diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/action_list.c | 124 |
1 files changed, 59 insertions, 65 deletions
diff --git a/include/action_list.c b/include/action_list.c index 9e987bc..fd45afd 100644 --- a/include/action_list.c +++ b/include/action_list.c @@ -177,44 +177,43 @@ void action_take(action_list_t *action) { dir = action->data1 >> 4; int8_t delta = deltas[dir]; - // Unfortunately num == 1 is a special case - if (num > 1) { - uint8_t steps, mask = 1<<(num-2), gaps_prime = gaps; - // Use the Kernighan method to count the set bits - for (steps = 1; gaps_prime; steps++) gaps_prime &= gaps_prime - 1; - // then from the destination to the source - for (uint8_t d = 0; d < num; d++) { - // transfer the top colour - colours[loc+steps*delta] <<= 1; - colours[loc+steps*delta] |= colours[loc] & 1; - colours[loc] >>= 1; - // increase the stone count, copy top stone if appropriate - celldat[loc+steps*delta] += NUM_INC; - if (d==0) { - celldat[loc+steps*delta] &= NUM_MASK; - celldat[loc+steps*delta] |= STONE_AT(loc); - celldat[loc] &= NUM_MASK; - celldat[loc] |= STONE_FLAT; // this should be optimised out :) - } - // decrement the count, the top colour - celldat[loc] -= NUM_INC; + // Use the Kernighan method to count the set bits + uint8_t steps = 1; + for (uint8_t _gaps = gaps; _gaps > 0; steps++) _gaps &= _gaps - 1; - if (gaps & mask) steps--; - mask >>= 1; - } - } else { - // Oh well - colours[loc+delta] <<= 1; - colours[loc+delta] |= colours[loc] & 1; - celldat[loc+delta] += NUM_INC; - celldat[loc+delta] &= NUM_MASK; - celldat[loc+delta] |= STONE_AT(loc); + // Move top stone type to destination + celldat[loc+steps*delta] &= NUM_MASK; // necessary for crushing + celldat[loc+steps*delta] |= STONE_AT(loc); + celldat[loc] &= NUM_MASK; + celldat[loc] |= STONE_FLAT; // should be optimised out - colours[loc] >>= 1; - celldat[loc] &= NUM_MASK; - celldat[loc] |= STONE_FLAT; // this should be optimised out :) - celldat[loc] -= NUM_INC; + uint8_t gap_bit = 0, total = 0; + // num == 1 is a special case + if (num > 1) { + gap_bit = 1 << (num - 2); + total = 1; + } + // move stuff starting at destination + for (uint8_t d = 0; d + 1 < num; d++, total++, gap_bit >>= 1) { + // We took a step, move everything over so far + if (gaps & gap_bit) { + colours[loc+steps*delta] <<= total; + colours[loc+steps*delta] |= colours[loc] & ((1 << total) - 1); + colours[loc] >>= total; + celldat[loc+steps*delta] += total*NUM_INC; + celldat[loc] -= total*NUM_INC; + // Reset for next step + total = 0; + steps--; + } } + total++; + // Move what remains (steps == 1 here always, so we simplify) + colours[loc+delta] <<= total; + colours[loc+delta] |= colours[loc] & ((1 << total) - 1); + colours[loc] >>= total; + celldat[loc+delta] += total*NUM_INC; + celldat[loc] -= total*NUM_INC; } // Next ply ply++; @@ -250,41 +249,36 @@ void action_undo(action_list_t *action) { } else { // See action_take for comments, this is the time reversal const uint8_t gaps = action->data0, - num = action->data1 & 0x0F, // unpack + num = action->data1 & 0x0F, dir = action->data1 >> 4; const int8_t delta = deltas[dir]; - uint8_t steps = 1, mask = 1; - if (num > 1) { - for (uint8_t d = 0; d < num; d++) { - colours[loc] <<= 1; - colours[loc] |= colours[loc+steps*delta] & 1; - colours[loc+steps*delta] >>= 1; - - celldat[loc] += NUM_INC; - if (d + 1 == num) { - celldat[loc] &= NUM_MASK; - celldat[loc] |= STONE_AT(loc+steps*delta); - celldat[loc+steps*delta] &= NUM_MASK; - celldat[loc+steps*delta] |= STONE_FLAT; - } - celldat[loc+steps*delta] -= NUM_INC; - - if (gaps & mask) steps++; - mask <<= 1; + uint8_t gap_bit = 1, total = (num > 1) ? 1 : 0, steps = 1; + for (uint8_t d = 0; d + 1 < num; d++, total++, gap_bit <<= 1) { + // We took a step, move everything over so far + if (gaps & gap_bit) { + colours[loc] <<= total; + colours[loc] |= colours[loc+steps*delta] & ((1 << total) - 1); + colours[loc+steps*delta] >>= total; + celldat[loc] += total*NUM_INC; + celldat[loc+steps*delta] -= total*NUM_INC; + // Reset for next step + total = 0; + steps++; } - } else { - colours[loc] <<= 1; - colours[loc] |= colours[loc+delta] & 1; - celldat[loc] += NUM_INC; - celldat[loc] &= NUM_MASK; - celldat[loc] |= STONE_AT(loc+delta); - - colours[loc+delta] >>= 1; - celldat[loc+delta] &= NUM_MASK; - celldat[loc+delta] |= STONE_FLAT; - celldat[loc+delta] -= NUM_INC; } + total++; + // Move what remains + colours[loc] <<= total; + colours[loc] |= colours[loc+steps*delta] & ((1 << total) - 1); + colours[loc+steps*delta] >>= total; + // celldat[loc] &= NUM_MASK; // not necessary, assumed STONE_FLAT + celldat[loc] += total*NUM_INC; + celldat[loc+steps*delta] -= total*NUM_INC; + // Top stone type + celldat[loc] |= STONE_AT(loc+steps*delta); + celldat[loc+steps*delta] &= NUM_MASK; + celldat[loc+steps*delta] |= STONE_STANDING; // optimised } } |