tools/util/image/image.go

package image

import (
	"fmt"
	"github.com/gographics/gmagick"
	"icloudapp.cn/tools/util"
	fileObj "icloudapp.cn/tools/util/file"
)

type Image struct {
	Cache
	Path string
}

func NewImage(path string) *Image {
	return &Image{
		Path: path,
	}
}

func (i *Image) Create(file, background string, size Size) (*gmagick.MagickWand, error) {
	if file != "" {
		file = fmt.Sprintf("%s/%s", i.Path, file)
		if !fileObj.IsFile(file) {
			return nil, util.NewError(fmt.Sprintf("文件 %s 不存在", file))
		}
	}
	imageMW := gmagick.NewMagickWand()

	if file != "" {
		if err := imageMW.ReadImage(file); err != nil {
			return nil, util.NewError(fmt.Sprintf("imageMW.ReadImageBlob:%s", err.Error()))
		}
	} else {
		if err := imageMW.ReadImageBlob(util.TransparentPNG()); err != nil {
			return nil, util.NewError(fmt.Sprintf("imageMW.ReadImageBlob:%s", err.Error()))
		}
	}
	fmt.Println("size", size)
	if err := imageMW.SetImageFormat("PNG"); err != nil {
		return nil, util.NewError("imageMW.SetImageFormat", err.Error())
	}
	if err := imageMW.ResizeImage(size.Width, size.Height, gmagick.FILTER_LANCZOS, 1); err != nil {
		return nil, util.NewError("imageMW.SetSize", err.Error())
	}

	if background != "" {
		if err := imageMW.SetImageBackgroundColor(Pixel(background)); err != nil {
			return nil, util.NewError(fmt.Sprintf("imageMW.SetImageBackgroundColor:%s", err.Error()))
		}
	}

	return imageMW, nil
}

func (i *Image) Thumb(file string, size *Size) (string, error) {
	if !fileObj.IsFile(file) {
		return "", util.NewError(fmt.Sprintf("文件 %s 不存在", file))
	}

	mw := gmagick.NewMagickWand()
	defer mw.Destroy()

	var err error

	if err = mw.ReadImage(file); err != nil {
		return "", err
	}

	width := mw.GetImageWidth()
	height := mw.GetImageHeight()

	imageScale := NewScale(width, height, 1.0)
	scale := imageScale.MinRatio(size.Width, size.Height)

	if err = mw.ResizeImage(scale.Width, scale.Height, gmagick.FILTER_LANCZOS, 1); err != nil {
		return "", err
	}
	//fmt.Println("DisplayImage:", os.Getenv("DISPLAY"))
	//err = mw.DisplayImage(os.Getenv("DISPLAY"))

	destFile := i.CacheFile(file, mw.GetImageFormat())
	if err = mw.WriteImage(destFile); err != nil {
		return "", err
	}
	return destFile, nil
}

func (i *Image) Cut(file string, size *Size, position string) (string, error) {
	if position == "" {
		position = "left"
	}

	mw := gmagick.NewMagickWand()
	defer mw.Destroy()
	var err error
	err = mw.ReadImage(file)

	if err != nil {
		return "", err
	}
	sourceWidth := mw.GetImageWidth()
	sourceHeight := mw.GetImageHeight()
	imageScale := NewScale(sourceWidth, sourceHeight, 1.0)

	scale := imageScale.MaxRatio(size.Width, size.Height)

	if err = mw.ResizeImage(scale.Width, scale.Height, gmagick.FILTER_LANCZOS, 1); err != nil {
		return "", err
	}
	x, y, width, height := i.Position(position, scale.Width, scale.Height, size)

	if err = mw.CropImage(width, height, x, y); err != nil {
		return "", err
	}

	destFile := i.CacheFile(file, mw.GetImageFormat())
	if err = mw.WriteImage(destFile); err != nil {
		return "", err
	}

	return destFile, nil
}

func (i *Image) Resize(image string, width, height uint, angle int) (*gmagick.MagickWand, error) {
	imageMV := gmagick.NewMagickWand()

	if err := imageMV.ReadImage(image); err != nil {
		return nil, util.NewError("Resize", "ReadImage", err.Error())
	}

	if err := imageMV.ResizeImage(width, height, gmagick.FILTER_LANCZOS, 1); err != nil {
		return nil, util.NewError("Resize", "ResizeImage", err.Error())
	}

	if err := imageMV.SetSize(width, height); err != nil {
		return nil, util.NewError("Resize", "SetSize", err.Error())
	}

	return imageMV, nil
}

// 计算 裁切的x、y及宽高
func (i *Image) Position(position string, width, height uint, size *Size) (dx, dy int, dWidth, dHeight uint) {
	x := 0
	y := 0
	scale := 1.0

	if width < size.Width {
		scale = CustomScale(width, size.Width)
		width = size.Width
	}
	if height < size.Height {
		scale = CustomScale(height, size.Height)
		height = size.Height
	}
	paddingLeft := width - size.Width
	paddingTop := height - size.Height

	if position == "right" {
		x = int(paddingLeft)
	}
	if position == "center" {
		x = int(paddingLeft / 2)
		y = int(paddingTop / 2)
	}

	if position == "right|center" {
		x = int(paddingLeft)
		y = int(paddingTop / 2)
	}
	if position == "left|center" {
		y = int(paddingTop / 2)
	}
	return x, y, uint(float64(size.Width) * scale), uint(float64(size.Height) * scale)
}

// Cache 获取缓存文件名
/*func (i *Image) CacheFile(file string, format string) string {
	if !fileObj.IsDir(i.Cache) {
		if err := os.Mkdir(i.Cache, 0755); err != nil {
			panic(err.Error())
		}
	}
	if file == "" {
		file = util.RandomStr(10)
	}
	destName := fmt.Sprintf("%x", md5.Sum([]byte(file)))
	destFile := fmt.Sprintf("%s/%s.%s", i.Cache, destName, strings.ToLower(format))
	return destFile
}*/