(draft) Add a special case for cell "details"

This special case of "details" value would print as ':' in the ASCII
display mode. It is used in "positive/negative" graph display only.

Signed-off-by: Kang-Che Sung <explorer09@gmail.com>

Author: Explorer09

Meter.c

@@ -1019,6 +1019,9 @@ static int GraphMeterMode_lookupCell(const Meter* this, const GraphDrawContext*
          blanksAtEnd = (blanksAtEnd % 8) / dotAlignment * dotAlignment;
          *details = (uint8_t)((*details >> blanksAtEnd) << blanksAtEnd);
       }
+      if (*details == 0x3C) {
+         *details = 0x24;
+      }
    }
    /* fallthrough */
 
@@ -1043,7 +1046,7 @@ static void GraphMeterMode_printCellDetails(uint8_t details) {
       // byte contains specific bit patterns, it indicates that only half cell
       // should be displayed in the ASCII display mode. The bits are supposed
       // to be filled in the Unicode display mode.
-      if ((details & 0x9C) == 0x14 || (details & 0x39) == 0x28) {
+      if ((details & 0x9C) == 0x14 || (details & 0x39) == 0x28 || details == 0x24) {
          if (details == 0x14 || details == 0x28) { // Special case
             details = 0x18;
          } else {
@@ -1081,6 +1084,8 @@ static void GraphMeterMode_printCellDetails(uint8_t details) {
       c = upperHalf;
    } else if ((details & 0x39) == 0x28) {
       c = lowerHalf;
+   } else if (details == 0x24) {
+      c = fullCell;
       // End of special cases
    } else if (popCount8(details) > 4) {
       c = fullCell;