// 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()
}
// plot places a plot at the specified location with the specified dimemsions
// using the specified settings, using the specified data
func plot(x, y, w, h openvg.VGfloat, settings plotset, d []rawdata) {
nd := len(d)
if nd < 2 {
fmt.Fprintf(os.Stderr, "%d is not enough points to plot\n", len(d))
return
}
// Compute the minima and maxima of the data
maxx, minx := d[0].x, d[0].x
maxy, miny := d[0].y, d[0].y
for _, v := range d {
if v.x > maxx {
maxx = v.x
}
if v.y > maxy {
maxy = v.y
}
if v.x < minx {
minx = v.x
}
if v.y < miny {
miny = v.y
}
}
// Prepare for a area or line chart by allocating
// polygon coordinates; for the horizon plot, you need two extra coordinates
// for the extrema.
needpoly := settings.opt["area"] || settings.opt["connect"]
var xpoly, ypoly []openvg.VGfloat
if needpoly {
xpoly = make([]openvg.VGfloat, nd+2)
ypoly = make([]openvg.VGfloat, nd+2)
// preload the extrema of the polygon,
// the bottom left and bottom right of the plot's rectangle
xpoly[0] = x
ypoly[0] = y
xpoly[nd+1] = x + w
ypoly[nd+1] = y
}
// Draw the plot's bounding rectangle
if settings.opt["showbg"] && !settings.opt["sameplot"] {
openvg.FillColor(settings.attr["bgcolor"])
openvg.Rect(x, y, w, h)
}
// Loop through the data, drawing items as specified
spacer := openvg.VGfloat(10.0)
for i, v := range d {
xp := fmap(v.x, minx, maxx, x, x+w)
yp := fmap(v.y, miny, maxy, y, y+h)
if needpoly {
xpoly[i+1] = xp
ypoly[i+1] = yp
}
if settings.opt["showbar"] {
openvg.StrokeColor(settings.attr["barcolor"])
openvg.StrokeWidth(settings.size["barsize"])
openvg.Line(xp, yp, xp, y)
}
if settings.opt["showdot"] {
openvg.FillColor(settings.attr["dotcolor"])
openvg.StrokeWidth(0)
openvg.Circle(xp, yp, settings.size["dotsize"])
}
if settings.opt["showx"] {
if i%int(settings.size["xinterval"]) == 0 {
openvg.FillColor("black")
openvg.TextMid(xp, y-(spacer*2), fmt.Sprintf("%d", int(v.x)), settings.attr["font"], int(settings.size["fontsize"]))
openvg.StrokeColor("silver")
openvg.StrokeWidth(1)
openvg.Line(xp, y, xp, y-spacer)
}
openvg.StrokeWidth(0)
}
}
// Done constructing the points for the area or line plots, display them in one shot
if settings.opt["area"] {
openvg.FillColor(settings.attr["areacolor"])
openvg.Polygon(xpoly, ypoly)
}
if settings.opt["connect"] {
openvg.StrokeColor(settings.attr["linecolor"])
openvg.StrokeWidth(settings.size["linesize"])
openvg.Polyline(xpoly[1:nd+1], ypoly[1:nd+1])
}
// Put on the y axis labels, if specified
if settings.opt["showy"] {
bot := openvg.VGfloat(math.Floor(float64(miny)))
top := openvg.VGfloat(math.Ceil(float64(maxy)))
yrange := top - bot
interval := yrange / openvg.VGfloat(settings.size["yinterval"])
for yax := bot; yax <= top; yax += interval {
yaxp := fmap(yax, bot, top, openvg.VGfloat(y), openvg.VGfloat(y+h))
openvg.FillColor("black")
openvg.TextEnd(x-spacer, yaxp, fmt.Sprintf("%.1f", yax), settings.attr["font"], int(settings.size["fontsize"]))
openvg.StrokeColor("silver")
openvg.StrokeWidth(1)
openvg.Line(x-spacer, yaxp, x, yaxp)
}
openvg.StrokeWidth(0)
}
// Finally, tack on the label, if specified
if len(settings.attr["label"]) > 0 {
openvg.FillColor(settings.attr["labelcolor"], 0.3)
openvg.TextMid(x+(w/2), y+(h/2), settings.attr["label"], settings.attr["font"], int(w/8)) // int(settings.size["fontsize"]))
}
openvg.StrokeWidth(0)
}
// refcard shows a reference card of shapes
func refcard(width, height int) {
shapenames := []string{
"Circle",
"Ellipse",
"Rectangle",
"Rounded Rectangle",
"Line",
"Polyline",
"Polygon",
"Arc",
"Quadratic Bezier",
"Cubic Bezier",
"Image",
}
top := openvg.VGfloat(height) * .95
sx := openvg.VGfloat(width) * 0.10
sy := top
sw := openvg.VGfloat(width) * .05
sh := openvg.VGfloat(height) * .045
dotsize := openvg.VGfloat(7.0)
spacing := openvg.VGfloat(2.0)
fontsize := int(openvg.VGfloat(height) * .033)
shapecolor := Color{202, 225, 255, 1.0}
openvg.Start(width, height)
openvg.FillRGB(128, 0, 0, 1)
openvg.TextEnd(openvg.VGfloat(width-20), openvg.VGfloat(height/2),
"OpenVG on the Raspberry Pi", "sans", fontsize+(fontsize/2))
openvg.FillRGB(0, 0, 0, 1)
for _, s := range shapenames {
openvg.Text(sx+sw+sw/2, sy, s, "sans", fontsize)
sy -= sh * spacing
}
sy = top
cx := sx + (sw / 2)
ex := sx + sw
openvg.FillRGB(shapecolor.red, shapecolor.green, shapecolor.blue, shapecolor.alpha)
openvg.Circle(cx, sy, sw)
coordpoint(cx, sy, dotsize, shapecolor)
sy -= sh * spacing
openvg.Ellipse(cx, sy, sw, sh)
coordpoint(cx, sy, dotsize, shapecolor)
sy -= sh * spacing
openvg.Rect(sx, sy, sw, sh)
coordpoint(sx, sy, dotsize, shapecolor)
sy -= sh * spacing
openvg.Roundrect(sx, sy, sw, sh, 20, 20)
coordpoint(sx, sy, dotsize, shapecolor)
sy -= sh * spacing
openvg.StrokeWidth(1)
openvg.StrokeRGB(204, 204, 204, 1)
openvg.Line(sx, sy, ex, sy)
coordpoint(sx, sy, dotsize, shapecolor)
coordpoint(ex, sy, dotsize, shapecolor)
sy -= sh
px := []openvg.VGfloat{sx, sx + (sw / 4), sx + (sw / 2), sx + ((sw * 3) / 4), sx + sw}
py := []openvg.VGfloat{sy, sy - sh, sy, sy - sh, sy}
openvg.Polyline(px, py) // , 5)
coordpoint(px[0], py[0], dotsize, shapecolor)
coordpoint(px[1], py[1], dotsize, shapecolor)
coordpoint(px[2], py[2], dotsize, shapecolor)
coordpoint(px[3], py[3], dotsize, shapecolor)
coordpoint(px[4], py[4], dotsize, shapecolor)
sy -= sh * spacing
py[0] = sy
py[1] = sy - sh
py[2] = sy - (sh / 2)
py[3] = py[1] - (sh / 4)
py[4] = sy
openvg.Polygon(px, py) // , 5)
sy -= (sh * spacing) + sh
openvg.Arc(sx+(sw/2), sy, sw, sh, 0, 180)
coordpoint(sx+(sw/2), sy, dotsize, shapecolor)
sy -= sh * spacing
var cy, ey openvg.VGfloat
cy = sy + (sh / 2)
ey = sy
openvg.Qbezier(sx, sy, cx, cy, ex, ey)
coordpoint(sx, sy, dotsize, shapecolor)
coordpoint(cx, cy, dotsize, shapecolor)
coordpoint(ex, ey, dotsize, shapecolor)
sy -= sh * spacing
ey = sy
cy = sy + sh
openvg.Cbezier(sx, sy, cx, cy, cx, sy, ex, ey)
coordpoint(sx, sy, dotsize, shapecolor)
coordpoint(cx, cy, dotsize, shapecolor)
coordpoint(cx, sy, dotsize, shapecolor)
coordpoint(ex, ey, dotsize, shapecolor)
sy -= (sh * spacing * 1.5)
openvg.Image(sx, sy, 110, 110, "starx.jpg")
openvg.End()
}