func TestArcsEPS() {
eps := vgeps.New(vg.Inches(4), vg.Inches(4), "arcs")
DrawArcs(eps)
if err := eps.Save("arcs.eps"); err != nil {
panic(err)
}
}
// crosshair draws a plus at the given point.
func crosshair(img draw.Image, x, y int, str string) {
c := vgimg.NewImage(img)
// drawPlots here because NewImage
// clears the canvas. Instead, the canvas
// should just be stored instead of being
// recreated at each redraw.
drawPlots(img)
c.SetColor(color.RGBA{R: 255, A: 255})
xc := vg.Inches(float64(x) / c.DPI())
yc := vg.Inches(float64(y) / c.DPI())
radius := vg.Points(5)
var p vg.Path
p.Move(xc-radius, yc)
p.Line(xc+radius, yc)
c.Stroke(p)
p = vg.Path{}
p.Move(xc, yc+radius)
p.Line(xc, yc-radius)
c.Stroke(p)
c.SetColor(color.Black)
c.FillString(font, vg.Length(0), vg.Length(0), str)
}
func TestFontsPDF() {
pdf := vgpdf.New(vg.Inches(4), vg.Inches(4))
DrawFonts(pdf)
if err := pdf.Save("fonts.pdf"); err != nil {
panic(err)
}
}
// DrawFontExtents draws some text and denotes the
// various extents and width with lines. Expects
// about a 4x4 inch canvas.
func DrawFontExtents(c vg.Canvas) {
x, y := vg.Inches(1), vg.Inches(2)
str := "Eloquent"
font, err := vg.MakeFont("Times-Roman", 18)
if err != nil {
panic(err)
}
width := font.Width(str)
ext := font.Extents()
des := ext.Descent
asc := ext.Ascent
c.FillString(font, x, y, str)
// baseline
path := vg.Path{}
path.Move(x, y)
path.Line(x+width, y)
c.Stroke(path)
// descent
c.SetColor(color.RGBA{G: 255, A: 255})
path = vg.Path{}
path.Move(x, y+des)
path.Line(x+width, y+des)
c.Stroke(path)
// ascent
c.SetColor(color.RGBA{B: 255, A: 255})
path = vg.Path{}
path.Move(x, y+asc)
path.Line(x+width, y+asc)
c.Stroke(path)
}
func TestFontExtentsEPS() {
eps := vgeps.New(vg.Inches(4), vg.Inches(4), "extents")
DrawFontExtents(eps)
if err := eps.Save("extents.eps"); err != nil {
panic(err)
}
}
func TestArcsPDF() {
pdf := vgpdf.New(vg.Inches(4), vg.Inches(4))
DrawArcs(pdf)
if err := pdf.Save("arcs.pdf"); err != nil {
panic(err)
}
}
func TestArcsSVG() {
img := vgsvg.New(vg.Inches(4), vg.Inches(4))
DrawArcs(img)
err := img.Save("arcs.svg")
if err != nil {
panic(err)
}
}
func TestFontsSVG() {
img := vgsvg.New(vg.Inches(4), vg.Inches(4))
DrawFonts(img)
err := img.Save("fonts.svg")
if err != nil {
panic(err)
}
}
func TestArcsIMG() {
img, err := vgimg.New(vg.Inches(4), vg.Inches(4))
if err != nil {
panic(err)
}
DrawArcs(img)
err = img.Save("arcs.png", png.Encode)
if err != nil {
panic(err)
}
}
func TestFontExtentsIMG() {
img, err := vgimg.New(vg.Inches(4), vg.Inches(4))
if err != nil {
panic(err)
}
DrawFontExtents(img)
err = img.Save("extents.png", png.Encode)
if err != nil {
panic(err)
}
}
//Save saves the board (i.e. all subplots, appropriately laid out) to the specified filename.
//It basically rips off the implementation of Save in plotinum to support various file formats.
func (b *Board) Save(width, height float64, file string) (err error) {
w, h := vg.Inches(width), vg.Inches(height)
var c interface {
vg.Canvas
Size() (w, h vg.Length)
io.WriterTo
}
switch ext := strings.ToLower(filepath.Ext(file)); ext {
case ".eps":
c = vgeps.NewTitle(w, h, file)
case ".jpg", ".jpeg":
c = vgimg.JpegCanvas{Canvas: vgimg.New(w, h)}
case ".pdf":
c = vgpdf.New(w, h)
case ".png":
c = vgimg.PngCanvas{Canvas: vgimg.New(w, h)}
case ".svg":
c = vgsvg.New(w, h)
case ".tiff":
c = vgimg.TiffCanvas{Canvas: vgimg.New(w, h)}
default:
return fmt.Errorf("Unsupported file extension: %s", ext)
}
for _, subplot := range b.SubPlots {
w, h := c.Size()
drawArea := plot.DrawArea{
Canvas: c,
Rect: subplot.ScaledRect(float64(w), float64(h)),
}
subplot.Plot.Draw(drawArea)
}
f, err := os.Create(file)
if err != nil {
return err
}
if _, err = c.WriteTo(f); err != nil {
return err
}
say.Println(0, say.Yellow("Saved %s", file))
return f.Close()
}
// Example_functions draws some functions.
func Example_functions() *plot.Plot {
p, err := plot.New()
if err != nil {
panic(err)
}
p.Title.Text = "Functions"
p.X.Label.Text = "X"
p.Y.Label.Text = "Y"
quad := plotter.NewFunction(func(x float64) float64 { return x * x })
quad.Color = color.RGBA{B: 255, A: 255}
exp := plotter.NewFunction(func(x float64) float64 { return math.Pow(2, x) })
exp.Dashes = []vg.Length{vg.Points(2), vg.Points(2)}
exp.Width = vg.Points(2)
exp.Color = color.RGBA{G: 255, A: 255}
sin := plotter.NewFunction(func(x float64) float64 { return 10*math.Sin(x) + 50 })
sin.Dashes = []vg.Length{vg.Points(4), vg.Points(5)}
sin.Width = vg.Points(4)
sin.Color = color.RGBA{R: 255, A: 255}
p.Add(quad, exp, sin)
p.Legend.Add("x^2", quad)
p.Legend.Add("2^x", exp)
p.Legend.Add("10*sin(x)+50", sin)
p.Legend.ThumbnailWidth = vg.Inches(0.5)
p.X.Min = 0
p.X.Max = 10
p.Y.Min = 0
p.Y.Max = 100
return p
}
// NewImage returns a new image canvas
// that draws to the given image. The
// minimum point of the given image
// should probably be 0,0.
func NewImage(img draw.Image) *Canvas {
w := float64(img.Bounds().Max.X - img.Bounds().Min.X)
h := float64(img.Bounds().Max.Y - img.Bounds().Min.Y)
draw.Draw(img, img.Bounds(), image.White, image.ZP, draw.Src)
gc := draw2d.NewGraphicContext(img)
gc.SetDPI(dpi)
gc.Scale(1, -1)
gc.Translate(0, -h)
c := &Canvas{
gc: gc,
img: img,
w: vg.Inches(w / dpi),
h: vg.Inches(h / dpi),
color: []color.Color{color.Black},
}
vg.Initialize(c)
return c
}
// Save saves the plot to an image file. Width and height
// are specified in inches, and the file format is determined
// by the extension. Supported extensions are
// .eps, .jpg, .jpeg, .pdf, .png, .svg, and .tiff.
func (p *Plot) Save(width, height float64, file string) (err error) {
w, h := vg.Inches(width), vg.Inches(height)
var c interface {
vg.Canvas
Size() (w, h vg.Length)
io.WriterTo
}
switch ext := strings.ToLower(filepath.Ext(file)); ext {
case ".eps":
c = vgeps.NewTitle(w, h, file)
case ".jpg", ".jpeg":
c = vgimg.JpegCanvas{Canvas: vgimg.New(w, h)}
case ".pdf":
c = vgpdf.New(w, h)
case ".png":
c = vgimg.PngCanvas{Canvas: vgimg.New(w, h)}
case ".svg":
c = vgsvg.New(w, h)
case ".tiff":
c = vgimg.TiffCanvas{Canvas: vgimg.New(w, h)}
default:
return fmt.Errorf("Unsupported file extension: %s", ext)
}
p.Draw(MakeDrawArea(c))
f, err := os.Create(file)
if err != nil {
return err
}
if _, err = c.WriteTo(f); err != nil {
return err
}
return f.Close()
}
// dataCoord returns the plot number and data
// coordinate of a screen coordinate. A negative
// plot numbers means that the screen coordinate
// is not in the data area of any plot.
func dataCoord(x, y int) (int, float64, float64) {
dpi := ps[0].dataArea.DPI()
pt := plot.Point{
X: vg.Inches(float64(x) / dpi),
Y: vg.Inches(float64(y) / dpi),
}
for i, p := range ps {
if p.dataArea.Contains(pt) {
da := p.dataArea
x := float64((pt.X - da.Min.X) / (da.Max().X - da.Min.X))
x *= (p.plot.X.Max - p.plot.X.Min)
x += p.plot.X.Min
y := float64((pt.Y - da.Min.Y) / (da.Max().Y - da.Min.Y))
y *= (p.plot.Y.Max - p.plot.Y.Min)
y += p.plot.Y.Min
return i, x, y
}
}
return -1, 0, 0
}
// NewImage returns a new image canvas
// that draws to the given image. The
// minimum point of the given image
// should probably be 0,0.
func NewImage(img draw.Image, name string) (*XImgCanvas, error) {
w := float64(img.Bounds().Max.X - img.Bounds().Min.X)
h := float64(img.Bounds().Max.Y - img.Bounds().Min.Y)
X, err := xgbutil.NewConn()
if err != nil {
return nil, err
}
keybind.Initialize(X)
ximg := xgraphics.New(X, image.Rect(0, 0, int(w), int(h)))
err = ximg.CreatePixmap()
if err != nil {
return nil, err
}
painter := NewXimgPainter(ximg)
gc := draw2d.NewGraphicContextWithPainter(ximg, painter)
gc.SetDPI(dpi)
gc.Scale(1, -1)
gc.Translate(0, -h)
wid := ximg.XShowExtra(name, true)
go func() {
xevent.Main(X)
}()
c := &XImgCanvas{
gc: gc,
w: vg.Inches(w / dpi),
h: vg.Inches(h / dpi),
color: []color.Color{color.Black},
x: X,
ximg: ximg,
wid: wid,
}
vg.Initialize(c)
return c, nil
}
func drawPng(b *bytes.Buffer, p *plot.Plot, width, height float64) {
w, h := vg.Inches(width), vg.Inches(height)
c := vgimg.PngCanvas{Canvas: vgimg.New(w, h)}
p.Draw(plot.MakeDrawArea(c))
c.WriteTo(b)
}
// DrawArcs draws some arcs to the canvas.
// The canvas is assumed to be 4 inches square.
func DrawArcs(c vg.Canvas) {
green := color.RGBA{G: 255, A: 255}
var p vg.Path
p.Move(vg.Inches(3), vg.Inches(2))
p.Arc(vg.Inches(2), vg.Inches(2), vg.Inches(1), 0, 2*math.Pi)
c.SetColor(color.RGBA{B: 255, A: 255})
c.Fill(p)
p = vg.Path{}
p.Move(vg.Inches(4), vg.Inches(2))
p.Line(vg.Inches(3), vg.Inches(2))
p.Arc(vg.Inches(2), vg.Inches(2), vg.Inches(1), 0, 5*math.Pi/2)
p.Line(vg.Inches(2), vg.Inches(4))
c.SetColor(color.RGBA{R: 255, A: 255})
c.SetLineWidth(vg.Points(3))
c.Stroke(p)
p = vg.Path{}
p.Move(vg.Inches(0), vg.Inches(2))
p.Line(vg.Inches(1), vg.Inches(2))
p.Arc(vg.Inches(2), vg.Inches(2), vg.Inches(1), math.Pi, -7*math.Pi/2)
p.Line(vg.Inches(2), vg.Inches(0))
c.SetColor(color.Black)
c.SetLineWidth(vg.Points(1))
c.Stroke(p)
p = vg.Path{}
p.Move(vg.Inches(0), vg.Inches(1))
p.Arc(vg.Inches(1), vg.Inches(1), vg.Inches(1), math.Pi, math.Pi/2)
c.SetLineWidth(vg.Points(3))
c.SetColor(green)
c.Stroke(p)
p = vg.Path{}
p.Move(vg.Inches(1), vg.Inches(0))
p.Arc(vg.Inches(1), vg.Inches(1), vg.Inches(1), 3*math.Pi/2, -math.Pi/2)
c.SetLineWidth(vg.Points(1))
c.SetColor(color.Black)
c.Stroke(p)
p = vg.Path{}
p.Move(vg.Inches(3), vg.Inches(2))
p.Arc(vg.Inches(3), vg.Inches(3), vg.Inches(1), 3*math.Pi/2, 3*math.Pi/2)
c.SetLineWidth(vg.Points(3))
c.SetColor(green)
c.Stroke(p)
p = vg.Path{}
p.Move(vg.Inches(2), vg.Inches(3))
p.Arc(vg.Inches(3), vg.Inches(3), vg.Inches(1), math.Pi, -3*math.Pi/2)
c.SetLineWidth(vg.Points(1))
c.SetColor(color.Black)
c.Stroke(p)
}