// 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) (*Canvas, 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 := NewPainter(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 := &Canvas{
Canvas: vgimg.NewWith(vgimg.UseImageWithContext(img, gc)),
x: X,
ximg: ximg,
wid: wid,
}
vg.Initialize(c)
return c, nil
}
func New(w, h vg.Length) *Canvas {
buf := new(bytes.Buffer)
c := &Canvas{
svg: svgo.New(buf),
w: w,
h: h,
buf: buf,
ht: w.Points(),
stk: []context{context{}},
}
// This is like svg.Start, except it uses floats
// and specifies the units.
fmt.Fprintf(buf, `<?xml version="1.0"?>
<!-- Generated by SVGo and Plotinum VG -->
<svg width="%.*gin" height="%.*gin"
xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink">`+"\n",
pr, w/vg.Inch,
pr, h/vg.Inch,
)
// Swap the origin to the bottom left.
// This must be matched with a </g> when saving,
// before the closing </svg>.
c.svg.Gtransform(fmt.Sprintf("scale(1, -1) translate(0, -%.*g)", pr, h.Dots(c)))
vg.Initialize(c)
return c
}
func TestTextGrobs(t *testing.T) {
// Output
file, err := os.Create("text.png")
if err != nil {
t.Fatalf("%", err)
}
pngCanvas := vgimg.PngCanvas{Canvas: vgimg.New(10*vg.Inch, 8*vg.Inch)}
vg.Initialize(pngCanvas)
allVP := Viewport{
X0: 0,
Y0: 0,
Width: 10 * vg.Inch,
Height: 8 * vg.Inch,
Canvas: pngCanvas,
}
bg := GrobRect{xmin: 0, ymin: 0, xmax: 1, ymax: 1, fill: BuiltinColors["gray60"]}
bg.Draw(allVP)
gridVP := allVP.Sub(0.1, 0.1, 0.35, 0.35)
drawTextGrid(gridVP, 0)
gridVP = allVP.Sub(0.55, 0.1, 0.35, 0.35)
drawTextGrid(gridVP, 45./180*math.Pi)
gridVP = allVP.Sub(0.1, 0.55, 0.35, 0.35)
drawTextGrid(gridVP, 135./180*math.Pi)
gridVP = allVP.Sub(0.55, 0.55, 0.35, 0.35)
drawTextGrid(gridVP, 90./180*math.Pi)
pngCanvas.WriteTo(file)
file.Close()
}
// New creates a new PDF Canvas.
func New(w, h vg.Length) *Canvas {
c := &Canvas{
doc: pdf.New(),
w: w,
h: h,
lineVisible: true,
}
c.page = c.doc.NewPage(unit(w), unit(h))
vg.Initialize(c)
return c
}
// NewTitle returns a new Canvas with the given title string.
func NewTitle(w, h vg.Length, title string) *Canvas {
c := &Canvas{
stk: []ctx{ctx{}},
w: w,
h: h,
buf: new(bytes.Buffer),
}
c.buf.WriteString("%%!PS-Adobe-3.0 EPSF-3.0\n")
c.buf.WriteString("%%Creator github.com/gonum/plot/vg/vgeps\n")
c.buf.WriteString("%%Title: " + title + "\n")
c.buf.WriteString(fmt.Sprintf("%%%%BoundingBox: 0 0 %.*g %.*g\n",
pr, w.Dots(DPI),
pr, h.Dots(DPI)))
c.buf.WriteString(fmt.Sprintf("%%%%CreationDate: %s\n", time.Now()))
c.buf.WriteString("%%Orientation: Portrait\n")
c.buf.WriteString("%%EndComments\n")
c.buf.WriteString("\n")
vg.Initialize(c)
return c
}
// NewWith returns a new image canvas created according to the specified
// options. The currently accepted options are UseWH,
// UseDPI, UseImage, and UseImageWithContext.
// Each of the options specifies the size of the canvas (UseWH, UseImage),
// the resolution of the canvas (UseDPI), or both (useImageWithContext).
// If size or resolution are not specified, defaults are used.
// It panics if size and resolution are overspecified (i.e., too many options are
// passed).
func NewWith(o ...option) *Canvas {
c := new(Canvas)
var g uint32
for _, opt := range o {
f := opt(c)
if g&f != 0 {
panic("incompatible options")
}
g |= f
}
if c.dpi == 0 {
c.dpi = DefaultDPI
}
if c.w == 0 { // h should also == 0.
if c.img == nil {
c.w = DefaultWidth
c.h = DefaultHeight
} else {
w := float64(c.img.Bounds().Max.X - c.img.Bounds().Min.X)
h := float64(c.img.Bounds().Max.Y - c.img.Bounds().Min.Y)
c.w = vg.Length(w/float64(c.dpi)) * vg.Inch
c.h = vg.Length(h/float64(c.dpi)) * vg.Inch
}
}
if c.img == nil {
w := c.w / vg.Inch * vg.Length(c.dpi)
h := c.h / vg.Inch * vg.Length(c.dpi)
c.img = draw.Image(image.NewRGBA(image.Rect(0, 0, int(w+0.5), int(h+0.5))))
}
if c.gc == nil {
h := float64(c.img.Bounds().Max.Y - c.img.Bounds().Min.Y)
c.gc = draw2dimg.NewGraphicContext(c.img)
c.gc.SetDPI(c.dpi)
c.gc.Scale(1, -1)
c.gc.Translate(0, -h)
}
draw.Draw(c.img, c.img.Bounds(), image.White, image.ZP, draw.Src)
c.color = []color.Color{color.Black}
vg.Initialize(c)
return c
}
func TestGraphicGrobs(t *testing.T) {
// Output
file, err := os.Create("grobs.png")
if err != nil {
t.Fatalf("%", err)
}
pngCanvas := vgimg.PngCanvas{Canvas: vgimg.New(10*vg.Inch, 8*vg.Inch)}
vg.Initialize(pngCanvas)
pngCanvas.Translate(-5*vg.Inch, -4*vg.Inch)
dot := func(x, y float64) {
pngCanvas.Push()
pngCanvas.SetColor(BuiltinColors["red"])
pngCanvas.SetLineWidth(5)
var p vg.Path
xr := vg.Length(x) * vg.Inch
yr := vg.Length(y) * vg.Inch
p.Move(xr-5, yr-5)
p.Line(xr-5, yr+5)
p.Line(xr+5, yr+5)
p.Line(xr+5, yr-5)
p.Close()
pngCanvas.Fill(p)
pngCanvas.Pop()
}
dot(0, 0)
dot(5, 0)
dot(0, 4)
allVP := Viewport{
X0: 0,
Y0: 0,
Width: 10 * vg.Inch,
Height: 8 * vg.Inch,
Canvas: pngCanvas,
}
innerVP := allVP.Sub(0.05, 0.05, 0.9, 0.9)
bg := GrobRect{xmin: 0, ymin: 0, xmax: 1, ymax: 1, fill: BuiltinColors["gray80"]}
bg.Draw(innerVP)
cols := []string{"red", "green", "blue", "cyan", "magenta", "yellow",
"white", "gray", "black"}
// Draw points in all shapes, three sizes and all builtin colors.
points := []Grob{}
x, y := 0.1, 0.1
for shape := DotPoint; shape <= StarPoint; shape++ {
for size := 2; size < 7; size += 2 {
y = 0.05
for _, col := range cols {
g := GrobPoint{
x: x,
y: y,
size: float64(size),
shape: shape,
color: BuiltinColors[col],
}
points = append(points, g)
y += 0.035
}
x += 0.021
}
}
x, y = 0.02, 0.05
for _, col := range cols {
g := GrobText{
x: x,
y: y,
text: col,
size: 10,
color: BuiltinColors[col],
vjust: 0.5,
hjust: 0,
}
points = append(points, g)
y += 0.035
}
x, y = 0.121, 0.36
for shape := DotPoint; shape <= StarPoint; shape++ {
dy := float64(shape%2) * 0.015
g := GrobText{
x: x,
y: y + dy,
text: shape.String(),
size: 10,
color: BuiltinColors["black"],
vjust: 0.5,
hjust: 0.5,
}
points = append(points, g)
x += 3 * 0.021
}
for _, grob := range points {
grob.Draw(innerVP)
}
// Draw lines with different styles and widths.
lines := []Grob{}
x, y = 0.1, 0.45
for lt := SolidLine; lt <= TwodashLine; lt++ {
x = 0.1
for size := 1; size < 8; size += 2 {
g := GrobLine{
x0: x,
y0: y,
x1: x + 0.18,
y1: y,
size: float64(size),
linetype: lt,
color: BuiltinColors["black"],
}
lines = append(lines, g)
x += 0.22
}
y += 0.04
}
for _, grob := range lines {
grob.Draw(innerVP)
}
// Draw rectangles
rectVP := innerVP.Sub(0.1, 0.7, 0.4, 0.3)
rect := []Grob{}
bgr := GrobRect{xmin: 0, ymin: 0, xmax: 1, ymax: 1, fill: BuiltinColors["gray40"]}
bgr.Draw(rectVP)
x, y = 0.0, 0.0
w, h := 0.5, 0.5
for _, col := range cols {
g := GrobRect{
xmin: x,
ymin: y,
xmax: x + w,
ymax: y + h,
fill: BuiltinColors[col],
}
rect = append(rect, g)
x += w
y += h
w /= 2
h /= 2
}
for _, grob := range rect {
grob.Draw(rectVP)
}
// Draw path
pathVP := innerVP.Sub(0.55, 0.7, 0.4, 0.3)
bgp := GrobRect{xmin: 0, ymin: 0, xmax: 1, ymax: 1, fill: BuiltinColors["gray"]}
bgp.Draw(pathVP)
sin := make([]struct{ x, y float64 }, 50)
for i := range sin {
k := float64(i) / float64(len(sin)-1)
x = k * 2 * math.Pi
println(float64(i)/float64(len(sin)), x, math.Sin(x))
y = 0.4 * math.Sin(x)
sin[i].x = k
sin[i].y = 0.55 + y
}
g := GrobPath{
points: sin,
size: 4,
linetype: SolidLine,
color: BuiltinColors["white"],
}
g.Draw(pathVP)
cos := make([]struct{ x, y float64 }, 25)
for i := range cos {
k := float64(i) / float64(len(cos)-1)
x = k * 4 * math.Pi
y = 0.3 * math.Cos(x)
cos[i].x = k
cos[i].y = 0.45 + y
}
g = GrobPath{
points: cos,
size: 2,
linetype: DottedLine,
color: BuiltinColors["green"],
}
g.Draw(pathVP)
pngCanvas.WriteTo(file)
file.Close()
}