C++ :: Ncurses - Highlighting A Line Of Characters On Screen

I am writing a program using ncurses that needs a function to highlight a line of characters on the screen. I started writing this function that took the x & y coordinates of a character on the screen and the length of characters after that to highlight. Whilst doing this I noticed that if I highlighted the last character in a row (maxX-1 in my example) it highlighted that character (as expected), and if I highlighted just the character before that (maxX-2) it also works. But if I do both, it highlights the whole row/line. Also, if there are characters in those spaces other than the 'space' character it works too, but for my program I need to be able to highlight empty spaces as well.

To highlight I am using inch() to get the character and addch() to print it because I am using some alternate characters that chgat() replaces with normal characters.

#include <ncurses.h>
int main(){
initscr();
start_color();
use_default_colors();
curs_set(0);
noecho();

int maxX=0, maxY=0;

[Code] ....