shark/mino/src/matrix.rs

624 lines
18 KiB
Rust

//! Data structures and operations on tetrix matrices. The matrix types in this module are
//! uncolored, since color information is generally not used by bots and many operations
//! can be made much more efficient by not tracking it.
use core::cmp::{max, min};
use core::ops::{Range, RangeFull};
/// Number of columns in a matrix.
pub const COLUMNS: i16 = 10;
/// Bitboard representation of a full row.
pub const FULL_ROW: u16 = u16::MAX;
/// Bitboard representation of an empty row.
pub const EMPTY_ROW: u16 = !((1u16 << COLUMNS) - 1);
/// Represents a "slice" to a tetris matrix bitboard.
///
/// Bitboards are represented rowwise, with each row represented by a u16 holding bits
/// describing if a cell is occupied (1) or not (0). The least significant bit describes
/// the leftmost column, and the most significant bits are all set, even past the logical
/// end of the matrix (columns 11+).
///
/// Logically, a matrix is considered infinite in every direction. Cells below the bottom
/// or beyond the left/right sides are all considered occupied. Cells above the physical
/// top of the matrix are considered unoccupied.
#[derive(Eq, PartialEq, Hash)]
#[repr(transparent)]
pub struct Mat([u16]);
impl Mat {
/// Constructs a new matrix from a slice of rowwise bitboard data.
pub const fn new(data: &[u16]) -> &Self {
if data.len() >= i16::MAX as usize {
panic!("matrix height overflows i16");
}
unsafe { core::mem::transmute(data) }
}
pub const EMPTY: &'static Self = Self::new(&[]);
/// Returns the number of columns in the matrix. This always returns `COLUMNS`.
#[inline]
pub const fn cols(&self) -> i16 {
COLUMNS
}
/// Returns the number of rows in the matrix.
#[inline]
pub const fn rows(&self) -> i16 {
// XXX(iitalics): this is guarunteed not to wrap, since we check len in `new`.
self.0.len() as i16
}
/// Returns true if the cells in row `y` selected by `mask` match the pattern `test`.
#[inline]
pub fn test_row(&self, y: i16, mask: u16, test: u16) -> bool {
(self[y] & mask) == test
}
/// Returns true if the cell at `(x,y)` is occupied.
#[inline]
pub fn get(&self, x: i16, y: i16) -> bool {
if (0..COLUMNS).contains(&x) {
self.test_row(y, 1 << x, 1 << x)
} else {
true
}
}
}
impl AsRef<Mat> for Mat {
fn as_ref(&self) -> &Mat {
self
}
}
// `mat[y]` = bit pattern of row `y`
impl core::ops::Index<i16> for Mat {
type Output = u16;
fn index(&self, y: i16) -> &u16 {
if y < 0 {
&FULL_ROW
} else {
self.0.get(y as usize).unwrap_or(&EMPTY_ROW)
}
}
}
// `mat[y0..y1]` = bit patterns of rows in range
impl core::ops::Index<Range<i16>> for Mat {
type Output = [u16];
fn index(&self, r: Range<i16>) -> &[u16] {
let y1 = min(max(r.end, 0), self.rows());
let y0 = min(max(r.start, 0), y1);
&self.0[y0 as usize..y1 as usize]
}
}
// `mat[..]` = bit patterns of all rows
impl core::ops::Index<RangeFull> for Mat {
type Output = [u16];
fn index(&self, _: RangeFull) -> &[u16] {
&self.0
}
}
impl core::fmt::Debug for Mat {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
write!(f, "mat!{{")?;
let mut sep = "";
for y in (0..self.rows()).rev() {
write!(f, "{sep}\"")?;
for x in 0..self.cols() {
let occ = self.get(x, y);
f.write_str(if occ { "x" } else { "." })?;
}
write!(f, "\"")?;
sep = ";";
}
write!(f, "}}")
}
}
#[cfg(any(feature = "ascii", test))]
#[doc(hidden)]
pub mod __ascii {
use super::*;
pub const fn parse<const N: usize>(strs: [&str; N]) -> [u16; N] {
let mut data = [EMPTY_ROW; N];
let mut i = 0;
while i < N {
let row = strs[i].as_bytes();
if row.len() != COLUMNS as usize {
panic!("wrong number of columns in ascii row");
}
let y = N - i - 1;
let mut x = 0i16;
while x < COLUMNS {
match row[x as usize] {
b'.' | b'_' | b' ' => {}
_ => data[y] |= 1 << x,
}
x += 1;
}
i += 1;
}
data
}
}
/// Matrix bitboard backed by a static u16 array of a given length. This type allows
/// writable operations such as changing if a cell is occupied or not, and growing or
/// shrinking the number of rows as long as it stays within the underlying capacity.
///
/// [`MatBuf`] implements [`Deref`], so it automatically inherits the methods of [`Mat`].
#[derive(Clone)]
pub struct MatBuf<const LEN: usize = 40> {
rows: i16,
buf: [u16; LEN],
}
impl MatBuf {
/// Returns a new empty [`MatBuf`] that is able to grow up to 40 rows.
pub fn new() -> Self {
Self::default()
}
}
impl<const LEN: usize> MatBuf<LEN> {
/// Returns a read-only view of this matrix.
#[inline]
pub fn as_mat(&self) -> &Mat {
Mat::new(&self.buf[0..self.rows as usize])
}
/// Modifies the cells in this matrix to be identical to those in `mat`.
///
/// Panics if the buffer space cannot fit the rows of `mat`.
#[inline]
pub fn copy_from(&mut self, mat: &Mat) {
let data = &mat[..];
if data.len() > LEN {
panic!("matrix cannot fit in available buffer space");
}
self.rows = mat.rows();
self.buf[..data.len()].copy_from_slice(data);
}
/// Resets the matrix so it is empty.
#[inline]
pub fn clear(&mut self) {
self.copy_from(Mat::EMPTY)
}
/// Modifies the cells in row `y` to have additional cells occupied according to the
/// bit pattern in `mask`.
///
/// Panics if the buffer space cannot fit the desired row.
#[inline]
pub fn fill_row(&mut self, y: i16, mask: u16) {
if y >= 0 {
self[y] |= mask;
}
}
/// Fills in the cell at the given (x,y) coordinate.
///
/// Panics if the buffer space cannot fit the desired cell.
pub fn set(&mut self, x: i16, y: i16) {
self.fill_row(y, if (0..COLUMNS).contains(&x) { 1 << x } else { 0 })
}
/// Removes any rows that are completely filled, shifting rows above down. Returns the
/// range of rows that were cleared.
pub fn clear_lines(&mut self) -> Range<i16> {
// TODO: this could be made faster if given the following assumptions:
// - provide lowest y that may contain filled rows
// - assume that filled rows must all be adjacent
let mut dst = 0usize;
let mut rng = self.rows..self.rows;
for y in 0..self.rows {
let i = y as usize;
if self.buf[i] == FULL_ROW || self.buf[i] == EMPTY_ROW {
rng.start = min(rng.start, y);
rng.end = y + 1;
} else {
self.buf[dst] = self.buf[i];
dst += 1;
}
}
self.rows = dst as i16;
rng
}
pub fn shift_up(&mut self) {
if self.rows as usize == LEN {
panic!("not enough available buffer space to shift up");
}
self.buf.copy_within(0..self.rows as usize, 1);
self.buf[0] = EMPTY_ROW;
self.rows += 1;
}
}
impl<const LEN: usize> Default for MatBuf<LEN> {
fn default() -> Self {
Self {
buf: [0; LEN],
rows: 0,
}
}
}
impl<const LEN: usize> core::ops::IndexMut<i16> for MatBuf<LEN> {
fn index_mut(&mut self, y: i16) -> &mut u16 {
if y < 0 || y as usize >= LEN {
panic!("row does not fit in available buffer space");
}
if y >= self.rows {
self.buf[self.rows as usize..(y + 1) as usize].fill(EMPTY_ROW);
self.rows = y + 1;
}
&mut self.buf[y as usize]
}
}
impl<const LEN: usize> core::ops::IndexMut<Range<i16>> for MatBuf<LEN> {
fn index_mut(&mut self, r: Range<i16>) -> &mut [u16] {
// FIXME: should this expand the buffer like `IndexMut<i16>` does?
let y1 = min(max(r.end, 0), self.rows);
let y0 = min(max(r.start, 0), y1);
&mut self.buf[y0 as usize..y1 as usize]
}
}
impl<const LEN: usize> core::ops::IndexMut<RangeFull> for MatBuf<LEN> {
fn index_mut(&mut self, _: RangeFull) -> &mut [u16] {
&mut self.buf[..self.rows as usize]
}
}
// boilerplate impl's that all defer to `self.as_mat()`
impl<const LEN: usize> AsRef<Mat> for MatBuf<LEN> {
#[inline]
fn as_ref(&self) -> &Mat {
self.as_mat()
}
}
impl<const LEN: usize> core::ops::Deref for MatBuf<LEN> {
type Target = Mat;
fn deref(&self) -> &Mat {
self.as_mat()
}
}
impl<const LEN: usize, Rhs: AsRef<Mat>> core::cmp::PartialEq<Rhs> for MatBuf<LEN> {
fn eq(&self, other: &Rhs) -> bool {
*self.as_mat() == *other.as_ref()
}
}
impl<const LEN: usize> core::cmp::Eq for MatBuf<LEN> {}
impl<const LEN: usize> core::fmt::Debug for MatBuf<LEN> {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
self.as_mat().fmt(f)
}
}
impl<const LEN: usize> core::hash::Hash for MatBuf<LEN> {
fn hash<H: core::hash::Hasher>(&self, state: &mut H) {
self.as_mat().hash(state);
}
}
impl<const LEN: usize> core::ops::Index<i16> for MatBuf<LEN> {
type Output = u16;
fn index(&self, y: i16) -> &u16 {
&self.as_mat()[y]
}
}
impl<const LEN: usize> core::ops::Index<Range<i16>> for MatBuf<LEN> {
type Output = [u16];
fn index(&self, r: Range<i16>) -> &[u16] {
&self.as_mat()[r]
}
}
impl<const LEN: usize> core::ops::Index<RangeFull> for MatBuf<LEN> {
type Output = [u16];
fn index(&self, _: RangeFull) -> &[u16] {
&self.as_mat()[..]
}
}
// TODO(?): MatVec, which is resizable
// TODO(?): test_row(), fill_row(), clear_lines() made into traits
#[cfg(test)]
mod test {
use super::*;
use crate::mat;
use alloc::vec::Vec;
use core::ops::RangeInclusive;
#[test]
fn test_bit_constants() {
for i in 0..16 {
let m = 1u16 << i;
let e = EMPTY_ROW & m != 0;
let f = FULL_ROW & m != 0;
assert!(f, "full, i={i}");
assert_eq!(e, i >= 10, "empty, i={i}");
}
}
const M1: &Mat = mat! {
"...x....x.";
"xx..xxxx.x";
};
const M2: &Mat = mat! {
".........x";
".........x";
"x.......xx";
"xxxx.xxxxx";
};
#[test]
fn test_dims() {
assert_eq!(Mat::EMPTY.rows(), 0);
assert_eq!(Mat::EMPTY.cols(), 10);
assert_eq!(M1.rows(), 2);
assert_eq!(M1.cols(), 10);
assert_eq!(M2.rows(), 4);
assert_eq!(M2.cols(), 10);
}
#[test]
fn test_index() {
assert_eq!(Mat::EMPTY[0], EMPTY_ROW);
assert_eq!(Mat::EMPTY[1], EMPTY_ROW);
assert_eq!(Mat::EMPTY[-1], FULL_ROW);
//
let m1_0 = 0b1011110011 | EMPTY_ROW;
let m1_1 = 0b0100001000 | EMPTY_ROW;
assert_eq!(M1[0], m1_0, "{:b}", M1[0]);
assert_eq!(M1[1], m1_1, "{:b}", M1[1]);
assert_eq!(M1[2], EMPTY_ROW);
assert_eq!(M1[-1], FULL_ROW);
assert_eq!(M1[0..2], [m1_0, m1_1]);
//
let m2_0 = 0b1111101111 | EMPTY_ROW;
let m2_1 = 0b1100000001 | EMPTY_ROW;
let m2_2 = 0b1000000000 | EMPTY_ROW;
let m2_3 = 0b1000000000 | EMPTY_ROW;
assert_eq!(M2[0..4], [m2_0, m2_1, m2_2, m2_3]);
assert_eq!(M2[0..1], [m2_0]);
assert_eq!(M2[2..4], [m2_2, m2_3]);
assert_eq!(M2[2..5], M2[2..4]);
assert_eq!(M2[-1..3], M2[0..3]);
}
fn occ(m: &Mat, y: i16, xs: RangeInclusive<i16>) -> Vec<bool> {
xs.map(|x| m.get(x, y)).collect()
}
#[test]
#[allow(clippy::just_underscores_and_digits)]
fn test_occupied() {
// get row data as bools
let __ = false;
let xx = true;
assert_eq!(
occ(M1, 0, -1..=10),
[xx, xx, xx, __, __, xx, xx, xx, xx, __, xx, xx]
);
assert_eq!(occ(M1, 1, 0..=9), [__, __, __, xx, __, __, __, __, xx, __]);
assert_eq!(occ(M2, 1, 0..=9), [xx, __, __, __, __, __, __, __, xx, xx],);
// test oob circumstances
for x in -16..=16 {
let oob = !(0..COLUMNS).contains(&x);
assert_eq!(M1.get(x, 2), oob, "M1,x={x},y=2");
assert_eq!(M1.get(x, 3), oob, "M1,x={x},y=3");
assert_eq!(M2.get(x, 4), oob, "M2,x={x},y=4");
assert_eq!(M2.get(x, 5), oob, "M2,x={x},y=5");
assert_eq!(M1.get(x, 16), oob, "M1,x={x},y=16");
assert_eq!(M2.get(x, 17), oob, "M2,x={x},y=17");
for y in -4..0 {
assert!(M1.get(x, y), "M1,x={x},y={y}");
assert!(M2.get(x, y), "M2,x={x},y={y}");
}
}
}
#[test]
fn test_mat_buf_size() {
macro_rules! mat_buf_size {
($n:literal) => {
core::mem::size_of::<MatBuf<$n>>()
};
}
assert_eq!(mat_buf_size!(0), core::mem::size_of::<[u16; 1]>());
assert_eq!(mat_buf_size!(1), core::mem::size_of::<[u16; 2]>());
assert_eq!(mat_buf_size!(10), core::mem::size_of::<[u16; 11]>());
assert_eq!(mat_buf_size!(40), core::mem::size_of::<[u16; 41]>());
assert_eq!(
core::mem::size_of::<MatBuf>(),
core::mem::size_of::<[u16; 41]>()
);
}
#[test]
fn test_mat_buf_copy_from() {
let mut buf = MatBuf::new();
assert_eq!(buf, Mat::EMPTY);
assert_eq!(buf.rows(), 0);
let mat = mat! {
"xxx.......";
"xx........";
"x.........";
};
buf.copy_from(mat);
assert_eq!(buf, mat);
assert_eq!(buf.rows(), 3);
}
#[test]
fn test_clear_lines_1() {
let mat0 = mat! {
".........."; // clear
".........."; // clear
"x.........";
".........."; // clear
".x.xxxxxxx";
"xxxxxxxxxx"; // clear
"x.xxxxxxxx";
};
let mat1 = mat! {
"x.........";
".x.xxxxxxx";
"x.xxxxxxxx";
};
let mut buf: MatBuf<7> = MatBuf::default();
assert_eq!(buf.rows(), 0);
buf.copy_from(mat0);
assert_eq!(buf.rows(), 7);
assert_eq!(buf.clear_lines(), 1..7);
assert_eq!(buf, mat1);
assert_eq!(buf.rows(), 3);
}
#[test]
fn test_clear_lines_2() {
let mut buf = MatBuf::new();
buf.copy_from(mat! {
".x.xxxxxxx";
"xxxxxxxxxx"; // clear
"xxxxxxxxxx"; // clear
"x.xxxxxxxx";
});
let tgt = mat! {
".x.xxxxxxx";
"x.xxxxxxxx";
};
assert_eq!(buf.clear_lines(), 1..3);
assert_eq!(buf, tgt);
assert_eq!(buf.clear_lines(), 2..2);
assert_eq!(buf, tgt);
}
#[test]
fn test_clear_lines_3() {
let mut buf = MatBuf::new();
buf.copy_from(mat! {
"xxxxxxxxxx"; // clear
"xxxxxxxxxx"; // clear
"xxxxxxxxxx"; // clear
});
let tgt = Mat::EMPTY;
assert_eq!(buf.clear_lines(), 0..3);
assert_eq!(buf, tgt);
assert_eq!(buf.clear_lines(), 0..0);
}
#[test]
fn test_set() {
let mut buf: MatBuf<4> = MatBuf::default();
buf.set(0, 0); // a
buf.set(9, 3); // b
buf.set(1, 1); // c
buf.set(2, 1); // d
buf.set(3, 1); // e
assert!(buf.get(0, 0));
assert!(buf.get(9, 3));
assert!(buf.get(1, 1));
assert!(buf.get(2, 1));
assert!(buf.get(3, 1));
let mat = mat! {
".........b";
"..........";
".cde......";
"a.........";
};
assert_eq!(buf, mat);
}
#[test]
fn test_fill() {
let mut buf: MatBuf<5> = MatBuf::default();
buf.fill_row(1, 0b110111); // a
let mat = mat! {
"aaa.aa....";
"..........";
};
assert_eq!(buf, mat);
buf.fill_row(3, 0b1000000000); // b
buf.fill_row(0, u16::MAX); // c
let mat = mat! {
".........b";
"..........";
"aaa.aa....";
"cccccccccc";
};
assert_eq!(buf, mat);
}
#[test]
#[should_panic]
fn test_set_oob() {
let mut buf: MatBuf<4> = MatBuf::default();
buf.set(0, 4);
}
#[test]
#[should_panic]
fn test_fill_oob() {
let mut buf: MatBuf<4> = MatBuf::default();
buf.fill_row(4, 0b1001);
}
#[test]
fn test_shift_up() {
let mat0 = mat! {
".x........";
"xxxxx.xxxx";
"x.xxxxxxxx";
".xxxxxxxxx";
};
let mat1 = mat! {
".x........";
"xxxxx.xxxx";
"x.xxxxxxxx";
".xxxxxxxxx";
"..........";
};
let mat2 = mat! {
".x........";
"xxxxx.xxxx";
"x.xxxxxxxx";
".xxxxxxxxx";
"..........";
"..........";
};
let mut buf = MatBuf::new();
buf.copy_from(mat0);
buf.shift_up();
assert_eq!(buf, mat1);
buf.shift_up();
assert_eq!(buf, mat2);
assert_eq!(buf.clear_lines(), 0..2);
assert_eq!(buf, mat0);
buf.shift_up();
assert_eq!(buf, mat1);
assert_eq!(buf.clear_lines(), 0..1);
}
}