func (line GrobLine) Draw(vp Viewport) {
vp.Canvas.SetColor(line.color)
vp.Canvas.SetLineWidth(vg.Points(line.size))
vp.Canvas.SetLineDash(dashLength[line.linetype%7], 0)
x0, y0 := vp.X(line.x0), vp.Y(line.y0)
x1, y1 := vp.X(line.x1), vp.Y(line.y1)
var p vg.Path
p.Move(x0, y0)
p.Line(x1, y1)
vp.Canvas.Stroke(p)
}
// DrawGlyph implements the Glyph interface.
func (BoxGlyph) DrawGlyph(c *Canvas, sty GlyphStyle, pt Point) {
x := (sty.Radius-sty.Radius*cosπover4)/2 + sty.Radius*cosπover4
var p vg.Path
p.Move(pt.X-x, pt.Y-x)
p.Line(pt.X+x, pt.Y-x)
p.Line(pt.X+x, pt.Y+x)
p.Line(pt.X-x, pt.Y+x)
p.Close()
c.Fill(p)
}
// DrawGlyph implements the Glyph interface.
func (SquareGlyph) DrawGlyph(c *Canvas, sty GlyphStyle, pt Point) {
c.SetLineStyle(LineStyle{Color: sty.Color, Width: vg.Points(0.5)})
x := (sty.Radius-sty.Radius*cosπover4)/2 + sty.Radius*cosπover4
var p vg.Path
p.Move(pt.X-x, pt.Y-x)
p.Line(pt.X+x, pt.Y-x)
p.Line(pt.X+x, pt.Y+x)
p.Line(pt.X-x, pt.Y+x)
p.Close()
c.Stroke(p)
}
// DrawGlyph implements the Glyph interface.
func (CrossGlyph) DrawGlyph(c *Canvas, sty GlyphStyle, pt Point) {
c.SetLineStyle(LineStyle{Color: sty.Color, Width: vg.Points(0.5)})
r := sty.Radius * cosπover4
var p vg.Path
p.Move(pt.X-r, pt.Y-r)
p.Line(pt.X+r, pt.Y+r)
c.Stroke(p)
p = vg.Path{}
p.Move(pt.X-r, pt.Y+r)
p.Line(pt.X+r, pt.Y-r)
c.Stroke(p)
}
func (path GrobPath) Draw(vp Viewport) {
vp.Canvas.Push()
vp.Canvas.SetColor(path.color)
vp.Canvas.SetLineWidth(vg.Points(path.size))
vp.Canvas.SetLineDash(dashLength[path.linetype], 0)
x, y := vp.X(path.points[0].x), vp.Y(path.points[0].y)
var p vg.Path
p.Move(x, y)
for i := 1; i < len(path.points); i++ {
x, y = vp.X(path.points[i].x), vp.Y(path.points[i].y)
p.Line(x, y)
}
vp.Canvas.Stroke(p)
vp.Canvas.Pop()
}
// DrawGlyph implements the GlyphDrawer interface.
func (CircleGlyph) DrawGlyph(c *Canvas, sty GlyphStyle, pt Point) {
var p vg.Path
p.Move(pt.X+sty.Radius, pt.Y)
p.Arc(pt.X, pt.Y, sty.Radius, 0, 2*math.Pi)
p.Close()
c.Fill(p)
}
// DrawGlyph implements the Glyph interface.
func (RingGlyph) DrawGlyph(c *Canvas, sty GlyphStyle, pt Point) {
c.SetLineStyle(LineStyle{Color: sty.Color, Width: vg.Points(0.5)})
var p vg.Path
p.Move(pt.X+sty.Radius, pt.Y)
p.Arc(pt.X, pt.Y, sty.Radius, 0, 2*math.Pi)
p.Close()
c.Stroke(p)
}
// StrokeLines draws a line connecting a set of points
// in the given Canvas.
func (c *Canvas) StrokeLines(sty LineStyle, lines ...[]Point) {
if len(lines) == 0 {
return
}
c.SetLineStyle(sty)
for _, l := range lines {
if len(l) == 0 {
continue
}
var p vg.Path
p.Move(l[0].X, l[0].Y)
for _, pt := range l[1:] {
p.Line(pt.X, pt.Y)
}
c.Stroke(p)
}
}
// DrawGlyph implements the Glyph interface.
func (PyramidGlyph) DrawGlyph(c *Canvas, sty GlyphStyle, pt Point) {
r := sty.Radius + (sty.Radius-sty.Radius*sinπover6)/2
var p vg.Path
p.Move(pt.X, pt.Y+r)
p.Line(pt.X-r*cosπover6, pt.Y-r*sinπover6)
p.Line(pt.X+r*cosπover6, pt.Y-r*sinπover6)
p.Close()
c.Fill(p)
}
// DrawGlyph implements the Glyph interface.
func (TriangleGlyph) DrawGlyph(c *Canvas, sty GlyphStyle, pt Point) {
c.SetLineStyle(LineStyle{Color: sty.Color, Width: vg.Points(0.5)})
r := sty.Radius + (sty.Radius-sty.Radius*sinπover6)/2
var p vg.Path
p.Move(pt.X, pt.Y+r)
p.Line(pt.X-r*cosπover6, pt.Y-r*sinπover6)
p.Line(pt.X+r*cosπover6, pt.Y-r*sinπover6)
p.Close()
c.Stroke(p)
}
func (rect GrobRect) Draw(vp Viewport) {
println("GrobRect.Draw: ", rect.String(), " to ", vp.String())
vp.Canvas.Push()
vp.Canvas.SetColor(rect.fill)
vp.Canvas.SetLineWidth(2)
xmin, ymin := vp.X(rect.xmin), vp.Y(rect.ymin)
xmax, ymax := vp.X(rect.xmax), vp.Y(rect.ymax)
println(xmin, ymin, " -- ", xmax, ymax)
var p vg.Path
p.Move(xmin, ymin)
p.Line(xmax, ymin)
p.Line(xmax, ymax)
p.Line(xmin, ymax)
p.Close()
vp.Canvas.Fill(p)
vp.Canvas.Pop()
}
// FillPolygon fills a polygon with the given color.
func (c *Canvas) FillPolygon(clr color.Color, pts []Point) {
if len(pts) == 0 {
return
}
c.SetColor(clr)
var p vg.Path
p.Move(pts[0].X, pts[0].Y)
for _, pt := range pts[1:] {
p.Line(pt.X, pt.Y)
}
p.Close()
c.Fill(p)
}
func (c *contour) path(trX, trY func(float64) vg.Length) vg.Path {
var pa vg.Path
p := c.front()
pa.Move(trX(p.X), trY(p.Y))
for i := len(c.backward) - 2; i >= 0; i-- {
p = c.backward[i]
pa.Line(trX(p.X), trY(p.Y))
}
for _, p := range c.forward {
pa.Line(trX(p.X), trY(p.Y))
}
return pa
}
// Plot draws the Line, implementing the plot.Plotter
// interface.
func (pts *Line) Plot(c draw.Canvas, plt *plot.Plot) {
trX, trY := plt.Transforms(&c)
ps := make([]draw.Point, len(pts.XYs))
for i, p := range pts.XYs {
ps[i].X = trX(p.X)
ps[i].Y = trY(p.Y)
}
if pts.ShadeColor != nil && len(ps) > 0 {
c.SetColor(*pts.ShadeColor)
minY := trY(plt.Y.Min)
var pa vg.Path
pa.Move(ps[0].X, minY)
for i := range pts.XYs {
pa.Line(ps[i].X, ps[i].Y)
}
pa.Line(ps[len(pts.XYs)-1].X, minY)
pa.Close()
c.Fill(pa)
}
c.StrokeLines(pts.LineStyle, c.ClipLinesXY(ps)...)
}
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()
}
func (point GrobPoint) Draw(vp Viewport) {
vp.Canvas.Push()
vp.Canvas.SetColor(point.color)
vp.Canvas.SetLineWidth(1)
x, y := vp.X(point.x), vp.Y(point.y)
s := vg.Points(point.size)
var p vg.Path
draw := vp.Canvas.Stroke
if point.shape >= SolidCirclePoint && point.shape <= SolidNablaPoint {
draw = vp.Canvas.Fill
}
switch point.shape {
case BlankPoint:
return
case DotPoint:
dpi := vp.Canvas.DPI()
p.Arc(x, y, vg.Inch/vg.Length(dpi), 0, 2*math.Pi)
p.Close()
vp.Canvas.Fill(p)
case CirclePoint, SolidCirclePoint:
p.Arc(x, y, vg.Points(point.size), 0, 2*math.Pi)
p.Close()
draw(p)
case SquarePoint, SolidSquarePoint:
p.Move(x-s, y-s)
p.Line(x+s, y-s)
p.Line(x+s, y+s)
p.Line(x-s, y+s)
p.Close()
draw(p)
case DiamondPoint, SolidDiamondPoint:
p.Move(x, y-s)
p.Line(x+s, y)
p.Line(x, y+s)
p.Line(x-s, y)
p.Close()
draw(p)
case DeltaPoint, SolidDeltaPoint:
ss := 0.57735 * s
p.Move(x, y+2*ss)
p.Line(x-s, y-ss)
p.Line(x+s, y-ss)
p.Close()
draw(p)
case NablaPoint, SolidNablaPoint:
ss := 0.57735 * s
p.Move(x, y-2*ss)
p.Line(x-s, y+ss)
p.Line(x+s, y+ss)
p.Close()
draw(p)
case CrossPoint:
ss := s / 1.3
p.Move(x-ss, y-ss)
p.Line(x+ss, y+ss)
p.Move(x-ss, y+ss)
p.Line(x+ss, y-ss)
draw(p)
case PlusPoint:
p.Move(x-s, y)
p.Line(x+s, y)
p.Move(x, y-s)
p.Line(x, y+s)
draw(p)
case StarPoint:
ss := s / 1.3
p.Move(x-ss, y-ss)
p.Line(x+ss, y+ss)
p.Move(x-ss, y+ss)
p.Line(x+ss, y-ss)
p.Move(x-s, y)
p.Line(x+s, y)
p.Move(x, y-s)
p.Line(x, y+s)
draw(p)
default:
println("Implement Draw for points " + point.shape.String())
}
vp.Canvas.Pop()
}
// Plot implements the Plot method of the plot.Plotter interface.
func (h *HeatMap) Plot(c draw.Canvas, plt *plot.Plot) {
pal := h.Palette.Colors()
if len(pal) == 0 {
panic("heatmap: empty palette")
}
// ps scales the palette uniformly across the data range.
ps := float64(len(pal)-1) / (h.Max - h.Min)
trX, trY := plt.Transforms(&c)
var pa vg.Path
cols, rows := h.GridXYZ.Dims()
for i := 0; i < cols; i++ {
var right, left float64
switch i {
case 0:
right = (h.GridXYZ.X(i+1) - h.GridXYZ.X(i)) / 2
left = -right
case cols - 1:
right = (h.GridXYZ.X(i) - h.GridXYZ.X(i-1)) / 2
left = -right
default:
right = (h.GridXYZ.X(i+1) - h.GridXYZ.X(i)) / 2
left = -(h.GridXYZ.X(i) - h.GridXYZ.X(i-1)) / 2
}
for j := 0; j < rows; j++ {
v := h.GridXYZ.Z(i, j)
if math.IsNaN(v) || math.IsInf(v, 0) {
continue
}
pa = pa[:0]
var up, down float64
switch j {
case 0:
up = (h.GridXYZ.Y(j+1) - h.GridXYZ.Y(j)) / 2
down = -up
case rows - 1:
up = (h.GridXYZ.Y(j) - h.GridXYZ.Y(j-1)) / 2
down = -up
default:
up = (h.GridXYZ.Y(j+1) - h.GridXYZ.Y(j)) / 2
down = -(h.GridXYZ.Y(j) - h.GridXYZ.Y(j-1)) / 2
}
x, y := trX(h.GridXYZ.X(i)+left), trY(h.GridXYZ.Y(j)+down)
dx, dy := trX(h.GridXYZ.X(i)+right), trY(h.GridXYZ.Y(j)+up)
if !c.Contains(draw.Point{x, y}) || !c.Contains(draw.Point{dx, dy}) {
continue
}
pa.Move(x, y)
pa.Line(dx, y)
pa.Line(dx, dy)
pa.Line(x, dy)
pa.Close()
var col color.Color
switch {
case v < h.Min:
col = h.Underflow
case v > h.Max:
col = h.Overflow
default:
col = pal[int((v-h.Min)*ps+0.5)] // Apply palette scaling.
}
if col != nil {
c.SetColor(col)
c.Fill(pa)
}
}
}
}
// naivePlot implements the a naive rendering approach for contours.
// It is here as a debugging mode since it simply draws line segments
// generated by conrec without further computation.
func (h *Contour) naivePlot(c draw.Canvas, plt *plot.Plot) {
var pal []color.Color
if h.Palette != nil {
pal = h.Palette.Colors()
}
trX, trY := plt.Transforms(&c)
// Sort levels prior to palette scaling since we can't depend on
// sorting as a side effect from calling contourPaths.
sort.Float64s(h.Levels)
// ps is a palette scaling factor to scale the palette uniformly
// across the given levels. This enables a discordance between the
// number of colours and the number of levels.
ps := float64(len(pal)-1) / (h.Levels[len(h.Levels)-1] - h.Levels[0])
if len(h.Levels) == 1 {
ps = 0
}
levelMap := make(map[float64]int)
for i, z := range h.Levels {
levelMap[z] = i
}
// Draw each line segment as conrec generates it.
var pa vg.Path
conrec(h.GridXYZ, h.Levels, func(_, _ int, l line, z float64) {
if math.IsNaN(z) {
return
}
pa = pa[:0]
x1, y1 := trX(l.p1.X), trY(l.p1.Y)
x2, y2 := trX(l.p2.X), trY(l.p2.Y)
if !c.Contains(draw.Point{x1, y1}) || !c.Contains(draw.Point{x2, y2}) {
return
}
pa.Move(x1, y1)
pa.Line(x2, y2)
pa.Close()
style := h.LineStyles[levelMap[z]%len(h.LineStyles)]
var col color.Color
switch {
case z < h.Min:
col = h.Underflow
case z > h.Max:
col = h.Overflow
case len(pal) == 0:
col = style.Color
default:
col = pal[int((z-h.Levels[0])*ps+0.5)] // Apply palette scaling.
}
if col != nil && style.Width != 0 {
c.SetLineStyle(style)
c.SetColor(col)
c.Stroke(pa)
}
})
}