func traceCurve(a, b, c, d pdf.Point, canvas *pdf.Canvas) {
path := new(pdf.Path)
path.Move(a)
path.Curve(b, c, d)
canvas.Stroke(path)
}
func main() {
doc := pdf.New()
canvas := doc.NewPage(pdf.USLetterWidth, pdf.USLetterHeight)
canvas.Translate(500, 500)
// canvas.SetColor(230, 100, 30)
canvas.SetStrokeColor(20, 40, 60)
path := new(pdf.Path)
path.Move(pdf.Point{0, 0})
path.Line(pdf.Point{0, 50})
canvas.Stroke(path)
text := new(pdf.Text)
text.SetFont(pdf.Helvetica, 14)
text.Text("Hello, World!")
canvas.DrawText(text)
canvas.Close()
err := doc.Encode(os.Stdout)
if err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
}
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()
}
// pdfPath returns a pdf.Path from a vg.Path.
func pdfPath(c *Canvas, path vg.Path) *pdf.Path {
p := new(pdf.Path)
for _, comp := range path {
switch comp.Type {
case vg.MoveComp:
p.Move(pdfPoint(comp.X, comp.Y))
case vg.LineComp:
p.Line(pdfPoint(comp.X, comp.Y))
case vg.ArcComp:
arc(p, comp)
case vg.CloseComp:
p.Close()
default:
panic(fmt.Sprintf("Unknown path component type: %d\n", comp.Type))
}
}
return p
}
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 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)
left := 5 * pdf.Cm
right := 15 * pdf.Cm
top := 15 * pdf.Cm
bottom := 10 * pdf.Cm
curve := new(pdf.Path)
a := pdf.Point{left, bottom}
b := pdf.Point{left, top}
c := pdf.Point{right, top}
d := pdf.Point{right, bottom}
curve.Move(a)
curve.Curve(b, c, d)
beneath := 5 * pdf.Cm
e := pdf.Point{left, beneath}
f := pdf.Point{right, beneath}
curve.Curve(f, e, a)
left = 6.5 * pdf.Cm
right = 13.5 * pdf.Cm
top = 13.5 * pdf.Cm
bottom = 10 * pdf.Cm
beneath = 6.5 * pdf.Cm
a = pdf.Point{left, 9 * pdf.Cm}
b = pdf.Point{left, top}
c = pdf.Point{right, top}
d = pdf.Point{right, 11 * pdf.Cm}
curve.Move(d)
curve.Curve(c, b, a)
e = pdf.Point{left, beneath}
f = pdf.Point{right, beneath}
curve.Curve(e, f, d)
canvas.FillStroke(curve)
canvas.Close()
file, err := os.Create("curves.pdf")
if err != nil {
log.Fatal(err)
}
err = doc.Encode(file)
if err != nil {
log.Fatal(err)
os.Exit(1)
}
file.Close()
}
