88 lines
3.1 KiB
Go
88 lines
3.1 KiB
Go
// Copyright 2010 The draw2d Authors. All rights reserved.
|
|
// created: 13/12/2010 by Laurent Le Goff
|
|
|
|
// Package draw2d is a pure go 2D vector graphics library with support
|
|
// for multiple output devices such as images (draw2d), pdf documents
|
|
// (draw2dpdf) and opengl (draw2dopengl), which can also be used on the
|
|
// google app engine. It can be used as a pure go Cairo alternative.
|
|
// draw2d is released under the BSD license.
|
|
//
|
|
// Features
|
|
//
|
|
// Operations in draw2d include stroking and filling polygons, arcs,
|
|
// Bézier curves, drawing images and text rendering with truetype fonts.
|
|
// All drawing operations can be transformed by affine transformations
|
|
// (scale, rotation, translation).
|
|
//
|
|
// Package draw2d follows the conventions of http://www.w3.org/TR/2dcontext for coordinate system, angles, etc...
|
|
//
|
|
// Installation
|
|
//
|
|
// To install or update the package draw2d on your system, run:
|
|
// go get -u github.com/llgcode/draw2d
|
|
//
|
|
// Quick Start
|
|
//
|
|
// Package draw2d itself provides a graphic context that can draw vector
|
|
// graphics and text on an image canvas. The following Go code
|
|
// generates a simple drawing and saves it to an image file:
|
|
// // Initialize the graphic context on an RGBA image
|
|
// dest := image.NewRGBA(image.Rect(0, 0, 297, 210.0))
|
|
// gc := draw2d.NewGraphicContext(dest)
|
|
//
|
|
// // Set some properties
|
|
// gc.SetFillColor(color.RGBA{0x44, 0xff, 0x44, 0xff})
|
|
// gc.SetStrokeColor(color.RGBA{0x44, 0x44, 0x44, 0xff})
|
|
// gc.SetLineWidth(5)
|
|
//
|
|
// // Draw a closed shape
|
|
// gc.MoveTo(10, 10) // should always be called first for a new path
|
|
// gc.LineTo(100, 50)
|
|
// gc.QuadCurveTo(100, 10, 10, 10)
|
|
// gc.Close()
|
|
// gc.FillStroke()
|
|
//
|
|
// // Save to file
|
|
// draw2d.SaveToPngFile("hello.png", dest)
|
|
//
|
|
// There are more examples here:
|
|
// https://github.com/llgcode/draw2d/tree/master/samples
|
|
//
|
|
// Drawing on pdf documents is provided by the draw2dpdf package.
|
|
// Drawing on opengl is provided by the draw2dgl package.
|
|
// See subdirectories at the bottom of this page.
|
|
//
|
|
// Testing
|
|
//
|
|
// The samples are run as tests from the root package folder `draw2d` by:
|
|
// go test ./...
|
|
//
|
|
// Or if you want to run with test coverage:
|
|
// go test -cover ./... | grep -v "no test"
|
|
//
|
|
// This will generate output by the different backends in the output folder.
|
|
//
|
|
// Acknowledgments
|
|
//
|
|
// Laurent Le Goff wrote this library, inspired by Postscript and
|
|
// HTML5 canvas. He implemented the image and opengl backend with the
|
|
// freetype-go package. Also he created a pure go Postscript
|
|
// interpreter, which can read postscript images and draw to a draw2d
|
|
// graphic context (https://github.com/llgcode/ps). Stani Michiels
|
|
// implemented the pdf backend with the gofpdf package.
|
|
//
|
|
// The package depends on freetype-go package for its rasterization
|
|
// algorithm.
|
|
//
|
|
// Packages using draw2d
|
|
//
|
|
// - https://github.com/llgcode/ps: Postscript interpreter written in Go
|
|
//
|
|
// - https://github.com/gonum/plot: drawing plots in Go
|
|
//
|
|
// - https://github.com/muesli/smartcrop: content aware image cropping
|
|
//
|
|
// - https://github.com/peterhellberg/karta: drawing Voronoi diagrams
|
|
//
|
|
// - https://github.com/vdobler/chart: basic charts in Go
|
|
package draw2d
|