vipsgen — Streamline image processing with Go bindings…

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About this project

vipsgen provides automated generation of type-safe and idiomatic Go bindings for the libvips image processing library. Say goodbye to complex manual bindings and embrace an efficient approach that adapts to your installation. With comprehensive support and seamless integration, vipsgen is designed to enhance image processing in Go applications.

vipsgen is a powerful Go binding generator designed for the libvips image processing library, known for its speed and efficiency. This tool addresses the limitations of existing Go bindings that rely on manual code, which can often be incomplete, error-prone, and challenging to maintain as libvips evolves.

Key Features

Comprehensive Coverage: Provides bindings for approximately 300 libvips operations, allowing developers to leverage a vast array of functionalities.
Type-Safe: Generates accurate Go types for libvips enums and structs, enhancing code reliability.
Idiomatic Go Code: Produces clear and natural Go-style code, streamlining the development experience.
Streaming Support: Integrates VipsSource bindings with io.ReadCloser for efficient streaming capabilities.

Usage Example

To demonstrate the power of vipsgen, consider the following Go code snippet:

package main

import (
	"fmt"
	"log"
	"net/http"
	"github.com/cshum/vipsgen/vips"
)

func main() {
	// Fetch an image via HTTP GET
	resp, err := http.Get("https://raw.githubusercontent.com/cshum/imagor/master/testdata/gopher.png")
	if err != nil {
		log.Fatalf("Failed to fetch image: %v", err)
	}
	defer resp.Body.Close()

	// Create a source from io.ReadCloser
	source := vips.NewSource(resp.Body)
	defer source.Close()

	// Load a thumbnail image with specified options
	image, err := vips.NewThumbnailSource(source, 800, &vips.ThumbnailSourceOptions{
		Height: 1000,
		FailOn: vips.FailOnError,
	})
	if err != nil {
		log.Fatalf("Failed to load image: %v", err)
	}
	defer image.Close()

	// Add a yellow border to the image
	border := 10
	if err := image.Embed(
		border, border,
		image.Width()+border*2,
		image.Height()+border*2,
		&vips.EmbedOptions{
			Extend:     vips.ExtendBackground,
			Background: []float64{255, 255, 0, 255},
		}); err != nil {
		log.Fatalf("Failed to add border: %v", err)
	}

	fmt.Printf("Processed image: %dx%d\n", image.Width(), image.Height())

	// Save the image as WebP with options
	err = image.Webpsave("resized-gopher.webp", &vips.WebpsaveOptions{
		Q:              85,
		Effort:         4,
		SmartSubsample: true,
	})
	if err != nil {
		log.Fatalf("Failed to save image as WebP: %v", err)
	}
	fmt.Println("Successfully saved processed images")
}

Code Generation

For users interested in generating custom bindings, vipsgen requires libvips to be built with GObject introspection support. Users can easily generate bindings with:

vipsgen -out ./vips

Command Line Options

The command line interface provides options to customize the output directory, templates, and debug settings. Use the following command to view available options:

Usage: vipsgen [options]

Options:
-out string            Output directory (default "./out")
-templates string      Template directory (uses embedded templates if not specified)
-extract               Extract embedded templates and exit
-extract-dir string    Directory to extract templates to (default "./templates")
-debug                 Enable debug json output

Contributions are welcomed to enhance the capabilities of vipsgen. This project presents a robust solution for developers looking to simplify image processing tasks in Go.