getReverseYBySlope static method
斜率 = (bx - ax) / (by - ay) 逆推得到ay
Implementation
static Offset getReverseYBySlope(
double slope, Offset bOffset /*bx, by*/, double ax) {
final ret = (bOffset.dx - ax) / slope;
final ay = bOffset.dy - ret;
return Offset(ax, ay);
}