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app/interface/main/creative/dao/drawimg/draw.go

@@ -0,0 +1,171 @@
+package drawimg
+
+import (
+	"errors"
+	"image"
+	"image/color"
+	"image/draw"
+	"io/ioutil"
+	"strconv"
+	"strings"
+
+	"go-common/library/log"
+
+	"github.com/golang/freetype/truetype"
+
+	"golang.org/x/image/math/fixed"
+)
+
+// DrawImg create img info.
+type DrawImg struct {
+	size         int
+	CanvasWidth  int
+	CanvasHeight int
+	File         string
+	txtWidth     int
+	srcImg       image.Image
+	Canvas       *image.NRGBA
+	c            *Context
+	f            *truetype.Font
+}
+
+// NewDrawImg create new img.
+func NewDrawImg(fontfile string, size int) (w *DrawImg) {
+	w = &DrawImg{
+		size: size,
+	}
+	f, err := w.readFont(fontfile, size)
+	if err != nil {
+		return
+	}
+	if f == nil {
+		return
+	}
+	w.f = f
+	return
+}
+
+//ReadSrcImg  read an image
+func (w *DrawImg) ReadSrcImg(path string) (img image.Image, err error) {
+	if img, err = Open(path); err != nil {
+		log.Error("readSrcImg error(%v)", err)
+	}
+	return
+}
+
+func (w *DrawImg) readFont(path string, size int) (f *truetype.Font, err error) {
+	fbs, err := ioutil.ReadFile(path)
+	if err != nil {
+		log.Error("readFont error(%v)", err)
+		return
+	}
+	f, err = ParseFont(fbs)
+	if err != nil {
+		log.Error("error(%v)", err)
+	}
+	cxt := NewContext()
+	if cxt == nil {
+		return
+	}
+	w.c = cxt
+	w.c.SetFont(f)
+	w.c.SetFontSize(float64(size))
+	return
+}
+
+func (w *DrawImg) imgWidth() int {
+	return w.srcImg.Bounds().Max.X
+}
+
+func (w *DrawImg) imgHeight() int {
+	return w.srcImg.Bounds().Max.Y
+}
+
+func (w *DrawImg) newImgWidth() int {
+	return w.txtWidth + w.imgWidth()
+}
+
+func (w *DrawImg) newCanvas(width, height int) *image.NRGBA {
+	return NewNRGBA(width, height, color.RGBA{255, 0, 0, 0})
+}
+
+func (w *DrawImg) fillColor(r, g, b, a int32) image.Image {
+	return &image.Uniform{color.NRGBA{uint8(r), uint8(g), uint8(b), uint8(a)}}
+}
+
+func (w *DrawImg) textWidth(text string) (err error) {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Error("draw set textWidth text(%s)|error(%v)", text, err)
+		}
+	}()
+	box, err := w.c.FontBox(text, w.pt(3, 5))
+	if err != nil {
+		log.Error("set textWidth text(%s)|error(%v)", text, err)
+		return
+	}
+	widthStr := strings.Split(Int26_6ToString(box.X), ":")[0]
+	wid, err := strconv.ParseInt(widthStr, 10, 64)
+	if err != nil {
+		log.Error("strconv.ParseInt widthStr(%+v)|error(%v)", widthStr, err)
+		return
+	}
+	w.txtWidth = int(wid)
+	return
+}
+
+func (w *DrawImg) pt(x, y int) fixed.Point26_6 {
+	return Pt(x, y+int(w.c.PointToFixed(float64(w.size))>>6))
+}
+
+func (w *DrawImg) setFont(text string, dstRgba *image.NRGBA, fsrc image.Image, pt fixed.Point26_6) (err error) {
+	w.c.SetClip(w.Canvas.Bounds())
+	w.c.SetDst(dstRgba)
+	w.c.SetSrc(fsrc)
+	_, err = w.c.DrawString(text, pt)
+	if err != nil {
+		log.Error("setFont error(%v)", err)
+	}
+	return
+}
+
+func (w *DrawImg) composite(dstCanvas *image.NRGBA, src image.Image, isLeft bool) {
+	var p image.Point
+	if isLeft {
+		p = image.Point{-int(w.txtWidth), 0}
+	} else {
+		p = image.ZP
+	}
+	draw.Draw(dstCanvas, image.Rect(0, 0, w.newImgWidth(), w.imgHeight()), src, p, draw.Over)
+}
+
+// Draw  write text to the left or right of img.
+func (w *DrawImg) Draw(text, savepath string, isLeft bool) (err error) {
+	if text == "" {
+		err = errors.New("draw: DrawText called with a empty text")
+		return
+	}
+	w.textWidth(text)
+	w.CanvasWidth = w.newImgWidth()
+	w.CanvasHeight = w.imgHeight()
+	w.Canvas = w.newCanvas(w.CanvasWidth, w.CanvasHeight)
+	if w.c == nil || w.Canvas == nil {
+		err = errors.New("draw: DrawText w.c or w.Canvas is nil")
+		return
+	}
+	draw.Draw(w.Canvas, w.Canvas.Bounds(), w.Canvas, image.ZP, draw.Src)
+	var pt fixed.Point26_6
+	if isLeft {
+		pt = w.pt(3, 5)
+	} else {
+		pt = w.pt(w.imgWidth(), 8)
+	}
+	black := w.fillColor(0, 0, 0, 125)
+	w.setFont(text, w.Canvas, black, pt)
+	blurRgba := Blur(w.Canvas, 6, 3.5)
+	white := w.fillColor(255, 255, 255, 180)
+	w.setFont(text, blurRgba, white, pt)
+	w.composite(blurRgba, w.srcImg, isLeft)
+	Save(blurRgba, savepath)
+	return
+}