dotfiles

st-scrollback-ringbuffer.diff (18818B)

---

 diff --git a/config.def.h b/config.def.h
 index 2cd740a..8b25d40 100644
 --- a/config.def.h
 +++ b/config.def.h
 @@ -201,6 +201,8 @@ static Shortcut shortcuts[] = {
  	{ TERMMOD,              XK_Y,           selpaste,       {.i =  0} },
  	{ ShiftMask,            XK_Insert,      selpaste,       {.i =  0} },
  	{ TERMMOD,              XK_Num_Lock,    numlock,        {.i =  0} },
 +	{ ShiftMask,            XK_Page_Up,     kscrollup,      {.i = -1} },
 +	{ ShiftMask,            XK_Page_Down,   kscrolldown,    {.i = -1} },
  };
  
  /*
 diff --git a/st.c b/st.c
 index 57c6e96..a3b3c9d 100644
 --- a/st.c
 +++ b/st.c
 @@ -43,6 +43,10 @@
  #define ISCONTROL(c)		(ISCONTROLC0(c) || ISCONTROLC1(c))
  #define ISDELIM(u)		(u && wcschr(worddelimiters, u))
  
 +#define TSCREEN term.screen[IS_SET(MODE_ALTSCREEN)]
 +#define TLINEOFFSET(y) (((y) + TSCREEN.cur - TSCREEN.off + TSCREEN.size) % TSCREEN.size)
 +#define TLINE(y) (TSCREEN.buffer[TLINEOFFSET(y)])
 +
  enum term_mode {
  	MODE_WRAP        = 1 << 0,
  	MODE_INSERT      = 1 << 1,
 @@ -109,12 +113,21 @@ typedef struct {
  	int alt;
  } Selection;
  
 +/* Screen lines */
 +typedef struct {
 +	Line* buffer;  /* ring buffer */
 +	int size;      /* size of buffer */
 +	int cur;       /* start of active screen */
 +	int off;       /* scrollback line offset */
 +	TCursor sc;    /* saved cursor */
 +} LineBuffer;
 +
  /* Internal representation of the screen */
  typedef struct {
  	int row;      /* nb row */
  	int col;      /* nb col */
 -	Line *line;   /* screen */
 -	Line *alt;    /* alternate screen */
 +	LineBuffer screen[2]; /* screen and alternate screen */
 +	int linelen;  /* allocated line length */
  	int *dirty;   /* dirtyness of lines */
  	TCursor c;    /* cursor */
  	int ocx;      /* old cursor col */
 @@ -203,6 +216,8 @@ static void tdeftran(char);
  static void tstrsequence(uchar);
  
  static void drawregion(int, int, int, int);
 +static void clearline(Line, Glyph, int, int);
 +static Line ensureline(Line);
  
  static void selnormalize(void);
  static void selscroll(int, int);
 @@ -408,11 +423,12 @@ int
  tlinelen(int y)
  {
  	int i = term.col;
 +	Line line = TLINE(y);
  
 -	if (term.line[y][i - 1].mode & ATTR_WRAP)
 +	if (line[i - 1].mode & ATTR_WRAP)
  		return i;
  
 -	while (i > 0 && term.line[y][i - 1].u == ' ')
 +	while (i > 0 && line[i - 1].u == ' ')
  		--i;
  
  	return i;
 @@ -521,7 +537,7 @@ selsnap(int *x, int *y, int direction)
  		 * Snap around if the word wraps around at the end or
  		 * beginning of a line.
  		 */
 -		prevgp = &term.line[*y][*x];
 +		prevgp = &TLINE(*y)[*x];
  		prevdelim = ISDELIM(prevgp->u);
  		for (;;) {
  			newx = *x + direction;
 @@ -536,14 +552,14 @@ selsnap(int *x, int *y, int direction)
  					yt = *y, xt = *x;
  				else
  					yt = newy, xt = newx;
 -				if (!(term.line[yt][xt].mode & ATTR_WRAP))
 +				if (!(TLINE(yt)[xt].mode & ATTR_WRAP))
  					break;
  			}
  
  			if (newx >= tlinelen(newy))
  				break;
  
 -			gp = &term.line[newy][newx];
 +			gp = &TLINE(newy)[newx];
  			delim = ISDELIM(gp->u);
  			if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
  					|| (delim && gp->u != prevgp->u)))
 @@ -564,14 +580,14 @@ selsnap(int *x, int *y, int direction)
  		*x = (direction < 0) ? 0 : term.col - 1;
  		if (direction < 0) {
  			for (; *y > 0; *y += direction) {
 -				if (!(term.line[*y-1][term.col-1].mode
 +				if (!(TLINE(*y-1)[term.col-1].mode
  						& ATTR_WRAP)) {
  					break;
  				}
  			}
  		} else if (direction > 0) {
  			for (; *y < term.row-1; *y += direction) {
 -				if (!(term.line[*y][term.col-1].mode
 +				if (!(TLINE(*y)[term.col-1].mode
  						& ATTR_WRAP)) {
  					break;
  				}
 @@ -602,13 +618,13 @@ getsel(void)
  		}
  
  		if (sel.type == SEL_RECTANGULAR) {
 -			gp = &term.line[y][sel.nb.x];
 +			gp = &TLINE(y)[sel.nb.x];
  			lastx = sel.ne.x;
  		} else {
 -			gp = &term.line[y][sel.nb.y == y ? sel.nb.x : 0];
 +			gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
  			lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
  		}
 -		last = &term.line[y][MIN(lastx, linelen-1)];
 +		last = &TLINE(y)[MIN(lastx, linelen-1)];
  		while (last >= gp && last->u == ' ')
  			--last;
  
 @@ -949,12 +965,15 @@ int
  tattrset(int attr)
  {
  	int i, j;
 +	int y = TLINEOFFSET(0);
  
  	for (i = 0; i < term.row-1; i++) {
 +		Line line = TSCREEN.buffer[y];
  		for (j = 0; j < term.col-1; j++) {
 -			if (term.line[i][j].mode & attr)
 +			if (line[j].mode & attr)
  				return 1;
  		}
 +		y = (y+1) % TSCREEN.size;
  	}
  
  	return 0;
 @@ -976,14 +995,17 @@ void
  tsetdirtattr(int attr)
  {
  	int i, j;
 +	int y = TLINEOFFSET(0);
  
  	for (i = 0; i < term.row-1; i++) {
 +		Line line = TSCREEN.buffer[y];
  		for (j = 0; j < term.col-1; j++) {
 -			if (term.line[i][j].mode & attr) {
 +			if (line[j].mode & attr) {
  				tsetdirt(i, i);
  				break;
  			}
  		}
 +		y = (y+1) % TSCREEN.size;
  	}
  }
  
 @@ -996,27 +1018,19 @@ tfulldirt(void)
  void
  tcursor(int mode)
  {
 -	static TCursor c[2];
 -	int alt = IS_SET(MODE_ALTSCREEN);
 -
  	if (mode == CURSOR_SAVE) {
 -		c[alt] = term.c;
 +		TSCREEN.sc = term.c;
  	} else if (mode == CURSOR_LOAD) {
 -		term.c = c[alt];
 -		tmoveto(c[alt].x, c[alt].y);
 +		term.c = TSCREEN.sc;
 +		tmoveto(term.c.x, term.c.y);
  	}
  }
  
  void
  treset(void)
  {
 -	uint i;
 -
 -	term.c = (TCursor){{
 -		.mode = ATTR_NULL,
 -		.fg = defaultfg,
 -		.bg = defaultbg
 -	}, .x = 0, .y = 0, .state = CURSOR_DEFAULT};
 +	int i, j;
 +	Glyph g = (Glyph){ .fg = defaultfg, .bg = defaultbg};
  
  	memset(term.tabs, 0, term.col * sizeof(*term.tabs));
  	for (i = tabspaces; i < term.col; i += tabspaces)
 @@ -1028,17 +1042,37 @@ treset(void)
  	term.charset = 0;
  
  	for (i = 0; i < 2; i++) {
 -		tmoveto(0, 0);
 -		tcursor(CURSOR_SAVE);
 -		tclearregion(0, 0, term.col-1, term.row-1);
 -		tswapscreen();
 +		term.screen[i].sc = (TCursor){{
 +			.fg = defaultfg,
 +			.bg = defaultbg
 +		}};
 +		term.screen[i].cur = 0;
 +		term.screen[i].off = 0;
 +		for (j = 0; j < term.row; ++j) {
 +			if (term.col != term.linelen)
 +				term.screen[i].buffer[j] = xrealloc(term.screen[i].buffer[j], term.col * sizeof(Glyph));
 +			clearline(term.screen[i].buffer[j], g, 0, term.col);
 +		}
 +		for (j = term.row; j < term.screen[i].size; ++j) {
 +			free(term.screen[i].buffer[j]);
 +			term.screen[i].buffer[j] = NULL;
 +		}
  	}
 +	tcursor(CURSOR_LOAD);
 +	term.linelen = term.col;
 +	tfulldirt();
  }
  
  void
  tnew(int col, int row)
  {
 -	term = (Term){ .c = { .attr = { .fg = defaultfg, .bg = defaultbg } } };
 +	int i;
 +	term = (Term){};
 +	term.screen[0].buffer = xmalloc(HISTSIZE * sizeof(Line));
 +	term.screen[0].size = HISTSIZE;
 +	term.screen[1].buffer = NULL;
 +	for (i = 0; i < HISTSIZE; ++i) term.screen[0].buffer[i] = NULL;
 +
  	tresize(col, row);
  	treset();
  }
 @@ -1046,14 +1080,42 @@ tnew(int col, int row)
  void
  tswapscreen(void)
  {
 -	Line *tmp = term.line;
 -
 -	term.line = term.alt;
 -	term.alt = tmp;
  	term.mode ^= MODE_ALTSCREEN;
  	tfulldirt();
  }
  
 +void
 +kscrollup(const Arg *a)
 +{
 +	int n = a->i;
 +
 +	if (IS_SET(MODE_ALTSCREEN))
 +		return;
 +
 +	if (n < 0) n = (-n) * term.row;
 +	if (n > TSCREEN.size - term.row - TSCREEN.off) n = TSCREEN.size - term.row - TSCREEN.off;
 +	while (!TLINE(-n)) --n;
 +	TSCREEN.off += n;
 +	selscroll(0, n);
 +	tfulldirt();
 +}
 +
 +void
 +kscrolldown(const Arg *a)
 +{
 +
 +	int n = a->i;
 +
 +	if (IS_SET(MODE_ALTSCREEN))
 +		return;
 +
 +	if (n < 0) n = (-n) * term.row;
 +	if (n > TSCREEN.off) n = TSCREEN.off;
 +	TSCREEN.off -= n;
 +	selscroll(0, -n);
 +	tfulldirt();
 +}
 +
  void
  tscrolldown(int orig, int n)
  {
 @@ -1062,15 +1124,29 @@ tscrolldown(int orig, int n)
  
  	LIMIT(n, 0, term.bot-orig+1);
  
 -	tsetdirt(orig, term.bot-n);
 -	tclearregion(0, term.bot-n+1, term.col-1, term.bot);
 +	/* Ensure that lines are allocated */
 +	for (i = -n; i < 0; i++) {
 +		TLINE(i) = ensureline(TLINE(i));
 +	}
  
 -	for (i = term.bot; i >= orig+n; i--) {
 -		temp = term.line[i];
 -		term.line[i] = term.line[i-n];
 -		term.line[i-n] = temp;
 +	/* Shift non-scrolling areas in ring buffer */
 +	for (i = term.bot+1; i < term.row; i++) {
 +		temp = TLINE(i);
 +		TLINE(i) = TLINE(i-n);
 +		TLINE(i-n) = temp;
 +	}
 +	for (i = 0; i < orig; i++) {
 +		temp = TLINE(i);
 +		TLINE(i) = TLINE(i-n);
 +		TLINE(i-n) = temp;
  	}
  
 +	/* Scroll buffer */
 +	TSCREEN.cur = (TSCREEN.cur + TSCREEN.size - n) % TSCREEN.size;
 +	/* Clear lines that have entered the view */
 +	tclearregion(0, orig, term.linelen-1, orig+n-1);
 +	/* Redraw portion of the screen that has scrolled */
 +	tsetdirt(orig+n-1, term.bot);
  	selscroll(orig, n);
  }
  
 @@ -1082,15 +1158,29 @@ tscrollup(int orig, int n)
  
  	LIMIT(n, 0, term.bot-orig+1);
  
 -	tclearregion(0, orig, term.col-1, orig+n-1);
 -	tsetdirt(orig+n, term.bot);
 +	/* Ensure that lines are allocated */
 +	for (i = term.row; i < term.row + n; i++) {
 +		TLINE(i) = ensureline(TLINE(i));
 +	}
  
 -	for (i = orig; i <= term.bot-n; i++) {
 -		temp = term.line[i];
 -		term.line[i] = term.line[i+n];
 -		term.line[i+n] = temp;
 +	/* Shift non-scrolling areas in ring buffer */
 +	for (i = orig-1; i >= 0; i--) {
 +		temp = TLINE(i);
 +		TLINE(i) = TLINE(i+n);
 +		TLINE(i+n) = temp;
 +	}
 +	for (i = term.row-1; i >term.bot; i--) {
 +		temp = TLINE(i);
 +		TLINE(i) = TLINE(i+n);
 +		TLINE(i+n) = temp;
  	}
  
 +	/* Scroll buffer */
 +	TSCREEN.cur = (TSCREEN.cur + n) % TSCREEN.size;
 +	/* Clear lines that have entered the view */
 +	tclearregion(0, term.bot-n+1, term.linelen-1, term.bot);
 +	/* Redraw portion of the screen that has scrolled */
 +	tsetdirt(orig, term.bot-n+1);
  	selscroll(orig, -n);
  }
  
 @@ -1197,6 +1287,7 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
  		"⎻", "─", "⎼", "⎽", "├", "┤", "┴", "┬", /* p - w */
  		"│", "≤", "≥", "π", "≠", "£", "·", /* x - ~ */
  	};
 +	Line line = TLINE(y);
  
  	/*
  	 * The table is proudly stolen from rxvt.
 @@ -1205,25 +1296,25 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
  	   BETWEEN(u, 0x41, 0x7e) && vt100_0[u - 0x41])
  		utf8decode(vt100_0[u - 0x41], &u, UTF_SIZ);
  
 -	if (term.line[y][x].mode & ATTR_WIDE) {
 +	if (line[x].mode & ATTR_WIDE) {
  		if (x+1 < term.col) {
 -			term.line[y][x+1].u = ' ';
 -			term.line[y][x+1].mode &= ~ATTR_WDUMMY;
 +			line[x+1].u = ' ';
 +			line[x+1].mode &= ~ATTR_WDUMMY;
  		}
 -	} else if (term.line[y][x].mode & ATTR_WDUMMY) {
 -		term.line[y][x-1].u = ' ';
 -		term.line[y][x-1].mode &= ~ATTR_WIDE;
 +	} else if (line[x].mode & ATTR_WDUMMY) {
 +		line[x-1].u = ' ';
 +		line[x-1].mode &= ~ATTR_WIDE;
  	}
  
  	term.dirty[y] = 1;
 -	term.line[y][x] = *attr;
 -	term.line[y][x].u = u;
 +	line[x] = *attr;
 +	line[x].u = u;
  }
  
  void
  tclearregion(int x1, int y1, int x2, int y2)
  {
 -	int x, y, temp;
 +	int x, y, L, S, temp;
  	Glyph *gp;
  
  	if (x1 > x2)
 @@ -1231,15 +1322,16 @@ tclearregion(int x1, int y1, int x2, int y2)
  	if (y1 > y2)
  		temp = y1, y1 = y2, y2 = temp;
  
 -	LIMIT(x1, 0, term.col-1);
 -	LIMIT(x2, 0, term.col-1);
 +	LIMIT(x1, 0, term.linelen-1);
 +	LIMIT(x2, 0, term.linelen-1);
  	LIMIT(y1, 0, term.row-1);
  	LIMIT(y2, 0, term.row-1);
  
 +	L = TLINEOFFSET(y1);
  	for (y = y1; y <= y2; y++) {
  		term.dirty[y] = 1;
  		for (x = x1; x <= x2; x++) {
 -			gp = &term.line[y][x];
 +			gp = &TSCREEN.buffer[L][x];
  			if (selected(x, y))
  				selclear();
  			gp->fg = term.c.attr.fg;
 @@ -1247,6 +1339,7 @@ tclearregion(int x1, int y1, int x2, int y2)
  			gp->mode = 0;
  			gp->u = ' ';
  		}
 +		L = (L + 1) % TSCREEN.size;
  	}
  }
  
 @@ -1261,7 +1354,7 @@ tdeletechar(int n)
  	dst = term.c.x;
  	src = term.c.x + n;
  	size = term.col - src;
 -	line = term.line[term.c.y];
 +	line = TLINE(term.c.y);
  
  	memmove(&line[dst], &line[src], size * sizeof(Glyph));
  	tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
 @@ -1278,7 +1371,7 @@ tinsertblank(int n)
  	dst = term.c.x + n;
  	src = term.c.x;
  	size = term.col - dst;
 -	line = term.line[term.c.y];
 +	line = TLINE(term.c.y);
  
  	memmove(&line[dst], &line[src], size * sizeof(Glyph));
  	tclearregion(src, term.c.y, dst - 1, term.c.y);
 @@ -2082,7 +2175,7 @@ tdumpline(int n)
  	char buf[UTF_SIZ];
  	const Glyph *bp, *end;
  
 -	bp = &term.line[n][0];
 +	bp = &TLINE(n)[0];
  	end = &bp[MIN(tlinelen(n), term.col) - 1];
  	if (bp != end || bp->u != ' ') {
  		for ( ; bp <= end; ++bp)
 @@ -2469,11 +2562,11 @@ check_control_code:
  	if (selected(term.c.x, term.c.y))
  		selclear();
  
 -	gp = &term.line[term.c.y][term.c.x];
 +	gp = &TLINE(term.c.y)[term.c.x];
  	if (IS_SET(MODE_WRAP) && (term.c.state & CURSOR_WRAPNEXT)) {
  		gp->mode |= ATTR_WRAP;
  		tnewline(1);
 -		gp = &term.line[term.c.y][term.c.x];
 +		gp = &TLINE(term.c.y)[term.c.x];
  	}
  
  	if (IS_SET(MODE_INSERT) && term.c.x+width < term.col) {
 @@ -2486,7 +2579,7 @@ check_control_code:
  			tnewline(1);
  		else
  			tmoveto(term.col - width, term.c.y);
 -		gp = &term.line[term.c.y][term.c.x];
 +		gp = &TLINE(term.c.y)[term.c.x];
  	}
  
  	tsetchar(u, &term.c.attr, term.c.x, term.c.y);
 @@ -2517,6 +2610,11 @@ twrite(const char *buf, int buflen, int show_ctrl)
  	Rune u;
  	int n;
  
 +	if (TSCREEN.off) {
 +		TSCREEN.off = 0;
 +		tfulldirt();
 +	}
 +
  	for (n = 0; n < buflen; n += charsize) {
  		if (IS_SET(MODE_UTF8)) {
  			/* process a complete utf8 char */
 @@ -2543,56 +2641,85 @@ twrite(const char *buf, int buflen, int show_ctrl)
  }
  
  void
 -tresize(int col, int row)
 +clearline(Line line, Glyph g, int x, int xend)
  {
  	int i;
 +	g.mode = 0;
 +	g.u = ' ';
 +	for (i = x; i < xend; ++i) {
 +		line[i] = g;
 +	}
 +}
 +
 +Line
 +ensureline(Line line)
 +{
 +	if (!line) {
 +		line = xmalloc(term.linelen * sizeof(Glyph));
 +	}
 +	return line;
 +}
 +
 +void
 +tresize(int col, int row)
 +{
 +	int i, j;
  	int minrow = MIN(row, term.row);
  	int mincol = MIN(col, term.col);
 +	int linelen = MAX(col, term.linelen);
  	int *bp;
 -	TCursor c;
  
 -	if (col < 1 || row < 1) {
 +	if (col < 1 || row < 1 || row > HISTSIZE) {
  		fprintf(stderr,
  		        "tresize: error resizing to %dx%d\n", col, row);
  		return;
  	}
  
 -	/*
 -	 * slide screen to keep cursor where we expect it -
 -	 * tscrollup would work here, but we can optimize to
 -	 * memmove because we're freeing the earlier lines
 -	 */
 -	for (i = 0; i <= term.c.y - row; i++) {
 -		free(term.line[i]);
 -		free(term.alt[i]);
 +	/* Shift buffer to keep the cursor where we expect it */
 +	if (row <= term.c.y) {
 +		term.screen[0].cur = (term.screen[0].cur - row + term.c.y + 1) % term.screen[0].size;
 +	}
 +
 +	/* Resize and clear line buffers as needed */
 +	if (linelen > term.linelen) {
 +		for (i = 0; i < term.screen[0].size; ++i) {
 +			if (term.screen[0].buffer[i]) {
 +				term.screen[0].buffer[i] = xrealloc(term.screen[0].buffer[i], linelen * sizeof(Glyph));
 +				clearline(term.screen[0].buffer[i], term.c.attr, term.linelen, linelen);
 +			}
 +		}
 +		for (i = 0; i < minrow; ++i) {
 +			term.screen[1].buffer[i] = xrealloc(term.screen[1].buffer[i], linelen * sizeof(Glyph));
 +			clearline(term.screen[1].buffer[i], term.c.attr, term.linelen, linelen);
 +		}
  	}
 -	/* ensure that both src and dst are not NULL */
 -	if (i > 0) {
 -		memmove(term.line, term.line + i, row * sizeof(Line));
 -		memmove(term.alt, term.alt + i, row * sizeof(Line));
 +	/* Allocate all visible lines for regular line buffer */
 +	for (j = term.screen[0].cur, i = 0; i < row; ++i, j = (j + 1) % term.screen[0].size)
 +	{
 +		if (!term.screen[0].buffer[j]) {
 +			term.screen[0].buffer[j] = xmalloc(linelen * sizeof(Glyph));
 +		}
 +		if (i >= term.row) {
 +			clearline(term.screen[0].buffer[j], term.c.attr, 0, linelen);
 +		}
  	}
 -	for (i += row; i < term.row; i++) {
 -		free(term.line[i]);
 -		free(term.alt[i]);
 +	/* Resize alt screen */
 +	term.screen[1].cur = 0;
 +	term.screen[1].size = row;
 +	for (i = row; i < term.row; ++i) {
 +		free(term.screen[1].buffer[i]);
 +	}
 +	term.screen[1].buffer = xrealloc(term.screen[1].buffer, row * sizeof(Line));
 +	for (i = term.row; i < row; ++i) {
 +		term.screen[1].buffer[i] = xmalloc(linelen * sizeof(Glyph));
 +		clearline(term.screen[1].buffer[i], term.c.attr, 0, linelen);
  	}
  
  	/* resize to new height */
 -	term.line = xrealloc(term.line, row * sizeof(Line));
 -	term.alt  = xrealloc(term.alt,  row * sizeof(Line));
  	term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
  	term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
  
 -	/* resize each row to new width, zero-pad if needed */
 -	for (i = 0; i < minrow; i++) {
 -		term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
 -		term.alt[i]  = xrealloc(term.alt[i],  col * sizeof(Glyph));
 -	}
 -
 -	/* allocate any new rows */
 -	for (/* i = minrow */; i < row; i++) {
 -		term.line[i] = xmalloc(col * sizeof(Glyph));
 -		term.alt[i] = xmalloc(col * sizeof(Glyph));
 -	}
 +	/* fix tabstops */
  	if (col > term.col) {
  		bp = term.tabs + term.col;
  
 @@ -2602,26 +2729,16 @@ tresize(int col, int row)
  		for (bp += tabspaces; bp < term.tabs + col; bp += tabspaces)
  			*bp = 1;
  	}
 +
  	/* update terminal size */
  	term.col = col;
  	term.row = row;
 +	term.linelen = linelen;
  	/* reset scrolling region */
  	tsetscroll(0, row-1);
  	/* make use of the LIMIT in tmoveto */
  	tmoveto(term.c.x, term.c.y);
 -	/* Clearing both screens (it makes dirty all lines) */
 -	c = term.c;
 -	for (i = 0; i < 2; i++) {
 -		if (mincol < col && 0 < minrow) {
 -			tclearregion(mincol, 0, col - 1, minrow - 1);
 -		}
 -		if (0 < col && minrow < row) {
 -			tclearregion(0, minrow, col - 1, row - 1);
 -		}
 -		tswapscreen();
 -		tcursor(CURSOR_LOAD);
 -	}
 -	term.c = c;
 +	tfulldirt();
  }
  
  void
 @@ -2633,14 +2750,15 @@ resettitle(void)
  void
  drawregion(int x1, int y1, int x2, int y2)
  {
 -	int y;
 +	int y, L;
  
 +	L = TLINEOFFSET(y1);
  	for (y = y1; y < y2; y++) {
 -		if (!term.dirty[y])
 -			continue;
 -
 -		term.dirty[y] = 0;
 -		xdrawline(term.line[y], x1, y, x2);
 +		if (term.dirty[y]) {
 +			term.dirty[y] = 0;
 +			xdrawline(TSCREEN.buffer[L], x1, y, x2);
 +		}
 +		L = (L + 1) % TSCREEN.size;
  	}
  }
  
 @@ -2655,14 +2773,15 @@ draw(void)
  	/* adjust cursor position */
  	LIMIT(term.ocx, 0, term.col-1);
  	LIMIT(term.ocy, 0, term.row-1);
 -	if (term.line[term.ocy][term.ocx].mode & ATTR_WDUMMY)
 +	if (TLINE(term.ocy)[term.ocx].mode & ATTR_WDUMMY)
  		term.ocx--;
 -	if (term.line[term.c.y][cx].mode & ATTR_WDUMMY)
 +	if (TLINE(term.c.y)[cx].mode & ATTR_WDUMMY)
  		cx--;
  
  	drawregion(0, 0, term.col, term.row);
 -	xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
 -			term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
 +	if (TSCREEN.off == 0)
 +		xdrawcursor(cx, term.c.y, TLINE(term.c.y)[cx],
 +				term.ocx, term.ocy, TLINE(term.ocy)[term.ocx]);
  	term.ocx = cx;
  	term.ocy = term.c.y;
  	xfinishdraw();
 diff --git a/st.h b/st.h
 index fd3b0d8..3cea73b 100644
 --- a/st.h
 +++ b/st.h
 @@ -19,6 +19,7 @@
  
  #define TRUECOLOR(r,g,b)	(1 << 24 | (r) << 16 | (g) << 8 | (b))
  #define IS_TRUECOL(x)		(1 << 24 & (x))
 +#define HISTSIZE            2000
  
  enum glyph_attribute {
  	ATTR_NULL       = 0,
 diff --git a/x.c b/x.c
 index bd23686..25785a6 100644
 --- a/x.c
 +++ b/x.c
 @@ -59,6 +59,8 @@ static void zoom(const Arg *);
  static void zoomabs(const Arg *);
  static void zoomreset(const Arg *);
  static void ttysend(const Arg *);
 +void kscrollup(const Arg *);
 +void kscrolldown(const Arg *);
  
  /* config.h for applying patches and the configuration. */
  #include "config.h"