Golang cairo.Surface类(方法)实例源码

func (m *Map) DrawEdges(ctx *cairo.Surface) {
	m.Edges.Do(func(f interface{}) {
		e, _ := f.(*Edge)
		e.Line().Draw(ctx)
	})
	m.Verticies.Do(func(v interface{}) {
		ctx.SetSourceRGBA(0., 0., 0., 1.)
		v.(*Vertex).Draw(ctx)
	})
}

func (m *Map) DrawDebugEdges(ctx *cairo.Surface) {
	m.Edges.Do(func(f interface{}) {
		e, _ := f.(*Edge)
		ctx.SetSourceRGBA(0., float64((e.Generation*20)%255)/255., 0., 1.)
		e.Line().Draw(ctx)
	})
	m.Verticies.Do(func(v interface{}) {
		ctx.SetSourceRGBA(0., 0., 0., 1.)
		v.(*Vertex).Draw(ctx)
	})
}

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 (l *Line) DrawEndpoints(ctx *cairo.Surface) {
	ctx.MoveTo(l.start.Float64())
	ctx.LineTo(l.end.Float64())
	ctx.Stroke()
	l.start.Draw(ctx)
	l.end.Draw(ctx)
}

func (p *Point) Draw(ctx *cairo.Surface) {
	ctx.Arc(p.x.Float64(), p.y.Float64(), .1, 0., 2.*math.Pi)
	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.
	})
}