// 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 := float64(w) * 0.50 lmargin := float64(w) * 0.10 top := float64(h) * .9 mid := float64(h) * .6 bot := float64(h) * .3 fontsize := 24 leading := 40.0 lfontsize := fontsize * 2 midb := ((leading * 2) + (leading / 2)) - float64(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() }
// imgtest draws images at the corners and center func imagetest(w, h int) { openvg.Start(w, h) imgw := 422 imgh := 238 fiw := float64(imgw) fih := float64(imgh) fw := float64(w) fh := float64(h) cx := (fw / 2) - (fiw / 2) cy := (fh / 2) - (fih / 2) ulx := 0.0 uly := fh - fih urx := fw - fiw ury := uly llx := 0.0 lly := 0.0 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() }
// 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 float64 np := 10 polyx := make([]float64, np) polyy := make([]float64, np) openvg.Start(width, height) for i := 0; i < n; i++ { openvg.FillRGB(randcolor(), randcolor(), randcolor(), rand.Float64()) 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() { 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) }
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() }
// 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 := float64(w) / 2 midy := float64(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)-float64(fontsize*2), s, "sans", fontsize) 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() }
//planets is an exploration of scale func planets(width, height int, message string) { w := float64(width) h := float64(height) y := h / 2 margin := 100.0 minsize := 7.0 labeloc := 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() }
// 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) tw := 300.0 for x, y := 50.0, float64(h)-100.0; x < float64(w/2); x += 400 { textwrap(x, y, tw, forlo, "sans", 12, 24, 0.25, "black") textwrap(x, y-400, tw, forlo, "sans", 12, 24, 0.5, "black") tw -= 100 } openvg.End() }
// main plots data from specified files or standard input in a // grid where plotc specifies the number of columns. func main() { w, h := openvg.Init() openvg.Start(w, h) openvg.FillColor("white") openvg.Rect(0, 0, gwidth, gheight) filenames := flag.Args() if len(filenames) == 0 { doplot(beginx, beginy, "") } else { plotgrid(beginx, beginy, filenames) } openvg.End() bufio.NewReader(os.Stdin).ReadByte() openvg.Finish() }
func InitDisplay(iw, ih int) { sWidth, sHeight = openvg.Init() iWidth, iHeight = iw, ih out = make([]C.VGubyte, iw*ih*VG_CHANS) // clear screen to opaque black openvg.StartColor(sWidth, sHeight, "black", 1.0) openvg.End() // apply scale transform so images fill the screen ScaleImage(float64(sWidth)/float64(iWidth), float64(sHeight)/float64(iHeight)) fmt.Printf("Image display initialised to (%d, %d)\n", iw, ih) }
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() }
// clock displays the current time func (d *display) clock(smartcolor bool) { if smartcolor { d.bgcolor = daycolor() } cdim := dimen{x: d.width / 2, y: d.height / 2, width: d.width / 2, height: d.height / 2} cdim.regionFill(d.bgcolor, d.textcolor) clocksize := d.width / 20 cs := int(clocksize) x := d.width * 0.95 y := d.height * 0.70 now := time.Now() openvg.TextEnd(x, y, now.Format("3:04 pm"), "sans", cs) openvg.TextEnd(x, y+(clocksize*2), now.Format("Monday January _2"), "sans", cs/2) openvg.End() }
func main() { width, height := openvg.Init() // OpenGL, etc initialization w2 := float64(width / 2) h2 := float64(height / 2) w := float64(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 gradient(width, height int) { w := float64(width) h := float64(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() }
// hackernews shows the top n articles from Hackernews func (d *display) hackernews(n int) { hdim := dimen{x: 0, y: 0, width: d.width, height: d.height / 2} r, err := netread(HNTopURL) if err != nil { fmt.Fprintf(os.Stderr, "headline read error: %v\n", err) hdim.gerror(d.bgcolor, d.textcolor, "no headlines") return } var hnid HNTop err = json.NewDecoder(r).Decode(&hnid) if err != nil { fmt.Fprintf(os.Stderr, "decode: %v\n", err) hdim.gerror(d.bgcolor, d.textcolor, "no headlines") r.Close() return } r.Close() var item HNitem x := d.width / 2 y := d.height * 0.10 headsize := d.width / 80 spacing := headsize * 2.0 hdim.regionFill(d.bgcolor, d.textcolor) for i := n - 1; i >= 0; i-- { hnr, err := netread(fmt.Sprintf(HNItemfmt, hnid[i])) if err != nil { fmt.Fprintf(os.Stderr, "%v: getting id %d\n", err, hnid[i]) hnr.Close() continue } err = json.NewDecoder(hnr).Decode(&item) if err != nil { fmt.Fprintf(os.Stderr, "%v: decoding id %d\n", err, hnid[i]) hnr.Close() continue } openvg.TextMid(x, y, item.Title, "serif", int(headsize)) y += spacing hnr.Close() } openvg.Image(d.width*0.05, 15, 32, 32, "hn.png") 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() }
// sunearth shows the relative sizes of the sun and the earth func sunearth(w, h int) { var sun, earth, x, y float64 openvg.Start(w, h) openvg.Background(0, 0, 0) openvg.FillRGB(255, 255, 255, 1) for i := 0; i < w/4; i++ { x = randf(w) y = randf(h) openvg.Circle(x, y, 2) } earth = float64(w) * 0.010 sun = earth * 109 openvg.FillRGB(0, 0, 255, 1) openvg.Circle(float64(w/3), float64(h-(h/10)), earth) openvg.FillRGB(255, 255, 224, 1) openvg.Circle(float64(w), 0, sun) openvg.End() }
// testpattern shows a test pattern func testpattern(w, h int, s string) { var midx, midy1, midy2, midy3 float64 fontsize := 256 h2 := float64(h / 2) by := float64(h - 100) bx := float64(w - 100) tw1 := &FW{"mono", 0, fontsize} tw2 := &FW{"sans", 0, fontsize} tw3 := &FW{"serif", 0, fontsize} openvg.Start(w, h) // colored squares in the corners openvg.FillRGB(255, 0, 0, 1) openvg.Rect(0, 0, 100, 100) openvg.FillRGB(0, 255, 0, 1) openvg.Rect(0, by, 100, 100) openvg.FillRGB(0, 0, 255, 1) openvg.Rect(bx, 0, 100, 100) openvg.FillRGB(128, 128, 128, 1) openvg.Rect(bx, by, 100, 100) // for each font, (Sans, Serif, Mono), adjust the string to the w tw1.fitwidth(w, 20, s) tw2.fitwidth(w, 20, s) tw3.fitwidth(w, 20, s) midx = float64(w / 2) // Adjust the baselines to be medial midy1 = h2 + 20 + float64((tw1.fontsize)/2) midy2 = h2 - float64((tw2.fontsize)/2) midy3 = h2 - 20 - float64(tw2.fontsize) - float64((tw3.fontsize)/2) openvg.FillRGB(128, 128, 128, 1) openvg.TextMid(midx, midy1, s, tw1.font, tw1.fontsize) openvg.FillRGB(128, 0, 0, 1) openvg.TextMid(midx, midy2, s, tw2.font, tw2.fontsize) openvg.FillRGB(0, 0, 128, 1) openvg.TextMid(midx, midy3, s, tw3.font, tw3.fontsize) 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 }
// 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() }
// countdown shows a countdown display to the top of minute func (d *display) countdown() { tick := time.NewTicker(1 * time.Second) ty := d.height / 2 th := d.height / 20 size := d.width / 70 for delay := 60 - time.Now().Second(); delay > 0; delay-- { select { case <-tick.C: tx := d.width * (openvg.VGfloat(60-delay) / 60) openvg.BackgroundColor(d.bgcolor) openvg.FillColor("black") openvg.Rect(0, ty, d.width, th) openvg.FillColor("white") openvg.TextEnd(tx, ty+(th/4), fmt.Sprintf("start in %d ", delay), "sans", int(size)) openvg.Rect(tx, ty, d.width-tx, th) openvg.End() } } openvg.BackgroundColor(d.bgcolor) }
// advert is an ad for the package func advert(w, h int) { y := (6 * float64(h)) / 10 fontsize := (w * 4) / 100 f3 := fontsize / 3 s := "github.com/ajstarks/openvg" a := "*****@*****.**" imw := 110 imh := 110 midx := float64(w / 2) openvg.Start(w, h) openvg.FillRGB(128, 0, 0, 1) openvg.TextMid(midx, y-float64(fontsize/4), s, "sans", fontsize) y -= 150 openvg.FillRGB(128, 128, 128, 1) openvg.TextMid(midx, y, a, "sans", f3) openvg.Image(float64(w/2)-float64(imw/2), y-float64(imh*2), imw, imh, "starx.jpg") openvg.End() }
// nytheadlines retrieves data from the New York Times API, decodes and displays it. func (d *display) nytheadlines(section string, thumb bool) { hdim := dimen{x: 0, y: 0, width: d.width, height: d.height / 2} r, err := netread(fmt.Sprintf(NYTfmt, section, NYTAPIkey)) if err != nil { fmt.Fprintf(os.Stderr, "headline read error: %v\n", err) hdim.gerror(d.bgcolor, d.textcolor, "no headlines") return } defer r.Close() var data NYTHeadlines err = json.NewDecoder(r).Decode(&data) if err != nil { fmt.Fprintf(os.Stderr, "decode: %v\n", err) hdim.gerror(d.bgcolor, d.textcolor, "no headlines") return } x := d.width * 0.10 y := d.height * 0.10 thumbsize := int(d.height * 0.05) hdim.regionFill(d.bgcolor, d.textcolor) headsize := d.width / 80 spacing := openvg.VGfloat(thumbsize) for i := len(data.Results) - 1; i >= 0; i-- { openvg.Text(x, y, fromHTML.Replace(data.Results[i].Title), "serif", int(headsize)) if len(data.Results[i].Thumbnail) > 0 { img, imerr := netimage(data.Results[i].Thumbnail) if imerr != nil { continue } g := gift.New() g.Add(gift.Resize(0, thumbsize, gift.LanczosResampling)) gift.Resize(thumbsize, thumbsize, gift.BoxResampling) resized := image.NewRGBA(g.Bounds(img.Bounds())) g.Draw(resized, img) openvg.Img(x-100, y-(spacing*0.25), resized) } y = y + spacing } openvg.Image(d.width*0.05, 15, 30, 30, "poweredby_nytimes_30a.png") openvg.End() }
func imagetable(w, h int) { imgw, imgh := 422, 238 itable := []it{ {"desert0.jpg", imgw, imgh}, {"desert1.jpg", imgw, imgh}, {"desert2.jpg", imgw, imgh}, {"desert3.jpg", imgw, imgh}, {"desert4.jpg", imgw, imgh}, {"desert5.jpg", imgw, imgh}, {"desert6.jpg", imgw, imgh}, {"desert7.jpg", imgw, imgh}, //{"http://farm4.static.flickr.com/3546/3338566612_9c56bfb53e_m.jpg", 240, 164}, //{"http://farm4.static.flickr.com/3642/3337734413_e36baba755_m.jpg", 240, 164}, } offset := openvg.VGfloat(50) left := offset bot := openvg.VGfloat(h-imgh) - offset gutter := offset x := left y := bot openvg.Start(w, h) openvg.BackgroundColor("black") for _, iname := range itable { openvg.Image(x, y, iname.width, iname.height, iname.name) openvg.FillRGB(255, 255, 255, 0.3) openvg.Rect(x, y, openvg.VGfloat(imgw), 32) openvg.FillRGB(0, 0, 0, 1) openvg.TextMid(x+openvg.VGfloat(imgw/2), y+10, iname.name, "sans", 16) x += openvg.VGfloat(iname.width) + gutter if x > openvg.VGfloat(w) { x = left y -= openvg.VGfloat(iname.height) + gutter } } y = openvg.VGfloat(h) * 0.1 openvg.FillRGB(128, 128, 128, 1) openvg.TextMid(openvg.VGfloat(w/2), 100, "Joshua Tree National Park", "sans", 48) openvg.End() }
// advert is an ad for the package func advert(w, h int) { y := float64(h) / 4 fontsize := (w * 4) / 100 f3 := fontsize / 3 s := "github.com/ajstarks/openvg" a := "*****@*****.**" imw := 110 imh := 110 rw := float64(w / 4) rh := (rw * 2) / 3 midx := float64(w / 2) openvg.Start(w, h) makepi(midx-float64(rw/2), float64(h/2), rw, rh) openvg.FillRGB(128, 0, 0, 1) openvg.TextMid(midx, y-float64(fontsize/4), s, "sans", fontsize) y -= 100 openvg.FillRGB(128, 128, 128, 1) openvg.TextMid(midx, y, a, "sans", f3) openvg.Image(float64(w/2)-float64(imw/2), 20, imw, imh, "starx.jpg") openvg.End() }
// fontrange shows a range of fonts func fontrange(w, h int) { var x, lx, length float64 y := float64(h) / 2.0 w2 := float64(w) / 2.0 spacing := 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 += float64(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 += float64(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() }