--- title: 2 off by 1s make a right | daily.dev description: A live coding session focused on improving a custom GUI framework's textbox widget, built from scratch in Zig. The developer works through several bugs: fixing... canonical: https://daily.dev/posts/2-off-by-1s-make-a-right-j0va6miue twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: 2 off by 1s make a right | daily.dev og:description: A live coding session focused on improving a custom GUI framework's textbox widget, built from scratch in Zig. The developer works through several bugs: fixing... og:url: https://daily.dev/posts/2-off-by-1s-make-a-right-j0va6miue og:image: https://api.daily.dev/og/posts/j0Va6miuE.png og:image:alt: 2 off by 1s make a right 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. # 2 off by 1s make a right **[sphaerophoria](https://daily.dev/sources/sphaerophoria)** · 122 min read · 0 upvotes · 0 comments ## Summary A live coding session focused on improving a custom GUI framework's textbox widget, built from scratch in Zig. The developer works through several bugs: fixing cursor overflow past the right edge of the textbox, centering the cursor correctly between characters using inclusive/exclusive pixel boundary math, making clicks outside text jump the cursor to the correct position, and implementing smooth drift-based text scrolling when dragging the mouse outside the widget bounds. The session involves significant off-by-one debugging around pixel-level cursor placement and integer truncation bias. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: --- Tags: [#zig](https://daily.dev/tags/zig) [View this post on daily.dev](https://daily.dev/posts/2-off-by-1s-make-a-right-j0va6miue) ```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":"2 off by 1s make a right","url":"https://daily.dev/posts/2-off-by-1s-make-a-right-j0va6miue","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/2-off-by-1s-make-a-right-j0va6miue"},"datePublished":"2026-06-05T22:57:45.823Z","dateModified":"2026-06-05T23:23:35.396Z","description":"A live coding session focused on improving a custom GUI framework's textbox widget, built from scratch in Zig. 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