package main import "math" type Vertex struct{ X, Y, Z float64 } type Patch []Vertex func (p Patch) X() []float64 { f := make([]float64, len(p)) for i, v := range p { f[i] = v.X } return f } func (p Patch) Y() []float64 { f := make([]float64, len(p)) for i, v := range p { f[i] = v.Y } return f } func (p Patch) Z() []float64 { f := make([]float64, len(p)) for i, v := range p { f[i] = v.Z } return f } func rot(deg float64) (float64, float64) { rad := deg * math.Pi / 180.0 return math.Sin(rad), math.Cos(rad) } func (v Vertex) RotX(deg float64) Vertex { sin, cos := rot(deg) v.Y = cos*v.Y - sin*v.Z v.Z = sin*v.Y + cos*v.Z return v } func (v Vertex) RotY(deg float64) Vertex { sin, cos := rot(deg) v.X = cos*v.X + sin*v.Z v.Z = -sin*v.X + cos*v.Z return v } func (v Vertex) RotZ(deg float64) Vertex { sin, cos := rot(deg) v.X = cos*v.X - sin*v.Y v.Y = sin*v.X + cos*v.Y return v } func (v Vertex) Zoom(zoom float64) Vertex { v.X *= zoom v.Y *= zoom v.Z *= zoom return v } func (v Vertex) Project(p Plotter) { dist := 100000.0 v = v.Zoom(1000).RotZ(-15).RotX(-60) w, h := p.Dim() v.X *= dist / (2*dist - v.Z) v.Y *= dist / (2*dist - v.Z) v.X += float64(w) / 2 v.Y += float64(h) / 3 p.Plot(int(v.X), int(v.Y)) }