Creating a Game World - Learning C# by Programming Games - page 48

of several integer values, such as the number of seconds passed, the number of mil-
liseconds passed, and so on. For example, this expression gives us the milliseconds
fraction of the total time passed since the game has started:

gameTime.TotalGameTime.Milliseconds

For example, if 13 minutes, 12 seconds, and 345 milliseconds have passed since
the game has started, the result of this expression will be 345. In this example,
TotalGameTime is a property of the type/class GameTime and this gives us a variable
of type TimeSpan , which in turn has a property called MilliSeconds . By the way, there
is also a way to obtain the total passed game time in milliseconds, which would be
792,345 milliseconds ( ( 13 ∗ 60 + 12 ) ∗ 1000 + 345). You can get this value with the

following expression:

gameTime.TotalGameTime.TotalMilliseconds

Since the parameter gameTime is of type GameTime , we can make use of all these
properties to obtain information contained within the variable. Once we have this
information, we can store it in another variable (or do something else with it):

int red = gameTime.TotalGameTime.Milliseconds;

We are now going to use the variable red to create yet another variable, but one of
the type Color . We will store a new color in this variable. Once we have done this,
we can pass it as a parameter to the method Clear of the GraphicsDevice class. Let us
first declare this variable:

Color background;

We name this variable background and the type of background is Color . Now that we
have declared this variable, we can give it some value. Because the Color type is quite
a complicated type, we cannot simply assign it a number like we did with the integer
type. A Color variable needs to be constructed from three different numbers: the
R (red), G (green), and B (blue) values. Constructing a value of a more complicated
type is done with the keyword new and the name of the type written after it. We
can then pass the information needed to construct the value as parameters between
parentheses. For example, we can create the color black and store it in a variable as
follows:

Color blackColor = new Color(0, 0, 0);

The three parameters given to construct this variable are separated by a comma
and they are written between parentheses. After creating the blackColor variable, the
memory will look like this: