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package bimg
/*
#cgo pkg-config: vips
#include "vips/vips.h"
*/
import "C"
import (
"math"
)
const (
BICUBIC Interpolator = iota
BILINEAR
NOHALO
)
func Resize(buf []byte, o Options) ([]byte, error) {
// detect (if possible) the file type
defer C.vips_thread_shutdown()
image, err := vipsRead(buf)
if err != nil {
return nil, err
}
//var tmpImage *C.struct__VipsImage
/*
// feed it
imageLength := C.size_t(len(buf))
imageBuf := unsafe.Pointer(&buf[0])
debug("buffer: %s", buf[0])
C.vips_jpegload_buffer_seq(imageBuf, imageLength, &image)
*/
// defaults
if o.Quality == 0 {
o.Quality = QUALITY
}
// get WxH
inWidth := int(image.Xsize)
inHeight := int(image.Ysize)
// crop
if o.Crop {
left, top := calculateCrop(inWidth, inHeight, o.Width, o.Height, o.Gravity)
o.Width = int(math.Min(float64(inWidth), float64(o.Width)))
o.Height = int(math.Min(float64(inHeight), float64(o.Height)))
image, err = vipsExtract(image, left, top, o.Width, o.Height)
if err != nil {
return nil, err
}
//err := C.vips_extract_area_0(image, &tmpImage, C.int(left), C.int(top), C.int(o.Width), C.int(o.Height))
//C.g_object_unref(C.gpointer(image))
//image = tmpImage
}
// rotate
r := Rotation{180}
image, err = Rotate(image, r)
if err != nil {
return nil, err
}
// Finally save
//var ptr unsafe.Pointer
//length := C.size_t(0)
//C.vips_jpegsave_custom(image, &ptr, &length, 1, C.int(o.Quality), 0)
//C.g_object_unref(C.gpointer(image))
//C.g_object_unref(C.gpointer(newImage))
// get back the buffer
//buf = C.GoBytes(ptr, C.int(length))
// cleanup
//C.g_free(C.gpointer(ptr))
buf, err = vipsSave(image, vipsSaveOptions{Quality: o.Quality})
if err != nil {
return nil, err
}
C.vips_error_clear()
return buf, nil
}
type Rotation struct {
angle int
}
func (a Rotation) calculate() int {
angle := a.angle
divisor := angle % 90
if divisor != 0 {
angle = a.angle - divisor
}
return angle
}
func Rotate(image *C.struct__VipsImage, r Rotation) (*C.struct__VipsImage, error) {
//vips := &Vips{}
return vipsRotate(image, r.calculate())
}
const (
CENTRE Gravity = iota
NORTH
EAST
SOUTH
WEST
)
func calculateCrop(inWidth, inHeight, outWidth, outHeight int, gravity Gravity) (int, int) {
left, top := 0, 0
switch gravity {
case NORTH:
left = (inWidth - outWidth + 1) / 2
case EAST:
left = inWidth - outWidth
top = (inHeight - outHeight + 1) / 2
case SOUTH:
left = (inWidth - outWidth + 1) / 2
top = inHeight - outHeight
case WEST:
top = (inHeight - outHeight + 1) / 2
default:
left = (inWidth - outWidth + 1) / 2
top = (inHeight - outHeight + 1) / 2
}
return left, top
}