<< Chapter < Page Chapter >> Page >

Test for a collision of the sprite with an edge

Listing 4 tests to determine if the upper-right corner of the sprite has encountered the right edge of the game window or if the upper-left corner of thesprite has encountered the left edge of the game window. If so, the sign of stepsX is changed to cause the direction of motion of the sprite to be reversed. You will see how the change in sign causes a reversal inthe direction of motion shortly.

Test for sprite out of bounds vertically

The code in Listing 5 tests to determine if the sprite has encountered the bottom or top edges of the game window. If so, the sign is changed on stepsY to cause the sprite to reverse its vertical direction of motion.

Listing 5 . Test for sprite out of bounds vertically.

if(((spritePosition.Y + myTexture.Height)>Window.ClientBounds.Height) ||(spritePosition.Y<0)) { stepsY *= -1;//Out of bounds, reverse direction}//end if

The logic in Listing 5 is essentially the same as the logic in Listing 4 with the difference being that Listing 5 deals with vertical motion and the top and bottom edges of the game window instead of horizontal motion and the left andright edges of the game window.

Change the current position of the sprite

Listing 6 changes the current position of the sprite by adding the incremental distances, stepX and stepY , to the current horizontal and vertical coordinates of the sprite.

Listing 6 . Change the current position of the sprite.

spritePosition.X += stepsX;//move horizontal spritePosition.Y += stepsY;//move vertical

Move to the right and down

The incremental distances were initialized with positive values in Listing 2 . Adding positive incremental distance values to the current coordinate valuescauses the position of the sprite to move to the right and down.

Reverse the direction of motion

The logic in Listing 4 and Listing 5 reverses the sign on the incremental distance values when the sprite encounters a left, right, top, or bottom edge ofthe game window.

Adding a negative incremental distance value to the current horizontal coordinate of the sprite causes it to be moved to the left. Adding a negativeincremental distance value to the current vertical coordinate of the sprite causes it to be moved up the screen.

No visible movement at this time

Simply changing the current horizontal and vertical coordinates of the sprite does not produce a visible change in position. The visible change in positionhappens later in the Draw method when the game window is cleared to a constant color and the sprite is redrawn in the game window in itsnew position.

The Draw method in this program was not modified relative to the version in the earlier module titled Xna0118-The XNA Framework and the Game Class . You can view the code in the Draw method in Listing 9 near the end of the module.

The remainder of the overridden Update method

The remainder of the overridden Update method is shown in Listing 7 .

Listing 7 . The remainder of the overridden Update method.

//The following statement is always required. base.Update(gameTime);}//end Update

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Xna game studio. OpenStax CNX. Feb 28, 2014 Download for free at https://legacy.cnx.org/content/col11634/1.6
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Xna game studio' conversation and receive update notifications?