使用浮点数进行最精确的线交叉纵坐标计算？

I'm computing the ordinate y of a point on a line at a given abscissa x. The line is defined by its two end points coordinates (x0,y0)(x1,y1). End points coordinates are floats and the computation must be done in float precision for use in GPU.I'm computing the ordinate y of a point on a li