问题是，当你执行乘法（或其他算术运算）你正在使用一个文字，如0.15。默认情况下，这个值将被编译器视为一个双精度值，所以当乘上一个浮点数时，会导致较大的双精度结果。为了解决这个问题，你需要将文字标记为.15f，以便将它们视为浮点文字。

The problem is that when you perform your multiplication (or other arithmetic operation) you are working with a literal such as 0.15. This value by default will be treated as a double by the compiler and so when multiplied against a float it results in the larger double result. To get around this you need to mark the literals as .15f so that they are treated as float literals.