Starfield

1// Starfield — warp drive.
2// 3D star projection with motion trails.
3 
4state stars = []
5state initialized = false
6 
7let cx = float(screen_width()) / 2.0
8let cy = float(screen_height()) / 2.0
9let delta = dt()
10let depth = 1000.0
11let fov = 400.0
12 
13fn clip(v)
14    if v > 30000.0 then 30000.0 else if v < -30000.0 then -30000.0 else v end end
15end
16 
17if !initialized then
18    let temp = []
19    for i in range(0, 200) do
20        push(temp, {
21            x: random(-400.0, 400.0),
22            y: random(-300.0, 300.0),
23            z: random(50.0, depth),
24            pz: depth
25        })
26    end
27    stars = temp
28    initialized = true
29end
30 
31let speed = 300.0
32let new_stars = []
33for s in stars do
34    let pz = s.z
35    let nz = s.z - speed * delta
36 
37    if nz < 30.0 then
38        push(new_stars, {
39            x: random(-400.0, 400.0),
40            y: random(-300.0, 300.0),
41            z: depth,
42            pz: depth
43        })
44    else
45        push(new_stars, { x: s.x, y: s.y, z: nz, pz: pz })
46    end
47end
48stars = new_stars
49 
50// === Draw ===
51clear(0, 0, 8)
52 
53for s in stars do
54    let sx = clip(s.x / s.z * fov + cx)
55    let sy = clip(s.y / s.z * fov + cy)
56    let psx = clip(s.x / s.pz * fov + cx)
57    let psy = clip(s.y / s.pz * fov + cy)
58 
59    let brightness = int((1.0 - s.z / depth) * 255.0)
60    let b = min(255, max(40, brightness))
61    draw_line(int(psx), int(psy), int(sx), int(sy), b, b, b)
62end
63 
64draw_text("Starfield", 16, 12, 14, 180, 180, 220)