Layout Engine

The Layout Engine is a core component of the Output Renderer responsible for processing structured data and style rules to compute the precise position, size, and flow of all graphical and textual elements (e.g., text blocks, images, tables, UI controls) within a defined output area or viewport. It resolves constraints, handles dynamic content, and generates the final geometric instructions for the rendering stage.

The engine receives a content tree (e.g., a DOM, document object model) and a set of associated style rules (e.g., CSS). It performs a multi-pass calculation: first, it determines the intrinsic dimensions of elements; then, it applies the CSS box model, calculating margins, borders, padding, and content dimensions; finally, it executes a layout algorithm (like block formatting, flexbox, or grid) to position each element relative to its containing blocks and siblings, resolving any conflicts or overflows. The output is a detailed layout tree with exact coordinates for the renderer to paint.