53 lines
1.2 KiB
Rust
53 lines
1.2 KiB
Rust
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use crate::processor::Direction;
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use std::mem::transmute;
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pub(crate) fn as_signed(unsigned: u8) -> i8 {
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unsafe {
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return transmute(unsigned);
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}
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}
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pub(crate) fn get_bit(byte: u8, flag: u8) -> bool {
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let mask = 1 << flag;
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let got = byte & mask;
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return got > 0x0;
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}
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pub(crate) fn set_or_clear_bit(byte: u8, flag: u8, condition: bool) -> u8 {
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if condition {
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set_bit(byte, flag)
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} else {
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clear_bit(byte, flag)
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}
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}
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pub(crate) fn set_bit(byte: u8, flag: u8) -> u8 {
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byte | (1 << flag)
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}
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pub(crate) fn clear_bit(byte: u8, flag: u8) -> u8 {
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byte & (!(1 << flag))
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}
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pub(crate) fn rotate(byte: u8, direction: &Direction) -> (u8, bool) {
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match direction {
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Direction::Left => {
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let carry = get_bit(byte, 7);
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let r = byte << 1;
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return (r, carry);
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}
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Direction::Right => {
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let carry = get_bit(byte, 0);
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let r = byte >> 1;
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return (r, carry);
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}
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}
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}
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pub(crate) fn get_rotation_carry(direction: &Direction) -> u8 {
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match direction {
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Direction::Left => 0b1,
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Direction::Right => 0b10000000,
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}
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}
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