Backends

JustPIC uses KernelAbstractions backends directly. The CPU path is JustPIC.CPU; CUDA, AMDGPU, and Metal backends are activated by loading their respective packages.

Allocate backend arrays with TA(backend) and pass the same backend to init_particles:

using JustPIC

backend = JustPIC.CPU
T = TA(backend)(zeros(Float32, 32, 32))
particles = init_particles(backend, 16, 24, 8, grid_vx, grid_vy)

The high-level particle, interpolation, and advection routines then dispatch on the arrays stored in particles:

V = TA(backend).(V_cpu)
advection!(particles, RungeKutta2(), V, dt)

Keep shared code backend-generic: do not branch on Array, CuArray, or vendor-specific array types. Use Float32 when targeting Metal, which does not support Float64 kernels.

For mixed CPU/GPU simulations, keep the JustPIC backend on the CPU and copy only the fields needed by GPU calculations. See Mixed CPU and GPU.