同平面 meaning in English

coplanar

Then , studies and improves some basic algorithms , including determining orientation of planar polygon , determining point inclusion of polygon , determining relationship of location between contours in the same plane , extracting skeleton of contour , reducing the data for contours
研究并改进了一些轮廓线相关的基础算法，包括平面多边形的方向判别、点在多边形内外位置关系判别、同平面内两个多边形间的相互位置关系判别、轮廓多边形的特征骨架计算、轮廓线数据的精简。