Index: exposurses.c
==================================================================
--- exposurses.c
+++ exposurses.c
@@ -30,11 +30,10 @@
 	"12",		
 	"13",		
 	"14",		
 	"15",		
 	"16",		
-	NULL
 };
 
 char *iso_array[] = {
 	"50",
 	"100",
@@ -41,14 +40,14 @@
 	"200",
 	"400",
 	"800",
 	"1600",
 	"3200",
-	NULL
 };
 
 char *shutter_array[] = {
+	"OVER",
 	"1/1000",
 	"1/500",
 	"1/250",
 	"1/125",
 	"1/60",
@@ -56,23 +55,24 @@
 	"1/15",
 	"1/8",
 	"1/4",
 	"1/2",
 	"1",
-	NULL
+	"UNDER",
 };
 
 char *aperture_array[] = {
+	"UNDER",
 	"f/1.4",
 	"f/2",
 	"f/2.8",
 	"f/4",
 	"f/5.6",
 	"f/8",
 	"f/11",
 	"f/16",
-	NULL
+	"OVER",
 };
 
 ITEM **exposure_items;
 ITEM **iso_items;
 ITEM **shutter_items;
@@ -85,17 +85,19 @@
 WINDOW *iso_win;
 WINDOW *shutter_win;
 WINDOW *aperture_win;
 
 void selection(char *name);
-void add_menu(char **array, ITEM **items, MENU *men, WINDOW *win, int n, int xpos, char *title);
 void remove_menu(ITEM **items, MENU *men, int n);
 void print_in_middle(WINDOW *win, int starty, int startx, int width, char *string, chtype color);
+MENU *add_menu(ITEM **items);
+WINDOW *add_window(int xpos, char *title);
+ITEM **add_item(char **array, int n);
 int exposure(int iso);
 double shutter(int exposure, double aperture);
 double aperture(int exposure, double shutter);
-int nearest_match(double x, int menu);
+int nearest_match(double x, int menu, int n_array);
 double fraction_to_double(char *fraction);
 /* No one will ever need more than 9 bytes! */
 char exposure_sel[9] = "";
 char iso_sel[9] = "";
 char shutter_sel[9] = "";
@@ -126,15 +128,40 @@
 	/* Can't really avoid finding array sizes here */
 	n_exposure = ARRAY_SIZE(exposure_array);
 	n_iso = ARRAY_SIZE(iso_array);
 	n_shutter = ARRAY_SIZE(shutter_array);
 	n_aperture = ARRAY_SIZE(aperture_array);
-	add_menu(exposure_array, exposure_items, exposure_menu, exposure_win, n_exposure, 4, "EV");
-	add_menu(iso_array, iso_items, iso_menu, iso_win, n_iso, 45, "ISO");
-	add_menu(shutter_array, shutter_items, shutter_menu, shutter_win, n_shutter, 86, "Shutter");
-	add_menu(aperture_array, aperture_items, aperture_menu, aperture_win, n_aperture, 127, "Aperture");
-
+	/* http://stackoverflow.com/a/2620158/208793 */
+	exposure_items = add_item(exposure_array, n_exposure);
+	iso_items = add_item(iso_array, n_iso);
+	aperture_items = add_item(aperture_array, n_aperture);
+	shutter_items = add_item(shutter_array, n_shutter);
+	exposure_menu = add_menu(exposure_items);
+	iso_menu = add_menu(iso_items);
+	shutter_menu = add_menu(shutter_items);
+	aperture_menu = add_menu(aperture_items);
+	exposure_win = add_window(4, "EV");
+	iso_win = add_window(45, "ISO");
+	shutter_win = add_window(86, "Shutter");
+	aperture_win = add_window(127, "Aperture");
+	/* Don't know how to avoid the repition below */
+	set_menu_win(exposure_menu, exposure_win);
+	set_menu_win(iso_menu, iso_win);
+	set_menu_win(shutter_menu, shutter_win);
+	set_menu_win(aperture_menu, aperture_win);
+	set_menu_sub(exposure_menu, derwin(exposure_win, 6, 38, 3, 1));
+	set_menu_sub(iso_menu, derwin(iso_win, 6, 38, 3, 1));
+	set_menu_sub(shutter_menu, derwin(shutter_win, 6, 38, 3, 1));
+	set_menu_sub(aperture_menu, derwin(aperture_win, 6, 38, 3, 1));
+	post_menu(exposure_menu);
+	post_menu(iso_menu);
+	post_menu(shutter_menu);
+	post_menu(aperture_menu);
+	wrefresh(exposure_win);
+	wrefresh(iso_win);
+	wrefresh(shutter_win);
+	wrefresh(aperture_win);
 	attron(COLOR_PAIR(2));
 	mvprintw(LINES - 2, 0, "Select EV");
 	/*mvprintw(LINES - 2, 0, "Select ISO and then one of Shutter/Aperture to calculate other of Shutter/Aperture");*/
 	mvprintw(LINES - 1, 0, "Arrow keys to navigate, Enter to select, Q to exit");
 	attroff(COLOR_PAIR(2));
@@ -173,118 +200,143 @@
 				cur = current_item(*menu);
 				p = item_userptr(cur);
 				/* Learning notes - Don't understand this bit */
 				/* Is this a function pointer? */
 				p((char *)item_name(cur));
-				
-				switch (selection_counter) {
-					case 1: { /* Exposure selected */
-						selection_counter += 1;
-						menu_counter += 1;
-						move(LINES - 2, 0);
-						clrtoeol();
-						mvprintw(LINES - 2, 0, "Select ISO");
-						refresh();
-						menu = &iso_menu;
-						win = &iso_win;
-					}
-					break;
-					case 2: { /* ISO Selected */
-						selection_counter += 1;
-						menu_counter += 1;
-						move(LINES - 2, 0);
-						clrtoeol();
-						mvprintw(LINES - 2, 0, "Select Shutter or Aperture");
-						refresh();
-						menu = &shutter_menu;
-						win = &shutter_win;
-					}
-					break;
-					case 3: { /* Shutter or Aperture selected */
-						if (strcmp("", shutter_sel) == 0) {
-							char aperture_sel_[4] = "";
-							strncpy(aperture_sel_, aperture_sel+2, 3);
-							/* Using menu_driver to go up/down to force refresh and correct highlighting */
-							menu_driver(shutter_menu, REQ_SCR_UPAGE);
-							menu_driver(shutter_menu, REQ_SCR_DPAGE);
-							/* There is probably a nicer way to format the below */
-							set_menu_pattern(
-								shutter_menu,
-								shutter_array[nearest_match(
-									shutter(exposure(atoi(iso_sel)), strtod(aperture_sel_, NULL)),
-									2
-								)]
-							);
-							menu_driver(shutter_menu, REQ_DOWN_ITEM);
-							menu_driver(shutter_menu, REQ_UP_ITEM);
-							wrefresh(shutter_win);
-						}
-						if (strcmp("", aperture_sel) == 0) {
-							menu_driver(aperture_menu, REQ_SCR_UPAGE);
-							menu_driver(aperture_menu, REQ_SCR_DPAGE);
-							set_menu_pattern(
-								aperture_menu,
-								aperture_array[nearest_match(
-									aperture(exposure(atoi(iso_sel)), fraction_to_double(shutter_sel)),
-									3
-								)]
-							);
-							menu_driver(aperture_menu, REQ_DOWN_ITEM);
-							menu_driver(aperture_menu, REQ_UP_ITEM);
-							wrefresh(aperture_win);
-						}
-						/* clear the selections for next time */
-						strcpy(iso_sel, "");
-						strcpy(shutter_sel, "");
-						strcpy(aperture_sel, "");
-						/* And set defaults back to start */
-						selection_counter = 1;
-						menu_counter = 1;
-						menu = &exposure_menu;
-						win = &exposure_win;
-						move(LINES - 2, 0);
-						clrtoeol();
-						mvprintw(LINES - 2, 0, "Select EV");
-						refresh();
-					}
-					break;
-				}
-			}
-			break;
-		}
-		wrefresh(win);
+				/* need to igore over/under if selected, probably easier than try to prevent selection */
+				if (!((strcmp("OVER", shutter_sel) == 0)
+						|| (strcmp("UNDER", shutter_sel) == 0) 
+						|| (strcmp("OVER", aperture_sel) == 0) 
+						|| (strcmp("UNDER", aperture_sel) == 0))) {
+					switch (selection_counter) {
+						case 1: { /* Exposure selected */
+							selection_counter += 1;
+							menu_counter += 1;
+							move(LINES - 2, 0);
+							clrtoeol();
+							mvprintw(LINES - 2, 0, "Select ISO");
+							refresh();
+							menu = &iso_menu;
+							win = &iso_win;
+						}
+						break;
+						case 2: { /* ISO Selected */
+							selection_counter += 1;
+							menu_counter += 1;
+							move(LINES - 2, 0);
+							clrtoeol();
+							mvprintw(LINES - 2, 0, "Select Shutter or Aperture");
+							refresh();
+							menu = &shutter_menu;
+							win = &shutter_win;
+						}
+						break;
+						case 3: { /* Shutter or Aperture selected */
+							if (strcmp("", shutter_sel) == 0) {
+								char aperture_sel_[4] = "";
+								strncpy(aperture_sel_, aperture_sel+2, 3);
+								/* Using menu_driver to go up/down to force refresh and correct highlighting */
+								menu_driver(shutter_menu, REQ_SCR_UPAGE);
+								menu_driver(shutter_menu, REQ_SCR_DPAGE);
+								/* There is probably a nicer way to format the below */
+								set_menu_pattern(
+									shutter_menu,
+									shutter_array[nearest_match(
+										shutter(exposure(atoi(iso_sel)), strtod(aperture_sel_, NULL)),
+										3,
+										n_shutter
+									)]
+								);
+								menu_driver(shutter_menu, REQ_DOWN_ITEM);
+								menu_driver(shutter_menu, REQ_UP_ITEM);
+								wrefresh(shutter_win);
+							}
+							if (strcmp("", aperture_sel) == 0) {
+								menu_driver(aperture_menu, REQ_SCR_UPAGE);
+								menu_driver(aperture_menu, REQ_SCR_DPAGE);
+								set_menu_pattern(
+									aperture_menu,
+									aperture_array[nearest_match(
+										aperture(exposure(atoi(iso_sel)), fraction_to_double(shutter_sel)),
+										4,
+										n_aperture
+									)]
+								);
+								menu_driver(aperture_menu, REQ_DOWN_ITEM);
+								menu_driver(aperture_menu, REQ_UP_ITEM);
+								wrefresh(aperture_win);
+							}
+							/* clear the selections for next time */
+							strcpy(iso_sel, "");
+							strcpy(shutter_sel, "");
+							strcpy(aperture_sel, "");
+							/* And set defaults back to start */
+							selection_counter = 1;
+							menu_counter = 1;
+							menu = &exposure_menu;
+							win = &exposure_win;
+							move(LINES - 2, 0);
+							clrtoeol();
+							mvprintw(LINES - 2, 0, "Select EV");
+							refresh();
+						}
+						break;
+					}
+				}
+				/* If over/under need to clear selection so know which is blank
+				 * when a proper selection is made */
+				if ((strcmp("OVER", shutter_sel) == 0) || (strcmp("UNDER", shutter_sel) == 0)) {
+					strcpy(shutter_sel, "");
+				}
+				if ((strcmp("OVER", aperture_sel) == 0) || (strcmp("UNDER", aperture_sel) == 0)) {
+					strcpy(aperture_sel, "");
+				}
+			}
+			break;
+		}
+		wrefresh(*win);
 	}	
 	/* Unpost and free all the memory taken up */
 	remove_menu(exposure_items, exposure_menu, n_exposure);
 	remove_menu(iso_items, iso_menu, n_iso);
 	remove_menu(shutter_items, shutter_menu, n_shutter);
 	remove_menu(aperture_items, aperture_menu, n_aperture);
 	endwin();
 }
 
-void add_menu(char **array, ITEM **items, MENU *men, WINDOW *win, int n, int xpos, char *title) {
+ITEM **add_item(char **array, int n) {
 	int i;
+	ITEM **local_items;
 
-	items = (ITEM **)calloc(n, sizeof(ITEM *));
+	local_items = (ITEM **)calloc(n, sizeof(ITEM *));
 	for(i = 0; i<n; ++i) {
-		items[i] = new_item(array[i], array[i]);
-		set_item_userptr(items[i], selection);
-	}
-	men = new_menu((ITEM **)items);
-	win = newwin(10, 40, 4, xpos);
-	keypad(win, TRUE);
-	set_menu_win(men, win);
-	set_menu_sub(men, derwin(win, 6, 38, 3, 1));
-	set_menu_format(men, 5, 1);
-	set_menu_mark(men, " * ");
-	box(win, 0, 0);
-	print_in_middle(win, 1, 0, 40, title, COLOR_PAIR(1));
-	mvwaddch(win, 2, 0, ACS_LTEE);
-	mvwhline(win, 2, 1, ACS_HLINE, 38);
-	mvwaddch(win, 2, 39, ACS_RTEE);
-	post_menu(men);
-	wrefresh(win);
+		local_items[i] = new_item(array[i], array[i]);
+		set_item_userptr(local_items[i], selection);
+	}
+	return local_items;
+}
+
+MENU *add_menu(ITEM **items) {
+	MENU *local_menu;
+
+	local_menu = new_menu((ITEM **)items);
+	set_menu_format(local_menu, 5, 1);
+	set_menu_mark(local_menu, " * ");
+	return local_menu;
+}
+
+WINDOW *add_window(int xpos, char *title) {
+	WINDOW *local_win;
+
+	local_win = newwin(10, 40, 4, xpos);
+	keypad(local_win, TRUE);
+	box(local_win, 0, 0);
+	print_in_middle(local_win, 1, 0, 40, title, COLOR_PAIR(1));
+	mvwaddch(local_win, 2, 0, ACS_LTEE);
+	mvwhline(local_win, 2, 1, ACS_HLINE, 38);
+	mvwaddch(local_win, 2, 39, ACS_RTEE);
+	return local_win;
 }
 
 void remove_menu(ITEM **items, MENU *men, int n) {
 	int i;
 
@@ -348,61 +400,78 @@
 double aperture (int exposure, double shutter) {
 	/* EV = log2 (N^2/t) */
 	return sqrt(pow(2, exposure) * shutter);
 }
 
-int nearest_match (double x, int menu) {
+int nearest_match (double x, int menu, int n_array) {
 	/* Need to search array for closest match */
 	int n;
-	int diff_idx = 0;
+	int diff_idx = 1;
 	char array_value_str[9];
 	double array_value_db;
 	double diff;
 
 	/* Need a starting value for difference */
 	switch(menu) {
-		case 1:
-			array_value_db = strtod(iso_array[0], NULL);
-			break;
-		case 2:
-			array_value_db = fraction_to_double(shutter_array[0]);
-			break;
-		case 3:
-			strncpy(array_value_str, aperture_array[0]+2, 4);
+		case 3:
+			array_value_db = fraction_to_double(shutter_array[1]);
+			break;
+		case 4:
+			strncpy(array_value_str, aperture_array[1]+2, 4);
 			array_value_db = strtod(array_value_str, NULL);
 			break;
 	}
 	diff = fabs(array_value_db - x);
 	/* lots of repetition here but pointers to arrays seem to be a bad thing */
+	/* Could do from n = 3 (2 above) until != under/over
+	 * but also need to do something like if diff is more than twice max/min then under/over */
 	switch(menu) {
-		case 1:
-			for ( n = 1; iso_array[n] != NULL; ++n ) {
-				array_value_db = strtod(iso_array[n], NULL);
-				if (fabs(array_value_db - x) < diff) { 
-					diff_idx = n;
-					diff = fabs(array_value_db - x);
-				}
-			}
-			break;
-		case 2:
-			for ( n = 1; shutter_array[n] != NULL; ++n ) {
+		case 3:
+			for ( n = 2; n < n_array-1; ++n ) {
 				array_value_db = fraction_to_double(shutter_array[n]);
 				if (fabs(array_value_db - x) < diff) {
 					diff_idx = n;
 					diff = fabs(array_value_db - x);
 				}
+			}
+			/* Check if at extremities and then if under/over exposed */
+			if (diff_idx == 1) {
+				if (diff >= fraction_to_double(shutter_array[1])/2) { /* diff is greater than diff of next one down minus max/min */
+					diff_idx = 0;
+				}
+			}
+			if (diff_idx == n_array-2) {
+				if (diff >= fraction_to_double(shutter_array[n_array-2])*2) {
+					diff_idx = n_array-1;	
+				}
 			}
 			break;
-		case 3:
-			for ( n = 1; aperture_array[n] != NULL; ++n ) {
+		case 4:
+			for ( n = 2; n < n_array-1; ++n ) {
 				strncpy(array_value_str, aperture_array[n]+2, 4);
 				array_value_db = strtod(array_value_str, NULL);
 				if (fabs(array_value_db - x) < diff) { 
 					diff_idx = n;
 					diff = fabs(array_value_db - x);
 				}
 			}
+			/* Apertures similarly. Although progression is fiddlier.*/
+			if (diff_idx == 1) {
+				strncpy(array_value_str, aperture_array[1]+2, 4);
+				array_value_db = strtod(array_value_str, NULL);
+				if (diff >= array_value_db/sqrt(2.0)) { /* diff is greater than diff of next one down minus max/min */
+					diff_idx = 0;
+				}
+			}
+			if (diff_idx == n_array-2) {
+				strncpy(array_value_str, aperture_array[n_array-2]+2, 4);
+				array_value_db = strtod(array_value_str, NULL);
+				if (diff >= array_value_db*sqrt(2.0)) {
+					diff_idx = n_array-1;	
+				}
+			}
+
 			break;
 	}
 	return diff_idx;
 }