Features

Quick Start

brew install vips pkg-config

export CGO_CFLAGS_ALLOW="-Xpreprocessor"

go get -u github.com/cshum/vipsgen/vips

package mainimport ("log""net/http""github.com/cshum/vipsgen/vips")funcmain() {// Fetch an image from http.Getresp,err:=http.Get("https://raw.githubusercontent.com/cshum/imagor/master/testdata/gopher.png")iferr!=nil {log.Fatalf("Failed to fetch image: %v",err)}deferresp.Body.Close()// Create source from io.ReadClosersource:=vips.NewSource(resp.Body)defersource.Close()// source needs to remain available during image lifetime// Shrink-on-load via creating image from thumbnail source with optionsimage,err:=vips.NewThumbnailSource(source,800,&vips.ThumbnailSourceOptions{Height:1000,FailOn:vips.FailOnError,// Fail on first error})iferr!=nil {log.Fatalf("Failed to load image: %v",err)}deferimage.Close()// always close images to free memory// Add a yellow border using vips_embedborder:=10iferr:=image.Embed(border,border,image.Width()+border*2,image.Height()+border*2,&vips.EmbedOptions{Extend:vips.ExtendBackground,// extend with colour from the background propertyBackground: []float64{255,255,0,255},// Yellow border},);err!=nil {log.Fatalf("Failed to add border: %v",err)}log.Printf("Processed image: %dx%d\n",image.Width(),image.Height())// Save the result as WebP file with optionserr=image.Webpsave("resized-gopher.webp",&vips.WebpsaveOptions{Q:85,// Quality factor (0-100)Effort:4,// Compression effort (0-6)SmartSubsample:true,// Better chroma subsampling})iferr!=nil {log.Fatalf("Failed to save image as WebP: %v",err)}log.Println("Successfully saved processed images")}

Code Generation

go install github.com/cshum/vipsgen/cmd/vipsgen@latest

vipsgen -out ./vips

package mainimport ("yourproject/vips")

Command Line 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

How Code Generation Works

┌─────────────────────────────────────────────────────────────┐│                    Go Method Layer                          ││  • Methods on *Image struct                                 ││  • Go enums and structs                                     │  │  • Options structs for optional parameters                  ││  • Type conversions (Go <-> C)                              │└─────────────────────────────────────────────────────────────┘                               │┌─────────────────────────────────────────────────────────────┐│                   Go Binding Layer                          ││  • vipsgenAbc() - required parameters only                  ││  • vipsgenAbcWithOptions() - with optional parameters       ││  • C array handling and memory management                   ││  • String conversions and cleanup                           ││  • Error handling and resource management                   │└─────────────────────────────────────────────────────────────┘                               │┌─────────────────────────────────────────────────────────────┐│                     C Layer                                 ││  • vipsgen_abc() - required args only                       ││  • vipsgen_abc_with_options() - all parameters              ││  • VipsOperation dynamic dispatch                           ││  • Proper VipsArray creation and cleanup                    │└─────────────────────────────────────────────────────────────┘                               │┌─────────────────────────────────────────────────────────────┐│                    libvips                                  ││  • vips_abc() - original variadic functions                 ││  • VipsOperation object system                              ││  • GObject introspection metadata                           │└─────────────────────────────────────────────────────────────┘

// Basic function - required arguments only, calls vips_resize directlyintvipsgen_resize(VipsImage*in,VipsImage**out,doublescale) {returnvips_resize(in,out,scale,NULL);}// With options - uses VipsOperation for optional parametersintvipsgen_resize_with_options(VipsImage*in,VipsImage**out,doublescale,VipsKernelkernel,doublegap,doublevscale) {VipsOperation*operation=vips_operation_new("resize");if (!operation)return1;if (vips_object_set(VIPS_OBJECT(operation),"in",in,NULL)||vips_object_set(VIPS_OBJECT(operation),"scale",scale,NULL)||vipsgen_set_int(operation,"kernel",kernel)||vipsgen_set_double(operation,"gap",gap)||vipsgen_set_double(operation,"vscale",vscale)    ) {g_object_unref(operation);return1;    }intresult=vipsgen_operation_execute(operation,"out",out,NULL);returnresult;}

// vipsgenResize vips_resize resize an imagefuncvipsgenResize(in*C.VipsImage,scalefloat64) (*C.VipsImage,error) {varout*C.VipsImageiferr:=C.vipsgen_resize(in,&out,C.double(scale));err!=0 {returnnil,handleImageError(out)    }returnout,nil}// vipsgenResizeWithOptions vips_resize resize an image with optional argumentsfuncvipsgenResizeWithOptions(in*C.VipsImage,scalefloat64,kernelKernel,gapfloat64,vscalefloat64) (*C.VipsImage,error) {varout*C.VipsImageiferr:=C.vipsgen_resize_with_options(in,&out,C.double(scale),C.VipsKernel(kernel),C.double(gap),C.double(vscale));err!=0 {returnnil,handleImageError(out)    }returnout,nil}

// ResizeOptions optional arguments for vips_resizetypeResizeOptionsstruct {// Kernel Resampling kernelKernelKernel// Gap Reducing gapGapfloat64// Vscale Vertical scale image by this factorVscalefloat64}// DefaultResizeOptions creates default value for vips_resize optional argumentsfuncDefaultResizeOptions()*ResizeOptions {return&ResizeOptions{Kernel:Kernel(5),Gap:2,    }}// Resize vips_resize resize an imagefunc (r*Image)Resize(scalefloat64,options*ResizeOptions)error {ifoptions!=nil {// Use the WithOptions variant when options are providedout,err:=vipsgenResizeWithOptions(r.image,scale,options.Kernel,options.Gap,options.Vscale)iferr!=nil {returnerr        }r.setImage(out)returnnil    }// Use the basic variant for required parameters onlyout,err:=vipsgenResize(r.image,scale)iferr!=nil {returnerr    }r.setImage(out)returnnil}

Contributing

Development Workflow

Special Thanks togovips

License