Re: 100 Different Colors

[Jan-Marek Glogowski <glogow fbihome de>]

Hi

> I need to create 100 little squares and each of them
> has to be a different color. They can't just be a
> random color: they have to follow the colors of the
> standard color spectrum/palette. For example, the
> first one is dark blue, then lighter blue, ... ,
> green, ... , red.

Std. color spectrum? Maybe like the circle in the GtkColorSelectionDialog?

Algo:
r = max, g = 0, b = 0
r = max , g = max, b = 0
r = 0, g = max, b = 0
r = 0, g = max, b = max
r = 0, g = 0, b = max
r = max, g = 0, b = max
back to step 1

See GtkColorSelection source

> From the GDK Manual:

gdk_gc_set_rgb_fg_color () - set the foreground color of a GC using an
unallocated color.

GdkColor - red, green, blue ... is a value between 0 and 65535, with 65535
indicating full intensitiy.

GdkGC *gc;
GdkColor c;

gc = gdk_gc_new (widget->window);

for (i=0; i<100; i++) {
  c.pixel = 0;
  c.red   = G_MAXUINT16;
  c.blue  = (i % 33 / 99) * G_MAXUINT16;
  c.green = i/99 * G_MAXUINT16;
  gdk_gc_set_rgb_fg_color( gc, &c );
  gdk_draw_rectangle (widget->window, gc, TRUE, i*15,
    0, 11, 11);
}

HTH

Jan-Marek