// imgtest draws images at the corners and center
func imagetest(w, h int) {
openvg.Start(w, h)
imgw := 422
imgh := 238
fiw := openvg.VGfloat(imgw)
fih := openvg.VGfloat(imgh)
fw := openvg.VGfloat(w)
fh := openvg.VGfloat(h)
vgzero := openvg.VGfloat(0.0)
cx := (fw / 2) - (fiw / 2)
cy := (fh / 2) - (fih / 2)
ulx := vgzero
uly := fh - fih
urx := fw - fiw
ury := uly
llx := vgzero
lly := vgzero
lrx := urx
lry := lly
openvg.Start(w, h)
openvg.Background(0, 0, 0)
openvg.Image(cx, cy, imgw, imgh, "desert1.jpg")
openvg.Image(ulx, uly, imgw, imgh, "desert2.jpg")
openvg.Image(urx, ury, imgw, imgh, "desert3.jpg")
openvg.Image(llx, lly, imgw, imgh, "desert4.jpg")
openvg.Image(lrx, lry, imgw, imgh, "desert5.jpg")
openvg.End()
}
func main() {
var color string
openvg.Start(width, height)
openvg.Background(200, 200, 200)
for i := 0; i < niter; i++ {
x := random(0, width)
y := random(height/3, (height*2)/3)
r := random(0, 10000)
switch {
case r >= 0 && r <= 2500:
color = "white"
case r > 2500 && r <= 5000:
color = "maroon"
case r > 5000 && r <= 7500:
color = "gray"
case r > 7500 && r <= 10000:
color = "black"
}
openvg.FillColor(color, openvg.VGfloat(opacity))
openvg.Circle(openvg.VGfloat(x), openvg.VGfloat(y), openvg.VGfloat(size))
}
openvg.End()
bufio.NewReader(os.Stdin).ReadByte()
openvg.Finish()
}
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)
}
// rain shows raindrops
func (d *dimen) rain(color string) {
dd := dimen{x: 0, y: 0, width: d.width / 6, height: d.height / 6}
for i := 0; i < 20; i++ {
dd.x = d.x + d.width*openvg.VGfloat(rand.Float64())
dd.y = d.y + d.height*openvg.VGfloat(rand.Float64())
dd.drop(color)
}
}
// snow shows the snow icon
func (d *dimen) snow(color string) {
df := dimen{x: 0, y: 0, width: d.width / 6, height: d.height / 6}
for i := 0; i < 20; i++ {
df.x = d.x + d.width*openvg.VGfloat(rand.Float64())
df.y = d.y + d.height*openvg.VGfloat(rand.Float64())
df.flake(color)
}
}
// show the current time, weather and headlines
func main() {
var (
section = flag.String("h", "u.s.", "headline type (arts, health, sports, science, technology, u.s., world, hn)")
location = flag.String("loc", "40.6213,-74.4395", "lat,long for weather")
bgcolor = flag.String("bg", "slateblue", "background color")
textcolor = flag.String("tc", "white", "text color")
width = flag.Int("width", 0, "screen width")
height = flag.Int("height", 0, "screen height")
smartcolor = flag.Bool("sc", false, "smart colors")
thumb = flag.Bool("tn", false, "show thumbnails")
)
flag.Parse()
// initial display
dw, dh := openvg.Init()
if *width > 0 && *height > 0 {
dw, dh = *width, *height
}
openvg.Start(dw, dh)
canvas := display{
width: openvg.VGfloat(dw),
height: openvg.VGfloat(dh),
bgcolor: *bgcolor,
textcolor: *textcolor,
}
canvas.countdown()
openvg.End()
canvas.clock(*smartcolor)
canvas.weather(*location)
canvas.headlines(*section, *thumb)
// update on specific intervals, shutdown on interrupt
dateticker := time.NewTicker(1 * time.Minute)
weatherticker := time.NewTicker(5 * time.Minute)
headticker := time.NewTicker(10 * time.Minute)
sigint := make(chan os.Signal, 1)
signal.Notify(sigint, os.Interrupt)
for {
select {
case <-dateticker.C:
canvas.clock(*smartcolor)
case <-weatherticker.C:
canvas.weather(*location)
case <-headticker.C:
canvas.headlines(*section, *thumb)
case <-sigint:
openvg.Finish()
os.Exit(0)
}
}
}
// raspberry pi, scaled to the screen dimensions
func raspi(w, h int, s string) {
midx := openvg.VGfloat(w) / 2
midy := openvg.VGfloat(h) / 2
rw := midx
rh := (rw * 2) / 3
fontsize := w / 25
openvg.Start(w, h)
openvg.Background(255, 255, 255)
makepi(midx-(rw/2), midy-(rh/2), rw, rh)
openvg.FillRGB(128, 0, 0, 1)
openvg.TextMid(midx, midy-(rh/2)-openvg.VGfloat(fontsize*2), s, "sans", fontsize)
openvg.End()
}
func arrowhand(cx, cy, px, py, r openvg.VGfloat, t float64, value int, color string) {
ax := []openvg.VGfloat{cx, 0, px, 0, cx}
ay := []openvg.VGfloat{cy, 0, py, 0, cy}
t = minadjust(t, value) * deg2rad
rf := float64(r * 0.9)
tf := math.Pi / 45.0
ax[1] = cx + openvg.VGfloat(rf*math.Cos(t-tf))
ay[1] = cy + openvg.VGfloat(rf*math.Sin(t-tf))
ax[3] = cx + openvg.VGfloat(rf*math.Cos(t+tf))
ay[3] = cy + openvg.VGfloat(rf*math.Sin(t+tf))
openvg.FillColor(color)
openvg.Polygon(ax, ay)
}
//planets is an exploration of scale
func planets(width, height int, message string) {
w := openvg.VGfloat(width)
h := openvg.VGfloat(height)
y := h / 2
margin := openvg.VGfloat(100.0)
minsize := openvg.VGfloat(7.0)
labeloc := openvg.VGfloat(100.0)
bgcolor := "black"
labelcolor := "white"
maxsize := (h / 2) * 0.05
origin := sun.distance
mostDistant := neptune.distance
firstSize := mercury.radius
lastSize := neptune.radius
openvg.Start(width, height)
openvg.BackgroundColor(bgcolor)
for _, p := range solarSystem {
x := vmap(p.distance, origin, mostDistant, margin, w-margin)
r := vmap(p.radius, firstSize, lastSize, minsize, maxsize)
if p.name == "Sun" {
openvg.FillRGB(p.color.Red, p.color.Green, p.color.Blue, 1)
openvg.Circle(margin-(r/2), y, r)
} else {
light(x, y, r, p.color)
openvg.Circle(x, y, r)
if p.name == "Saturn" {
ringwidth := r * 2.35 // Saturn's rings are over 2x the planet radius
openvg.StrokeWidth(3)
openvg.StrokeRGB(p.color.Red, p.color.Green, p.color.Blue, 1)
openvg.Line((x - ringwidth/2), y, (x + ringwidth/2), y)
openvg.StrokeWidth(0)
}
}
if p.name == "Earth" && len(message) > 1 {
openvg.StrokeColor(labelcolor)
openvg.StrokeWidth(1)
openvg.Line(x, y+(r/2), x, y+labeloc)
openvg.StrokeWidth(0)
openvg.FillColor(labelcolor)
openvg.TextMid(x, y+labeloc+10, message, "sans", 12)
}
}
openvg.End()
}
func draw(w, h openvg.VGfloat) {
paintBG(w, h)
var p particle
var grav = openvg.VGfloat(gravity)
for i := 0; i < nparticles; i++ {
p = particles[i]
openvg.FillRGB(p.r, p.g, p.b, 1)
openvg.Circle(p.x, p.y, p.radius)
// Apply the velocity
p.x += p.vx
p.y += p.vy
p.vx *= 0.98
if p.vy > 0 {
p.vy *= 0.97
}
// Gravity
p.vy -= grav
// Stop p leaving the canvas
if p.x < -50 {
p.x = w + 50
}
if p.x > w+50 {
p.x = -50
}
// When particle reaches the bottom of screen reset velocity & start posn
if p.y < -50 {
p.x = 0
p.y = 0
p.vx = openvg.VGfloat(rand.Intn(maxrand)%30) + 30
p.vy = openvg.VGfloat(rand.Intn(maxrand)%20) + 40
if directionRTL {
p.vx *= -1
p.x = w
}
}
if p.y > h+50 {
p.y = -50
}
particles[i] = p
}
openvg.End()
}
func combohand(cx, cy, px, py, r, stroke openvg.VGfloat, t float64, value int, color string) {
thinr := float64(r * 0.25)
t = minadjust(t, value) * deg2rad
tx := cx + openvg.VGfloat(thinr*math.Cos(t))
ty := cy + openvg.VGfloat(thinr*math.Sin(t))
openvg.FillColor(color)
openvg.Ellipse(px, py, stroke*2, stroke*2)
openvg.Ellipse(tx, ty, stroke*2, stroke*2)
openvg.StrokeWidth(stroke)
openvg.StrokeColor(color)
openvg.Line(cx, cy, tx, ty)
openvg.StrokeWidth(stroke * 2)
openvg.Line(tx, ty, px, py)
openvg.StrokeWidth(0)
}
// raspberry pi, scaled to the screen dimensions
func main() {
w, h := openvg.Init()
midx := openvg.VGfloat(w) / 2
midy := openvg.VGfloat(h) / 2
rw := midx
rh := (rw * 2) / 3
fontsize := w / 25
openvg.Start(w, h)
openvg.Background(255, 255, 255)
makepi(midx-(rw/2), midy-(rh/2), rw, rh)
makepi(200, 100, 75, 50)
openvg.FillRGB(128, 0, 0, 1)
openvg.TextMid(midx, midy-(rh/2)-openvg.VGfloat(fontsize*2), "The Raspberry Pi", "sans", fontsize)
WaitEnd()
}
func main() {
width, height := openvg.Init()
w := openvg.VGfloat(width)
h := openvg.VGfloat(height)
y := h / 2
var (
margin openvg.VGfloat = 100.0
minsize openvg.VGfloat = 7.0
labeloc openvg.VGfloat = 100.0
)
bgcolor := "black"
labelcolor := "white"
maxsize := (h / 2) * 0.05
origin := sun.distance
mostDistant := neptune.distance
firstSize := mercury.radius
lastSize := neptune.radius
openvg.Start(width, height)
openvg.BackgroundColor(bgcolor)
for _, p := range solarSystem {
x := vmap(p.distance, origin, mostDistant, margin, w-margin)
r := vmap(p.radius, firstSize, lastSize, minsize, maxsize)
if p.name == "Sun" {
openvg.FillRGB(p.color.Red, p.color.Green, p.color.Blue, 1)
openvg.Circle(margin-(r/2), y, r)
} else {
light(x, y, r, p.color)
openvg.Circle(x, y, r)
}
if p.name == "Earth" && len(os.Args) > 1 {
openvg.StrokeColor(labelcolor)
openvg.StrokeWidth(1)
openvg.Line(x, y+(r/2), x, y+labeloc)
openvg.StrokeWidth(0)
openvg.FillColor(labelcolor)
openvg.TextMid(x, y+labeloc+10, os.Args[1], "sans", 12)
}
}
openvg.End()
bufio.NewReader(os.Stdin).ReadByte()
openvg.Finish()
}
// adjust the font to fit within a width
func (f *FW) fitwidth(width, adj int, s string) {
f.tw = openvg.TextWidth(s, f.font, f.fontsize)
for f.tw > openvg.VGfloat(width) {
f.fontsize -= adj
f.tw = openvg.TextWidth(s, f.font, f.fontsize)
}
}
// flake shows the snowflake icon
func (d *dimen) flake(color string) {
x, y, w, h := d.x, d.y, d.width, d.height
cx := x + (w / 2)
cy := y + (h / 2)
r := w * 0.30
openvg.StrokeColor(color)
openvg.StrokeWidth(w / 20)
for t := 0.0; t < 2*math.Pi; t += math.Pi / 4 {
c := openvg.VGfloat(math.Cos(t))
s := openvg.VGfloat(math.Sin(t))
x1 := (r * c) + cx
y1 := (r * s) + cy
openvg.Line(cx, cy, x1, y1)
}
openvg.StrokeWidth(0)
}
// rshapes draws shapes with random colors, openvg.Strokes, and sizes.
func rshapes(width, height, n int) {
var sx, sy, cx, cy, px, py, ex, ey, pox, poy openvg.VGfloat
np := 10
polyx := make([]openvg.VGfloat, np)
polyy := make([]openvg.VGfloat, np)
openvg.Start(width, height)
for i := 0; i < n; i++ {
openvg.FillRGB(randcolor(), randcolor(), randcolor(), openvg.VGfloat(rand.Float32()))
openvg.Ellipse(randf(width), randf(height), randf(200), randf(100))
openvg.Circle(randf(width), randf(height), randf(100))
openvg.Rect(randf(width), randf(height), randf(200), randf(100))
openvg.Arc(randf(width), randf(height), randf(200), randf(200), randf(360), randf(360))
sx = randf(width)
sy = randf(height)
openvg.StrokeRGB(randcolor(), randcolor(), randcolor(), 1)
openvg.StrokeWidth(randf(5))
openvg.Line(sx, sy, sx+randf(200), sy+randf(100))
openvg.StrokeWidth(0)
sx = randf(width)
sy = randf(height)
ex = sx + randf(200)
ey = sy
cx = sx + ((ex - sx) / 2.0)
cy = sy + randf(100)
openvg.Qbezier(sx, sy, cx, cy, ex, ey)
sx = randf(width)
sy = randf(height)
ex = sx + randf(200)
ey = sy
cx = sx + ((ex - sx) / 2.0)
cy = sy + randf(100)
px = cx
py = sy - randf(100)
openvg.Cbezier(sx, sy, cx, cy, px, py, ex, ey)
pox = randf(width)
poy = randf(height)
for j := 0; j < np; j++ {
polyx[j] = pox + randf(200)
polyy[j] = poy + randf(100)
}
openvg.Polygon(polyx, polyy) // , np)
pox = randf(width)
poy = randf(height)
for j := 0; j < np; j++ {
polyx[j] = pox + randf(200)
polyy[j] = poy + randf(100)
}
openvg.Polyline(polyx, polyy) // , np)
}
openvg.FillRGB(128, 0, 0, 1)
openvg.Text(20, 20, "OpenVG on the Raspberry Pi", "sans", 32)
openvg.End()
}
func main() {
width, height := openvg.Init() // OpenGL, etc initialization
w2 := openvg.VGfloat(width / 2)
h2 := openvg.VGfloat(height / 2)
w := openvg.VGfloat(width)
openvg.Start(width, height) // Start the picture
openvg.BackgroundColor("black") // Black background
openvg.FillRGB(44, 100, 232, 1) // Big blue marble
openvg.Circle(w2, 0, w) // The "world"
openvg.FillColor("white") // White text
openvg.TextMid(w2, h2, "hello, world", "serif", width/10) // Greetings
openvg.End() // End the picture
bufio.NewReader(os.Stdin).ReadBytes('\n') // Pause until [RETURN]
openvg.Finish() // Graphics cleanup
}
func main() {
setOptions()
rand.Seed(time.Now().Unix())
w, h := openvg.Init()
width, height := openvg.VGfloat(w), openvg.VGfloat(h)
initParticles(width, height)
openvg.Start(w, h)
i := 0
for {
draw(width, height)
i++
if alternate && i == nswitch { // switch launch direction every nswitch draws
directionRTL = !directionRTL
i = 0
}
}
}
// tb draws a block of text
func tb(w, h int) {
para := []string{
"For lo,",
"the winter is past,",
"the rain is over and gone",
"the flowers appear on the earth;",
"the time for the singing of birds is come,",
"and the voice of the turtle is heard in our land",
}
tmargin := openvg.VGfloat(w) * 0.50
lmargin := openvg.VGfloat(w) * 0.10
top := openvg.VGfloat(h) * .9
mid := openvg.VGfloat(h) * .6
bot := openvg.VGfloat(h) * .3
fontsize := 24
leading := openvg.VGfloat(40.0)
lfontsize := fontsize * 2
midb := ((leading * 2) + (leading / 2)) - openvg.VGfloat(lfontsize/2)
openvg.Start(w, h)
openvg.FillRGB(49, 79, 79, 1)
textlines(tmargin, top, para, "serif", fontsize, leading)
textlines(tmargin, mid, para, "sans", fontsize, leading)
textlines(tmargin, bot, para, "mono", fontsize, leading)
openvg.Text(lmargin, top-midb, "Serif", "sans", lfontsize)
openvg.Text(lmargin, mid-midb, "Sans", "sans", lfontsize)
openvg.Text(lmargin, bot-midb, "Mono", "sans", lfontsize)
openvg.End()
}
// Initialize _all_ the particles
func initParticles(w, h openvg.VGfloat) {
particles = make([]particle, nparticles)
for i := 0; i < nparticles; i++ {
particles[i].x = 0
particles[i].y = 0
particles[i].vx = openvg.VGfloat(rand.Intn(maxrand)%30) + 30
particles[i].vy = openvg.VGfloat(rand.Intn(maxrand)%20) + 40
particles[i].r = uint8(rand.Intn(255))
particles[i].g = uint8(rand.Intn(255))
particles[i].b = uint8(rand.Intn(255))
particles[i].radius = openvg.VGfloat(rand.Intn(maxrand)%20) + 20
if directionRTL {
particles[i].vx *= -1
particles[i].x = w
}
}
}
func gradient(width, height int) {
w := openvg.VGfloat(width)
h := openvg.VGfloat(height)
stops := []openvg.Offcolor{
{0.0, openvg.RGB{255, 255, 255}, 1.0},
{0.5, openvg.RGB{128, 128, 128}, 1.0},
{1.0, openvg.RGB{0, 0, 0}, 1.0},
}
x1 := w / 8
x2 := (w * 3) / 8
y1 := h / 3
y2 := (h * 2) / 3
cx := (w * 3) / 4
cy := (h / 2)
r := (x2 - x1)
fx := cx + (r / 4)
fy := cy + (r / 4)
openvg.Start(width, height)
openvg.BackgroundRGB(128, 128, 128, 1)
openvg.FillLinearGradient(x1, y1, x2, y2, stops)
openvg.Rect(x1, y1, x2-x1, y2-y1)
openvg.FillRadialGradient(cx, cy, fx, fy, r, stops)
openvg.Circle(cx, cy, r)
openvg.FillRGB(0, 0, 0, 0.3)
openvg.Circle(x1, y1, 10)
openvg.Circle(x2, y2, 10)
openvg.Circle(cx, cy, 10)
openvg.Circle(cx+r/2, cy, 10)
openvg.Circle(fx, fy, 10)
openvg.FillColor("black")
SansTypeface := "sans"
openvg.TextMid(x1, y1-20, "(x1, y1)", SansTypeface, 18)
openvg.TextMid(x2, y2+10, "(x2, y2)", SansTypeface, 18)
openvg.TextMid(cx, cy, "(cx, cy)", SansTypeface, 18)
openvg.TextMid(fx, fy, "(fx, fy)", SansTypeface, 18)
openvg.TextEnd(cx+(r/2)+20, cy, "r", SansTypeface, 18)
openvg.TextMid(x1+((x2-x1)/2), h/6, "Linear Gradient", SansTypeface, 36)
openvg.TextMid(cx, h/6, "Radial Gradient", SansTypeface, 36)
openvg.End()
}
// textplay exercises text functions
func textplay(w, h int) {
forlo := `For lo, the winter is past, the rain is over and gone. The flowers appear on the earth, the time for the singing of birds is come, and the voice of the turtle is heard in our land.`
// forsince := `For since by man came death, by man came also the resurrection of the dead, for as in Adam all die, even so in Christ shall all be made alive.`
openvg.Start(w, h)
var (
tw openvg.VGfloat = 300
begin openvg.VGfloat = 50
xincr openvg.VGfloat = 400
offset openvg.VGfloat = 100
)
for x, y := begin, openvg.VGfloat(h)-offset; x < openvg.VGfloat(w/2); x += xincr {
textwrap(x, y, tw, forlo, "sans", 12, 24, 0.25, "black")
textwrap(x, y-400, tw, forlo, "sans", 12, 24, 0.5, "black")
tw -= offset
}
openvg.End()
}
func main() {
var loop = flag.Bool("loop", false, "Loop the show")
var resize = flag.Bool("resize", false, `Resize image to fit the screen.`)
var bgcolor = flag.String("bg", "black", `Background color (named color or rgb(r,g,b)).`)
var delay = flag.Duration("delay", 2*time.Second, "Delay between pictures")
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "usage: %s [ flags ] images...\n", os.Args[0])
flag.PrintDefaults()
os.Exit(1)
}
flag.Parse()
w, h := openvg.Init()
images := []image.Image{}
imgcount := 0
for _, imgfile := range flag.Args() {
fmt.Fprintf(os.Stderr, "loading %q ", imgfile)
img, err := getimage(imgfile, w, h, *resize)
if err != nil {
fmt.Fprintln(os.Stderr, err)
continue
}
images = append(images, img)
imgcount++
fmt.Fprintln(os.Stderr, "ok")
}
for {
for _, img := range images {
ib := img.Bounds()
imw, imh := ib.Max.X-ib.Min.X, ib.Max.Y-ib.Min.Y
openvg.Start(w, h)
openvg.BackgroundColor(*bgcolor)
x, y := openvg.VGfloat(w)/2-openvg.VGfloat(imw)/2, openvg.VGfloat(h)/2-openvg.VGfloat(imh)/2
openvg.Img(x, y, img)
openvg.End()
time.Sleep(*delay)
}
if !*loop {
break
}
}
}
func main() {
width, height := openvg.Init() // OpenGL, etc initialization
w := openvg.VGfloat(width)
h := openvg.VGfloat(height)
openvg.Start(width, height) // Start the picture
openvg.BackgroundColor("white") // Black background
openvg.FillColor("black")
var x, y, spacing openvg.VGfloat
x = w * 0.10
y = h * 0.90
fontsize := 24
spacing = openvg.VGfloat(fontsize) * 2
var data = []string{
"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
"\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f",
"\x20\x21\x22\x23\x24\x25\x26\x27\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f",
"\x30\x31\x32\x33\x34\x35\x36\x37\x38\x39\x3a\x3b\x3c\x3d\x3e\x3f",
"\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x4a\x4b\x4c\x4d\x4e\x4f",
"\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f",
"\x60\x61\x62\x63\x64\x65\x66\x67\x68\x69\x6a\x6b\x6c\x6d\x6e\x6f",
"\x70\x71\x72\x73\x74\x75\x76\x77\x78\x79\x7a\x7b\x7c\x7d\x7e\x7f",
"\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f",
"\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f",
"\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf",
"\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf",
"\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf",
"\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf",
"\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef",
"\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff",
}
for i, s := range data {
openvg.Text(x-(spacing*2), y, fmt.Sprintf("%2x", i), "mono", fontsize)
openvg.Text(x, y, s, "mono", fontsize)
y -= spacing
}
openvg.End() // End the picture
bufio.NewReader(os.Stdin).ReadBytes('\n') // Pause until [RETURN]
openvg.Finish() // Graphics cleanup
}
func face(x, y, r openvg.VGfloat, ts int) {
var fx, fy, va openvg.VGfloat
va = openvg.VGfloat(ts) / 2.0
secsize := openvg.VGfloat(ts) / 3
radius := float64(r)
ir := radius * 1.2
// hour display
openvg.FillColor(digitcolor)
openvg.StrokeColor(digitcolor)
openvg.StrokeWidth(5)
for h := 12; h > 0; h-- {
t := hourangles[h%12] * deg2rad
fx = x + openvg.VGfloat(radius*math.Cos(t))
fy = y + openvg.VGfloat(radius*math.Sin(t))
ix := x + openvg.VGfloat(ir*math.Cos(t))
iy := y + openvg.VGfloat(ir*math.Sin(t))
if showdigits {
openvg.TextMid(fx, fy-va, hourdigits[h%12], "sans", ts)
} else {
openvg.Line(fx, fy, ix, iy)
}
}
// second display
openvg.FillColor(dotcolor)
openvg.StrokeColor(dotcolor)
openvg.StrokeWidth(2)
re := radius * edge
for a := 0.0; a < 360; a += 6.0 {
t := a * deg2rad
sx := x + openvg.VGfloat(re*math.Cos(t))
sy := y + openvg.VGfloat(re*math.Sin(t))
if showdots {
openvg.Ellipse(sx, sy, secsize, secsize)
} else {
ix := x + openvg.VGfloat(ir*math.Cos(t))
iy := y + openvg.VGfloat(ir*math.Sin(t))
openvg.Line(sx, sy, ix, iy)
}
}
openvg.StrokeWidth(0)
}
// rotext draws text, rotated around the center of the screen, progressively faded
func rotext(w, h, n int, s string) {
fade := (100.0 / openvg.VGfloat(n)) / 100.0
deg := 360.0 / openvg.VGfloat(n)
x := openvg.VGfloat(w) / 2.0
y := openvg.VGfloat(h) / 2.0
alpha := openvg.VGfloat(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()
}
// sun shows the icon for clear weather
func (d *dimen) sun(color string) {
x, y, w, h := d.x, d.y, d.width, d.height
cx := x + (w / 2)
cy := y + (h / 2)
r0 := w * 0.50
r1 := w * 0.45
r2 := w * 0.30
openvg.FillColor(color)
openvg.Circle(cx, cy, r0)
openvg.StrokeColor(color)
openvg.StrokeWidth(w / 30)
for t := 0.0; t < 2*math.Pi; t += math.Pi / 6 {
c := openvg.VGfloat(math.Cos(t))
s := openvg.VGfloat(math.Sin(t))
x1 := (r1 * c) + cx
y1 := (r1 * s) + cy
x2 := (r2 * c) + cx
y2 := (r2 * s) + cy
openvg.Line(x1, y1, x2, y2)
}
openvg.StrokeWidth(0)
}
func main() {
width, height := openvg.Init() // OpenGL, etc initialization
w2 := openvg.VGfloat(width / 2)
h2 := openvg.VGfloat(height / 2)
w := openvg.VGfloat(width)
stops := []openvg.Offcolor{
{0.0, openvg.RGB{44, 100, 232}, 1.0}, // blue-ish
{0.5, openvg.RGB{22, 50, 151}, 1.0}, // darker blue
{1.0, openvg.RGB{88, 200, 255}, 1.0}, // lighter blue
}
openvg.Start(width, height) // Start the picture
openvg.BackgroundColor("black") // Black background
openvg.FillRadialGradient(w2, 0, w2, w2, w*.5, stops) // Big blue marble
openvg.Circle(w2, 0, w) // The "world"
openvg.FillColor("white") // White text
openvg.TextMid(w2, h2, "hello, world", "serif", width/10) // Greetings
openvg.SaveEnd("hvg.raw") // End the picture
bufio.NewReader(os.Stdin).ReadBytes('\n') // Pause until [RETURN]
openvg.Finish() // Graphics cleanup
}
// fontrange shows a range of fonts
func fontrange(w, h int) {
var x, lx, length openvg.VGfloat
y := openvg.VGfloat(h) / 2.0
w2 := openvg.VGfloat(w) / 2.0
spacing := openvg.VGfloat(50.0)
s2 := spacing / 2.0
sizes := []int{6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 21, 24, 36, 48, 60, 72, 96}
openvg.Start(w, h)
openvg.Background(255, 255, 255)
// compute the length so we can center
length = 0.0
for _, s := range sizes {
length += openvg.VGfloat(s) + spacing
}
length -= spacing
lx = w2 - (length / 2) // center point
// for each size, display a character and label
x = lx
for _, s := range sizes {
openvg.FillRGB(128, 0, 0, 1)
openvg.TextMid(x, y, "a", "serif", s)
openvg.FillRGB(128, 128, 128, 1)
openvg.TextMid(x, y-spacing, fmt.Sprintf("%d", s), "sans", 16)
x += openvg.VGfloat(s) + spacing
}
// draw a openvg.Line below the characters, a curve above
x -= spacing
openvg.StrokeRGB(150, 150, 150, 0.5)
openvg.StrokeWidth(2)
openvg.Line(lx, y-s2, x, y-s2)
openvg.FillRGB(255, 255, 255, 1)
openvg.Qbezier(lx, y+s2, x, y+s2, x, y+(spacing*3))
openvg.End()
}
func main() {
var nr = flag.Int("n", 500, "number of objects")
var message = flag.String("m", "Go/OpenVG", "message")
var bgcolor = flag.String("bg", "white", "background color")
var fgcolor = flag.String("fg", "maroon", "text color")
flag.Parse()
rseed()
width, height := openvg.Init()
fw := openvg.VGfloat(width)
fh := openvg.VGfloat(height)
openvg.Start(width, height)
openvg.BackgroundColor(*bgcolor)
for i := 0; i < *nr; i++ {
red := uint8(rand.Intn(255))
green := uint8(rand.Intn(255))
blue := uint8(rand.Intn(255))
alpha := randf()
x := randf() * fw
y := randf() * fh
radius := randf() * fw / 10
openvg.FillRGB(red, green, blue, alpha)
openvg.Circle(x, y, radius)
}
openvg.FillColor(*fgcolor)
openvg.TextMid(fw/2, fh/2, *message, "sans", width/25)
openvg.End()
bufio.NewReader(os.Stdin).ReadBytes('\n')
openvg.Finish()
}