Function fill_deterministic

tests/fl/gfx/blur.cpp:609–615

Helper: fill pixel arrays with deterministic test data.

// Helper: fill pixel arrays with deterministic test data.
static void fill_deterministic(CRGB *pixels, int n) {
    for (int i = 0; i < n; ++i) {
        pixels[i] = CRGB(static_cast<uint8_t>((i * 37 + 17) & 0xFF),
                         static_cast<uint8_t>((i * 59 + 31) & 0xFF),
                         static_cast<uint8_t>((i * 83 + 47) & 0xFF));
    }
}

FL_TEST_CASE("CanvasMapped 3x3 - uniform interior unchanged") {
    const int W = 5, H = 5;