getYFromPrice method

double getYFromPrice(
  1. double screenY
)

根据屏幕Y坐标计算对应的价格

Implementation

double getYFromPrice(double screenY) {
  // 反向计算：price = maxValue - (screenY - chartRect.top) / scaleY
  return maxValue - (screenY - chartRect.top) / scaleY;
}