callKb method

dynamic callKb(
  1. dynamic x1,
  2. dynamic y1,
  3. dynamic x2,
  4. dynamic y2,
  5. dynamic draw,
)

Implementation

callKb(x1, y1, x2, y2, draw) {
  draw['k'] = (y2 - y1) / (x2 - x1);
  draw['b'] = y1 - draw['k'] * x1;
  // print(
  //     '计算kb x1 $x1 y1 $y1 x2 $x2 y2 $y2  k= ${(y2 - y1) / (x2 - x1)} b=${y1 - draw['k'] * x1}  $draw');
  //直线的话 无斜率 这里写死1 在计算y坐标时当做一个标记
  if (!draw['k'].isFinite) {
    //无限数值
    draw['k'] = 1;
    draw['b'] = 0;
  }
}