static enum out_color_mode
guessIndexed(struct FlattenSpec *spec,rgba *allPixels[])
{
if( allPixels == NULL ) {
if (spec->gimpish_indexed && colormapLength ) {
unsigned i ;
init_palette_hash();
for( i=0; i<colormapLength; i++ )
lookup_or_intern(NEWALPHA(colormap[i],255));
if( lookup_or_intern( FULLALPHA(spec->default_pixel) ?
spec->default_pixel : 0 ) >= 0 )
return COLOR_INDEXED ;
}
} else {
init_palette_hash() ;
if( palettify_rows(allPixels,spec->dim.width,spec->dim.height) ) {
/* Might grayscale sometimes be preferred? No, that is what
* -g is for! */
return COLOR_INDEXED ;
}
}
return COLOR_BY_CONTENTS ;
}
int
palettify_row(rgba *row,unsigned ncols)
{
index_t *newrow = (index_t*)row ;
assert(sizeof(index_t) <= sizeof(rgba));
unsigned i ;
for( i=0; i<ncols; i++ ) {
int j = lookup_or_intern(row[i]) ;
if( j < 0 ) {
unpalettify_row(row,i);
return 0 ;
}
newrow[i] = j ;
}
return 1 ;
}