% FLYING THROUGH SPACE, By Peter  Watt

%I put commenting in for those that like green
% this is my version of the classic windows screen saver Flying Through
% space

% mine is better than windows because you can change the star colour
% and it follows the mouse

% code is kind of rough because i've butcherd through a lot of this to
% make is less  lines than it used to be, (more than 200 lines long
%without comments), it still does the same thing that it did before
% mabey even better


% CONSTANTS


const NUM_OF_STARS := 100 % you can change this if your computer 

%lags or  if you want more or less stars
const MAX_DIS := 200 % controls how far off the screen the star can go
const PROX := 10
const MIDX := maxx div 2
const MIDY := maxy div 2
const SPEED := 10 % if you change this one the program gets messed
const MOUSE_RANGE := 300 % if you make this lower the stars will   
                                            %follow   the mouse more


%%%%%%VARIABLES%%%%%%% (no duh)

var DelayFactor : nat2 := 300 % delay decreaser
var Xm, Ym, Click : int % mouse
var Key : array char of boolean % nuff said
var Rc : int % random color var
var Length : array 1 .. NUM_OF_STARS of real4 % distance between each
% star
% I could have used the Math.Distance subprogram but my computer is
%messed and
% doesn't allow it
var X : array 1 .. NUM_OF_STARS of int % the x co-ordinate of each star
var Dx : array 1 .. NUM_OF_STARS of int % holds how fast the star moves
% horazontally
var Y : array 1 .. NUM_OF_STARS of int % the Y co-ordinate of each star
var Dy : array 1 .. NUM_OF_STARS of int % like Dx but for the Y
var SX : array 1 .. NUM_OF_STARS of int % used to find the slope
 %between the  star and the mouse
var SY : array 1 .. NUM_OF_STARS of int % same as SX (almost)
var Size : array 1 .. NUM_OF_STARS of int %  holds how big each star is
% if a star is big it looks
%closer (used to give a felling of depth)
var Size2 : array 1 .. NUM_OF_STARS of real % used to increment the
%star size
var C : array 1 .. NUM_OF_STARS of int


%%%%%MAIN%%%%%%%%%


setscreen ("graphics:max,max,nobuttonbar,offscreenonly,nocursor")
% the nocursor parameter dosen't work on my computer (then again it's
%7 years old please tell me if you have the same problem)




% this section  initializes each var for each star
% that last line had a ryme
Rc := 0
for Index : 1 .. NUM_OF_STARS

    randint (X (Index), 1, maxx)
    randint (Y (Index), 1, maxy)
    Dx (Index) := 0
    Dy (Index) := 0
    Size2 (Index) := 1
    Size (Index) := 1
    randint (C (Index), 1, 15)

end for

colorback (7)

cls
loop


    Input.KeyDown (Key)


    % changes star color if space bar is pressed
    if Key (' ') then
        loop
            randint (Rc, 0, 15)
            exit when Rc not= 7
        end loop


    end if

    mousewhere (Xm, Ym, Click)

    %
    %

    % it is in a for because to repeat every thing for every star
    for Index : 1 .. NUM_OF_STARS
        % this finds the length and slope between the star and the mouse
        % this is were the Math.Distance sub-prog would have been nice
        Length (Index) := sqrt ((X (Index) - Xm) ** 2 + (Y (Index) - Ym) ** 2)


        SX (Index) := X (Index) - Xm
        SY (Index) := Y (Index) - Ym


        % this for structure is used to fond the direction that the stars should
        %be moving in based on the slope and length

        if Length (Index) > PROX then
            Dx (Index) := SX (Index) div (Length (Index) div SPEED)
            Dy (Index) := SY (Index) div (Length (Index) div SPEED)
        end if
        % the size of the star is incresed to make it seem like it is
        % coming closer, it only increases by .07 because i didnt want them 
         %to get to big to fast
        Size2 (Index) := Size2 (Index) + .07 % if you think .07 is to slow

 %then by all means change it
        Size (Index) := round (Size2 (Index)) % can't use a real in a draw 
 %command oviosly




        % this section moves the stars and reposistions them if they go
 %        offscreen

        X (Index) := X (Index) + (Dx (Index))
        Y (Index) := Y (Index) + (Dy (Index))
        % this if is used to check   if the stars are on screen
        if X (Index) > maxx + MAX_DIS or X (Index) < -MAX_DIS or
                Y (Index) > maxy + MAX_DIS or Y (Index) < -MAX_DIS then


            % if they aren't then the co-ordinates for the star are randomized
            loop
                randint (X (Index), Xm - MOUSE_RANGE, Xm + MOUSE_RANGE)
                randint (Y (Index), Ym - MOUSE_RANGE, Ym + MOUSE_RANGE)
                Length (Index) := sqrt ((X (Index) - Xm) ** 2 + (Y (Index) - Ym) ** 2)
                exit when Length (Index) > 4
            end loop
            % this brings makes the star seem far away again
            Size2 (Index) := 1
            Size (Index) := 1


        end if
        % and of course this draw command draws the star , try 
 %commenting it out and see what happens
        drawfilloval (X (Index), Y (Index), Size (Index), Size (Index), Rc)

        % okay if you want th stars to be different colours then uncomment
        % the nex line
        %drawfilloval (X (Index), Y (Index), Size (Index), Size (Index), C (Index))



    end for



    % this section is used to make it appear as though the stars are
  %speeding up you can comment it out if you think it laggs the program
   %or it looks bad
    %
    if DelayFactor > 0 then
        DelayFactor := DelayFactor - 10
    end if
    delay (DelayFactor)



    % okay this for structure i got from Adam Bielinski (from his forces
    %engine witch was very cool)
    % what it does is blurs the screen by drawing random lines that are
    %the same colour as the background and gives a cool effect try 
    %replacing  cls with this block to get the blur effect
    for Blur : 1 .. 300
        drawline (Rand.Int (1, 800) * 2 - 400, Rand.Int (1, 600) * 2 - 300,
            Rand.Int (1, 800) * 2 - 400,
            Rand.Int (1, 600) * 2 - 300, 7)
    end for
    View.Update
    %cls % clears screen (only do this if you don't wish to use the blur)


end loop
% i would lIke to apologize for the inCorrect grammEr and spelling in this
%program

var win1:int:=Window.Open("fullscreen")