So I stole this from this kind of classic gaming sites that had sort of the description of Space Invaders
and go to the site if you want.
It's got lots of interesting stuff about it.
But the game in general.
So it starts so the object of the game is to shoot the invaders with your missile base while avoiding
their shots and preventing invasion.
Ok massing a high score is a further objective and one that must be prioritize against your continued
survival.
Each game screen starts with five rows of 11 invaders the bottom two rows score 10 points or her large
invader.
The middle two rows are 20 points for the medium the beer and the top rows scores 30 points for each
small innovators.
Ours will be all the same size.
Don't worry the big meeting in small here.
This makes each screen worth a total of nine hundred ninety points.
The score for each screen can be dramatically increased by the destruction of the mystery value spaceship.
When I call the UFO that frequently flies from one side of the screen to the other mystery UFO should
have points value of 50 to 200 points temporary sanctuary.
Can you SOP's beneath the four Bs shields shields are destructible by both the player and the aliens.
Only the part of the shield hit by either player.
You are either a player missile or an alien bomb should be destroyed not the entire issue.
So like parts of the shield can be kind of broken.
It's what's saying here.
Invader's travel sideways and each time they touch the side they drop down one line on the screen and
when one day they need to drop 11 lines at each to reach the bottom to invade from screen 2 through
9.
They start progressively lower down on the screen so this is this is actually talking about the games.
So if you actually won the game the next time they spawn because you just kind of keep going.
They start one mind lower than they did before.
OK screen 10 the game reverts to the screen 1 a start position and the cycle begins again.
So again essentially what happens is they start kind of the highest on the first on the first try.
And if you destroy them all and then kind of that will sort of restart the game then they'll start one
line lower until they reach 10 and then they kind of recycle back to the first first time.
There is no time limit except for the fact that if you do not shoot them all before they reach the bottom
the bottom of the screen the game ends.
So the more invaders the player shoots the faster.
Maybe aliens move when the invaders are low enough to touch the base shelters.
They erased them as they pass.
That's very important.
OK.
And the last invader Missouri quickly or us any missiles drop by.
She's interested say bombs.
Bombs dropped by the invader on the row above invasion row will not harm the players missile.
So.
So Alien bombs and players missile can't collide other words the aliens can have a maximum of three
bombs on the street in that time the player can only have one missile shots on the screen at one time.
If the player is hit the game should pause and the player should be showing the exploding animation
so the player can get hit in the head explode.
And what we'll do is you'll have to press a button or a key to continue the game if an alien is hit
they should explode for a short time then disappear.
There should be an intro screen game over screen.
The player can enter their name in high Group high score screen so there's different screens to this
game.
It's quite a bit more complicated than say battleship for example.
It should be a high score table that can be seen from the initial welcome screen and after the game
is over.
And the player enters his three letter name so it will show up after they kind of enter their name.
See what score the.
So all the regular aliens are two by four in terms of size two rows four columns.
Player is two by five.
And the alien ufo is two by six and you can see all the sprites are actually going to be drawing sprites.
So you can see all the sprites here of what everything is going to look like.
You can change the sprites however you like but easier are the ones I'm going to use.
OK.
And notice that there they have animations.
There's ones prayed for this thirty point alien will look like this.
Maybe the initial spray will like this and then when he moves he'll kind of like this.
And similarly for these aliens OK the UFO doesn't change at all.
And the players.
In actual game play doesn't change but the explosion will actually have an animation.
OK and here's what the shields will look like.
Here's what the alien bomb will look like.
So the alien bomb is also animating things so that's important.
So go from this list.
And then back here and make that and the alien explosion just like this.
We could change it to be the same size as well.
If you want to look at if you want to look like this that is all you want.
It doesn't matter too much and that's it.
So what can we start understanding about what kind of data we want.
So let's take a look.
So when you're a player
so.
You're.
Only some humans need the shields
any kind of alien bombs
player missiles.
They all need sort of states that the game can be in.
So games it's because for example says here there's intro screen of Game Over screen high score screen
as well as many different states that the game will be in.
That will need to to figure out the scores on the score and a high score table.
OK.
So these are just kind of general observations.
Sensage general data maybe they Here's all the general data that I kind of glean from this description.
So let's kind of break it down.
So let's start with the player
so where will have what each a position
it'll have.
It only has one missile and the player can only have one missile shot on screen and when times are going
to give it to where a missile has animations state Guess what if they're so usually it doesn't have
animations to eat.
But what if it got hit and it's exploding.
No it will have to kind of go between these two animations and this animation state it has the size
of the Spryte
it has.
It didn't actually say up here.
It just kind of a weird sort of added a couple things to this description but I didn't add that it had
we have lives.
In fact we have three lives OK.
And then it's game over.
And the player also has a score as well.
So how many points he currently has.
So that's kind of the major stuff player.
So what about the aliens.
So I'm going to break up the aliens into kind of the regular ten twenty thirty point aliens and just
distinguish them from the mystery UFO.
And so I'm going to call the regular aliens the aliens swarm.
And so this is the actual This isn't an individual it's actually all all the 10 20 and 30 point aliens.
So as one kind of unit
the aliens swarm in general has a position.
They have a direction that they're kind of moving in.
So either left or right.
They also have animations which animations state they're in because when they move they change their
animation for your scene.
Space Invaders played a.
They also have size of each alien.
They have a state that they're in.
So
they really only have three states alive.
Dead or exploding because they have to explode for a while says somewhere around here.
Feelings hit.
They should explode for a short period of time then disappear.
So they'll have kind of an exploding state as it were.
And of course they have alien bombs.
And notice I'm not giving them points here.
Right.
All kind of deal with that some other way.
Rosca have the feeling you know and that we actually have eyes for this bright and the actual position
that they're in and points that they that it's worth game which is random from 50 so it can have a value
of 50 to 100 200 points.
So it's that we miss or we miss the actual shields.
Right here.
So that's actually that's it for you.
Well so the shield itself will have a Spryte and notice that these don't like this doesn't have a sprite.
This doesn't have a spray.
This doesn't have a sprite currently.
But this will have a sprites.
And the reason why is because the spray can change.
Unlike the aliens which doesn't really change the only change in terms of animation which we already
factored in to ours.
And similarly with the glare the player doesn't really change he just has a animation state if he's
exploding but the shield itself will have an actual sprite because the Spryte say the middle seat sprite
say.
This one got steroid so it could look like this if it got hit in the middle right.
So that's important to capture.
So have a sprites and they'll all have position
so
we'll also have let's say a position
in those that position really just has it's just an x y coordinates.
The alien bomb
will also have a position
and it will have the
the animation state could be of four different states.
Could be like this.
This this this.
That's four states it could be in kind of similarly sort of the missile that we have for the player
right.
So call it missile really is just a position.
So
that's kind of it's in the Spryte will use for it.
It's kind of an aside.
It will just be kind of a vertical line like this.
So again this won't change.
Therefore we don't need an animation stage and we don't need to set the sprite in here because it will
change all day kind of more subtly.
The we said we need game states right.
So maybe we actually need kind of a game structure as well.
So we actually have the game stee in here.
Maybe that current level that we're on like it said above
is it's so onscreen one they need to drop all of minds right so screen to really there should be level
1 and level 2.
So we're going to have that level here and we're going to have the size of the window in the game as
well.
There's going to be extra stuff that we're not think of right now but again we're just sort of thinking
in terms of what we may need just based off the description and all the sprites that we have.
So we're kind of thinking out loud and sort of doing the best we can with what you know.
For now often when you're in the game you'll have to make revisions and do different maybe maybe add
some more data that you of missed.
So but usually when you kind of go through it the first time you should really just do what we're doing
right now and sort of think about all the things we're going to need logically.
And if you have to make changes to it later that's OK.
So we have scores.
Obviously it's just going to score value and it said we could enter a name so maybe a name is all.
And so the high score table
as well which I think is going to make vector school is gay
so if there's anything really missing
in terms of kind of the broad overview of the actual data for the game but I'm sure there'll be some
things that we need to add or change over the course of doing this game.
OK.
So I want to in the next lecture go over the actual implementation of the data so making all the strokes
and kind of thinking about everything we're going to need.
And so I will see you in the next lecture.