Make Swap Hands use PROGMEM (qmk#12284)

This converts the array that the Swap Hands feature uses to use PROGMEM, and to read from that array, as such. Since this array never changes at runtime, there is no reason to keep it in memory. Especially for AVR boards, as memory is a precious resource.
BorisTestov · May 10, 2021 · cc004f5 · cc004f5
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Showing 4 changed files with 5 additions and 4 deletions.
diff --git a/docs/feature_swap_hands.md b/docs/feature_swap_hands.md
@@ -7,7 +7,7 @@ The swap-hands action allows support for one-handed typing without requiring a s
 The configuration table is a simple 2-dimensional array to map from column/row to new column/row. Example `hand_swap_config` for Planck:
 
 ```C
-const keypos_t hand_swap_config[MATRIX_ROWS][MATRIX_COLS] = {
+const keypos_t PROGMEM hand_swap_config[MATRIX_ROWS][MATRIX_COLS] = {
   {{11, 0}, {10, 0}, {9, 0}, {8, 0}, {7, 0}, {6, 0}, {5, 0}, {4, 0}, {3, 0}, {2, 0}, {1, 0}, {0, 0}},
   {{11, 1}, {10, 1}, {9, 1}, {8, 1}, {7, 1}, {6, 1}, {5, 1}, {4, 1}, {3, 1}, {2, 1}, {1, 1}, {0, 1}},
   {{11, 2}, {10, 2}, {9, 2}, {8, 2}, {7, 2}, {6, 2}, {5, 2}, {4, 2}, {3, 2}, {2, 2}, {1, 2}, {0, 2}},

diff --git a/docs/ja/feature_swap_hands.md b/docs/ja/feature_swap_hands.md
@@ -12,7 +12,7 @@
 設定テーブルは列/行から新しい列/行にマップするための単純な2次元配列です。Planck の `hand_swap_config` の例:
 
 ```C
-const keypos_t hand_swap_config[MATRIX_ROWS][MATRIX_COLS] = {
+const keypos_t PROGMEM hand_swap_config[MATRIX_ROWS][MATRIX_COLS] = {
   {{11, 0}, {10, 0}, {9, 0}, {8, 0}, {7, 0}, {6, 0}, {5, 0}, {4, 0}, {3, 0}, {2, 0}, {1, 0}, {0, 0}},
   {{11, 1}, {10, 1}, {9, 1}, {8, 1}, {7, 1}, {6, 1}, {5, 1}, {4, 1}, {3, 1}, {2, 1}, {1, 1}, {0, 1}},
   {{11, 2}, {10, 2}, {9, 2}, {8, 2}, {7, 2}, {6, 2}, {5, 2}, {4, 2}, {3, 2}, {2, 2}, {1, 2}, {0, 2}},

diff --git a/tmk_core/common/action.c b/tmk_core/common/action.c
@@ -133,7 +133,8 @@ void process_hand_swap(keyevent_t *event) {
     bool             do_swap = event->pressed ? swap_hands : swap_state[pos.row] & (col_bit);
 
     if (do_swap) {
-        event->key = hand_swap_config[pos.row][pos.col];
+        event->key.row = pgm_read_byte(&hand_swap_config[pos.row][pos.col].row);
+        event->key.col = pgm_read_byte(&hand_swap_config[pos.row][pos.col].col);
         swap_state[pos.row] |= col_bit;
     } else {
         swap_state[pos.row] &= ~(col_bit);

diff --git a/tmk_core/common/action.h b/tmk_core/common/action.h
@@ -78,7 +78,7 @@ extern bool disable_action_cache;
 /* Code for handling one-handed key modifiers. */
 #ifdef SWAP_HANDS_ENABLE
 extern bool           swap_hands;
-extern const keypos_t hand_swap_config[MATRIX_ROWS][MATRIX_COLS];
+extern const keypos_t PROGMEM hand_swap_config[MATRIX_ROWS][MATRIX_COLS];
 #    if (MATRIX_COLS <= 8)
 typedef uint8_t swap_state_row_t;
 #    elif (MATRIX_COLS <= 16)