如何使三角代码更有效

Question

我需要帮助才能使我的代码更有效率,并将其清理一下.

由于此所示的图像,X和Y可以围绕整个屏幕任何位置,我想找到的角度吨.有没有办法可以减少这里的行数？

注意:原点位于左上角,向右/向下移动正向移动

o := MiddleOfScreenX - x;
a := MiddleOfScreenY - y;

t := Abs(Degrees(ArcTan(o / a)));

if(x > MiddleOfScreenX)then
  begin
    if(y > MiddleOfScreenY)then
      t := 180 + t
    else
      t := 360 - t;
  end
else
  if(y > MiddleOfScreenY)then
    t := 180 - t;

代码是pascal,但是其他语言中使用类似语法或c ++或java的答案也很好.

:= sets the variable to that value
Abs() result is the absolute of that value (removes negatives)
Degrees() converts from radians to degrees
ArcTan() returns the inverse tan

Answer 1

有关C函数,请参阅http://www.cplusplus.com/reference/clibrary/cmath/atan2/.

atan2需要2个独立的参数,因此可以确定象限.

pascal可能有arctan2见http://www.freepascal.org/docs-html/rtl/math/arctan2.html或http://www.gnu-pascal.de/gpc/Run-Time-System.html

o := MiddleOfScreenX - x;
a := MiddleOfScreenY - y;

t := Degrees(ArcTan2(o, a));