Converting from viewport cooridantes to 2d coordinates.

Questions & Answers
1

I have my game objects in coordinate system starting (0,0) at lower left and increasing x and y upwards (1,1) at the top right , what’s the easy way to convert it to the 2d coordinate (0,0) at the centre and -x to left ,positive x to right , -y downwards and +y upwards (and its size is 0,0 at centre to screen width and height).

2

I’m not quite sure what your last sentence means: “its size is 0,0 at centre to screen width and height”. So what is at the bottom left hand corner of the new coordinate system? Screen width/2 and screen height/2?

I think you might be describing this:

NewX = (OldX - 0.5) * Screen.width;
NewY = (1 - (OldY - 0.5)) * Screen.height;