From cf921b2e647136dc34568e0fff78b67c14c8e2fa Mon Sep 17 00:00:00 2001 From: tslil clingman Date: Sun, 24 Jan 2021 19:06:49 -0500 Subject: Working on action lists to refactor --- include/action_list.c | 262 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 262 insertions(+) create mode 100644 include/action_list.c (limited to 'include/action_list.c') diff --git a/include/action_list.c b/include/action_list.c new file mode 100644 index 0000000..198cd08 --- /dev/null +++ b/include/action_list.c @@ -0,0 +1,262 @@ +#include "action_list.h" + +// =================================================================== +// Helper method declarations +// =================================================================== + +static inline action_list_t * +action_list_prepend(action_list_t *list, const enum A_TYPE type, + const uint8_t loc, const uint8_t data0, + const uint8_t data1); + +static inline void previous_ply(void); + +static inline void +push_stones(const int8_t location, const uint8_t count, + const uint8_t new_colours, + const enum STONE_VARIANT top_stone); + +// =================================================================== +// Exported method implementations +// =================================================================== + +void action_list_free(action_list_t *list) { + action_list_t *n = NULL; + while (list) { + n = list->next; + free(list); + list = n; + } +} + +// Keep track of move offsets +static int8_t deltas[4]; + +void action_list_init(const uint8_t new_board_size) { + board_size = new_board_size; + deltas[0] = +board_size; + deltas[1] = -board_size; + deltas[2] = -1; + deltas[3] = +1; +} + +action_list_t *action_list_generate(void) { + + action_list_t *result = NULL; + + const uint8_t black = (ply & 1), + material = (black) ? black_count : white_count, + flat = material & 127, + cap = (ply > 2 && (material & 128)), + standing = (ply > 2 && (material & 127)); + + // Step across the board + for (uint8_t row = 0; row < board_size; row++) { + for (uint8_t col = 0; col < board_size; col++) { + // We'll need these at various points, the location of this + // square and the maximum number of stones we could pick up + const uint8_t loc = THE_COORDS(col, row); + const uint8_t count = (COUNT_AT(loc) > board_size) ? board_size : COUNT_AT(loc); + // Only try moves after CPS + if (count && ((colours[loc] & 1) == current_colour) && ply>2) { + // There are stones, let's try moving them + + // Pre-compute end-stops + uint8_t end_stops[4][2]; // (end, not_crush) + + // These are upper bounds, not counting walls and such. UP DOWN LEFT RIGHT + end_stops[0][0] = (board_size - row - 1 > count) ? count : board_size - row - 1; + end_stops[1][0] = (row > count) ? count : row; + end_stops[2][0] = (col > count) ? count : col; + end_stops[3][0] = (board_size - col - 1 > count) ? count : board_size - col - 1; + + // Now we check for caps and walls + const uint8_t cap_top = STONE_AT(loc) == STONE_CAPSTONE; + for (uint8_t d = 0; d < board_size-1; d++){ + end_stops[d][1] = 1; + const uint8_t stop = end_stops[d][0]; + end_stops[d][0] = 0; + for (uint8_t k = 1; k <= stop; k++) { + const uint8_t stone = STONE_AT(loc+k*deltas[d]); + if (stone == STONE_STANDING) { + if (cap_top) { + end_stops[d][1] = 0; + end_stops[d][0]++; + } + break; + } else if (stone == STONE_CAPSTONE) { + break; + } + end_stops[d][0]++; + } + } + /* + * For each direction, generate all possible ordered integer + * partitions of 1 ≤ num ≤ count whose number of summands is + * exactly 1 ≤ summands ≤ min(end_stops[dir], num) -- we write + * summands as steps + */ + for (enum MOVE_DIRECTION dir = M_UP; dir <= M_RIGHT; dir++) { + uint8_t gaps, t, idx, mask; + for (uint8_t num = 1; num <= count; num++) { + for (uint8_t steps = 1; + steps <= end_stops[dir][0] && steps <= num; + steps++) { + // TODO: Generalise to board_size! + gaps = 0x07 >> (board_size-steps-1); + // 0b0000[0111] because 4-1=3 and 5-1=4 + do { + /* + * We skip the partition if it calls for multiple stones at + * the end with a crush. + */ + const uint8_t last_drop_check = + (num > 1) ? (gaps & 1<<(num - 2)) : 1; + if (end_stops[dir][1] || last_drop_check) + result = action_list_prepend(result, A_MOVE, loc, (dir<<4) | num, gaps); + /* + * With thanks to + * https://graphics.stanford.edu/~seander/bithacks.html#NextBitPermutation + * we have the following magic to generate the next + * permutation of steps-many set bits + */ + t = (gaps | (gaps - 1)); + gaps = (t + 1) | (((~t & -~t) - 1) >> (__builtin_ctz(gaps) + 1)); + } while (gaps && (gaps + 1 <= (1<<(num-1)))); + } + } + } + } else if (material && count == 0) { + // Empty square, generate placements + if (flat) { + result = action_list_prepend(result, A_PLACE, loc, STONE_FLAT, 0); + if (standing) + result = action_list_prepend(result, A_PLACE, loc, STONE_STANDING, 0); + } + if (cap) + result = action_list_prepend(result, A_PLACE, loc, STONE_CAPSTONE, 0); + } + } + } + return result; +} + +void action_take(action_list_t *action) { + const uint8_t loc = action->loc; + if (action->type == A_PLACE) { + const uint8_t black = (ply&1); + switch (action->data0) { + STONE_FLAT: { + if (black) black_count--; + else white_count--; + colours[loc] = current_colour; + celldat[loc] = NUM_INC | STONE_FLAT; + break; + } + STONE_STANDING: { + if (black) black_count--; + else white_count--; + colours[loc] = current_colour; + celldat[loc] = NUM_INC | STONE_STANDING; + break; + } + default: { + if (black) black_count &= 127; + else white_count &= 127; + colours[loc] = current_colour; + celldat[loc] = NUM_INC | STONE_CAPSTONE; + break; + } + } + } else { + uint8_t drops[board_size]; // we only ever need board_size-1 in + // drops actually, the last spot is to + // skip a bounds check at (*) later + + const uint8_t gaps = action->data0, + num = action->data1 & 0x0F, // unpack + dir = action->data1 & 0xF0; + uint8_t steps, mask; + // Translate to a drop sequence + drops[0] = 1; mask = 1; steps = 0; + for (uint8_t d = 0; d + 1 < num; d++) { + if (gaps & mask) { + steps++; + drops[steps] = 1; // (*) no bounds check + } else { + drops[steps] += 1; + } + mask <<= 1; + } + // Push stones onto subesquent stack + uint8_t j = num; + for (uint8_t k = 0; k <= steps; k++) { + j -= drops[k]; + push_stones(loc+(k+1)*deltas[dir], + drops[k], + (colours[loc] >> j) & (0xFFFF >> (0x10 - drops[k])), + (k == steps - 1) ? STONE_AT(loc) : STONE_FLAT); + } + // Drop them from the source + colours[loc] >>= num; + const uint8_t dec_count = celldat[loc] - (num << NUM_SHIFT); + celldat[loc] = dec_count & NUM_MASK; + } + // Always + next_ply(); +}; + +void action_undo(action_list_t *action) { + const uint8_t loc = action->loc; + if (action->type == A_PLACE) { + const uint8_t black = (ply&1); + celldat[loc] = 0; + if (action->data0 == STONE_CAPSTONE) { + if (black) black_count |= 128; + else white_count |= 128; + } else { + if (black) black_count++; + else white_count++; + } + } else { + // TODO ??? + } + previous_ply(); +}; + +// =================================================================== +// Helper method implementations +// =================================================================== + +static inline action_list_t * +action_list_prepend(action_list_t *list, const enum A_TYPE type, + const uint8_t loc, const uint8_t data0, + const uint8_t data1) { + action_list_t *new = malloc(sizeof(action_list_t)); + // TODO: trap errno + new->loc = loc; + new->next = list; + new->data0 = data0; + new->data1 = data1; + return new; +} + +static inline void +previous_ply(void) { + if (ply>0) ply--; + if (ply == 1) { + current_colour = C_WHITE; + } else { + if (current_colour == C_BLACK) current_colour = C_WHITE; + else current_colour = C_BLACK; + } +} + +static inline void +push_stones(const int8_t location, const uint8_t count, + const uint8_t new_colours, + const enum STONE_VARIANT top_stone) { + colours[location] = (colours[location] << count) | new_colours; + celldat[location] = top_stone + | ((celldat[location] + ((count << NUM_SHIFT))) & NUM_MASK); +} -- cgit v1.2.3