// crop returns a new DrawArea corresponding to the receiver
// area with the given number of inches added to the minimum
// and maximum x and y values of the DrawArea's Rect.
func (da DrawArea) crop(minx, miny, maxx, maxy vg.Length) DrawArea {
minpt := Point{
X: da.Min.X + minx,
Y: da.Min.Y + miny,
}
sz := Point{
X: da.Max().X + maxx - minpt.X,
Y: da.Max().Y + maxy - minpt.Y,
}
return DrawArea{
Canvas: vg.Canvas(da),
Rect: Rect{Min: minpt, Size: sz},
}
}
// padY returns a DrawArea that is padded vertically
// so that glyphs will no be clipped.
func padY(p *Plot, da DrawArea) DrawArea {
glyphs := p.GlyphBoxes(p)
b := bottomMost(&da, glyphs)
yAxis := verticalAxis{p.Y}
glyphs = append(glyphs, yAxis.GlyphBoxes(p)...)
t := topMost(&da, glyphs)
miny := da.Min.Y - b.Min.Y
maxy := da.Max().Y - (t.Min.Y + t.Size.Y)
by := vg.Length(b.Y)
ty := vg.Length(t.Y)
n := (by*maxy - ty*miny) / (by - ty)
m := ((by-1)*maxy - ty*miny + miny) / (by - ty)
return DrawArea{
Canvas: vg.Canvas(da),
Rect: Rect{
Min: Point{Y: n, X: da.Min.X},
Size: Point{Y: m - n, X: da.Size.X},
},
}
}
// padX returns a DrawArea that is padded horizontally
// so that glyphs will no be clipped.
func padX(p *Plot, da DrawArea) DrawArea {
glyphs := p.GlyphBoxes(p)
l := leftMost(&da, glyphs)
xAxis := horizontalAxis{p.X}
glyphs = append(glyphs, xAxis.GlyphBoxes(p)...)
r := rightMost(&da, glyphs)
minx := da.Min.X - l.Min.X
maxx := da.Max().X - (r.Min.X + r.Size.X)
lx := vg.Length(l.X)
rx := vg.Length(r.X)
n := (lx*maxx - rx*minx) / (lx - rx)
m := ((lx-1)*maxx - rx*minx + minx) / (lx - rx)
return DrawArea{
Canvas: vg.Canvas(da),
Rect: Rect{
Min: Point{X: n, Y: da.Min.Y},
Size: Point{X: m - n, Y: da.Size.Y},
},
}
}