Objective C - Creating Angles From Current Time

I'm trying to write code to draw a clock on the screen of an iOS device. I need to get the angle of a line (seconds, minutes, hours hands of clock) from the current time. My code accurately grabs the time, but for some reason, all of the angles I receive end up being the same (no matter what time it is).

If it helps, the angle I am constantly receiving is:

-1.5707963267948966

Here is the code I use to get the angles:

secondsTheta = ((seconds/60) * (2 * M_PI)) - (M_PI / 2);
minutesTheta = ((minutes/60) + (seconds/3600)) * (2 * M_PI) - (M_PI / 2);
hoursTheta = ((hours/12) + (minutes/720) + (seconds/43200)) * (2 * M_PI) - (M_PI / 2);

My thought is that something is funky with M_PI, but I don't know what would be...but as I said, the seconds, minutes, and hours variables are correct. They are declared in my header file as ints,开发者_开发问答 and I know that [NSDateComponents seconds](etc) returns an NSInteger, but I don't think that should matter for this basic math.

Since the seconds, minutes, and hours variables are declared as ints the division will not give you the correct values. An int divided by another init will result in an int, what is needed for the result is a float. In order to have the compiler use floating point arithmetic it is necessary that one of the operands be a floating point format number (float).

Example: 10 seconds divided by 60 (10/60) will use integer math and result in 0.
Example: 10.0 seconds divided by 60 (10/60) will use floating point math and result in 0.1.66666667.

Example:

secondsTheta = ((seconds/60.0) * (2 * M_PI)) - (M_PI / 2);

or

secondsTheta = (((float)seconds/60) * (2 * M_PI)) - (M_PI / 2);

Your seconds, minutes and hours are ints. Dividing ints by ints does integer arithmetic and truncates the values, so

seconds/60

will always give you 0. Objective C inherits this behavior from C and this is fairly common behavior among programming languages.