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The big picture

Sifting through all of this detail in an attempt to get a big picture view, we see that we should:

  • Override Initialize for any special initialization and for loading any non-graphic resources. For example, sound files arenon-graphic resources.
  • Override LoadContent to load all graphic resources.
  • Override UnloadContent if any graphic resources need to be unloaded.
  • Override Update to implement all of the game logic.
  • Override Draw to draw an individual frame based on values created and stored by the overridden Update method, such as the current position of a sprite.
  • Be aware that there are two different approaches to controlling the timing of the game loop, depending on whether the IsFixedTimeStep property of the Game object is true or false. The default value is true, meaning that the game will attempt to callthe Update method on a fixed time interval even if that means that the Draw method doesn't get called during some iterations of the game loop.

The constructor for the Game1 class

Listing 5 shows the declaration of two instance variables followed by the constructor for the Game1 class. One of the instance variables is used in the constructor and the other is used later in theprogram.

Listing 5 . Constructor for the Game1 class.

GraphicsDeviceManager graphics; SpriteBatch spriteBatch;public Game1() { graphics = new GraphicsDeviceManager(this);Content.RootDirectory = "Content"; }// end constructor

What is a constructor?

A constructor is a special method-like structure that is executed once and only once during the instantiation of an object.

The first statement in the Main method in Listing 2 uses the new operator to cause the constructor to be executed. When the constructor completes its task, it returns a reference to theobject just constructed. That reference is stored in the local reference variable of type Game1 named game in Listing 2 .

A new GraphicsDeviceManager object

The first statement in the constructor in Listing 5 instantiates a new object of the class GraphicsDeviceManager and stores that object's reference in the instance variable named graphics .

The documentation for GraphicsDeviceManager isn't very descriptive. Here is some of what Aaron Reed (the author of the Learning XNA books from O'Reilly) has to say on the topic.

"This (GraphicsDeviceManager) is a very important object because it provides you, as a developer, with a way to access the graphics device on your ... The GraphicsDeviceManager object has a property calledGraphicsDevice that represents the actual graphics device on your machine."

He goes on to explain how the GraphicsDevice object acts as a conduit between your XNA program and the physical graphics device on yourmachine.

Passing the this keyword as a parameter

Note the parameter that is passed to the GraphicsDeviceManager constructor in Listing 5 . The documentation tells us that the parameter must be of type Game and is the Game that the GraphicsDeviceManager should be associated with.

I don't recall having discussed the keyword this earlier in this collection of modules. According to Jesse Liberty ( Programming C# from O'Reilly)

Questions & Answers

differentiate between demand and supply giving examples
Lambiv Reply
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Lambiv
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appreciation
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In economics, a perfect market refers to a theoretical construct where all participants have perfect information, goods are homogenous, there are no barriers to entry or exit, and prices are determined solely by supply and demand. It's an idealized model used for analysis,
Ezea
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other things being equal
AI-Robot
When MP₁ becomes negative, TP start to decline. Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of lab
Kelo
Extuples Suppose that the short-run production function of certain cut-flower firm is given by: Q=4KL-0.6K2 - 0.112 • Where is quantity of cut flower produced, I is labour input and K is fixed capital input (K-5). Determine the average product of labour (APL) and marginal product of labour (MPL)
Kelo
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Shukri
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Shukri
what is monopoly mean?
Habtamu Reply
What is different between quantity demand and demand?
Shukri Reply
Quantity demanded refers to the specific amount of a good or service that consumers are willing and able to purchase at a give price and within a specific time period. Demand, on the other hand, is a broader concept that encompasses the entire relationship between price and quantity demanded
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Economic growth as an increase in the production and consumption of goods and services within an economy.but Economic development as a broader concept that encompasses not only economic growth but also social & human well being.
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Jabir
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Asui
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In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities, where neither p
Cornelius
In economics, the contract curve refers to the set of points in an Edgeworth box diagram where both parties involved in a trade cannot be made better off without making one of them worse off. It represents the Pareto efficient allocations of goods between two individuals or entities,
Cornelius
Suppose a consumer consuming two commodities X and Y has The following utility function u=X0.4 Y0.6. If the price of the X and Y are 2 and 3 respectively and income Constraint is birr 50. A,Calculate quantities of x and y which maximize utility. B,Calculate value of Lagrange multiplier. C,Calculate quantities of X and Y consumed with a given price. D,alculate optimum level of output .
Feyisa Reply
Answer
Feyisa
c
Jabir
the market for lemon has 10 potential consumers, each having an individual demand curve p=101-10Qi, where p is price in dollar's per cup and Qi is the number of cups demanded per week by the i th consumer.Find the market demand curve using algebra. Draw an individual demand curve and the market dema
Gsbwnw Reply
suppose the production function is given by ( L, K)=L¼K¾.assuming capital is fixed find APL and MPL. consider the following short run production function:Q=6L²-0.4L³ a) find the value of L that maximizes output b)find the value of L that maximizes marginal product
Abdureman
types of unemployment
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What is the difference between perfect competition and monopolistic competition?
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Source:  OpenStax, Xna game studio. OpenStax CNX. Feb 28, 2014 Download for free at https://legacy.cnx.org/content/col11634/1.6
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