python调用dll出现精度问题解决

extern __declspec(dllexport) void LinearCompute(GoFloat64 currentX, GoFloat64 currentY, GoFloat64 targetX, GoFloat64 targetY, GoFloat64* resultX, GoFloat64* resultY);

from ctypes import *

# c_double 声明c 双精度小数变量
result_x = c_double(0)
result_y = c_double(0)

x_c = 1400.
y_c = 1450.
x_t = 1500.
y_t = 5600.

# byref 调用指针
dll.LinearCompute(c_double(x_c), c_double(y_c), c_double(x_t), c_double(y_t), byref(result_x), byref(result_y))

print(result_x.value, '  ', result_y.value)

from ctypes import *
from decimal import *

result_x = c_double(0)
result_y = c_double(0)

x_c = Decimal(1400)
y_c = Decimal(1450)

x_t = Decimal(1500)
y_t = Decimal(5600)

dll.LinearCompute(c_double(x_c), c_double(y_c), c_double(x_t), c_double(y_t), byref(result_x), byref(result_y))

print(result_x.value, '  ', result_y.value)

from decimal import *

print(Decimal(1.1) + Decimal(3.3))
print(Decimal(1.1) - Decimal(3.3))
print(Decimal(1.1) * Decimal(3.3))
print(Decimal(1.1) / Decimal(3.3))

#输出结果
'''
4.399999999999999911182158030
-2.199999999999999733546474090
3.630000000000000097699626167
0.3333333333333333781908292778
'''