GDI + Line Drawing + Palette Rotation - Rainbow effect

[TouchingVirus]

Hey to all here @ tek-tips..

The rainbow effect is what i am looking for here...it is annoying me

//Start of line drawing...
 
// get the graphics device context 
    hdc = GetDC(hwnd);

    // create a random colored pen
    hpen = CreatePen(PS_SOLID,1,RGB(rand()%256,rand()%256,rand()%256));

    // select the pen into context
    old_hpen = SelectObject(hdc,hpen);

    // move to a random postion
    MoveToEx(hdc, rand()%WINDOW_WIDTH, rand()%WINDOW_HEIGHT, NULL);

    // draw a line
    LineTo(hdc,rand()%WINDOW_WIDTH, rand()%WINDOW_HEIGHT);

    // now delete the pen
    SelectObject(hdc,old_hpen);
    DeleteObject(hpen);
    
    // release the device context
    ReleaseDC(hwnd,hdc);
   

// End of line drawing

The above code was taken from "Windows Game Prgoramming For Dummies" and is a random line drawing snippet with random line colors ...

I want to have a window say 320x255, i can create that, but....

i want to draw a horizontal line from 0,0 to 320,0 and i want it to be violet..
i want to draw another horizontal line from 0,1 to 320,1 and i want it to be a lighter shade of violet...

the process continues until i have encorporated violet,indigo,blue,green,yellow,orange & red into the lines..

then a pallete rotation, so that it scrolls and looks like a rainbow,

If my explanation is too longwinded or not clear, i have got a program with the exact effect i can send you, but its a DOS program written in mode13h -> obviously not what i want here

 

[Cagliostro]

I think it isn't the best idea ti use GDI. Getter is to use OpenGL or DirectX.

Ion Filipski

 

[TouchingVirus]

I was thinking the same thing, however, i only got to the section on directX last night lol, so i havnt the faintest idea where to start

Any assistance on how to do it would be GREATLY appreciated, i really got into programming coz i wanted to do this...and a few other cool techniques

 

[Cagliostro]

Take a look at:

http://www.codeproject.com/useritems/grausteroids.asp

http://www.programmersheaven.com/zone10/cat98/25847.htm

http://www.codeguru.com

google.com

Ion Filipski