Physics: trajectory, axis, lever

[Khris]

It doesn't matter whether you begin with a positive or negative y. Why would a ball fly differently if you moved the point of origin...?

Remember that a computer screen's origin is at the top-left, not bottom left.
Thus I start with a negative y acceleration, to represent movement directed upwards. Gravity points downwards, i.e. is a positive acceleration; this is reflected by adding 0.1 to the y movement every game loop (leading to the y movement's magnitude getting smaller, zero, then bigger again).

Long story short: I had working code producing a nice trajectory using very similar values.

[beomoud]

just start trying any of these solutions and we're here if you need anything

[rbaleksandar]

Thank you so much for all the explanations. I'll need lots of time for what I want to do... But I hope at the end it'll be a well done work

[Wonkyth]

Remember that a computer screen's origin is at the top-left, not bottom left.

This has always confused me.

[rbaleksandar]

Actually I didn't know that...Well, I've mostly programmed in Java and there when you use Swing for example it's the same...Good to know that it's the same here

[Khris]

I'm pretty sure that every language that supports graphic commands has their origin at the top-left.
This convention is as old as computers and stems from everything being text-based where the top-most line is naturally the first one.

If it's that confusing, there's always the possibility to have the origin at the bottom left in your calculations, then do y=Screen.Height-1-y at the drawing stage.

[rbaleksandar]

Thanks again btw You're right about this convention...But never thought of it being included in AGS