Wide character support.

Thanks "Eon S. Jeon" <esjeon@hyunmu.am>!

TODO

@@ -1,7 +1,6 @@
 vt emulation
 ------------
 
-* wide-character support in conjunction with fallback xft code 
 * double-height support
 
 code & interface

st.c

@@ -27,6 +27,7 @@
 #include <X11/keysym.h>
 #include <X11/Xft/Xft.h>
 #include <fontconfig/fontconfig.h>
+#include <wchar.h>
 
 #include "arg.h"
 
@@ -96,6 +97,8 @@ enum glyph_attribute {
 	ATTR_ITALIC    = 16,
 	ATTR_BLINK     = 32,
 	ATTR_WRAP      = 64,
+	ATTR_WIDE      = 128,
+	ATTR_WDUMMY    = 256,
 };
 
 enum cursor_movement {
@@ -165,7 +168,7 @@ typedef unsigned short ushort;
 
 typedef struct {
 	char c[UTF_SIZ]; /* character code */
-	uchar mode;      /* attribute flags */
+	ushort mode;      /* attribute flags */
 	ulong fg;        /* foreground  */
 	ulong bg;        /* background  */
 } Glyph;
@@ -719,8 +722,13 @@ selsnap(int mode, int *x, int *y, int direction) {
 				}
 			}
 
+			if(term.line[*y][*x+direction].mode & ATTR_WDUMMY) {
+				*x += direction;
+				continue;
+			}
+
 			if(strchr(worddelimiters,
-					term.line[*y][*x + direction].c[0])) {
+					term.line[*y][*x+direction].c[0])) {
 				break;
 			}
 
@@ -932,7 +940,7 @@ selcopy(void) {
 				/* nothing */;
 
 			for(x = 0; gp <= last; x++, ++gp) {
-				if(!selected(x, y))
+				if(!selected(x, y) || (gp->mode & ATTR_WDUMMY))
 					continue;
 
 				size = utf8size(gp->c);
@@ -1533,6 +1541,16 @@ tsetchar(char *c, Glyph *attr, int x, int y) {
 		}
 	}
 
+	if(term.line[y][x].mode & ATTR_WIDE) {
+		if(x+1 < term.col) {
+			term.line[y][x+1].c[0] = ' ';
+			term.line[y][x+1].mode &= ~ATTR_WDUMMY;
+		}
+	} else if(term.line[y][x].mode & ATTR_WDUMMY) {
+		term.line[y][x-1].c[0] = ' ';
+		term.line[y][x-1].mode &= ~ATTR_WIDE;
+	}
+
 	term.dirty[y] = 1;
 	term.line[y][x] = *attr;
 	memcpy(term.line[y][x].c, c, UTF_SIZ);
@@ -2222,6 +2240,15 @@ void
 tputc(char *c, int len) {
 	uchar ascii = *c;
 	bool control = ascii < '\x20' || ascii == 0177;
+	long u8char;
+	int width;
+
+	if(len == 1) {
+		width = 1;
+	} else {
+		utf8decode(c, &u8char);
+		width = wcwidth(u8char);
+	}
 
 	if(iofd != -1) {
 		if(xwrite(iofd, c, len) < 0) {
@@ -2469,9 +2496,20 @@ tputc(char *c, int len) {
 			(term.col - term.c.x - 1) * sizeof(Glyph));
 	}
 
+	if(term.c.x+width > term.col)
+		tnewline(1);
+
 	tsetchar(c, &term.c.attr, term.c.x, term.c.y);
+
+	if(width == 2) {
+		term.line[term.c.y][term.c.x].mode |= ATTR_WIDE;
 		if(term.c.x+1 < term.col) {
-		tmoveto(term.c.x+1, term.c.y);
+			term.line[term.c.y][term.c.x+1].c[0] = '\0';
+			term.line[term.c.y][term.c.x+1].mode = ATTR_WDUMMY;
+		}
+	}
+	if(term.c.x+width < term.col) {
+		tmoveto(term.c.x+width, term.c.y);
 	} else {
 		term.c.state |= CURSOR_WRAPNEXT;
 	}
@@ -3173,7 +3211,7 @@ xdraws(char *s, Glyph base, int x, int y, int charlen, int bytelen) {
 				xp, winy + frc[i].font->ascent,
 				(FcChar8 *)u8c, u8cblen);
 
-		xp += xw.cw;
+		xp += xw.cw * wcwidth(u8char);
 	}
 
 	/*
@@ -3193,18 +3231,27 @@ xdraws(char *s, Glyph base, int x, int y, int charlen, int bytelen) {
 void
 xdrawcursor(void) {
 	static int oldx = 0, oldy = 0;
-	int sl;
+	int sl, width, curx;
 	Glyph g = {{' '}, ATTR_NULL, defaultbg, defaultcs};
 
 	LIMIT(oldx, 0, term.col-1);
 	LIMIT(oldy, 0, term.row-1);
 
+	curx = term.c.x;
+
+	/* adjust position if in dummy */
+	if(term.line[oldy][oldx].mode & ATTR_WDUMMY)
+		oldx--;
+	if(term.line[term.c.y][curx].mode & ATTR_WDUMMY)
+		curx--;
+
 	memcpy(g.c, term.line[term.c.y][term.c.x].c, UTF_SIZ);
 
 	/* remove the old cursor */
 	sl = utf8size(term.line[oldy][oldx].c);
+	width = (term.line[oldy][oldx].mode & ATTR_WIDE)? 2 : 1;
 	xdraws(term.line[oldy][oldx].c, term.line[oldy][oldx], oldx,
-			oldy, 1, sl);
+			oldy, width, sl);
 
 	/* draw the new one */
 	if(!(IS_SET(MODE_HIDE))) {
@@ -3216,26 +3263,28 @@ xdrawcursor(void) {
 			}
 
 			sl = utf8size(g.c);
-			xdraws(g.c, g, term.c.x, term.c.y, 1, sl);
+			width = (term.line[term.c.y][curx].mode & ATTR_WIDE)\
+				? 2 : 1;
+			xdraws(g.c, g, term.c.x, term.c.y, width, sl);
 		} else {
 			XftDrawRect(xw.draw, &dc.col[defaultcs],
-					borderpx + term.c.x * xw.cw,
+					borderpx + curx * xw.cw,
 					borderpx + term.c.y * xw.ch,
 					xw.cw - 1, 1);
 			XftDrawRect(xw.draw, &dc.col[defaultcs],
-					borderpx + term.c.x * xw.cw,
+					borderpx + curx * xw.cw,
 					borderpx + term.c.y * xw.ch,
 					1, xw.ch - 1);
 			XftDrawRect(xw.draw, &dc.col[defaultcs],
-					borderpx + (term.c.x + 1) * xw.cw - 1,
+					borderpx + (curx + 1) * xw.cw - 1,
 					borderpx + term.c.y * xw.ch,
 					1, xw.ch - 1);
 			XftDrawRect(xw.draw, &dc.col[defaultcs],
-					borderpx + term.c.x * xw.cw,
+					borderpx + curx * xw.cw,
 					borderpx + (term.c.y + 1) * xw.ch - 1,
 					xw.cw, 1);
 		}
-		oldx = term.c.x, oldy = term.c.y;
+		oldx = curx, oldy = term.c.y;
 	}
 }
 
@@ -3284,6 +3333,7 @@ drawregion(int x1, int y1, int x2, int y2) {
 	Glyph base, new;
 	char buf[DRAW_BUF_SIZ];
 	bool ena_sel = sel.ob.x != -1;
+	long u8char;
 
 	if(sel.alt ^ IS_SET(MODE_ALTSCREEN))
 		ena_sel = 0;
@@ -3301,6 +3351,8 @@ drawregion(int x1, int y1, int x2, int y2) {
 		ic = ib = ox = 0;
 		for(x = x1; x < x2; x++) {
 			new = term.line[y][x];
+			if(new.mode == ATTR_WDUMMY)
+				continue;
 			if(ena_sel && selected(x, y))
 				new.mode ^= ATTR_REVERSE;
 			if(ib > 0 && (ATTRCMP(base, new)
@@ -3313,10 +3365,10 @@ drawregion(int x1, int y1, int x2, int y2) {
 				base = new;
 			}
 
-			sl = utf8size(new.c);
+			sl = utf8decode(new.c, &u8char);
 			memcpy(buf+ib, new.c, sl);
 			ib += sl;
-			++ic;
+			ic += (new.mode & ATTR_WIDE)? 2 : 1;
 		}
 		if(ib > 0)
 			xdraws(buf, base, ox, y, ic, ib);