Website updates, part 3

While updating my website build process over the past week (part 1, part 2), I decided I should also revisit my page layouts. Last year, I started learning about responsive design, studied the theory, and implemented it on my site. I converted 514 out of around 600 pages, and said “The rest are either unimportant or impractical to convert.” Of the ones I didn't convert, some were in a 450px width and most in a 600px width. I wanted to see if I could convert the 450px pages to 600px at least.

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Website updates, part 2

In part 1 I described some of the things I was doing to improve how my site is built. I had planned to implement the translation of each XHTML file to HTML in Python, but that didn't quite work out. I went back to my primary goals:

  1. Versioning of references to JS, CSS resources, so that I can improve browser caching of my pages.
  2. Tracking dependencies so that if something a page depends on is modified, the page is rebuilt.
  3. Custom macros for each project.

I was hoping to implement all of this in November before I started my December project, but I didn't. So I decided to focus on the most important part, versioning.


Website updates, part 1

I finished mapgen4 last week and wanted to "sharpen my tools" before I started the next project. My website is over 20 years old and spans 5 domains. The build process has grown over time, supporting all the different tools I've used over the decades.

There are a few features I've wanted to add to my static site generator:

  1. Versioning of js, css resources so that I can increase the expiration cache time. This should improve load time. I've been doing this manually and want to automate it.
  2. Dependency tracking, so that if something includes another thing, and that thing changes, the first thing gets rebuilt. This should reduce content mismatch errors.
  3. Custom macros for each project that get expanded at build time. This should make it easier to write new pages.


Mapgen4: finished

Not with a bang but a whimper

Back in July, I started mapgen4, the successor to mapgen2, my Voronoi-polygon map generator from 2010. Back in August I posted that I had planned to finish the map generator “in a month”, and then write a tutorial.

That was three months ago.

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Math explorables

There are times when I'm on YouTube watching a math video that I think, “oh, that would be fun to play with!” What I should do is recreate the diagram in Desmos or Geogebra. But instead I just move on to another video. Recently I decided I should try making some diagrams, in part to improve my Javascript/web skills, but in part because it seemed like it'd be fun! So I did this for two math videos:

Mathologer multiplication on a circle
3Blue1Brown Feynman's Last Lecture

Both of these were quick, under an hour (mostly fiddling with colors, line widths, transparency, etc): an ellipse from line segments, multiplication with modulo on a circle.


Procedural face generator

I've had my red blob logo since 1987. I doodle various facial expressions on the blobs, and also experiment with mathematical representations.


Mapgen4: beta

I put mapgen4 on hold a few weeks ago because I was having some seemingly random unreproducible freezes, where it would still calculate the map updates but it wouldn't draw them. I had tried everything (or so I thought), gotten frustrated, and taken a break. I often find that I need to take a break from something, and then when I get back to it, I figure out the problem. During this break I've been "productively procrastinating", working on several other things that I've wanted to do, including map generation on a sphere, a procedural face generator, improving touch support on many of my pages, and improving my tower defense pathfinding page. I ended up also experimenting with a better interface for my mouse-drag code, a recursive renderer in Vue.js, and a D3 + Vue.js experiment in which Vue keeps track of dependencies for D3.

Mapgen4's style takes inspiration from hand drawn fantasy maps


Tower Defense page: distance fields

One reason I prefer having web pages instead of videos or academic papers is that they're easy to update over time. I'm still updating pages I wrote over 20 years ago.

Yesterday I was reviewing the Tower Defense page (2014) and decided the gap between the diagram at the top:

Tower Defense page: introductory diagram

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Touch events on the pathfinding pages, part 2

I've been avoiding mapgen4 for a few weeks now. I ran into a really annoying bug that frustrated me enough that I wanted to give up. I still need to get back to it, but I'm “productively procrastinating”. Instead of sitting around being frustrated, I'm getting other things done: map generation on a sphere, a procedural face generator, and adding touch event support to my pathfinding pages.

When I wrote the A* tutorial, I didn't consider touch events at all. The traffic I got from mobile/tablet was small. I soon added some touch event handling, but it was incomplete. I figured I'd fix it later. Well, it's been four years now. It's time to fix it finally! (Update: I think my touch event handlers used to work, but I think they stopped working when Chrome 56 and Safari 11.1 changed event handlers to default to passive sometime in late 2017 / early 2018; see this and this)


Map generation on a sphere, part 2

I spent 9 days working on map generation on a sphere. The first 2 days were geometry: points, triangles, polygons on a sphere. The next 7 days were maps:

  • elevation: mapgen4's noise approach looked ok, but I wasn't happy with it, so I switched to using plate tectonics, which looked nice
  • moisture: mapgen4's evaporation+wind+rainfall relied too much on a grid, so I wasn't able to use it; I ended up assigning biomes randomly
  • rivers: mapgen4's binary tree forest works on graphs, and worked great on a sphere
  • rendering: mapgen4's elevation rendering uses outlines and a custom projection which are designed for flat maps, and I wrote a new simple renderer

I wrote up my notes and am going back to working on mapgen4. I'm also putting all the (messy) code up on github.

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Map generation on a sphere, part 1

I ran into a showstopper with mapgen4. It unpredictably "freezes" in the sense that inputs have no effect, even though both the map generation and rendering are running. I'm taking a break from that for ProcGen 2018 - 9 days to work on a procedural generation project.

I decided to play with procedural map generation on a sphere. I've long wanted to try generating entire planets instead of flat maps. See this project and this project to get an idea of what I'm wanting to learn how to do.

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Mapgen4: river representation

I've reached the point in mapgen4 development when I just want it to be over. So I'm cutting all remaining features and am focusing on finishing. Most of the remaining work isn't interesting enough to blog about so I'm going to describe the river representation I started using last year. It's worked very well for the needs of this project. Take a look at the rivers in this screenshot:

Rivers are binary trees

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Mapgen4: outlines

Usually when I make a map generator I focus on the underlying algorithms and data. The data will be used by a game project, so the visuals are meant to be informative and not necessarily pretty. For this project I wanted to make the output pretty. I previously blogged about the unusual projection I'm using for the graphics. It allows you to see the rivers and coastlines top-down but see the mountains from the side. There are two other interesting graphical tricks I'm using to make the maps prettier.

Non-photorealistic shading

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Mapgen4: bug fixes

The past week has been troubleshooting. The biggest problem was water pouring out of my house's electrical panel, but that's not what this blog post is about. I've been working on bugs in the map generator. There are some bugs I've been putting off because I didn't understand them.

The first problem was that rivers haven't been reaching the ocean. This has been a problem for a while, but I didn't want to fix it until I stopped changing the algorithm. I'm mostly happy with the river algorithm now so I decided to investigate. One thing that the Game AI Summit at GDC emphasizes is building debug visualizations; I'm a fan of that technique and tried it here:

Debugging coastal and river triangles

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Mapgen4: oblique projection

One of my goals for mapgen4 was to explore non-realistic approaches, both to map generation and to map rendering. I wanted to explain the unusual projection I'm using.

For procedurally generated wilderness maps, it's very common to see a top-down view, often using colors to represent height or biomes:

Top-down view

It's simple to implement, especially in 2D, and it shows the areas of the map, including coastlines and rivers and lakes. You can see where the mountains are, but only because of the color and lighting.

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Mapgen4: rainfall

Last time I rewrote elevation painting. The next thing I wanted to work on was biomes. I'm not actually even sure I need them, but I wanted to try a variant of an approach I had tried in the 1990s and again in 2009:

Rain cycle

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Mapgen4: elevation painting, revisited

A few weeks ago I described elevation painting for mapgen4. The idea was to let the user paint areas for mountains, valleys, and oceans, and then use distance fields to interpolate between the areas. After some user testing, I decided to abandon this approach.

When I originally implemented it, I painted mountains and valleys on a minimap. On the main map, I used distance fields to transition between the mountain and valley areas.

Elevation constraints (red and green), and resulting elevation

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Mapgen4: river appearance

Earlier this week I moved all the heavy computation into its own thread. The rest of the week I wanted to work on rivers. The last time I worked on rivers, I replaced the slow CPU-based renderer with a fast GPU-based renderer. However, the output was ugly:

Jagged rivers from my previous river renderer
Jagged rivers

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Mapgen4: threads

Today I am making mapgen4 multithreaded. I'm trying to blog more often, so I'm putting my notes here instead of keeping them to myself.

Multithreaded Javascript? Yes, with Web Workers. I've known about these for a while but I've never used them until now. The basics:

  • Web Workers are more like separate processes rather than threads. They have their own memory. Some browsers support shared memory but it's not something I can count on right now. Introduction and reference.
  • Workers can communicate by sending a message to another worker. The message is a data-only object (no functions or resources). Details.
  • You can also transfer data to another worker, if it's a contiguous array. This is particularly useful for large arrays of numbers such as WebGL data or, in my case, mapgen4 data including the Voronoi mesh. It avoids a copy.

I find that I learn best by reading a little bit and then playing with something. So I decided to make a simple worker and try it out.

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Mapgen4: elevation painting

Last week I described the plan for elevation in mapgen4. The goal was to allow painting mountains, valleys, and oceans on the map. I used a jittered grid to pick positions for mountain peaks, and then implemented three distance fields:

  1. Distance from closest mountain peak. I use this to create distinct mountains instead of noise-based continuous mountains.
  2. Distance from coastline. On the ocean side, I use this to make shallow water near the coast. On the land side, I use this to keep mountains away from coasts. (not sure I should)
  3. Distance from mountain ranges. I use this to make a gradual drop from mountains to valleys.

I continued optimizing. The main map regeneration is now around 400ms for the one-time initialization and 120ms to regenerate the map while painting. I implemented a simple paint interface, with small/medium/large brushes and ocean/valley/mountain tools. It works on touch devices too, and it feels pretty good on a tablet.

Example painted map
Map painting

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Mapgen4: elevation

Last week I posted about mapgen4, the procedural map generation project I'm working on this summer. I had been trying to limit the scope of the project, and also shifting my thinking from maps for a game to maps that look pretty. I've been spending a lot of time optimizing and restructuring the code for this. It occurred to me that I'm approaching elevation all wrong.

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Mapgen4: goals

I've been posting on Twitter but was reminded that I should be posting more to my blog. I don't want Twitter to be the only place to read about what I'm doing.

Screenshot of a procedurally generated map

Back in 2010 I had written an influential article about map generation, making maps specifically designed for one game. I made a Flash demo called mapgen2. At the time I didn't emphasize enough how each of the layers of the process could be different. Many people took the recipe as the way to do it, even though the recipe was specifically for the needs of that one game. In mapgen2 the rivers depended on elevation which depended on coastlines. But it could've been coastlines depended on elevation which depended on rivers. There are lots of different ways to glue the pieces together. In 2017, I wanted to go back and try a different recipe with the same ingredients (Voronoi, elevation, rivers, biomes, etc.). For a while I thought the new project, mapgen4, will do all the things! I experimented with lots of things but the task seemed overwhelming. I decided to step back and limit my scope. I rebuilt the same algorithms with the new framework (HTML5, and more efficient data structures), and launched that as an HTML5 version of mapgen2. Then I put everything on hold.

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Delaunator guide

I decided that I should work on a new tutorial this summer. What better than to take all the map experiments I worked on last summer, and turn them into a procedural voronoi-map generation tutorial? As I worked on the outline and some of the initial diagrams I realized this was going to be big: poisson disc, delaunay, voronoi, elevation, climate, biomes, oceans, rivers, towns, roads, natural resourcess, and so much more. And starting with something big often leads to failure. So I needed something smaller.

I decided that I should start with just the structural part: Delaunay and Voronoi, and how they can be used for game maps: poisson disc, jitted grid, delaunay, voronoi, graph properties, neighbors, traversal, lookups, iterators, ghost elements, centroid vs incenter vs circumcenter, rounded regions, subdivision, and more. While working on the outline for this I realized again that it was going to be big. And starting with something big often leads to failure. So I needed something even smaller.

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Modifying spelling

Back in 2016 I started a mini-project to play with neural networks. I concluded that the approach I used didn't give me enough control over the procedural generation. I wanted to revisit the project and focus on word manipulation (the problem I wanted to solve) instead of neural networks (the tool I was learning). Over the past week I read a lot, played with some code, and learned more about English. I tried modifying the spelling of existing words. Example:

Four skore and seven yirz ago our fatherz brougt forth on this kontinent, a noo nation, konceived in Liberty, and dedikated too the propozition that all men are kreated ekual.

I wrote up the results, including an interactive demo and instructions for compiling and using the software and dataset I found. I don't know what I will do with this, but it was interesting and I hope it's useful to someone.

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Thoughts on explorable explanations

Conversations with several people over the past few months have led me to wonder about the purpose of the interactive diagrams in my articles. I see lots of interactive diagrams but most are not integrated into text. The interactive diagrams are cool. They make me feel like a pioneer exploring a new medium. They're exciting! I like making them! But … that doesn't mean I should be making them.

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April updates: hex grid guide, load time

The past 7 weeks I've been working on my guide to hexagonal grids. Over the years I accumulated a long list of TO DO items on my Trello page, and I finally went through that list and implemented lots of them. Two blog posts ago I described rewriting it from an imperative style to a declarative style, and switching from manual to automatic dependency tracking. In the last blog post I described many of the improvements I made to the diagrams, including several new ones.

As I've added to the page over the years, it's become slower and slower. The main problem is the page loading time. The HTML loads, then the Javascript loads, then the Javascript runs to create the diagrams, sample code, and some of the text of the page. If you follow a link to a specific section, the browser jumps to that section, but then the layout changes as more content is added to the page by the Javascript. This is an unpleasant experience.


April updates: hex grid guide, iteration

One of my goals this year is to iterate more. I have a tendency to "launch" a page and then move on to the next topic. Instead, for the first few months of the year I decided I would go through my existing pages to:

  1. figure out how the content could be better (explanations, diagrams, user interface, little details)
  2. figure out how the tech could be better (load time, animation code, diagramming code, code structure)

Over the past 6 weeks I've been working on my guide to hexagonal grids. I first worked on the tech, switching from an imperative style to a declarative style, and also switching to a library with automatic dependency tracking. Then I worked on content updates, some of which I described in my previous blog post. In the past week I've been going through my list on trello and implementing more content updates:

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April updates: hex grid guide

“We can rebuild it—we have the technology.”

Over the past few weeks I've been reimplementing my guide to hexagonal grids. I'm generally not a fan of rewrites that have no end-user benefits but there are lots of improvements I want to make to the page, and the convoluted code was making it harder to make the changes I wanted. I ended up spending 60 hours on this, reduced the number of lines of code from 2400 to 1400, and reduced the total Javascript sent to the browser (gzipped) from 85k to 54k. A large part of this was rewriting the diagrams to use Vue.js instead of D3.js. As much as I love D3, there's not much on the hexagon guide that benefits from it, and I ended up using it as a nicer JQuery. In a previous blog post I described wanting dependency tracking. That's why Vue.js worked well for this page. I think React would've been a reasonable choice as well, but on this page Vue fit my needs better.

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March updates: lots of small things

One of my goals this year is to publish in smaller chunks instead of trying to do everything in "one big launch". This is what I've been working on over the past few weeks:

Using Vue with Canvas

In my last post I had said I was trying out some libraries to automatically track dependencies for me. The one I'm playing with right now is Vue.js. It can track dependencies between data and the HTML/SVG elements. For example if I write SVG:

<circle :cx="center.x" :cy="center.y" r="30"/>

and I have it hooked up to data:

data: {
  center: {x: 100, y: 150}

then Vue will remember that the circle depends on those x and y properties. If I modify the data with center.x = 75; Vue will detect this and update the circle. This is quite convenient!

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How I implement my interactive diagrams, part 2

In the last post I described how I structure my interactive diagrams and gave some examples. In this post I'll describe what I'd like to do for future diagrams.

Flow diagram: controls → input → algorithm → output → visualization

When I started writing interactive diagrams I used d3.js, which is a great visualization toolkit. At the time I thought data visualization was the hardest part of what I was doing, and I needed a library for that. Since then, I've seen other libraries — React, Riot, Ember, Mithril, Intercooler, Marko, Vue, Aurelia, Ractive, Rax, Svelte, MobX, Moon, Dio, Etch, Hyperapp, S/Surplus, Preact, Polymer, lit-html, Elm, and many more — that have given me different ways to look at the problem. I've realized that the visualization isn't the hardest part of what I'm trying to do. There are two two big problems I want a library to help me with:

  • How do I update the visualization?
  • Which algorithms do I need to run again?

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