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The Move method

This method causes the sprite to move in the direction of the direction vector if the elapsed time since the last move exceeds the elapsed time targetbased on the specified speed.

The Move method begins in Listing 6 .

Listing 6 . Beginning of the Move method.

public void Move(GameTime gameTime) { //Accumulate elapsed time since the last move.elapsedTime += gameTime.ElapsedGameTime.Milliseconds;if(elapsedTime>elapsedTimeTarget){ //It's time to make a move. Set the elapsed// time to a value that will attempt to produce // the specified speed on the average.elapsedTime -= elapsedTimeTarget;

The sprite doesn't necessarily move every time the Move method is called. Instead, it uses the incoming parameter to compute theelapsed time since the last time that it actually moved.

To move or not to move

If that elapsed time exceeds the target that is based on the specified speed in moves/millisecond , then it reduces the elapsed time value by the target value and makes an adjustment to the position value. Changing the position value will cause the sprite to move in the game window the next time it is drawn.

Keeping up on the average

By reducing the elapsed time by the target time instead of setting it to zero, the sprite attempts to achieve the target speed on the average . For example, assume that for some reason, there is a long delay between calls tothe Move method and the elapsed time value is two or three times greater than the target time. This means that the sprite has gotten behind and is not in the position thatit should be in. In that case, the sprite will move every time the Move method is called for several successive calls to the Move method. (In other words, the sprite will experience a short spurt in speed.)This should cause it to catch up and be in the correct position once it does catch up.

Of course, if the elapsed time between calls to the Move method is greater than the target time over the long term, the sprite will neverbe able to keep up.

Code in the body of the if statement

If the conditional expression for the if statement in Listing 6 returns true, then the last statement in Listing 6 along with the remainder of the body of the if statement will be executed. Otherwise, that statement and the remaining body of the if statement will be skipped.

The remaining body of the if statement begins in Listing 7 .

Add the direction vector to the position vector

One of the advantages of treating the position and the direction as 2D vectors based on the structure named Vector2 is that the Vector2 structure provides various methods that can be used to manipulate vectors.

The code in Listing 7 calls the Add method of the Vector2 class to add the direction vector to the position vector returning the sum of the two vectors. The sum is saved as the new positionvector.

Listing 7 . Add the direction vector to the position vector.

position = Vector2.Add(position,direction);

In case you are unfamiliar with the addition of 2D vectors, if you add a pair of 2D vectors, the X component of the sum is the sum of the X components and theY component of the sum is the sum of the Y components.

Questions & Answers

it is the relatively stable flow of income
Chidubem Reply
what is circular flow of income
Divine Reply
branches of macroeconomics
SHEDRACK Reply
what is Flexible exchang rate?
poudel Reply
is gdp a reliable measurement of wealth
Atega Reply
introduction to econometrics
Husseini Reply
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Tom
Why is unemployment rate never zero at full employment?
Priyanka Reply
bcoz of existence of frictional unemployment in our economy.
Umashankar
what is flexible exchang rate?
poudel
due to existence of the pple with disabilities
Abdulraufu
the demand of a good rises, causing the demand for another good to fall
Rushawn Reply
is it possible to leave every good at the same level
Joseph
I don't think so. because check it, if the demand for chicken increases, people will no longer consume fish like they used to causing a fall in the demand for fish
Anuolu
is not really possible to let the value of a goods to be same at the same time.....
Salome
Suppose the inflation rate is 6%, does it mean that all the goods you purchase will cost 6% more than previous year? Provide with reasoning.
Geetha Reply
Not necessarily. To measure the inflation rate economists normally use an averaged price index of a basket of certain goods. So if you purchase goods included in the basket, you will notice that you pay 6% more, otherwise not necessarily.
Waeth
discus major problems of macroeconomics
Alii Reply
what is the problem of macroeconomics
Yoal
Economic growth Stable prices and low unemployment
Ephraim
explain inflationcause and itis degre
Miresa Reply
what is inflation
Getu
increase in general price levels
WEETO
Good day How do I calculate this question: C= 100+5yd G= 2000 T= 2000 I(planned)=200. Suppose the actual output is 3000. What is the level of planned expenditures at this level of output?
Chisomo Reply
how to calculate actual output?
Chisomo
how to calculate the equilibrium income
Beshir
Criteria for determining money supply
Thapase Reply
who we can define macroeconomics in one line
Muhammad
Aggregate demand
Mohammed
C=k100 +9y and i=k50.calculate the equilibrium level of output
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money as unit of account means what?
Kalombe
A unit of account is something that can be used to value goods and services and make calculations
Jim
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Muhammad
I want to know how can we define macroeconomics in one line
Muhammad
it must be .9 or 0.9 no Mpc is greater than 1 Y=100+.9Y+50 Y-.9Y=150 0.1Y/0.1=150/0.1 Y=1500
Kalombe
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Kalombe
hi can someone help me on this question If a negative shocks shifts the IS curve to the left, what type of policy do you suggest so as to stabilize the level of output? discuss your answer using appropriate graph.
Galge Reply
if interest rate is increased this will will reduce the level of income shifting the curve to the left ◀️
Kalombe
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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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