--- title: Merging contours because my monitor broke | daily.dev description: A live coding session building a contour merging algorithm for a custom font rendering engine. The author explains font contour winding order rules, signed... canonical: https://daily.dev/posts/merging-contours-because-my-monitor-broke-w3mzuz0qd twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Merging contours because my monitor broke | daily.dev og:description: A live coding session building a contour merging algorithm for a custom font rendering engine. The author explains font contour winding order rules, signed... og:url: https://daily.dev/posts/merging-contours-because-my-monitor-broke-w3mzuz0qd og:image: https://api.daily.dev/og/posts/w3mZuZ0Qd.png og:image:alt: Merging contours because my monitor broke og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Merging contours because my monitor broke **[sphaerophoria](https://daily.dev/sources/sphaerophoria)** · 143 min read · 0 upvotes · 0 comments ## Summary A live coding session building a contour merging algorithm for a custom font rendering engine. The author explains font contour winding order rules, signed distance fields, and why inside edges need to be removed before GPU-based SDF generation. The session covers implementing a graph structure in Zig where contour edges are split at intersection points using line-line intersection math, with OpenGL visualization to debug the results. The work is motivated by building a custom Twitch chat client with its own GUI framework and text renderer. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [mccloskeybr](https://daily.dev/posts/mccloskeybr-fbtxis0yu) · Hacker News · 0 upvotes · 0 comments - [A Recursive Algorithm to Render Signed Distance Fields](https://daily.dev/posts/a-recursive-algorithm-to-render-signed-distance-fields-nwfom4ttj) · Pointers Gone Wild · 23 upvotes · 0 comments --- Tags: [#zig](https://daily.dev/tags/zig), [#graph-theory](https://daily.dev/tags/graph-theory) [View this post on daily.dev](https://daily.dev/posts/merging-contours-because-my-monitor-broke-w3mzuz0qd) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Merging contours because my monitor broke","url":"https://daily.dev/posts/merging-contours-because-my-monitor-broke-w3mzuz0qd","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/merging-contours-because-my-monitor-broke-w3mzuz0qd"},"datePublished":"2026-03-09T23:02:45.507Z","dateModified":"2026-03-10T00:50:15.814Z","description":"A live coding session building a contour merging algorithm for a custom font rendering engine. 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