TODO

Advection (Medium Flow):

You use a semi-Lagrangian approach (backtracking coordinates: src_x = x - vx * dt) with bilinear interpolation.

Observation: This introduces numerical diffusion (blurring), which acts as artificial damping. This is actually good for stability in a visual simulation, even if energy isn't perfectly conserved.


Optimize the update loop (Pointer Swapping)
Currently, you have pressure and pressure_scratch (implied or used in flow). In high-performance FDTD, we usually avoid copying data back and forth. Instead of: