Example #1
0
//showtext displays text
func showtext(x, y openvg.VGfloat, t, align, font string, fs openvg.VGfloat) {
	//t := s // fromUTF8(s)
	fontsize := int(fs)
	switch align {
	case "center", "middle", "mid", "c":
		openvg.TextMid(x, y, t, font, fontsize)
	case "right", "end", "e":
		openvg.TextEnd(x, y, t, font, fontsize)
	default:
		openvg.Text(x, y, t, font, fontsize)
	}
}
Example #2
0
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()
}
Example #3
0
func main() {
	var (
		filename     = flag.String("f", "svgcolors.txt", "input file")
		fontname     = flag.String("font", "sans", "fontname")
		neg          = flag.Bool("neg", false, "negative")
		showrgb      = flag.Bool("rgb", false, "show RGB")
		showcode     = flag.Bool("showcode", true, "show colors and codes")
		circsw       = flag.Bool("circle", true, "circle swatch")
		outline      = flag.Bool("outline", false, "outline swatch")
		fontsize     = flag.Int("fs", 12, "fontsize")
		rowsize      = flag.Int("r", 32, "rowsize")
		colw         = flag.Float64("c", 340, "column size")
		swatch       = flag.Float64("s", 16, "swatch size")
		gutter       = flag.Float64("g", 12, "gutter")
		err          error
		tcolor, line string
	)

	flag.Parse()
	f, oerr := os.Open(*filename)
	if oerr != nil {
		fmt.Fprintf(os.Stderr, "%v\n", oerr)
		return
	}
	width, height := openvg.Init()

	openvg.Start(width, height)
	fw := openvg.VGfloat(width)
	fh := openvg.VGfloat(height)
	if *neg {
		openvg.FillColor("black")
		openvg.Rect(0, 0, fw, fh)
		tcolor = "white"
	} else {
		openvg.FillColor("white")
		openvg.Rect(0, 0, fw, fh)
		tcolor = "black"
	}
	top := fh - 32.0
	left := openvg.VGfloat(32.0)
	cw := openvg.VGfloat(*colw)
	sw := openvg.VGfloat(*swatch)
	g := openvg.VGfloat(*gutter)
	in := bufio.NewReader(f)

	for x, y, nr := left, top, 0; err == nil; nr++ {
		line, err = in.ReadString('\n')
		fields := strings.Split(strings.TrimSpace(line), "\t")
		if nr%*rowsize == 0 && nr > 0 {
			x += cw
			y = top
		}
		if len(fields) == 3 {
			var red, green, blue uint8
			fmt.Sscanf(fields[2], "%d,%d,%d", &red, &green, &blue)
			openvg.FillRGB(red, green, blue, 1)
			if *outline {
				openvg.StrokeColor("black")
				openvg.StrokeWidth(1)
			}
			if *circsw {
				openvg.Circle(x+sw/2, y+sw/2, sw)
			} else {
				openvg.Rect(x, y, sw, sw)
			}
			openvg.StrokeWidth(0)
			openvg.FillColor(tcolor)
			openvg.Text(x+sw+openvg.VGfloat(*fontsize/2), y, fields[0], *fontname, *fontsize)
			var label string
			if *showcode {
				if *showrgb {
					label = fields[1]
				} else {
					label = fields[2]
				}
				openvg.FillColor("gray")
				openvg.TextEnd(x+cw-(sw+g), y, label, *fontname, *fontsize)
			}
		}
		y -= (sw + g)
	}
	openvg.End()
	bufio.NewReader(os.Stdin).ReadBytes('\n')
	openvg.Finish()
}
Example #4
0
// 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)
}
Example #5
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()
}