TABLE I.

Basic Fast Algorithm for Geometry Independent Speeds

Step 1: Initialize arrays φ̂ and F̂, and the lists Lout and Lin. Step 2: Compute speed F for all points in Lout and Lin and store sign in F̂. Step 3: Scan through the two lists Lout and Lin and update: Outward evolution. Scan through Lout. For each point x ∈ Lout, switch_in(x) if F̂(x) > 0. Eliminate redundant points in Lin. Scan through Lin. For each point x ∈ Lin, if ∀y ∈ N(x), φ̂(y) < 0, delete x from Lin, and set φ̂(x) = −3. Inward evolution. Scan through Lin. For each point x ∈ Lin, switch_out(x) if F̂(x) < 0. Eliminate redundant points in Lout. Scan through Lout. For each point x ∈ Lout, if ∀y ∈ N(x), φ̂(y) > 0, delete x from Lout, and set φ̂(x) = 3. Step 4: If the stopping condition is not satisfied, go to Step 2.