func main() {
surf := cairo.ImageSurfaceCreate(cairo.FormatRGB24, 640, 480)
cr := cairo.Create(surf.Surface)
cr.Arc(320, 240, 40, 0, math.Pi)
path := cr.CopyPath()
iter := path.Iter()
for seg := iter.Next(); seg != nil; seg = iter.Next() {
log.Printf("seg %s %#v", seg.Type, seg)
}
}
func demo() (success bool) {
defer func() {
if err := recover(); err != nil {
log.Println("recovered error:", err)
success = true
}
}()
// Normally you should use one of the cairo.FormatXXX constants, but
// this program is demonstrating a panic.
cairo.ImageSurfaceCreate(cairo.Format(1000), 640, 480)
return
}
func main() {
size := 320
margin := 10
innerSize := size - (margin * 2)
step := 15
surf := cairo.ImageSurfaceCreate(cairo.FormatARGB32, size, size)
cr := cairo.Create(surf.Surface)
cr.SetSourceRGB(1, 1, 1)
cr.Paint()
cr.SetAntialias(cairo.AntialiasBest)
// Offset by 0.5 to get pixel-aligned lines.
cr.Translate(float64(margin)+0.5, float64(margin)+0.5)
cr.SetSourceRGB(0, 0, 0)
cr.SetLineWidth(1)
for i := 0; i <= innerSize; i += step {
cr.MoveTo(0, float64(i))
cr.LineTo(float64(i), float64(innerSize))
cr.Stroke()
cr.MoveTo(float64(i), 0)
cr.LineTo(float64(innerSize), float64(i))
cr.Stroke()
}
surf.Flush()
f, err := os.Create("example.png")
if err != nil {
panic(err)
}
defer f.Close()
err = surf.WriteToPNG(f)
if err != nil {
panic(err)
}
}