render

Documentation

Overview

Package render provides visualization rendering for dependency graphs.

Overview

This package contains the rendering pipeline that transforms dependency graphs into visual outputs. It provides:

• Generic format conversion (SVG to PDF/PNG)
• Tower visualization (in [tower] subpackage)
• Node-link diagrams (in [nodelink] subpackage)

Format Conversion

The ToPDF and ToPNG functions convert any SVG to other formats using the external rsvg-convert tool (from librsvg). These are used by both tower and node-link renderers.

svg := tower.RenderSVG(layout, opts...)
pdf, err := render.ToPDF(svg)
png, err := render.ToPNG(svg, 2.0)  // 2x scale

Tower Visualization

The [tower] subpackage renders dependency graphs as stacked physical towers where blocks rest on what they depend on. This is Stacktower's signature visualization style, inspired by XKCD #2347.

Key tower subpackages:

• tower/layout: Block position computation
• tower/ordering: Row ordering algorithms (barycentric, optimal)
• tower/sink: Output formats (SVG, JSON)
• tower/styles: Visual styles (handdrawn, simple)

Node-Link Diagrams

The [nodelink] subpackage renders traditional directed graph diagrams using Graphviz. Nodes appear as boxes connected by arrows.

dot := nodelink.ToDOT(g, nodelink.Options{})
svg, err := nodelink.RenderSVG(dot)
pdf, err := render.ToPDF(svg)

[tower]: github.com/matzehuels/stacktower/pkg/render/tower tower/layout: github.com/matzehuels/stacktower/pkg/render/tower/layout tower/ordering: github.com/matzehuels/stacktower/pkg/render/tower/ordering tower/sink: github.com/matzehuels/stacktower/pkg/render/tower/sink tower/styles: github.com/matzehuels/stacktower/pkg/render/tower/styles [nodelink]: github.com/matzehuels/stacktower/pkg/render/nodelink

Index

• func ToPDF(svg []byte) ([]byte, error)
• func ToPNG(svg []byte, scale float64) ([]byte, error)

Functions

func ToPDF

func ToPDF(svg []byte) ([]byte, error)

ToPDF converts SVG bytes to PDF using rsvg-convert. Requires librsvg: brew install librsvg (macOS), apt install librsvg2-bin (Linux).

func ToPNG

func ToPNG(svg []byte, scale float64) ([]byte, error)

ToPNG converts SVG bytes to PNG using rsvg-convert with the given scale factor. Scale of 2.0 produces a 2x resolution image. Requires librsvg: brew install librsvg (macOS), apt install librsvg2-bin (Linux).