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"Called when the game determines it is time to draw a frame. Override this method with game-specific rendering code.

Note that significant changes were made to the required contents of the Game.Draw method in XNA 4.0 as compared to XNA 3.1.

Game loop timing

As you learned earlier, Update and Draw are called at different rates depending on whether IsFixedTimeStep is true or false.

If IsFixedTimeStep is false, Update and Draw will be called sequentially as often as possible.

If IsFixedTimeStep is true, Update will be called at the interval specified in TargetElapsedTime , while Draw will continue to be called as often as possible. For more information on fixed-step and variable-step game loops, see Application Model Overview ."

Because this program doesn't override the Update method, it doesn't matter how often the Draw method is called. Each time it is drawn, the sprite is drawn in the same position as shown in Figure 3 and Figure 4 .

More general information

What is a sprite?

According to the 2D Graphics Overview ,

"Sprites are 2D bitmaps drawn directly on the screen, as opposed to being drawn in 3D space. Sprites are commonly used to display information such ashealth bars, number of lives, or text such as scores. Some games, especially older games, are composed entirely of sprites."

What is a bitmap?

According to the documentation for the Bitmap class,

"A bitmap consists of the pixel data for a graphics image and its attributes. There are many standard formats for saving a bitmap to a file. GDI+ supports thefollowing file formats: BMP, GIF, EXIG, JPG, PNG and TIFF."

What is GDI+?

According to the documentation ,

"Microsoft Windows GDI+ is a class-based API for C/C++ programmers. It enables applications to use graphics and formatted text on both the videodisplay and the printer. Applications based on the Microsoft Win32 API do not access graphics hardware directly. Instead, GDI+ interacts with device driverson behalf of applications."

What about our image?

Working backwards through the above information, we started with an image file named gorightarrow.png . We manually added the file to the Content folder producing a game asset with an Asset Name of gorightarrow (see Figure 7 ).

Then we called the Load method in Listing 6 to load the contents of the file into an object of type Texture2D and saved that object's reference in the instance variable named myTexture . At that point in the process, we had converted the contents of our image fileinto a format that can be thought of as a sprite. The variable named myTexture contains a reference to our sprite.

Beginning of the Game.Draw method

The Game.Draw method begins in Listing 7 . I am referring to the method here as Game.Draw to distinguish it from the method named SpriteBatch.Draw , which we will encounter shortly.

Listing 7 . Beginning of the Game.Draw method.

protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.CornflowerBlue);

GameTime information

Each time the Game.Draw method is executed, the incoming parameter contains time information encapsulated in an object of type GameTime . According to the documentation, the GameTime object provides a

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
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da
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Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
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Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
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Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
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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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