func main() {
var cx, cy, cw, ch, midy int
message := "Now is the time for all good men to come to the aid of the party"
w, h := openvg.Init()
var speed openvg.VGfloat = 15.0
var x openvg.VGfloat = 0
midy = (h / 2)
fontsize := w / 50
cx = 0
ch = fontsize * 2
cw = w
cy = midy - (ch / 2)
rx, ry, rw, rh := openvg.VGfloat(cx), openvg.VGfloat(cy), openvg.VGfloat(cw), openvg.VGfloat(ch)
// scroll the text, only in the clipping rectangle
for x = 0; x < rw+speed; x += speed {
openvg.Start(w, h)
openvg.Background(255, 255, 255)
openvg.FillRGB(0, 0, 0, .2)
openvg.Rect(rx, ry, rw, rh)
openvg.ClipRect(cx, cy, cw, ch)
openvg.Translate(x, ry+openvg.VGfloat(fontsize/2))
openvg.FillRGB(0, 0, 0, 1)
openvg.Text(0, 0, message, "sans", fontsize)
openvg.ClipEnd()
openvg.End()
}
bufio.NewReader(os.Stdin).ReadBytes('\n')
openvg.Finish()
os.Exit(0)
}
// rotext draws text, rotated around the center of the screen, progressively faded
func rotext(w, h, n int, s string) {
fade := (100.0 / float64(n)) / 100.0
deg := 360.0 / float64(n)
x := float64(w) / 2.0
y := float64(h) / 2.0
alpha := 1.0
size := w / 8
openvg.Start(w, h)
openvg.Background(0, 0, 0)
openvg.Translate(x, y)
for i := 0; i < n; i++ {
openvg.FillRGB(255, 255, 255, alpha)
openvg.Text(0, 0, s, "serif", size)
alpha -= fade // fade
size += n // enlarge
openvg.Rotate(deg)
}
openvg.End()
}