// ImageToPdfDirect converts image to PDF using gpdf
func ImageToPdfDirect(w io.Writer, r io.Reader) error {
img, _, err := image.Decode(r)
if err != nil {
return err
}
ib := img.Bounds().Canon().Size()
doc := pdf.New()
canvas := doc.NewPage(pdf.A4Width, pdf.A4Height)
canvas.Translate(pdf.Cm, canvas.CropBox().Max.Y-pdf.Cm)
// TODO: A4 Portrait ratio vs. ib ratio
ir := float32(ib.X) / float32(ib.Y)
bb := canvas.CropBox()
cbw, cbh := int(bb.Max.X-bb.Min.X), int(bb.Max.Y-bb.Min.Y)
if ir > float32(cbw/cbh) {
bb.Max.Y = bb.Min.Y + pdf.Unit(1.0/ir*float32(cbw))
} else {
bb.Max.X = bb.Min.X + pdf.Unit(ir*float32(cbh))
}
canvas.DrawImage(img, bb)
if err = canvas.Close(); err != nil {
return err
}
return doc.Encode(w)
}
func main() {
doc := pdf.New()
canvas := doc.NewPage(pdf.A4Width, pdf.A4Height)
path := new(pdf.Path)
bottomLeft := pdf.Point{borderWidth, borderWidth}
topRight := pdf.Point{pdf.A4Width - borderWidth, pdf.A4Height - borderWidth}
path.Rectangle(pdf.Rectangle{bottomLeft, topRight})
canvas.Stroke(path)
staffOrigin := pdf.Point{bottomLeft.X + pdf.Unit(10), bottomLeft.Y + pdf.Unit(500)}
largeStaff := engraving.NewStaffSpec(engraving.RastralZero)
engraving.EngraveStaff(staffOrigin, 12*pdf.Cm, largeStaff.Height(), 0.1*pdf.Pt, canvas)
engraving.EngraveSurrogateNoteHead(staffOrigin, largeStaff.StaffSpace(), canvas)
nextNote := pdf.Point{}
nextNote.X = pdf.Unit(staffOrigin.X + largeStaff.StaffSpace())
nextNote.Y = pdf.Unit(staffOrigin.Y + largeStaff.IndexOffset(0))
engraving.EngraveSurrogateNoteHead(nextNote, largeStaff.StaffSpace(), canvas)
nextNote.X = pdf.Unit(staffOrigin.X + (2 * largeStaff.StaffSpace()))
nextNote.Y = pdf.Unit(staffOrigin.Y + largeStaff.IndexOffset(7))
engraving.EngraveSurrogateNoteHead(nextNote, largeStaff.StaffSpace(), canvas)
nextNote.X = pdf.Unit(staffOrigin.X + (3 * largeStaff.StaffSpace()))
nextNote.Y = pdf.Unit(staffOrigin.Y + largeStaff.IndexOffset(-1))
engraving.EngraveSurrogateNoteHead(nextNote, largeStaff.StaffSpace(), canvas)
nextNote.X = pdf.Unit(staffOrigin.X + (4 * largeStaff.StaffSpace()))
nextNote.Y = pdf.Unit(staffOrigin.Y + largeStaff.IndexOffset(2))
engraving.EngraveSurrogateNoteHead(nextNote, largeStaff.StaffSpace(), canvas)
smallStaff := engraving.NewStaffSpec(engraving.RastralEight)
staffOrigin.Y = staffOrigin.Y + 5*pdf.Cm
engraving.EngraveStaff(staffOrigin, 12*pdf.Cm, smallStaff.Height(), 0.1*pdf.Pt, canvas)
canvas.Close()
err := doc.Encode(os.Stdout)
if err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
}
func EngraveSurrogateNoteHead(origin pdf.Point, size pdf.Unit, canvas *pdf.Canvas) {
outline := new(pdf.Path)
topRight := pdf.Point{origin.X + size, origin.Y + size}
outline.Rectangle(pdf.Rectangle{origin, topRight})
mid := pdf.Point{origin.X + pdf.Unit(size/2), origin.Y + pdf.Unit(size/2)}
midPoints := new(pdf.Path)
midPoints.Move(pdf.Point{mid.X, origin.Y})
midPoints.Line(pdf.Point{mid.X, origin.Y + size})
midPoints.Move(pdf.Point{origin.X, mid.Y})
midPoints.Line(pdf.Point{origin.X + size, mid.Y})
canvas.Push()
canvas.SetColor(0.6, 0.6, 0.6)
canvas.Fill(outline)
canvas.SetLineWidth(pdf.Unit(0.1))
canvas.Stroke(midPoints)
canvas.Pop()
}
func EngraveStaff(origin pdf.Point, width, height, lineWidth pdf.Unit, canvas *pdf.Canvas) {
path := new(pdf.Path)
noteHeight := pdf.Unit(height / 4)
for i := 0; i < 5; i++ {
path.Move(origin)
path.Line(pdf.Point{origin.X + width, origin.Y})
origin.Y = origin.Y + noteHeight
}
canvas.Push()
canvas.SetLineWidth(lineWidth)
canvas.Stroke(path)
canvas.Pop()
}
// unit returns a pdf.Unit, converted from a vg.Length.
func unit(l vg.Length) pdf.Unit {
return pdf.Unit(l.Points()) * pdf.Pt
}
func unit(f float64) pdf.Unit {
return pdf.Unit(f) * pdf.Cm
}
func (s StaffSpec) IndexOffset(index int) pdf.Unit {
offset := pdf.Unit(s.StaffSpace() / 2)
return pdf.Unit(index-1) * offset
}
func (s StaffSpec) StaffSpace() pdf.Unit {
return pdf.Unit(s.height / 4)
}
