Hi. As a newbie I have a lot of questions...

Is there the possibility to change PERMANENTLY the coordinates system for the screen? Normally the (0,0) is upper left, (width-1,height-1) lower right.

I found a partial solution by means of translate()+scale() in draw() but they are far from being intuitive. You even need to resize strokeWeight().
I was think of something to set once for all in setup().

Sometimes it would be nice to use different systems: i.e. if you want to visualize the sin() function it would be nice to redefine the screen as y+1.1 up, y-1.1 down, x-5 left, x+5 right. Every point() and strokeWeight() would be resized accordingly.

Is there any library available to provide this function?
Apok

Definitely: scale() changes strokeWeight().

Apok wrote on Aug 26^th, 2009, 1:31pm:


My "problem": I was visualizing y=sin(x) and my code contained "ugly" scale corrections to represent the function in a 400x400 screen.

So I used map() but every time I wanted to print a point, line, etc I had to remember to use map(). Not elegant at all.

Last try: I used a combination of translate() and scale() to represent correctly my interval (y=+1 top, y=-1 bottom, x=-1 left, x=+1 right) but then I needed to remember to correct strokeWeight() around the code because of the changed scale factor.
Code:

translate(0, height);
scale(width/2, -height/2); // this is to scale x&y and reverse y
translate(1.0, 1.0);  // (0,0) is screen center
strokeWeight(1.0/width);  // stroke has to be compensate
                             // for the scale change 

Wouldn't it be better to have a single function in setup() to define which part of screen to magnify (with or without stroke magnification)?
It would be great to study mathematical functions. As soon as a function is "out of screen" you just change a parameter and automatically the rest of the code is ok.

Is there any library that provides it?

Apok