Understanding part of the coordinate system

[Petunien]

Hi,

I need your help to understand a part of the coordinate system.

At the moment, if the player shoots, the bullet goes exactly to the x/y-coordinate where the mouse was clicked.

But I wanna the bullet going outside of the window (1024x768 pixels), so I can delete it.

My question:

Assumed the player shoots at 500/600.
The y-coordinate of the bullet has therefore to be at least -600. But the x-coordinate has to change too, relative to the y-coordinate.

On 1024x768 the ratio is 4:3. What would be the target coordinates?
Aww, I'm bad at explaining problems. Especially in English.

This image could help:

http://www.abload.de/img/problemd3l12.jpg

I still suck at math, I hope it changes.

Greets

[clepto]

i don't quite understand what you want...
you want to get the coordinates of the target point? (based on image)

if yes you can check in the update() if the x and y coordinate is out of the window and then get the other one...example:

-- suppose the window is 700x800

Code: Select all

if x >= 700 then
    y = get-bullet-y-coordinates
elseif y >= 800 then
    x = get-bullet-x-coordinates
end 

but if you want just to delete the bullet you need to check if only one coordinate (x or y) is out of the window!

hope it helps

[Petunien]

I forgot to say that the bullet doesn't go that way. That's the way it should go.

As I wrote, the bullet at the moment goes exactly to the point where the mouse was clicked.

And based on the image, I would like if someone could say me what the coordinates are and how he was able to figure them out.

[clepto]

the shooter is in 500/600 right?
the target is in the question mark?

the bullet doesn't follow the red line?

you want the coordinated of the mouse click?

sorry for not understanding

[Petunien]

the shooter is in 500/600 right?
the target is in the question mark?

The player clicked at 500/600. The bullet goes to 500/600.
The question mark stands for the coordinates I want to know.

the bullet doesn't follow the red line?

No, therefore I asked how to get the coordinates where the question mark is, so I can move the bullet to those coordinates.

Sorry for not writing in correct english.

[clepto]

english is not my first language either

we know the x coordinates, its the x size of the window...

the y now...hmm..thats diffucult

can i ask something? the player clicked in 500/600 so the bullet has to go there...from where does the bullet start? why you need this coordinates?

[Petunien]

english is not my first language either

May ask where you are from?

we know the x coordinates, its the x size of the window...

I don't understand.

the y now...hmm..thats diffucult

Surely easy math.

can i ask something? the player clicked in 500/600 so the bullet has to go there...from where does the bullet start? why you need this coordinates?

The bullet starts from the player x/y coordinate. Basically I need these coordinates to let the bullet fly outside the window.

Deleting them while flying doesn't look that good.

[clepto]

I am from Greece

look at the image here http://ubuntuone.com/5LdkdGaRtE0TR4vX3SEiq3
i hope it helps a bit

[Petunien]

Oh, greets to Greece.

Heh, I think we understand ourselves not correctly.

I think it's better to wait also here until someone comes.

[clepto]

haha thats what i was thinking

edit: just one more thing, why you need specific coordinates to get the bullet out of the window? just keep increasing the coordinates and check if its out of the window! Goodnight!