Changing The 16 Standard Colors

If you aren't happy with the 16 standard colors that Pro-SiMPLE provides, you can use the setrgbpalette function in C++ to change them to 16 colors of your own choosing.

The following listing is an illustration of how you might create a task that changes all the palette colors (except for black) to a "rainbow" selection of colors:

   Task new palette
   Common Int r[]={0,63,63,63,63,63,47,31,31,47,47,47,55,59,59,63}
   Common Int g[]={0,31,39,47,55,63,63,63,55,47,39,31,31,31,31,31}
   Common Int b[]={0,31,31,31,31,31,31,31,47,63,63,63,63,63,52,42}
   graph on
   Do i=1,15
      +setpalette (i_, i_);
      +setrgbpalette (i_, r_[i_], g_[i_], b_[i_]);
   Loop

   Pro-SiMPLE
   real=-0.77195; imag=-0.116
   incr=0.0000025
   Do y=0,479
      r=real
      Do x=0,639
         color=mandelbrot (r, imag, 256)
         If (color!=256) color=1+color%15
         point color (color); plot (x, y)
         r=r+incr
      Loop
      imag=imag+incr
   Loop
   delay (1000)
   new palette @
   delay (1000)

"Animating" The New Color Palette

After you have established a new set of colors in the palette, it is possible to create some interesting animation effects simply by continually incrementing (or decrementing) each color entry to be that of its neighbor, as is shown in the following task. [The delta calling parameter specifies whether the colors are to be cycled forward (+1) or backward (-1) through the palette.]

   Task cycle colors (Int delta)
   Common Int offset=0
   lo=1; hi=15
   If delta>0
      lo=15; hi=1
   Endif
   flushkbd
   Do
      read quitkey
      offset=cycle (offset+delta, 15)
      Do k=lo,hi
         color=1+(k+offset-1)%15
         +setpalette (k_, color_);
      Loop
      delay (50)
   Loop

"Animating" The Standard Color Palette

Suppose you are happy with the original 16 Standard colors. Can you just invoke the cyclecolors task to animate them? Unfortunately, no. (Actually, you can. But some of the colors will appear slightly darker than they should.) To remedy the problem, simply invoke the following systempalette task to set the original system colors as the "new" ones to be used in the palette:

   Task system palette
   Common Int r[]={0,0,0,0,2,2,2,2,1,1,1,1,3,3,3,3}
   Common Int g[]={0,0,2,2,0,0,1,2,1,1,3,3,1,1,3,3}
   Common Int b[]={0,2,0,2,0,2,0,2,1,3,1,3,1,3,1,3}
   graph on
   Do i=0,15
      +setpalette (i_, i_);
      +setrgbpalette (i_, 21*r_[i_], 21*g_[i_], 21*b_[i_]);
   Loop

The following example program draws a series of concentric solid circles (in the Standard 16 colors), and then "animates" them:

   Pro-SiMPLE
   Do r=240,10,-10
      solid color (1+(r/10)%15)
      solid circle (320, 240, r)
   Loop
   system palette @
   cycle colors (-1) @