// DataCanvas returns a new draw.Canvas that
// is the subset of the given draw area into which
// the plot data will be drawn.
func (p *Plot) DataCanvas(da draw.Canvas) draw.Canvas {
if p.Title.Text != "" {
da.Max.Y -= p.Title.Height(p.Title.Text) - p.Title.Font.Extents().Descent
da.Max.Y -= p.Title.Padding
}
p.X.sanitizeRange()
x := horizontalAxis{p.X}
p.Y.sanitizeRange()
y := verticalAxis{p.Y}
return padY(p, padX(p, da.Crop(y.size(), x.size(), 0, 0)))
}
// Draw draws a plot to a draw.Canvas.
//
// Plotters are drawn in the order in which they were
// added to the plot. Plotters that implement the
// GlyphBoxer interface will have their GlyphBoxes
// taken into account when padding the plot so that
// none of their glyphs are clipped.
func (p *Plot) Draw(c draw.Canvas) {
if p.BackgroundColor != nil {
c.SetColor(p.BackgroundColor)
c.Fill(c.Rectangle.Path())
}
if p.Title.Text != "" {
c.FillText(p.Title.TextStyle, c.Center().X, c.Max.Y, -0.5, -1, p.Title.Text)
c.Max.Y -= p.Title.Height(p.Title.Text) - p.Title.Font.Extents().Descent
c.Max.Y -= p.Title.Padding
}
p.X.sanitizeRange()
x := horizontalAxis{p.X}
p.Y.sanitizeRange()
y := verticalAxis{p.Y}
ywidth := y.size()
x.draw(padX(p, c.Crop(ywidth, 0, 0, 0)))
xheight := x.size()
y.draw(padY(p, c.Crop(0, xheight, 0, 0)))
dataC := padY(p, padX(p, c.Crop(ywidth, xheight, 0, 0)))
for _, data := range p.plotters {
data.Plot(dataC, p)
}
p.Legend.draw(c.Crop(ywidth, 0, 0, 0).Crop(0, xheight, 0, 0))
}