private var enemyVector:Vector.<enemy_mc> use .net framework code 128 code set c implement toembed code128 for .net

iPhone Notice how the base type Code 128C for .NET is declared using a dot (.) then writing the class name between angle brackets (< and >).

Then you would construct it declaring base type again, this way:. enemyVector=new Vector.& lt;enemy_mc>();. Now the question is: whe Code 128 Code Set B for .NET n should you use a Vector rather than an Array You should use a Vector every time you are dealing with collections of data of the same type, as Vector management has been proved to be faster than Array management. Again, the increased performance in this game would be unnoticeable since the data we manage isn"t that big, anyway it"s important you know how to use vectors.

Back to our enemies, we have to make them move in a random direction at a constant speed, but we said tougher enemies will move faster, so it"s time to learn some trigonometry basics. Look at this picture:. We have a circle, and a radius that we know has the same length no matter its angle. The radius represents the constant enemy speed, to be split into horizontal and vertical speed, called vx and vy..

[ 195 ]. Astro-PANIC!. Thanks to trigonometry, .NET ANSI/AIM Code 128 we can determine vx by multiplying the radius by the cosine of the angle formed by the radius and the horizontal axis, and vy multiplying the radius by the sine of such angle. This concept can be translated into AS3 adding these lines at the end of placeEnemy function:.

private function placeEn emy(enemy_level:uint):void { ...

var dir:Number = Math.random()*Math.PI*2; enemy.

xspeed=enemy_level*Math.cos(dir); enemy.yspeed=enemy_level*Math.

sin(dir); enemyVector.push(enemy); }. Let"s see how we can cho Code 128 Code Set B for .NET ose a random direction:. var dir:Number = Math.ra ndom()*Math.PI*2;.

dir is the variable whic VS .NET Code 128B h stores the random direction. It"s a random number between 0 and 360 degrees, just expressed in radians.

The radian is the standard unit of. angular measure, and des cribes the plane angle subtended by a circular arc as the length of the arc divided by the radius of the arc.. Math.PI returns the valu .net framework Code-128 e of PI, 3.

141592653589793. enemy.xspeed=enemy_level *Math.cos(dir); enemy.

yspeed=enemy_level*Math.sin(dir);. Once we know enemy direc barcode code 128 for .NET tion, it"s easy to determine its horizontal and vertical speed thanks to the trigonometry formulas you just learned. Just notice how speed is multiplied by enemy_level argument.

This way the latest enemies to be added are the faster and consequently the harder to kill. This simple feature will allow us to have levels with increasing difficulty, with a new, fastest enemy spaceship to be added at every level..

enemyVector.push(enemy);. Finally, the enemy itsel visual .net code-128c f is added to enemyVector Vector with push method as if it was an array, since push works in the same way for both Arrays and Vectors. Everything is now ready to make onEnterFrm function iterate through enemyVector Vector and update each enemy position according to its x and y speed.

. [ 196 ]. 6
. Add this line to onEnter Frm function:. private function onEnter VS .NET Code 128 Code Set B Frm(e:Event) { ..

. enemyVector.forEach(manageEnemy); }.

forEach method (notice the uppercase E) executes a function for each item in the Vector.
This means manageEnemy f VS .NET ANSI/AIM Code 128 unction will be executed for each enemyVector item, but you can"t define this function as you like, because it must have some mandatory arguments. The function has to be created with three arguments: the current Vector item, the index of such item, and the Vector itself.

Also, the function won"t return anything, so we will declare as void. This is manageEnemy function:. private function manageE nemy(c:enemy_mc,index:int,v:Vector.<enemy_ mc>):void { var currentEnemy:enemy_mc = c; currentEnemy.x+=currentEnemy.

xspeed; currentEnemy.y+=currentEnemy.yspeed; if (currentEnemy.

x<25) { currentEnemy.x=25; currentEnemy.xspeed*=-1; } if (currentEnemy.

x>615) { currentEnemy.x=615; currentEnemy.xspeed*=-1; } if (currentEnemy.

y<25) { currentEnemy.y=25; currentEnemy.yspeed*=-1; } if (currentEnemy.

y>455) { currentEnemy.y=455; currentEnemy.yspeed*=-1; } }.

let"s see first how it h .NET barcode standards 128 as been declared:. private function manageE nemy(c:enemy_mc,index:int,v:Vector.<enemy_ mc>):void [ 197 ]. Astro-PANIC!. As you can see, the thre e arguments are the current enemy, its index in the Vector and the Vector itself. All arguments are automatically passed to the function; you don"t have to worry about anything when calling it in the forEach method. Then in comes a line I used only for the sake of layout:.

var currentEnemy:enemy_m USS Code 128 for .NET c = c;. I was forced to call the first argument c to make a function declaration fit in a single row, but obviously it would have been better to call it currentEnemy, so I just created a variable with a more appropriate name.. currentEnemy.x+=currentE VS .NET Code 128 Code Set A nemy.

xspeed; currentEnemy.y+=currentEnemy.yspeed;.

That"s how I update curr entEnemy position according to its xspeed and yspeed properties. Enemies cannot fly off the stage, so the remaining lines are just to make them bounce inside stage edges. I will explain only the first situation: when the enemy is about to leave the stage to the left.

. if (currentEnemy.x<25 Code 128B for .NET ) { .

.. }.

The if statement checks if enemy x position is less than 25 (enemy"s radius). This would mean the enemy is flying off the stage to the left, and we must prevent it. First we stop it at the very leftmost position it can go with:.

currentEnemy.x=25;. Then, we invert its hori zontal speed this way:. currentEnemy.x=25;. The remaining if stateme nts check and prevent the enemies from flying off the stage respectively to right, up, and down sides. Test the movie and you will see three enemies moving and bouncing around the stage, at a constant speed while each one has a different speed..

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