></span></span><span class=vlist-r><span class=vlist style=height:0.15em><span></span></span></span></span></span></span></span></span></span></span>
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<div class="language-typescript codeBlockContainer_Ckt0 theme-code-block" style="--prism-background-color:hsl(230, 1%, 98%);--prism-color:hsl(230, 8%, 24%)"><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-typescript codeBlock_bY9V thin-scrollbar" style="background-color:hsl(230, 1%, 98%);color:hsl(230, 8%, 24%)"><code class=codeBlockLines_e6Vv><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token keyword" style="color:hsl(301, 63%, 40%)">export</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">function</span><span class="token plain"> </span><span class="token function" style="color:hsl(221, 87%, 60%)">mixColor</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">(</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  color1</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  color2</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  colorSpeed</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">)</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">return</span><span class="token plain"> color1 </span><span class="token operator" style="color:hsl(221, 87%, 60%)">*</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">(</span><span class="token number" style="color:hsl(35, 99%, 36%)">1</span><span class="token plain"> </span><span class="token operator" style="color:hsl(221, 87%, 60%)">-</span><span class="token plain"> colorSpeed</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">)</span><span class="token plain"> </span><span class="token operator" style="color:hsl(221, 87%, 60%)">+</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">    color2 </span><span class="token operator" style="color:hsl(221, 87%, 60%)">*</span><span class="token plain"> colorSpeed</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">}</span><br></span></code></pre><div class=buttonGroup__atx><button type=button aria-label="Copy code to clipboard" title=Copy class=clean-btn><span class=copyButtonIcons_eSgA aria-hidden=true><svg viewBox="0 0 24 24" class=copyButtonIcon_y97N><path fill=currentColor d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"/></svg><svg viewBox="0 0 24 24" class=copyButtonSuccessIcon_LjdS><path fill=currentColor d=M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L2
<p>Color speed values work just like transform weights. A value of 1
means we take the transform color and ignore the previous color state.
A value of 0 means we keep the current color state and ignore the
transform color.</p>
<h3 class="anchor anchorWithStickyNavbar_LWe7" id=palette>Palette<a href=#palette class=hash-link aria-label="Direct link to Palette" title="Direct link to Palette"></a></h3>
<p>Now, we need to map the color coordinate to a pixel color. Fractal flames typically use
256 colors (each color has 3 values - red, green, blue) to define a palette.
The color coordinate then becomes an index into the palette.</p>
<p>There's one small complication: the color coordinate is continuous, but the palette
uses discrete colors. How do we handle situations where the color coordinate is
"in between" the colors of our palette?</p>
<p>One way to handle this is a step function. In the code below, we multiply the color coordinate
by the number of colors in the palette, then truncate that value. This gives us a discrete index:</p>
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<div class="language-typescript codeBlockContainer_Ckt0 theme-code-block" style="--prism-background-color:hsl(230, 1%, 98%);--prism-color:hsl(230, 8%, 24%)"><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-typescript codeBlock_bY9V thin-scrollbar" style="background-color:hsl(230, 1%, 98%);color:hsl(230, 8%, 24%)"><code class=codeBlockLines_e6Vv><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token keyword" style="color:hsl(301, 63%, 40%)">export</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">function</span><span class="token plain"> </span><span class="token function" style="color:hsl(221, 87%, 60%)">colorFromPalette</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">(</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  palette</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">[</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">]</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  colorIndex</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">)</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">[</span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">]</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">const</span><span class="token plain"> numColors </span><span class="token operator" style="color:hsl(221, 87%, 60%)">=</span><span class="token plain"> palette</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">.</span><span class="token plain">length </span><span class="token operator" style="color:hsl(221, 87%, 60%)">/</span><span class="token plain"> </span><span class="token number" style="color:hsl(35, 99%, 36%)">3</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">const</span><span class="token plain"> paletteIndex </span><span class="token operator" style="color:hsl(221, 87%, 60%)">=</span><span class="token plain"> Math</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">.</span><span class="token function" style="color:hsl(221, 87%, 60%)">floor</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">(</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">    co
<details class="details_lb9f alert alert--info details_b_Ee" data-collapsed=true><summary>As an alternative...</summary><div><div class=collapsibleContent_i85q><p>...you could interpolate between colors in the palette.
For example, <code>flam3</code> uses <a href=https://github.com/scottdraves/flam3/blob/7fb50c82e90e051f00efcc3123d0e06de26594b2/rect.c#L483-L486 target=_blank rel="noopener noreferrer">linear interpolation</a></div></div></details>
<p>In the diagram below, each color in the palette is plotted on a small vertical strip.
Putting the strips side by side shows the full palette used by the reference parameters:</p>
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<div style=width:100%;height:40></div>
<h3 class="anchor anchorWithStickyNavbar_LWe7" id=plotting>Plotting<a href=#plotting class=hash-link aria-label="Direct link to Plotting" title="Direct link to Plotting"></a></h3>
<p>We're now ready to plot our <span class=katex><span class=katex-mathml><math><semantics><mrow><mo stretchy=false>(</mo><msub><mi>x</mi><mi>f</mi></msub><mo separator=true>,</mo><msub><mi>y</mi><mi>f</mi></msub><mo separator=true>,</mo><msub><mi>c</mi><mi>f</mi></msub><mo stretchy=false>)</mo></mrow><annotation encoding=application/x-tex>(x_f,y_f,c_f)</annotation></semantics></math></span><span class=katex-html aria-hidden=true><span class=base><span class=strut style=height:1.0361em;vertical-align:-0.2861em></span><span class=mopen>(</span><span class=mord><span class="mord mathnormal">x</span><span class=msupsub><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:0.3361em><span style=top:-2.55em;margin-left:0em;margin-right:0.05em><span class=pstrut style=height:2.7em></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style=margin-right:0.10764em>f</span></span></span></span><span class=vlist-s></span></span><span class=vlist-r><span class=vlist style=height:0.2861em><span></span></span></span></span></span></span><span class=mpunct>,</span><span class=mspace style=margin-right:0.1667em></span><span class=mord><span class="mord mathnormal" style=margin-right:0.03588em>y</span><span class=msupsub><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:0.3361em><span style=top:-2.55em;margin-left:-0.0359em;margin-right:0.05em><span class=pstrut style=height:2.7em></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style=margin-right:0.10764em>f</span></span></span></span><span class=vlist-s></span></span><span class=vlist-r><span class=vlist style=height:0.2861em><span></span></span></span></span></span></span><span class=mpunct>,</span><span class=mspace style=margin-right:0.1667em></span><span class=mord><span class="mord mathnormal">c</span><span class=msupsub><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:0.3361em><span style=top:-2.55em;margin-left:0em;margin-right:0.05em><span class=pstrut style=height:2.7em></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style=margin-right:0.10764em>f</span></span></span></span><span class=vlist-s></span></span><span class=vlist-r><span class=vlist style=height:0.2861em><span></span></span></span></span></span></span><span class=mclose>)</span></span></span></span> coordinates. This time, we'll use a histogram
for each color channel (red, green, blue, alpha). After translating from color coordinate (<span class=katex><span class=katex-mathml><math><semantics><mrow><msub><mi>c</mi><mi>f</mi></msub></mrow><annotation encoding=application/x-tex>c_f</annotation></semantics></math></span><span class=katex-html aria-hidden=true><span class=base><span class=strut style=height:0.7167em;vertical-align:-0.2861em></span><span class=mord><span class="mord mathnormal">c</span><span class=msupsub><span class="vlist-t vlist-t2"><span class=vlist-r><span class=vlist style=height:0.3361em><span style=top:-2.55em;margin-left:0em;margin-right:0.05em><span class=pstrut style=height:2.7em></span><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight" style=margin-right:0.10764em>f</span></span></span></span><span class=vlist-s></span></span><span class=vlist-r><span class=vlist style=height:0.2861em><span></span></span></span></span></span></span></span></span></span>)
to RGB value, add that to the histogram:</p>
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<div class="language-typescript codeBlockContainer_Ckt0 theme-code-block" style="--prism-background-color:hsl(230, 1%, 98%);--prism-color:hsl(230, 8%, 24%)"><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-typescript codeBlock_bY9V thin-scrollbar" style="background-color:hsl(230, 1%, 98%);color:hsl(230, 8%, 24%)"><code class=codeBlockLines_e6Vv><span class="token-line code-block-hidden" style="color:hsl(230, 8%, 24%)"><span class="token keyword" style="color:hsl(301, 63%, 40%)">import</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"> Props </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">as</span><span class="token plain"> ChaosGameFinalProps </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">}</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">from</span><span class="token plain"> </span><span class="token string" style="color:hsl(119, 34%, 47%)">"../2-transforms/chaosGameFinal"</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class="token-line code-block-hidden" style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token keyword" style="color:hsl(301, 63%, 40%)">import</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"> randomBiUnit </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">}</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">from</span><span class="token plain"> </span><span class="token string" style="color:hsl(119, 34%, 47%)">"../src/randomBiUnit"</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class="token-line code-block-hidden" style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token keyword" style="color:hsl(301, 63%, 40%)">import</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"> randomChoice </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">}</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">from</span><span class="token plain"> </span><span class="token string" style="color:hsl(119, 34%, 47%)">"../src/randomChoice"</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class="token-line code-block-hidden" style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token keyword" style="color:hsl(301, 63%, 40%)">import</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"> camera</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"> histIndex </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">}</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">from</span><span class="token plain"> </span><span class="token string" style="color:hsl(119, 34%, 47%)">"../src/camera"</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">;</span><span class="token plain"></span><br></span><span class="token-line code-block-hidden" style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token keyword" style="color:hsl(301, 63%, 40%)">import</span><span class="token plain"> </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"> colorFromPalette </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">}</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)
<p>Finally, painting the image. With tone mapping, logarithms scale the image brightness to match
how it is perceived. With color, we use a similar method, but scale each color channel
by the alpha channel:</p>
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<div class="language-typescript codeBlockContainer_Ckt0 theme-code-block" style="--prism-background-color:hsl(230, 1%, 98%);--prism-color:hsl(230, 8%, 24%)"><div class=codeBlockContent_biex><pre tabindex=0 class="prism-code language-typescript codeBlock_bY9V thin-scrollbar" style="background-color:hsl(230, 1%, 98%);color:hsl(230, 8%, 24%)"><code class=codeBlockLines_e6Vv><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token keyword" style="color:hsl(301, 63%, 40%)">export</span><span class="token plain"> </span><span class="token keyword" style="color:hsl(301, 63%, 40%)">function</span><span class="token plain"> </span><span class="token function" style="color:hsl(221, 87%, 60%)">paintColor</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">(</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  width</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  height</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  red</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">[</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">]</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  green</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">[</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">]</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  blue</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">[</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">]</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">,</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain">  alpha</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> </span><span class="token builtin" style="color:hsl(119, 34%, 47%)">number</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">[</span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">]</span><span class="token plain"></span><br></span><span class=token-line style="color:hsl(230, 8%, 24%)"><span class="token plain"></span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">)</span><span class="token operator" style="color:hsl(221, 87%, 60%)">:</span><span class="token plain"> ImageData </span><span class="token punctuation" style="color:hsl(119, 34%, 47%)">{</span><span class="token plain"></span><br></span><span class
<p>And now, at long last, a full-color fractal flame:</p>
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<center><center><div style=width:75%;aspect-ratio:1/1></div></center></center>
<h2 class="anchor anchorWithStickyNavbar_LWe7" id=summary>Summary<a href=#summary class=hash-link aria-label="Direct link to Summary" title="Direct link to Summary"></a></h2>
<p>Tone mapping is the second major innovation of the fractal flame algorithm.
By tracking how often the chaos game encounters each pixel, we can adjust
brightness/transparency to reduce the visual "graining" of previous images.</p>
<p>Next, introducing a third coordinate to the chaos game makes color images possible,
the third major innovation of the fractal flame algorithm. Using a continuous
color scale and color palette adds a splash of excitement to the image.</p>
<p>The Fractal Flame Algorithm paper goes on to describe more techniques
not covered here. For example, image quality can be improved with density estimation
and filtering. New parameters can be generated by "mutating" existing
fractal flames. And fractal flames can even be animated to produce videos!</p>
<p>That said, I think this is a good place to wrap up. We went from
an introduction to the mathematics of fractal systems all the way to
generating full-color images. Fractal flames are a challenging topic,
but it's extremely rewarding to learn about how they work.</div></article><nav class="pagination-nav docusaurus-mt-lg" aria-label="Blog post page navigation"><a class="pagination-nav__link pagination-nav__link--prev" href=/2024/11/playing-with-fire-transforms><div class=pagination-nav__sublabel>Older post</div><div class=pagination-nav__label>Playing with fire: Transforms and variations</div></a></nav></main><div class="col col--2"><div class="tableOfContents_bqdL thin-scrollbar"><ul class="table-of-contents table-of-contents__left-border"><li><a href=#image-histograms class="table-of-contents__link toc-highlight">Image histograms</a><li><a href=#tone-mapping class="table-of-contents__link toc-highlight">Tone mapping</a><li><a href=#color class="table-of-contents__link toc-highlight">Color</a><ul><li><a href=#color-coordinate class="table-of-contents__link toc-highlight">Color coordinate</a><li><a href=#color-speed class="table-of-contents__link toc-highlight">Color speed</a><li><a href=#palette class="table-of-contents__link toc-highlight">Palette</a><li><a href=#plotting class="table-of-contents__link toc-highlight">Plotting</a></ul><li><a href=#summary class="table-of-contents__link toc-highlight">Summary</a></ul></div></div></div></div></div><footer class=footer><div class="container container-fluid"><div class="footer__bottom text--center"><div class=footer__copyright>Copyright © 2024 Bradlee Speice</div></div></div></footer></div>