Data commit

Task/Death-Star/11l/death-star.11l

@@ -0,0 +1,67 @@
+T Sphere
+   Float cx, cy, cz, r
+   F (cx, cy, cz, r)
+      .cx = cx
+      .cy = cy
+      .cz = cz
+      .r = r
+
+F dotp(v1, v2)
+   V d = dot(v1, v2)
+   R I d < 0 {-d} E 0.0
+
+F hit_sphere(sph, x0, y0)
+   V x = x0 - sph.cx
+   V y = y0 - sph.cy
+   V zsq = sph.r ^ 2 - (x ^ 2 + y ^ 2)
+   I zsq < 0
+      R (0B, 0.0, 0.0)
+   V szsq = sqrt(zsq)
+   R (1B, sph.cz - szsq, sph.cz + szsq)
+
+F draw_sphere(k, ambient, light)
+   V shades = ‘.:!*oe&#%@’
+   V pos = Sphere(20.0, 20.0, 0.0, 20.0)
+   V neg = Sphere(1.0, 1.0, -6.0, 20.0)
+
+   L(i) Int(floor(pos.cy - pos.r)) .< Int(ceil(pos.cy + pos.r) + 1)
+      V y = i + 0.5
+      L(j) Int(floor(pos.cx - 2 * pos.r)) .< Int(ceil(pos.cx + 2 * pos.r) + 1)
+         V x = (j - pos.cx) / 2.0 + 0.5 + pos.cx
+
+         V (h, zb1, zb2) = hit_sphere(pos, x, y)
+         Int hit_result
+         Float zs2
+         I !h
+            hit_result = 0
+         E
+            (h, V zs1, zs2) = hit_sphere(neg, x, y)
+            I !h
+               hit_result = 1
+            E I zs1 > zb1
+               hit_result = 1
+            E I zs2 > zb2
+               hit_result = 0
+            E I zs2 > zb1
+               hit_result = 2
+            E
+               hit_result = 1
+
+         V vec = (0.0, 0.0, 0.0)
+         I hit_result == 0
+            print(‘ ’, end' ‘’)
+            L.continue
+         E I hit_result == 1
+            vec = (x - pos.cx, y - pos.cy, zb1 - pos.cz)
+         E I hit_result == 2
+            vec = (neg.cx - x, neg.cy - y, neg.cz - zs2)
+         vec = normalize(vec)
+
+         V b = dotp(light, vec) ^ k + ambient
+         V intensity = Int((1 - b) * shades.len)
+         intensity = min(shades.len, max(0, intensity))
+         print(shades[intensity], end' ‘’)
+      print()
+
+V light = normalize((-50.0, 30.0, 50.0))
+draw_sphere(2, 0.5, light)