Function buildDefaultLUT

src/fl/channels/spi/parallel_device.cpp.hpp:99–128

@brief Build default LUT for parallel GPIO mapping @param gpio_pins Vector of GPIO pin numbers @param set_masks Output array of 256 set masks @param clear_masks Output array of 256 clear masks

/// @param set_masks Output array of 256 set masks
/// @param clear_masks Output array of 256 clear masks
void buildDefaultLUT(const fl::vector<u8>& gpio_pins,
                     u32* set_masks,
                     u32* clear_masks) {
    size_t num_pins = gpio_pins.size();

    // For each possible byte value (0-255)
    for (int byte_val = 0; byte_val < 256; byte_val++) {
        u32 set_mask = 0;
        u32 clear_mask = 0;

        // Map byte bits to GPIO pins
        for (size_t bit_pos = 0; bit_pos < num_pins && bit_pos < 8; bit_pos++) {
            u32 pin_mask = 1u << gpio_pins[bit_pos];

            if (byte_val & (1 << bit_pos)) {
                set_mask |= pin_mask;    // Set this pin high
            } else {
                clear_mask |= pin_mask;  // Clear this pin low
            }
        }

        // For pins beyond bit 7, always clear them (if num_pins > 8)
        for (size_t pin_idx = 8; pin_idx < num_pins; pin_idx++) {
            clear_mask |= (1u << gpio_pins[pin_idx]);
        }

        set_masks[byte_val] = set_mask;
        clear_masks[byte_val] = clear_mask;
    }
}

} // anonymous namespace