stl

Documentation

Overview

Package stl provides functionality for writing 3D models in STL (stereolithography) binary format.

STL is a widely used file format for 3D printing and computer-aided design (CAD). This package implements the binary STL format specification, which is more compact and efficient than the ASCII variant. The binary format consists of:

• An 80-byte header
• A 4-byte unsigned integer indicating the number of triangles
• Triangle data, where each triangle consists of:
• A normal vector (3 x 32-bit floats)
• Three vertices (9 x 32-bit floats)
• A 2-byte attribute count (unused in most applications)

This package provides optimized writing capabilities with buffered I/O and efficient memory usage, making it suitable for generating large 3D models.

Index

• func CreateContributionGeometry(contributions [][]types.ContributionDay, yearIndex int, maxContrib int) []types.Triangle
• func GenerateSTL(contributions [][]types.ContributionDay, outputPath, username string, year int) error
• func GenerateSTLRange(contributions [][][]types.ContributionDay, outputPath, username string, ...) error
• func WriteSTLBinary(filename string, triangles []types.Triangle) error

Functions

func CreateContributionGeometry

func CreateContributionGeometry(contributions [][]types.ContributionDay, yearIndex int, maxContrib int) []types.Triangle

CreateContributionGeometry generates geometry for a single year's worth of contributions

func GenerateSTL

func GenerateSTL(contributions [][]types.ContributionDay, outputPath, username string, year int) error

GenerateSTL creates a 3D model from GitHub contribution data and writes it to an STL file. It's a convenience wrapper around GenerateSTLRange for single year processing.

func GenerateSTLRange

func GenerateSTLRange(contributions [][][]types.ContributionDay, outputPath, username string, startYear, endYear int) error

GenerateSTLRange creates a 3D model from multiple years of GitHub contribution data. It handles the complete process from data validation through geometry generation to file output. Parameters:

• contributions: 3D slice of contribution data ([year][week][day])
• outputPath: destination path for the STL file
• username: GitHub username for the contribution data
• startYear: first year in the range
• endYear: last year in the range

func WriteSTLBinary

func WriteSTLBinary(filename string, triangles []types.Triangle) error

WriteSTLBinary writes triangles to a binary STL file with optimized buffering.

The binary STL format consists of: 1. 80-byte header - typically containing version/generator information 2. 4-byte unsigned integer - number of triangles 3. For each triangle:

• Normal vector: 3 x float32 (12 bytes)
• Vertex 1: 3 x float32 (12 bytes)
• Vertex 2: 3 x float32 (12 bytes)
• Vertex 3: 3 x float32 (12 bytes)
• Attribute byte count: uint16 (2 bytes, usually 0)