fli_pal_dirty_to (3) - Linux Man Pages
fli_pal_dirty_to: Indicate which parts of the palette have changed. Allegro game programming library.
NAMEfli_pal_dirty_from, fli_pal_dirty_to - Indicate which parts of the palette have changed. Allegro game programming library.
extern int fli_pal_dirty_from;
DESCRIPTIONThese variables are set by next_fli_frame() to indicate which part of the fli_palette has changed since the last call to reset_fli_variables(). If fli_pal_dirty_from is greater than fli_pal_dirty_to, the palette has not changed, otherwise colors fli_pal_dirty_from to fli_pal_dirty_to (inclusive) have altered. You can use these when updating the hardware palette, to avoid unnecessary calls to set_palette(). Example:
if (fli_pal_dirty_from <= fli_pal_dirty_to) set_palette_range(fli_palette, fli_pal_dirty_from, fli_pal_dirty_to, 1);