角度计算
E偏N-右-S E偏N-左-S E偏S-右-S E偏S-左-S

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N偏E-右-C N偏E-左-C N偏W-右-C N偏W-左-C

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S偏E-右-C S偏E-左-C S偏W-右-C S偏W-左-C

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W偏N-右-S W偏N-左-S W偏S-右-S W偏S-左-S