func main() {
log.SetFlags(0)
var err error
img, err = getImage()
if err != nil {
log.Fatalln(err)
}
fmt.Println("Using libcairo:", cairo.Version())
count := 0
logerr := func(name string, err error) {
count++
log.Printf("%s: %s", name, err)
}
for _, example := range examples {
nm := example.Name
outname := nm + ".pdf"
outfile, err := os.Create(outname)
if err != nil {
logerr(nm, err)
continue
}
defer outfile.Close()
surface, err := pdf.New(outfile, 595, 842) //A4
if err != nil {
logerr(nm, err)
continue
}
defer surface.Close()
context, err := cairo.New(surface)
if err != nil {
logerr(nm, err)
continue
}
defer context.Close()
if err = example.Run(context); err != nil {
logerr(nm, err)
continue
}
if err = context.Err(); err != nil {
logerr(nm, err)
}
}
fmt.Printf("%d of %d examples failed\n", count, len(examples))
}
//When generating landscape PostScript output the surface should not be created
//with a width greater than the height. Instead create the surface
//with a height greater than the width and rotate the cairo drawing context.
//The "%PageOrientation" DSC comment is used by PostScript viewers to indicate
//the orientation of the page.
//
//The steps to create a landscape page are:
//Set the page size to a portrait size.
//Rotate user space 90 degrees counterclockwise and move the origin
//to the correct location.
//Insert the "%PageOrientation: Landscape" DSC comment.
func Example_landscape() {
draw := func(c *cairo.Context, text string, width, height int) error {
const Border = 50
border := cairo.Pt(Border, Border)
size := cairo.Pt(float64(width), float64(height))
c.
Rectangle(cairo.Rectangle{border, border.Sub(size)}).
SetLineWidth(2).
Stroke()
c.
SelectFont("Sans", 0, 0).
SetFontSize(60).
MoveTo(cairo.Pt(200, float64(height)/3)).
ShowText(text)
c.
SetFontSize(18).
MoveTo(cairo.Pt(120, float64(height)*2/3.)).
ShowText(fmt.Sprintf("Width: %d points\t\tHeight: %d points"))
return nil
}
//A4
const (
PageWidth = 595
PageHeight = 842
)
surface, err := New(os.Stdout, PageWidth, PageHeight, false, nil, nil)
if err != nil {
log.Println(err)
return
}
defer surface.Close()
c, err := cairo.New(surface)
if err != nil {
log.Println(err)
return
}
defer c.Close()
//Print portrait page
surface.AddComment("PageOrientation", "Portrait")
err = draw(c, "Portrait", PageWidth, PageHeight)
if err != nil {
log.Println(err)
return
}
surface.ShowPage()
//Print landscape page
surface.AddComment("PageOrientation", "Landscape")
//Move the origin to landscape origin and rotate counterclockwise
c.
Translate(cairo.Pt(0, PageHeight)).
Rotate(-math.Pi / 2)
err = draw(c, "Landscape", PageHeight, PageWidth)
if err != nil {
log.Println(err)
return
}
surface.ShowPage()
}