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