func (m *Map) ColourFaces(ctx *cairo.Surface, brush func(*Face) (float64, float64, float64, float64)) {
m.Faces.Do(func(f interface{}) {
F := f.(*Face)
ctx.SetSourceRGBA(brush(F))
e := F.boundary
ctx.MoveTo(e.start.Float64())
for f := e.Next(); f != e; f = f.Next() {
ctx.LineTo(f.start.Float64())
}
ctx.ClosePath()
ctx.Fill()
})
}
func (m *Map) ColourDebugFaces(ctx *cairo.Surface) {
n := float64(m.Faces.Len())
i := 0.
m.Faces.Do(func(f interface{}) {
F, _ := f.(*Face)
if F.Value.(string) == "outer" {
return
}
e := F.boundary
ctx.MoveTo(e.start.Float64())
for f := e.Next(); f != e; f = f.Next() {
ctx.LineTo(f.start.Float64())
}
ctx.ClosePath()
if F.Value.(string) == "skeleton" {
ctx.SetSourceRGBA(0., 0., 1., 1.)
} else {
ctx.SetSourceRGBA(i/n, 0., 0., 1.)
}
ctx.Fill()
i = i + 1.
})
}
func (p *Point) Draw(ctx *cairo.Surface) {
ctx.Arc(p.x.Float64(), p.y.Float64(), .1, 0., 2.*math.Pi)
ctx.Fill()
}