Add partial SCS support

Allow G0 to be set to the DEC Special Graphics Character Set or ASCII.

ANSI.c

@@ -211,7 +211,7 @@ int   es_argc;			// escape sequence args count
 int   es_argv[MAX_ARG]; 	// escape sequence args
 TCHAR Pt_arg[MAX_PATH*2];	// text parameter for Operating System Command
 int   Pt_len;
-BOOL  shifted;
+BOOL  shifted, G0_special;
 int   screen_top = -1;		// initial window top when cleared
 
 
@@ -1573,7 +1573,7 @@ ParseAndPrintString( HANDLE hDev,
   {
     hConOut = hDev;
     state = 1;
-    shifted = FALSE;
+    shifted = G0_special = FALSE;
   }
   for (i = nNumberOfBytesToWrite, s = (LPCTSTR)lpBuffer; i > 0; i--, s++)
   {
@@ -1594,7 +1594,7 @@ ParseAndPrintString( HANDLE hDev,
 	  hBell = CreateThread( NULL, 4096, BellThread, NULL, 0, NULL );
       }
       else if (c == SO) shifted = TRUE;
-      else if (c == SI) shifted = FALSE;
+      else if (c == SI) shifted = G0_special;
       else PushBuffer( (WCHAR)c );
     }
     else if (state == 2)
@@ -1611,7 +1611,16 @@ ParseAndPrintString( HANDLE hDev,
       else if (c >= '\x20' && c <= '\x2f')
 	suffix2 = c;
       else if (suffix2 != 0)
+      {
+	if (suffix2 == '(')     // Designate G0 character set
+	{
+	  if (c == '0')
+	    shifted = G0_special = TRUE;
+	  else if (c == 'B')
+	    shifted = G0_special = FALSE;
+	}
 	state = 1;
+      }
       else if (c == 'E')        // NEL Next Line
       {
 	PushBuffer( '\n' );

readme.txt

@@ -202,6 +202,8 @@ Sequences Recognised
 	\eE		NEL	Next Line
 	\e[#b		REP	Repeat
 	\eM		RI	Reverse Index
+	\e(0		SCS	Select Character Set (DEC special graphics)
+	\e(B		SCS	Select Character Set (ASCII)
 	\e[#;#;#m	SGR	Select Graphic Rendition
 	\e[#d		VPA	Line Position Absolute
 	\e[#k		VPB	Line Position Backward
@@ -209,12 +211,14 @@ Sequences Recognised
 
     '\e' represents the escape character (ASCII 27); '#' represents a decimal
     number (optional, in most cases defaulting to 1); BEL, SO and SI are ASCII
-    7, 14 and 15.  Regarding SGR: bold will set the foreground intensity; blink
-    and underline will set the background intensity; conceal uses background as
-    foreground.  See "sequences.txt" for a more complete description.
+    7, 14 and 15.  See "sequences.txt" for a more complete description.
 
     Escape followed by a control character will display that character, not
-    perform its function.  An unrecognised sequence will preserve the escape.
+    perform its function; an unrecognised character will preserve the escape.
+
+    SO will select the G1 character set; SI will select the G0 set.  The G0
+    character set is set by SCS; the G1 character set is always the DEC
+    Special Graphics Character Set.
 
     I make a distinction between '\e[m' and '\e[0;...m'.  Both will restore the
     original foreground/background colors (and so '0' should be the first para-
@@ -230,20 +234,6 @@ Sequences Recognised
     scroll in a new window.
 
 
-Sequences Ignored
-=================
-
-    The following escape sequences are explicitly ignored.
-
-	\e(?		Designate G0 character set ('?' is any character).
-	\e)?		Designate G1 character set ('?' is any character).
-	\e[?... 	Private sequence
-	\e[>... 	Private sequence
-
-    The G0 character set is always ASCII; the G1 character set is always the
-    DEC Special Graphics Character Set.
-
-
 DEC Special Graphics Character Set
 ==================================
 
@@ -253,7 +243,7 @@ DEC Special Graphics Character Set
 
 	Char	Unicode Code Point & Name
 	----	-------------------------
-	_	U+00A0	No-Break Space (blank)
+	_	U+00A0	No-Break Space
 	`	U+2666	Black Diamond Suit
 	a	U+2592	Medium Shade
 	b	U+2409	Symbol For Horizontal Tabulation
@@ -330,7 +320,8 @@ Version History
     + added '+' intermediate byte to use the buffer, rather than the window;
     + added palette sequences;
     + added -pu to unload from the parent;
-    + added IND, NEL, RI, DA, DECCOLM, DECNCSM, DECSC & DECRC.
+    + added IND, NEL, RI, DA, DECCOLM, DECNCSM, DECSC & DECRC;
+    + added SCS, but only for special/ASCII (same as Win10).
 
     1.72 - 24 December, 2015:
     - handle STD_OUTPUT_HANDLE & STD_ERROR_HANDLE in WriteFile;

sequences.txt

@@ -124,6 +124,9 @@ M	move cursor up one line (scroll if necessary; always uses buffer)
 [u	move cursor to saved position (or top-left, if nothing was saved)
 8	as above
 
+(0	select the DEC Special Graphics Character Set
+(B	select ASCII
+
 [3h	display control characters (LF is also performed)
 [3l	perform control functions (the only such recognised during above)
 [?3h	set 132 columns