feat(#18, #17)

README.md

@@ -6,7 +6,7 @@ bimg is designed to be a small and efficient library with a generic and useful s
 It uses internally libvips, which requires a [low memory footprint](http://www.vips.ecs.soton.ac.uk/index.php?title=Speed_and_Memory_Use) 
 and it's typically 4x faster than using the quickest ImageMagick and GraphicsMagick settings or Go  native `image` package, and in some cases it's even 8x faster processing JPEG images. 
 
-It can read JPEG, PNG, WEBP, TIFF and Magick formats and it can output to JPEG, PNG and WEBP. It supports common [image transformation](#supported-image-operations) operations such as crop, resize, rotate... and conversion between multiple formats. 
+It can read JPEG, PNG, WEBP and TIFF formats and output to JPEG, PNG and WEBP. It supports common [image transformation](#supported-image-operations) operations such as crop, resize, rotate... and conversion between multiple formats. 
 
 For getting started, take a look to the [examples](#examples) and [programmatic API](https://godoc.org/github.com/h2non/bimg) documentation.
 

image.go

@@ -4,6 +4,7 @@ type Image struct {
 	buffer []byte
 }
 
+// Resize the image to fixed width and height
 func (i *Image) Resize(width, height int) ([]byte, error) {
 	options := Options{
 		Width:  width,
@@ -12,6 +13,7 @@ func (i *Image) Resize(width, height int) ([]byte, error) {
 	return i.Process(options)
 }
 
+// Extract area from the by X/Y axis
 func (i *Image) Extract(top, left, width, height int) ([]byte, error) {
 	options := Options{
 		Top:        top,
@@ -22,6 +24,17 @@ func (i *Image) Extract(top, left, width, height int) ([]byte, error) {
 	return i.Process(options)
 }
 
+// Enlarge the image from the by X/Y axis
+func (i *Image) Enlarge(width, height int) ([]byte, error) {
+	options := Options{
+		Width:   width,
+		Height:  height,
+		Enlarge: true,
+	}
+	return i.Process(options)
+}
+
+// Crop an image by width and height
 func (i *Image) Crop(width, height int) ([]byte, error) {
 	options := Options{
 		Width:  width,
@@ -31,6 +44,25 @@ func (i *Image) Crop(width, height int) ([]byte, error) {
 	return i.Process(options)
 }
 
+// Crop an image by width (auto height)
+func (i *Image) CropByWidth(width int) ([]byte, error) {
+	options := Options{
+		Width: width,
+		Crop:  true,
+	}
+	return i.Process(options)
+}
+
+// Crop an image by height (auto width)
+func (i *Image) CropByHeight(height int) ([]byte, error) {
+	options := Options{
+		Height: height,
+		Crop:   true,
+	}
+	return i.Process(options)
+}
+
+// Thumbnail the image by the a given width by aspect ratio 4:4
 func (i *Image) Thumbnail(pixels int) ([]byte, error) {
 	options := Options{
 		Width:   pixels,
@@ -41,21 +73,25 @@ func (i *Image) Thumbnail(pixels int) ([]byte, error) {
 	return i.Process(options)
 }
 
+// Rotate the image by given angle degrees (0, 90, 180 or 270)
 func (i *Image) Rotate(a Angle) ([]byte, error) {
 	options := Options{Rotate: a}
 	return i.Process(options)
 }
 
+// Flip the image about the vertical Y axis
 func (i *Image) Flip() ([]byte, error) {
 	options := Options{Flip: VERTICAL}
 	return i.Process(options)
 }
 
+// Flop the image about the horizontal X axis
 func (i *Image) Convert(t ImageType) ([]byte, error) {
 	options := Options{Type: t}
 	return i.Process(options)
 }
 
+// Transform the image by custom options
 func (i *Image) Process(o Options) ([]byte, error) {
 	image, err := Resize(i.buffer, o)
 	if err != nil {
@@ -65,18 +101,22 @@ func (i *Image) Process(o Options) ([]byte, error) {
 	return image, nil
 }
 
-func (i *Image) Type() string {
+// Get image metadata (size, alpha channel, profile, EXIF rotation)
-	return DetermineImageTypeName(i.buffer)
-}
-
 func (i *Image) Metadata() (ImageMetadata, error) {
 	return Metadata(i.buffer)
 }
 
+// Get image type format (jpeg, png, webp, tiff)
+func (i *Image) Type() string {
+	return DetermineImageTypeName(i.buffer)
+}
+
+// Get image size
 func (i *Image) Size() (ImageSize, error) {
 	return Size(i.buffer)
 }
 
+// Creates a new image
 func NewImage(buf []byte) *Image {
 	return &Image{buf}
 }

image_test.go

@@ -10,6 +10,11 @@ func TestImageResize(t *testing.T) {
 	if err != nil {
 		t.Errorf("Cannot process the image: %#v", err)
 	}
+
+	if assertSize(buf, 300, 240) {
+		t.Error("Invalid image size")
+	}
+
 	Write("fixtures/test_resize_out.jpg", buf)
 }
 
@@ -18,23 +23,64 @@ func TestImageExtract(t *testing.T) {
 	if err != nil {
 		t.Errorf("Cannot process the image: %#v", err)
 	}
+
+	if assertSize(buf, 300, 300) {
+		t.Error("Invalid image size")
+	}
+
 	Write("fixtures/test_extract_out.jpg", buf)
 }
 
+func TestImageEnlarge(t *testing.T) {
+	buf, err := initImage("test.png").Enlarge(500, 380)
+	if err != nil {
+		t.Errorf("Cannot process the image: %#v", err)
+	}
+
+	if assertSize(buf, 500, 380) {
+		t.Error("Invalid image size")
+	}
+
+	Write("fixtures/test_enlarge_out.jpg", buf)
+}
+
 func TestImageCrop(t *testing.T) {
 	buf, err := initImage("test.jpg").Crop(800, 600)
 	if err != nil {
 		t.Errorf("Cannot process the image: %#v", err)
 	}
+
+	if assertSize(buf, 800, 600) {
+		t.Error("Invalid image size")
+	}
+
 	Write("fixtures/test_crop_out.jpg", buf)
 }
 
-func TestImageFlip(t *testing.T) {
+func TestImageCropByWidth(t *testing.T) {
-	buf, err := initImage("test.jpg").Flip()
+	buf, err := initImage("test.jpg").CropByWidth(600)
 	if err != nil {
 		t.Errorf("Cannot process the image: %#v", err)
 	}
-	Write("fixtures/test_flip_out.jpg", buf)
+
+	if assertSize(buf, 600, 375) {
+		t.Error("Invalid image size")
+	}
+
+	Write("fixtures/test_crop_width_out.jpg", buf)
+}
+
+func TestImageCropByHeight(t *testing.T) {
+	buf, err := initImage("test.jpg").CropByHeight(300)
+	if err != nil {
+		t.Errorf("Cannot process the image: %#v", err)
+	}
+
+	if assertSize(buf, 800, 480) {
+		t.Error("Invalid image size")
+	}
+
+	Write("fixtures/test_crop_height_out.jpg", buf)
 }
 
 func TestImageThumbnail(t *testing.T) {
@@ -42,9 +88,22 @@ func TestImageThumbnail(t *testing.T) {
 	if err != nil {
 		t.Errorf("Cannot process the image: %#v", err)
 	}
+
+	if assertSize(buf, 100, 100) {
+		t.Error("Invalid image size")
+	}
+
 	Write("fixtures/test_thumbnail_out.jpg", buf)
 }
 
+func TestImageFlip(t *testing.T) {
+	buf, err := initImage("test.jpg").Flip()
+	if err != nil {
+		t.Errorf("Cannot process the image: %#v", err)
+	}
+	Write("fixtures/test_flip_out.jpg", buf)
+}
+
 func TestImageRotate(t *testing.T) {
 	buf, err := initImage("test_flip_out.jpg").Rotate(90)
 	if err != nil {
@@ -81,3 +140,14 @@ func initImage(file string) *Image {
 	buf, _ := Read(path.Join("fixtures", file))
 	return NewImage(buf)
 }
+
+func assertSize(buf []byte, width, height int) bool {
+	size, err := NewImage(buf).Size()
+	if err != nil {
+		return false
+	}
+	if size.Width != 220 || size.Height != 300 {
+		return false
+	}
+	return true
+}

resize.go

@@ -45,14 +45,14 @@ func Resize(buf []byte, o Options) ([]byte, error) {
 	inHeight := int(image.Ysize)
 
 	// image calculations
-	factor := imageCalculations(o, inWidth, inHeight)
+	factor := imageCalculations(&o, inWidth, inHeight)
 	shrink := int(math.Max(math.Floor(factor), 1))
 	residual := float64(shrink) / factor
 
 	// Do not enlarge the output if the input width *or* height are already less than the required dimensions
 	if o.Enlarge == false {
 		if inWidth < o.Width && inHeight < o.Height {
-			factor = 1
+			factor = 1.0
 			shrink = 1
 			residual = 0
 			o.Width = inWidth
@@ -169,7 +169,6 @@ func rotateImage(image *C.struct__VipsImage, o Options) (*C.struct__VipsImage, e
 	if o.Rotate > 0 {
 		image, err = vipsRotate(image, getAngle(o.Rotate))
 	}
-
 	if o.Flip > 0 {
 		image, err = vipsFlip(image, o.Flip)
 	}
@@ -223,7 +222,7 @@ func shrinkJpegImage(buf []byte, input *C.struct__VipsImage, factor float64, shr
 	return image, factor, err
 }
 
-func imageCalculations(o Options, inWidth, inHeight int) float64 {
+func imageCalculations(o *Options, inWidth, inHeight int) float64 {
 	factor := 1.0
 	xfactor := float64(inWidth) / float64(o.Width)
 	yfactor := float64(inHeight) / float64(o.Height)

vips.go

@@ -8,7 +8,6 @@ import "C"
 
 import (
 	"errors"
-	//"fmt"
 	"runtime"
 	"strings"
 	"sync"
@@ -20,44 +19,51 @@ var (
 	initialized bool = false
 )
 
-type vipsImage C.struct__VipsImage
-
 func init() {
-	runtime.LockOSThread()
-	defer runtime.UnlockOSThread()
-
 	if C.VIPS_MAJOR_VERSION <= 7 && C.VIPS_MINOR_VERSION < 40 {
-		panic("unsupported old vips version")
+		panic("unsupported old vips version!")
 	}
 
 	Initialize()
-
-	C.vips_concurrency_set(0)                   // default
-	C.vips_cache_set_max_mem(100 * 1024 * 1024) // 100 MB
-	C.vips_cache_set_max(500)                   // 500 operations
 }
 
+// Explicit thread-safe start of libvips.
+// You should only call this function if you previously shutdown libvips
 func Initialize() {
+	m.Lock()
+	runtime.LockOSThread()
+	defer m.Unlock()
+	defer runtime.UnlockOSThread()
+
 	err := C.vips_init(C.CString("bimg"))
 	if err != 0 {
 		Shutdown()
 		panic("unable to start vips!")
 	}
 
-	m.Lock()
+	C.vips_concurrency_set(0)                   // default
-	defer m.Unlock()
+	C.vips_cache_set_max_mem(100 * 1024 * 1024) // 100 MB
+	C.vips_cache_set_max(500)                   // 500 operations
 	initialized = true
 }
 
+// Explicit thread-safe libvips shutdown. Call this to drop caches.
+// If libvips was already initialized, the function is no-op
 func Shutdown() {
+	m.Lock()
+	defer m.Unlock()
+
 	if initialized == true {
-		m.Lock()
-		defer m.Unlock()
 		C.vips_shutdown()
 		initialized = false
 	}
 }
 
+// Output to stdout collected data for debugging purposes
+func VipsDebug() {
+	C.im__print_all()
+}
+
 func vipsRotate(image *C.struct__VipsImage, angle Angle) (*C.struct__VipsImage, error) {
 	var out *C.struct__VipsImage
 	defer C.g_object_unref(C.gpointer(image))
@@ -197,26 +203,6 @@ func vipsImageType(buf []byte) ImageType {
 	return imageType
 }
 
-func vipsExifOrientation(image *C.struct__VipsImage) int {
-	return int(C.vips_exif_orientation(image))
-}
-
-func vipsHasAlpha(image *C.struct__VipsImage) bool {
-	return int(C.has_alpha_channel(image)) > 0
-}
-
-func vipsHasProfile(image *C.struct__VipsImage) bool {
-	return int(C.has_profile_embed(image)) > 0
-}
-
-func vipsWindowSize(name string) float64 {
-	return float64(C.interpolator_window_size(C.CString(name)))
-}
-
-func vipsSpace(image *C.struct__VipsImage) string {
-	return C.GoString(C.vips_enum_nick_bridge(image))
-}
-
 type vipsSaveOptions struct {
 	Quality     int
 	Compression int
@@ -255,9 +241,30 @@ func vipsSave(image *C.struct__VipsImage, o vipsSaveOptions) ([]byte, error) {
 	return buf, nil
 }
 
+func vipsExifOrientation(image *C.struct__VipsImage) int {
+	return int(C.vips_exif_orientation(image))
+}
+
+func vipsHasAlpha(image *C.struct__VipsImage) bool {
+	return int(C.has_alpha_channel(image)) > 0
+}
+
+func vipsHasProfile(image *C.struct__VipsImage) bool {
+	return int(C.has_profile_embed(image)) > 0
+}
+
+func vipsWindowSize(name string) float64 {
+	return float64(C.interpolator_window_size(C.CString(name)))
+}
+
+func vipsSpace(image *C.struct__VipsImage) string {
+	return C.GoString(C.vips_enum_nick_bridge(image))
+}
+
 func catchVipsError() error {
 	s := C.GoString(C.vips_error_buffer())
 	C.vips_error_clear()
 	C.vips_thread_shutdown()
+	// clean image memory buffer?
 	return errors.New(s)
 }

vips.h

@@ -151,8 +151,10 @@ vips_init_image(void *buf, size_t len, int imageType, VipsImage **out) {
 		code = vips_webpload_buffer(buf, len, out, "access", VIPS_ACCESS_SEQUENTIAL, NULL);
 	} else if (imageType == TIFF) {
 		code = vips_tiffload_buffer(buf, len, out, "access", VIPS_ACCESS_SEQUENTIAL, NULL);
+#if (VIPS_MAJOR_VERSION >= 8)
 	} else if (imageType == MAGICK) {
 		code = vips_magickload_buffer(buf, len, out, "access", VIPS_ACCESS_SEQUENTIAL, NULL);
+#endif
 	}
 
 	// Listen for "postclose" signal to delete input buffer