1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177
#![forbid(unsafe_code)] use crate::ops::*; use crate::toodee::*; use crate::view::*; /// Provides implementations for translate (also known as scroll) operations, and other internal data /// movement operations such as flipping. pub trait TranslateOps<T> : TooDeeOpsMut<T> { /// Translate (or scroll) the area by moving `col_mid` to the first column and /// `row_mid` to the first row. /// /// All data is preserved by wrapping at the array edges, so `fill()` could be used /// to clear old data if required. /// /// # Examples /// /// ``` /// use toodee::{TooDee,TooDeeOps,TranslateOps}; /// let v = vec![42u32; 15]; /// let mut toodee : TooDee<u32> = TooDee::from_vec(5, 3, v); /// toodee[1][1] = 1; /// // move (1, 1) to (0, 0) /// toodee.translate_with_wrap((1, 1)); /// assert_eq!(toodee[0][0], 1); /// assert_eq!(toodee[1][1], 42); /// ``` /// /// ``` /// use toodee::{TooDee,TooDeeOps,TranslateOps}; /// let v = vec![42u32; 15]; /// let mut toodee : TooDee<u32> = TooDee::from_vec(5, 3, v); /// // set (4, 2) to 1 /// toodee[2][4] = 1; /// // move (4, 2) to (0, 0) /// toodee.translate_with_wrap((4, 2)); /// assert_eq!(toodee[0][0], 1); /// assert_eq!(toodee[2][4], 42); /// ``` fn translate_with_wrap(&mut self, mid: Coordinate) { let (mut col_mid, mut row_mid) = mid; let num_cols = self.num_cols(); let num_rows = self.num_rows(); assert!(col_mid <= num_cols); assert!(row_mid <= num_rows); if col_mid == num_cols { col_mid = 0; } if row_mid == num_rows { row_mid = 0; } if row_mid == 0 { if col_mid != 0 { // apply column rotation only for r in self.rows_mut() { r.rotate_left(col_mid); } } return; } if row_mid != 0 { let row_adj_abs = num_rows - row_mid; // This row swapping algorithm is pretty cool. I came up with it independently, // but it turns out that the concept is fairly well known. See // `core::slice::ptr_rotate()` for various strategies. let mut swap_count = 0; let mut base_row = 0; // TODO: tidy up and possibly create a simpler loop if col_mid == 0 while swap_count < num_rows { let mut mid = col_mid; let mut next_row = base_row + row_adj_abs; loop { if next_row >= num_rows { next_row -= num_rows; } swap_count += 1; if base_row == next_row { // finish up with a rotate if mid > 0 { self[base_row].rotate_left(mid); } break; } else { // The following logic performs a rotate while swapping, and // is more efficient than doing a swap then rotate. let (base_ref, next_ref) = self.row_pair_mut(base_row, next_row); if mid > 0 { base_ref[..mid].swap_with_slice(&mut next_ref[num_cols-mid..num_cols]); } if mid < num_cols { base_ref[mid..num_cols].swap_with_slice(&mut next_ref[..num_cols-mid]); } mid += col_mid; if mid >= num_cols { mid -= num_cols; } } next_row += row_adj_abs; } // TODO: We now know that we'll loop a further N = (num_rows / swap_count - 1) times. // This means we could start swapping in chunks of N, i.e., // ([base_row..base_row+N] -> [base_row+row_adj_abs..base_row+row_adj_abs+N], // which should more cache-friendly. if swap_count >= num_rows { break; } base_row += 1; // advance the base } } } /// Flips (or mirrors) the rows. /// /// # Examples /// /// ``` /// use toodee::{TooDee,TooDeeOps,TranslateOps}; /// let v = vec![42u32; 15]; /// let mut toodee : TooDee<u32> = TooDee::from_vec(5, 3, v); /// toodee[0][1] = 1; /// toodee.flip_rows(); /// assert_eq!(toodee[2][1], 1); /// ``` fn flip_rows(&mut self) { let mut iter = self.rows_mut(); while let (Some(r1), Some(r2)) = (iter.next(), iter.next_back()) { r1.swap_with_slice(r2); } } /// Flips (or mirrors) the columns. /// /// ``` /// use toodee::{TooDee,TooDeeOps,TranslateOps}; /// let v = vec![42u32; 15]; /// let mut toodee : TooDee<u32> = TooDee::from_vec(5, 3, v); /// toodee[1][1] = 1; /// toodee.flip_cols(); /// assert_eq!(toodee[1][3], 1); /// ``` fn flip_cols(&mut self) { for r in self.rows_mut() { r.reverse(); } } } impl<T> TranslateOps<T> for TooDeeViewMut<'_, T> {} impl<T> TranslateOps<T> for TooDee<T> {}