'計(jì)算夾角函數(shù)
QB<~+dW
Function ff_angle(x1 As Single, y1 As Single, x2 As Single, y2 As Single, x3 As Single, y3 As Single) As Single Q35D7wo'}
cax = x2 - x1 le150;7
cay = y2 - y1 iOdk)
cbx = x2 - x3 ]
L6LB\
cby = y2 - y3 *%n(t+'q
mo_jj = cax * cbx + cay * cby s?7"iE
mo_ca = Sqr(cax * cax + cay * cay) E#VF7 9L
mo_cb = Sqr(cbx * cbx + cby * cby) |0nt u+
cos_acb = mo_jj / (mo_ca * mo_cb) ~[Z,:=z
'ff_cos = cos_acb .YlhK=d4
If cos_acb >= 1 Then giHWC%/
nn = 0 *q*$%H
ElseIf cos_acb <= -1 Then \qkb8H
nn = 3.14159265258979 V|vXxWm/
Else ]-{A"tJ
nn = Atn(-cos_acb / Sqr(-cos_acb * cos_acb + 1)) + 2 * Atn(1) D}OhmOu3
End If >9Z7l63+}
'ff_angle = nn 2v`Q;%7O
ff_angle = nn * 180 / 3.14159265258979 K)#6&\0tT
End Function