Coordinate system in c# and other programming languages

[castajiz_2]

Hi again,

before a year ago when we were doing the graphics class at college my professor said that the coordinate system is reversed in programming that means that the Y axe is positive when facing down and the X axe is negative when facing right , however when using the graphics class in c #, the X axe is not negative on the right side instead it is POSITIVE! i said to myself that i will learn this basics but somehow i can t find Anything on google about this and when doing some project i nearly always end up using some false coordinates and the main reason is because i am stil not sure how this coordinate system works in programming and by the way Why is it Reversed in programming ??

[ddanbe]

Pixels on the screen are counted from the top left(0,0) of the screen. This is the way video works I guess.
So X goes from 0 to the horizontal screen(right) resolution(positive direction)
Y goes from 0 to the vertical screen(bottom) resolution(negative direction)

[castajiz_2]

finally, tnx, can you please suggest a site where i can look more on this , or anybody else?

[ddanbe]

Yes, what about DaniWeb? This is a snippet I posted here. Forget about the sawtooth, look for a Plot class. these days I would use the Chart component Available as of VS2010 I think.

[lolafuertes]

Just my cent.

Additional to the excelent info from ddanbe, here after a couple of links:
Windows forms coordinates on MSDN (here)
Coordinates systems on Wikipedia (here)

Only to say that the values to define a drawing point in a screen are always in positive values referred to the top-most/left-most corner of the screen. As X axis increases, the point is moved to the right and as Y increases, the point is moved down.

Hope this helps