void capture_from_motion(const Step& step_taken, GameState *gs)
{
const uint8_t color = step_taken.get_color();
Board capturable =
gs->get_color_board(color) & ~adj_friendly(*gs, color) & Board::capture_squares();
if (capturable.is_empty())
return;
uint8_t capture_idx = capturable.idx_and_reset();
assert(capturable.is_empty());
int8_t c, p;
gs->color_and_piece_at(capture_idx, &c, &p);
gs->remove_piece_at(c, p, capture_idx);
}
bool detect_capture_from_motion(const GameState& gs, const Step& step_taken, Step *capture)
{
if (!possible_capture_from_motion(gs, step_taken))
return false;
const unsigned char color = step_taken.get_color();
const Board capturable = gs.get_color_board(color) & ~adj_friendly(gs, color);
const char capture_idxs[] = {18, 21, 42, 45};
for(int i=0; i < 4; ++i) {
if (capturable.contains(capture_idxs[i])) {
// we have a capture!
int8_t c, p;
gs.color_and_piece_at(capture_idxs[i], &c, &p);
// assert(c == color);
*capture = Step(color, p, capture_idxs[i], CAPTURE);
return true;
}
}
return false;
}
bool GameState::move_piece(const Step &s)
{
assert(s.is_motion());
const uint8_t c = s.get_color(), p = s.get_piece(), pos = s.get_position(), finish = s.get_finish();
return move_piece(c, p, pos, finish);
}
bool GameState::add_piece_at(const Step &s)
{
return add_piece_at(s.get_color(), s.get_piece(), s.get_position());
}