commit 2f6aaf6ce302c6530260343c5cc8d0138fdae745
parent 0037784cdeaedeead108414c0232f31e7a1e38b6
Author: wael <40663@protonmail.com>
Date: Sun, 24 Apr 2022 02:07:33 +0300
[st][patch][scrollback] add new reflow patch
Diffstat:
2 files changed, 1484 insertions(+), 0 deletions(-)
diff --git a/st.suckless.org/patches/scrollback/index.md b/st.suckless.org/patches/scrollback/index.md
@@ -17,6 +17,11 @@ efficient scrolling:
* [st-scrollback-ringbuffer-0.8.5.diff](st-scrollback-ringbuffer-0.8.5.diff)
+Apply the following patch on top of the [original scrollback patch (=>0.8.5)](st-scrollback-0.8.5.diff) to allow
+column and row reflow.
+
+* [st-scrollback-reflow-0.8.5.diff](st-scrollback-reflow-0.8.5.diff)
+
Apply the following patch on top of the previous to allow scrolling
using `Shift+MouseWheel`.
@@ -70,3 +75,4 @@ Authors
* Jacob Prosser - <geriatricjacob@cumallover.me>
* Timo Röhling - <timo@gaussglocke.de> (ring buffer implementation)
* [Alexander Arkhipov](gopher://mineeyes.cyou/) - <scm_2022@mineeyes.cyou> (0.8.5 update)
+* Ashish Kumar Yadav - <ashishkumar.yadav@students.iiserpune.ac.in> (reflow implementation)
diff --git a/st.suckless.org/patches/scrollback/st-scrollback-reflow-0.8.5.diff b/st.suckless.org/patches/scrollback/st-scrollback-reflow-0.8.5.diff
@@ -0,0 +1,1478 @@
+diff --git a/st.c b/st.c
+index 91e7077..a76d983 100644
+--- a/st.c
++++ b/st.c
+@@ -36,6 +36,7 @@
+ #define STR_BUF_SIZ ESC_BUF_SIZ
+ #define STR_ARG_SIZ ESC_ARG_SIZ
+ #define HISTSIZE 2000
++#define RESIZEBUFFER 1000
+
+ /* macros */
+ #define IS_SET(flag) ((term.mode & (flag)) != 0)
+@@ -43,9 +44,22 @@
+ #define ISCONTROLC1(c) (BETWEEN(c, 0x80, 0x9f))
+ #define ISCONTROL(c) (ISCONTROLC0(c) || ISCONTROLC1(c))
+ #define ISDELIM(u) (u && wcschr(worddelimiters, u))
+-#define TLINE(y) ((y) < term.scr ? term.hist[((y) + term.histi - \
+- term.scr + HISTSIZE + 1) % HISTSIZE] : \
+- term.line[(y) - term.scr])
++
++#define TLINE(y) ( \
++ (y) < term.scr ? term.hist[(term.histi + (y) - term.scr + 1 + HISTSIZE) % HISTSIZE] \
++ : term.line[(y) - term.scr] \
++)
++
++#define TLINEABS(y) ( \
++ (y) < 0 ? term.hist[(term.histi + (y) + 1 + HISTSIZE) % HISTSIZE] : term.line[(y)] \
++)
++
++#define UPDATEWRAPNEXT(alt, col) do { \
++ if ((term.c.state & CURSOR_WRAPNEXT) && term.c.x + term.wrapcwidth[alt] < col) { \
++ term.c.x += term.wrapcwidth[alt]; \
++ term.c.state &= ~CURSOR_WRAPNEXT; \
++ } \
++} while (0);
+
+ enum term_mode {
+ MODE_WRAP = 1 << 0,
+@@ -57,6 +71,12 @@ enum term_mode {
+ MODE_UTF8 = 1 << 6,
+ };
+
++enum scroll_mode {
++ SCROLL_RESIZE = -1,
++ SCROLL_NOSAVEHIST = 0,
++ SCROLL_SAVEHIST = 1
++};
++
+ enum cursor_movement {
+ CURSOR_SAVE,
+ CURSOR_LOAD
+@@ -118,10 +138,11 @@ typedef struct {
+ int row; /* nb row */
+ int col; /* nb col */
+ Line *line; /* screen */
+- Line *alt; /* alternate screen */
+ Line hist[HISTSIZE]; /* history buffer */
+- int histi; /* history index */
+- int scr; /* scroll back */
++ int histi; /* history index */
++ int histf; /* nb history available */
++ int scr; /* scroll back */
++ int wrapcwidth[2]; /* used in updating WRAPNEXT when resizing */
+ int *dirty; /* dirtyness of lines */
+ TCursor c; /* cursor */
+ int ocx; /* old cursor col */
+@@ -179,26 +200,37 @@ static void tprinter(char *, size_t);
+ static void tdumpsel(void);
+ static void tdumpline(int);
+ static void tdump(void);
+-static void tclearregion(int, int, int, int);
++static void tclearregion(int, int, int, int, int);
+ static void tcursor(int);
++static void tclearglyph(Glyph *, int);
++static void tresetcursor(void);
+ static void tdeletechar(int);
+ static void tdeleteline(int);
+ static void tinsertblank(int);
+ static void tinsertblankline(int);
+-static int tlinelen(int);
++static int tlinelen(Line len);
++static int tiswrapped(Line line);
++static char *tgetglyphs(char *, const Glyph *, const Glyph *);
++static size_t tgetline(char *, const Glyph *);
+ static void tmoveto(int, int);
+ static void tmoveato(int, int);
+ static void tnewline(int);
+ static void tputtab(int);
+ static void tputc(Rune);
+ static void treset(void);
+-static void tscrollup(int, int, int);
+-static void tscrolldown(int, int, int);
++static void tscrollup(int, int, int, int);
++static void tscrolldown(int, int);
++static void treflow(int, int);
++static void rscrolldown(int);
++static void tresizedef(int, int);
++static void tresizealt(int, int);
+ static void tsetattr(const int *, int);
+ static void tsetchar(Rune, const Glyph *, int, int);
+ static void tsetdirt(int, int);
+ static void tsetscroll(int, int);
+ static void tswapscreen(void);
++static void tloaddefscreen(int, int);
++static void tloadaltscreen(int, int);
+ static void tsetmode(int, int, const int *, int);
+ static int twrite(const char *, int, int);
+ static void tfulldirt(void);
+@@ -212,7 +244,10 @@ static void tstrsequence(uchar);
+ static void drawregion(int, int, int, int);
+
+ static void selnormalize(void);
+-static void selscroll(int, int);
++static void selscroll(int, int, int);
++static void selmove(int);
++static void selremove(void);
++static int regionselected(int, int, int, int);
+ static void selsnap(int *, int *, int);
+
+ static size_t utf8decode(const char *, Rune *, size_t);
+@@ -412,17 +447,46 @@ selinit(void)
+ }
+
+ int
+-tlinelen(int y)
++tlinelen(Line line)
+ {
+- int i = term.col;
++ int i = term.col - 1;
++
++ for (; i >= 0 && !(line[i].mode & (ATTR_SET | ATTR_WRAP)); i--);
++ return i + 1;
++}
+
+- if (TLINE(y)[i - 1].mode & ATTR_WRAP)
+- return i;
++int
++tiswrapped(Line line)
++{
++ int len = tlinelen(line);
+
+- while (i > 0 && TLINE(y)[i - 1].u == ' ')
+- --i;
++ return len > 0 && (line[len - 1].mode & ATTR_WRAP);
++}
+
+- return i;
++char *
++tgetglyphs(char *buf, const Glyph *gp, const Glyph *lgp)
++{
++ while (gp <= lgp)
++ if (gp->mode & ATTR_WDUMMY) {
++ gp++;
++ } else {
++ buf += utf8encode((gp++)->u, buf);
++ }
++ return buf;
++}
++
++size_t
++tgetline(char *buf, const Glyph *fgp)
++{
++ char *ptr;
++ const Glyph *lgp = &fgp[term.col - 1];
++
++ while (lgp > fgp && !(lgp->mode & (ATTR_SET | ATTR_WRAP)))
++ lgp--;
++ ptr = tgetglyphs(buf, fgp, lgp);
++ if (!(lgp->mode & ATTR_WRAP))
++ *(ptr++) = '\n';
++ return ptr - buf;
+ }
+
+ void
+@@ -462,10 +526,11 @@ selextend(int col, int row, int type, int done)
+
+ sel.oe.x = col;
+ sel.oe.y = row;
+- selnormalize();
+ sel.type = type;
++ selnormalize();
+
+- if (oldey != sel.oe.y || oldex != sel.oe.x || oldtype != sel.type || sel.mode == SEL_EMPTY)
++ if (oldey != sel.oe.y || oldex != sel.oe.x ||
++ oldtype != sel.type || sel.mode == SEL_EMPTY)
+ tsetdirt(MIN(sel.nb.y, oldsby), MAX(sel.ne.y, oldsey));
+
+ sel.mode = done ? SEL_IDLE : SEL_READY;
+@@ -492,36 +557,43 @@ selnormalize(void)
+ /* expand selection over line breaks */
+ if (sel.type == SEL_RECTANGULAR)
+ return;
+- i = tlinelen(sel.nb.y);
+- if (i < sel.nb.x)
++
++ i = tlinelen(TLINE(sel.nb.y));
++ if (sel.nb.x > i)
+ sel.nb.x = i;
+- if (tlinelen(sel.ne.y) <= sel.ne.x)
+- sel.ne.x = term.col - 1;
++ if (sel.ne.x >= tlinelen(TLINE(sel.ne.y)))
++ sel.ne.x = term.col - 1;
+ }
+
+ int
+-selected(int x, int y)
++regionselected(int x1, int y1, int x2, int y2)
+ {
+- if (sel.mode == SEL_EMPTY || sel.ob.x == -1 ||
+- sel.alt != IS_SET(MODE_ALTSCREEN))
++ if (sel.ob.x == -1 || sel.mode == SEL_EMPTY ||
++ sel.alt != IS_SET(MODE_ALTSCREEN) || sel.nb.y > y2 || sel.ne.y < y1)
+ return 0;
+
+- if (sel.type == SEL_RECTANGULAR)
+- return BETWEEN(y, sel.nb.y, sel.ne.y)
+- && BETWEEN(x, sel.nb.x, sel.ne.x);
++ return (sel.type == SEL_RECTANGULAR) ? sel.nb.x <= x2 && sel.ne.x >= x1
++ : (sel.nb.y != y2 || sel.nb.x <= x2) &&
++ (sel.ne.y != y1 || sel.ne.x >= x1);
++}
+
+- return BETWEEN(y, sel.nb.y, sel.ne.y)
+- && (y != sel.nb.y || x >= sel.nb.x)
+- && (y != sel.ne.y || x <= sel.ne.x);
++int
++selected(int x, int y)
++{
++ return regionselected(x, y, x, y);
+ }
+
+ void
+ selsnap(int *x, int *y, int direction)
+ {
+ int newx, newy, xt, yt;
++ int rtop = 0, rbot = term.row - 1;
+ int delim, prevdelim;
+ const Glyph *gp, *prevgp;
+
++ if (!IS_SET(MODE_ALTSCREEN))
++ rtop += -term.histf + term.scr, rbot += term.scr;
++
+ switch (sel.snap) {
+ case SNAP_WORD:
+ /*
+@@ -536,7 +608,7 @@ selsnap(int *x, int *y, int direction)
+ if (!BETWEEN(newx, 0, term.col - 1)) {
+ newy += direction;
+ newx = (newx + term.col) % term.col;
+- if (!BETWEEN(newy, 0, term.row - 1))
++ if (!BETWEEN(newy, rtop, rbot))
+ break;
+
+ if (direction > 0)
+@@ -547,13 +619,13 @@ selsnap(int *x, int *y, int direction)
+ break;
+ }
+
+- if (newx >= tlinelen(newy))
++ if (newx >= tlinelen(TLINE(newy)))
+ break;
+
+ gp = &TLINE(newy)[newx];
+ delim = ISDELIM(gp->u);
+- if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
+- || (delim && gp->u != prevgp->u)))
++ if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim ||
++ (delim && !(gp->u == ' ' && prevgp->u == ' '))))
+ break;
+
+ *x = newx;
+@@ -570,18 +642,14 @@ selsnap(int *x, int *y, int direction)
+ */
+ *x = (direction < 0) ? 0 : term.col - 1;
+ if (direction < 0) {
+- for (; *y > 0; *y += direction) {
+- if (!(TLINE(*y-1)[term.col-1].mode
+- & ATTR_WRAP)) {
++ for (; *y > rtop; *y -= 1) {
++ if (!tiswrapped(TLINE(*y-1)))
+ break;
+- }
+ }
+ } else if (direction > 0) {
+- for (; *y < term.row-1; *y += direction) {
+- if (!(TLINE(*y)[term.col-1].mode
+- & ATTR_WRAP)) {
++ for (; *y < rbot; *y += 1) {
++ if (!tiswrapped(TLINE(*y)))
+ break;
+- }
+ }
+ }
+ break;
+@@ -592,40 +660,34 @@ char *
+ getsel(void)
+ {
+ char *str, *ptr;
+- int y, bufsize, lastx, linelen;
+- const Glyph *gp, *last;
++ int y, lastx, linelen;
++ const Glyph *gp, *lgp;
+
+- if (sel.ob.x == -1)
++ if (sel.ob.x == -1 || sel.alt != IS_SET(MODE_ALTSCREEN))
+ return NULL;
+
+- bufsize = (term.col+1) * (sel.ne.y-sel.nb.y+1) * UTF_SIZ;
+- ptr = str = xmalloc(bufsize);
++ str = xmalloc((term.col + 1) * (sel.ne.y - sel.nb.y + 1) * UTF_SIZ);
++ ptr = str;
+
+ /* append every set & selected glyph to the selection */
+ for (y = sel.nb.y; y <= sel.ne.y; y++) {
+- if ((linelen = tlinelen(y)) == 0) {
++ Line line = TLINE(y);
++
++ if ((linelen = tlinelen(line)) == 0) {
+ *ptr++ = '\n';
+ continue;
+ }
+
+ if (sel.type == SEL_RECTANGULAR) {
+- gp = &TLINE(y)[sel.nb.x];
++ gp = &line[sel.nb.x];
+ lastx = sel.ne.x;
+ } else {
+- gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
++ gp = &line[sel.nb.y == y ? sel.nb.x : 0];
+ lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
+ }
+- last = &TLINE(y)[MIN(lastx, linelen-1)];
+- while (last >= gp && last->u == ' ')
+- --last;
+-
+- for ( ; gp <= last; ++gp) {
+- if (gp->mode & ATTR_WDUMMY)
+- continue;
+-
+- ptr += utf8encode(gp->u, ptr);
+- }
++ lgp = &line[MIN(lastx, linelen-1)];
+
++ ptr = tgetglyphs(ptr, gp, lgp);
+ /*
+ * Copy and pasting of line endings is inconsistent
+ * in the inconsistent terminal and GUI world.
+@@ -636,10 +698,10 @@ getsel(void)
+ * FIXME: Fix the computer world.
+ */
+ if ((y < sel.ne.y || lastx >= linelen) &&
+- (!(last->mode & ATTR_WRAP) || sel.type == SEL_RECTANGULAR))
++ (!(lgp->mode & ATTR_WRAP) || sel.type == SEL_RECTANGULAR))
+ *ptr++ = '\n';
+ }
+- *ptr = 0;
++ *ptr = '\0';
+ return str;
+ }
+
+@@ -648,9 +710,15 @@ selclear(void)
+ {
+ if (sel.ob.x == -1)
+ return;
++ selremove();
++ tsetdirt(sel.nb.y, sel.ne.y);
++}
++
++void
++selremove(void)
++{
+ sel.mode = SEL_IDLE;
+ sel.ob.x = -1;
+- tsetdirt(sel.nb.y, sel.ne.y);
+ }
+
+ void
+@@ -851,10 +919,8 @@ void
+ ttywrite(const char *s, size_t n, int may_echo)
+ {
+ const char *next;
+- Arg arg = (Arg) { .i = term.scr };
+-
+- kscrolldown(&arg);
+
++ kscrolldown(&((Arg){ .i = term.scr }));
+ if (may_echo && IS_SET(MODE_ECHO))
+ twrite(s, n, 1);
+
+@@ -990,7 +1056,7 @@ tsetdirtattr(int attr)
+ for (i = 0; i < term.row-1; i++) {
+ for (j = 0; j < term.col-1; j++) {
+ if (term.line[i][j].mode & attr) {
+- tsetdirt(i, i);
++ term.dirty[i] = 1;
+ break;
+ }
+ }
+@@ -1000,7 +1066,8 @@ tsetdirtattr(int attr)
+ void
+ tfulldirt(void)
+ {
+- tsetdirt(0, term.row-1);
++ for (int i = 0; i < term.row; i++)
++ term.dirty[i] = 1;
+ }
+
+ void
+@@ -1017,51 +1084,116 @@ tcursor(int mode)
+ }
+ }
+
++void
++tresetcursor(void)
++{
++ term.c = (TCursor){ { .mode = ATTR_NULL, .fg = defaultfg, .bg = defaultbg },
++ .x = 0, .y = 0, .state = CURSOR_DEFAULT };
++}
++
+ void
+ treset(void)
+ {
+ uint i;
++ int x, y;
+
+- term.c = (TCursor){{
+- .mode = ATTR_NULL,
+- .fg = defaultfg,
+- .bg = defaultbg
+- }, .x = 0, .y = 0, .state = CURSOR_DEFAULT};
++ tresetcursor();
+
+ memset(term.tabs, 0, term.col * sizeof(*term.tabs));
+ for (i = tabspaces; i < term.col; i += tabspaces)
+ term.tabs[i] = 1;
+ term.top = 0;
++ term.histf = 0;
++ term.scr = 0;
+ term.bot = term.row - 1;
+ term.mode = MODE_WRAP|MODE_UTF8;
+ memset(term.trantbl, CS_USA, sizeof(term.trantbl));
+ term.charset = 0;
+
++ selremove();
+ for (i = 0; i < 2; i++) {
+- tmoveto(0, 0);
+- tcursor(CURSOR_SAVE);
+- tclearregion(0, 0, term.col-1, term.row-1);
++ tcursor(CURSOR_SAVE); /* reset saved cursor */
++ for (y = 0; y < term.row; y++)
++ for (x = 0; x < term.col; x++)
++ tclearglyph(&term.line[y][x], 0);
+ tswapscreen();
+ }
++ tfulldirt();
+ }
+
+ void
+ tnew(int col, int row)
+ {
+- term = (Term){ .c = { .attr = { .fg = defaultfg, .bg = defaultbg } } };
+- tresize(col, row);
+- treset();
++ int i, j;
++
++ for (i = 0; i < 2; i++) {
++ term.line = xmalloc(row * sizeof(Line));
++ for (j = 0; j < row; j++)
++ term.line[j] = xmalloc(col * sizeof(Glyph));
++ term.col = col, term.row = row;
++ tswapscreen();
++ }
++ term.dirty = xmalloc(row * sizeof(*term.dirty));
++ term.tabs = xmalloc(col * sizeof(*term.tabs));
++ for (i = 0; i < HISTSIZE; i++)
++ term.hist[i] = xmalloc(col * sizeof(Glyph));
++ treset();
+ }
+
++/* handle it with care */
+ void
+ tswapscreen(void)
+ {
+- Line *tmp = term.line;
++ static Line *altline;
++ static int altcol, altrow;
++ Line *tmpline = term.line;
++ int tmpcol = term.col, tmprow = term.row;
+
+- term.line = term.alt;
+- term.alt = tmp;
++ term.line = altline;
++ term.col = altcol, term.row = altrow;
++ altline = tmpline;
++ altcol = tmpcol, altrow = tmprow;
+ term.mode ^= MODE_ALTSCREEN;
+- tfulldirt();
++}
++
++void
++tloaddefscreen(int clear, int loadcursor)
++{
++ int col, row, alt = IS_SET(MODE_ALTSCREEN);
++
++ if (alt) {
++ if (clear)
++ tclearregion(0, 0, term.col-1, term.row-1, 1);
++ col = term.col, row = term.row;
++ tswapscreen();
++ }
++ if (loadcursor)
++ tcursor(CURSOR_LOAD);
++ if (alt)
++ tresizedef(col, row);
++}
++
++void
++tloadaltscreen(int clear, int savecursor)
++{
++ int col, row, def = !IS_SET(MODE_ALTSCREEN);
++
++ if (savecursor)
++ tcursor(CURSOR_SAVE);
++ if (def) {
++ col = term.col, row = term.row;
++ tswapscreen();
++ term.scr = 0;
++ tresizealt(col, row);
++ }
++ if (clear)
++ tclearregion(0, 0, term.col-1, term.row-1, 1);
++}
++
++int
++tisaltscreen(void)
++{
++ return IS_SET(MODE_ALTSCREEN);
+ }
+
+ void
+@@ -1069,17 +1201,22 @@ kscrolldown(const Arg* a)
+ {
+ int n = a->i;
+
+- if (n < 0)
+- n = term.row + n;
++ if (!term.scr || IS_SET(MODE_ALTSCREEN))
++ return;
+
+- if (n > term.scr)
+- n = term.scr;
++ if (n < 0)
++ n = MAX(term.row / -n, 1);
+
+- if (term.scr > 0) {
++ if (n <= term.scr) {
+ term.scr -= n;
+- selscroll(0, -n);
+- tfulldirt();
++ } else {
++ n = term.scr;
++ term.scr = 0;
+ }
++
++ if (sel.ob.x != -1 && !sel.alt)
++ selmove(-n); /* negate change in term.scr */
++ tfulldirt();
+ }
+
+ void
+@@ -1087,92 +1224,118 @@ kscrollup(const Arg* a)
+ {
+ int n = a->i;
+
++ if (!term.histf || IS_SET(MODE_ALTSCREEN))
++ return;
++
+ if (n < 0)
+- n = term.row + n;
++ n = MAX(term.row / -n, 1);
+
+- if (term.scr <= HISTSIZE-n) {
++ if (term.scr + n <= term.histf) {
+ term.scr += n;
+- selscroll(0, n);
+- tfulldirt();
++ } else {
++ n = term.histf - term.scr;
++ term.scr = term.histf;
+ }
++
++ if (sel.ob.x != -1 && !sel.alt)
++ selmove(n); /* negate change in term.scr */
++ tfulldirt();
+ }
+
+ void
+-tscrolldown(int orig, int n, int copyhist)
++tscrolldown(int top, int n)
+ {
+- int i;
++ int i, bot = term.bot;
+ Line temp;
+
+- LIMIT(n, 0, term.bot-orig+1);
+- if (copyhist) {
+- term.histi = (term.histi - 1 + HISTSIZE) % HISTSIZE;
+- temp = term.hist[term.histi];
+- term.hist[term.histi] = term.line[term.bot];
+- term.line[term.bot] = temp;
+- }
+-
++ if (n <= 0)
++ return;
++ n = MIN(n, bot-top+1);
+
+- tsetdirt(orig, term.bot-n);
+- tclearregion(0, term.bot-n+1, term.col-1, term.bot);
++ tsetdirt(top, bot-n);
++ tclearregion(0, bot-n+1, term.col-1, bot, 1);
+
+- for (i = term.bot; i >= orig+n; i--) {
++ for (i = bot; i >= top+n; i--) {
+ temp = term.line[i];
+ term.line[i] = term.line[i-n];
+ term.line[i-n] = temp;
+ }
+
+- if (term.scr == 0)
+- selscroll(orig, n);
++ if (sel.ob.x != -1 && sel.alt == IS_SET(MODE_ALTSCREEN))
++ selscroll(top, bot, n);
+ }
+
+ void
+-tscrollup(int orig, int n, int copyhist)
++tscrollup(int top, int bot, int n, int mode)
+ {
+- int i;
++ int i, j, s;
++ int alt = IS_SET(MODE_ALTSCREEN);
++ int savehist = !alt && top == 0 && mode != SCROLL_NOSAVEHIST;
+ Line temp;
+
+- LIMIT(n, 0, term.bot-orig+1);
+-
+- if (copyhist) {
+- term.histi = (term.histi + 1) % HISTSIZE;
+- temp = term.hist[term.histi];
+- term.hist[term.histi] = term.line[orig];
+- term.line[orig] = temp;
++ if (n <= 0)
++ return;
++ n = MIN(n, bot-top+1);
++
++ if (savehist) {
++ for (i = 0; i < n; i++) {
++ term.histi = (term.histi + 1) % HISTSIZE;
++ temp = term.hist[term.histi];
++ for (j = 0; j < term.col; j++)
++ tclearglyph(&temp[j], 1);
++ term.hist[term.histi] = term.line[i];
++ term.line[i] = temp;
++ }
++ term.histf = MIN(term.histf + n, HISTSIZE);
++ s = n;
++ if (term.scr) {
++ j = term.scr;
++ term.scr = MIN(j + n, HISTSIZE);
++ s = j + n - term.scr;
++ }
++ if (mode != SCROLL_RESIZE)
++ tfulldirt();
++ } else {
++ tclearregion(0, top, term.col-1, top+n-1, 1);
++ tsetdirt(top+n, bot);
+ }
+
+- if (term.scr > 0 && term.scr < HISTSIZE)
+- term.scr = MIN(term.scr + n, HISTSIZE-1);
+-
+- tclearregion(0, orig, term.col-1, orig+n-1);
+- tsetdirt(orig+n, term.bot);
+-
+- for (i = orig; i <= term.bot-n; i++) {
++ for (i = top; i <= bot-n; i++) {
+ temp = term.line[i];
+ term.line[i] = term.line[i+n];
+ term.line[i+n] = temp;
+ }
+
+- if (term.scr == 0)
+- selscroll(orig, -n);
++ if (sel.ob.x != -1 && sel.alt == alt) {
++ if (!savehist) {
++ selscroll(top, bot, -n);
++ } else if (s > 0) {
++ selmove(-s);
++ if (-term.scr + sel.nb.y < -term.histf)
++ selremove();
++ }
++ }
+ }
+
+ void
+-selscroll(int orig, int n)
++selmove(int n)
+ {
+- if (sel.ob.x == -1)
+- return;
++ sel.ob.y += n, sel.nb.y += n;
++ sel.oe.y += n, sel.ne.y += n;
++}
++
++void
++selscroll(int top, int bot, int n)
++{
++ /* turn absolute coordinates into relative */
++ top += term.scr, bot += term.scr;
+
+- if (BETWEEN(sel.nb.y, orig, term.bot) != BETWEEN(sel.ne.y, orig, term.bot)) {
++ if (BETWEEN(sel.nb.y, top, bot) != BETWEEN(sel.ne.y, top, bot)) {
+ selclear();
+- } else if (BETWEEN(sel.nb.y, orig, term.bot)) {
+- sel.ob.y += n;
+- sel.oe.y += n;
+- if (sel.ob.y < term.top || sel.ob.y > term.bot ||
+- sel.oe.y < term.top || sel.oe.y > term.bot) {
++ } else if (BETWEEN(sel.nb.y, top, bot)) {
++ selmove(n);
++ if (sel.nb.y < top || sel.ne.y > bot)
+ selclear();
+- } else {
+- selnormalize();
+- }
+ }
+ }
+
+@@ -1182,7 +1345,7 @@ tnewline(int first_col)
+ int y = term.c.y;
+
+ if (y == term.bot) {
+- tscrollup(term.top, 1, 1);
++ tscrollup(term.top, term.bot, 1, SCROLL_SAVEHIST);
+ } else {
+ y++;
+ }
+@@ -1272,89 +1435,93 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
+ } else if (term.line[y][x].mode & ATTR_WDUMMY) {
+ term.line[y][x-1].u = ' ';
+ term.line[y][x-1].mode &= ~ATTR_WIDE;
+- }
++ }
+
+ term.dirty[y] = 1;
+ term.line[y][x] = *attr;
+ term.line[y][x].u = u;
++ term.line[y][x].mode |= ATTR_SET;
+ }
+
+ void
+-tclearregion(int x1, int y1, int x2, int y2)
++tclearglyph(Glyph *gp, int usecurattr)
+ {
+- int x, y, temp;
+- Glyph *gp;
++ if (usecurattr) {
++ gp->fg = term.c.attr.fg;
++ gp->bg = term.c.attr.bg;
++ } else {
++ gp->fg = defaultfg;
++ gp->bg = defaultbg;
++ }
++ gp->mode = ATTR_NULL;
++ gp->u = ' ';
++}
+
+- if (x1 > x2)
+- temp = x1, x1 = x2, x2 = temp;
+- if (y1 > y2)
+- temp = y1, y1 = y2, y2 = temp;
++void
++tclearregion(int x1, int y1, int x2, int y2, int usecurattr)
++{
++ int x, y;
+
+- LIMIT(x1, 0, term.col-1);
+- LIMIT(x2, 0, term.col-1);
+- LIMIT(y1, 0, term.row-1);
+- LIMIT(y2, 0, term.row-1);
++ /* regionselected() takes relative coordinates */
++ if (regionselected(x1+term.scr, y1+term.scr, x2+term.scr, y2+term.scr))
++ selremove();
+
+ for (y = y1; y <= y2; y++) {
+ term.dirty[y] = 1;
+- for (x = x1; x <= x2; x++) {
+- gp = &term.line[y][x];
+- if (selected(x, y))
+- selclear();
+- gp->fg = term.c.attr.fg;
+- gp->bg = term.c.attr.bg;
+- gp->mode = 0;
+- gp->u = ' ';
+- }
++ for (x = x1; x <= x2; x++)
++ tclearglyph(&term.line[y][x], usecurattr);
+ }
+ }
+
+ void
+ tdeletechar(int n)
+ {
+- int dst, src, size;
+- Glyph *line;
+-
+- LIMIT(n, 0, term.col - term.c.x);
++ int src, dst, size;
++ Line line;
+
++ if (n <= 0)
++ return;
+ dst = term.c.x;
+- src = term.c.x + n;
++ src = MIN(term.c.x + n, term.col);
+ size = term.col - src;
+- line = term.line[term.c.y];
+-
+- memmove(&line[dst], &line[src], size * sizeof(Glyph));
+- tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
++ if (size > 0) { /* otherwise src would point beyond the array
++ https://stackoverflow.com/questions/29844298 */
++ line = term.line[term.c.y];
++ memmove(&line[dst], &line[src], size * sizeof(Glyph));
++ }
++ tclearregion(dst + size, term.c.y, term.col - 1, term.c.y, 1);
+ }
+
+ void
+ tinsertblank(int n)
+ {
+- int dst, src, size;
+- Glyph *line;
++ int src, dst, size;
++ Line line;
+
+- LIMIT(n, 0, term.col - term.c.x);
+-
+- dst = term.c.x + n;
++ if (n <= 0)
++ return;
++ dst = MIN(term.c.x + n, term.col);
+ src = term.c.x;
+ size = term.col - dst;
+- line = term.line[term.c.y];
+-
+- memmove(&line[dst], &line[src], size * sizeof(Glyph));
+- tclearregion(src, term.c.y, dst - 1, term.c.y);
++ if (size > 0) { /* otherwise dst would point beyond the array */
++ line = term.line[term.c.y];
++ memmove(&line[dst], &line[src], size * sizeof(Glyph));
++ }
++ tclearregion(src, term.c.y, dst - 1, term.c.y, 1);
+ }
+
+ void
+ tinsertblankline(int n)
+ {
+ if (BETWEEN(term.c.y, term.top, term.bot))
+- tscrolldown(term.c.y, n, 0);
++ tscrolldown(term.c.y, n);
+ }
+
+ void
+ tdeleteline(int n)
+ {
+ if (BETWEEN(term.c.y, term.top, term.bot))
+- tscrollup(term.c.y, n, 0);
++ tscrollup(term.c.y, term.bot, n, SCROLL_NOSAVEHIST);
+ }
+
+ int32_t
+@@ -1528,7 +1695,7 @@ tsetscroll(int t, int b)
+ void
+ tsetmode(int priv, int set, const int *args, int narg)
+ {
+- int alt; const int *lim;
++ const int *lim;
+
+ for (lim = args + narg; args < lim; ++args) {
+ if (priv) {
+@@ -1589,25 +1756,18 @@ tsetmode(int priv, int set, const int *args, int narg)
+ xsetmode(set, MODE_8BIT);
+ break;
+ case 1049: /* swap screen & set/restore cursor as xterm */
+- if (!allowaltscreen)
+- break;
+- tcursor((set) ? CURSOR_SAVE : CURSOR_LOAD);
+- /* FALLTHROUGH */
+ case 47: /* swap screen */
+- case 1047:
++ case 1047: /* swap screen, clearing alternate screen */
+ if (!allowaltscreen)
+ break;
+- alt = IS_SET(MODE_ALTSCREEN);
+- if (alt) {
+- tclearregion(0, 0, term.col-1,
+- term.row-1);
+- }
+- if (set ^ alt) /* set is always 1 or 0 */
+- tswapscreen();
+- if (*args != 1049)
+- break;
+- /* FALLTHROUGH */
++ if (set)
++ tloadaltscreen(*args == 1049, *args == 1049);
++ else
++ tloaddefscreen(*args == 1047, *args == 1049);
++ break;
+ case 1048:
++ if (!allowaltscreen)
++ break;
+ tcursor((set) ? CURSOR_SAVE : CURSOR_LOAD);
+ break;
+ case 2004: /* 2004: bracketed paste mode */
+@@ -1659,7 +1819,7 @@ void
+ csihandle(void)
+ {
+ char buf[40];
+- int len;
++ int n, x;
+
+ switch (csiescseq.mode[0]) {
+ default:
+@@ -1757,20 +1917,30 @@ csihandle(void)
+ case 'J': /* ED -- Clear screen */
+ switch (csiescseq.arg[0]) {
+ case 0: /* below */
+- tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
++ tclearregion(term.c.x, term.c.y, term.col-1, term.c.y, 1);
+ if (term.c.y < term.row-1) {
+- tclearregion(0, term.c.y+1, term.col-1,
+- term.row-1);
++ tclearregion(0, term.c.y+1, term.col-1, term.row-1, 1);
+ }
+ break;
+ case 1: /* above */
+- if (term.c.y > 1)
+- tclearregion(0, 0, term.col-1, term.c.y-1);
+- tclearregion(0, term.c.y, term.c.x, term.c.y);
++ if (term.c.y >= 1)
++ tclearregion(0, 0, term.col-1, term.c.y-1, 1);
++ tclearregion(0, term.c.y, term.c.x, term.c.y, 1);
+ break;
+ case 2: /* all */
+- tclearregion(0, 0, term.col-1, term.row-1);
+- break;
++ if (IS_SET(MODE_ALTSCREEN)) {
++ tclearregion(0, 0, term.col-1, term.row-1, 1);
++ break;
++ }
++ /* vte does this:
++ tscrollup(0, term.row-1, term.row, SCROLL_SAVEHIST); */
++
++ /* alacritty does this: */
++ for (n = term.row-1; n >= 0 && tlinelen(term.line[n]) == 0; n--);
++ if (n >= 0)
++ tscrollup(0, term.row-1, n+1, SCROLL_SAVEHIST);
++ tscrollup(0, term.row-1, term.row-n-1, SCROLL_NOSAVEHIST);
++ break;
+ default:
+ goto unknown;
+ }
+@@ -1778,24 +1948,24 @@ csihandle(void)
+ case 'K': /* EL -- Clear line */
+ switch (csiescseq.arg[0]) {
+ case 0: /* right */
+- tclearregion(term.c.x, term.c.y, term.col-1,
+- term.c.y);
++ tclearregion(term.c.x, term.c.y, term.col-1, term.c.y, 1);
+ break;
+ case 1: /* left */
+- tclearregion(0, term.c.y, term.c.x, term.c.y);
++ tclearregion(0, term.c.y, term.c.x, term.c.y, 1);
+ break;
+ case 2: /* all */
+- tclearregion(0, term.c.y, term.col-1, term.c.y);
++ tclearregion(0, term.c.y, term.col-1, term.c.y, 1);
+ break;
+ }
+ break;
+ case 'S': /* SU -- Scroll <n> line up */
+ DEFAULT(csiescseq.arg[0], 1);
+- tscrollup(term.top, csiescseq.arg[0], 0);
++ /* xterm, urxvt, alacritty save this in history */
++ tscrollup(term.top, term.bot, csiescseq.arg[0], SCROLL_SAVEHIST);
+ break;
+ case 'T': /* SD -- Scroll <n> line down */
+ DEFAULT(csiescseq.arg[0], 1);
+- tscrolldown(term.top, csiescseq.arg[0], 0);
++ tscrolldown(term.top, csiescseq.arg[0]);
+ break;
+ case 'L': /* IL -- Insert <n> blank lines */
+ DEFAULT(csiescseq.arg[0], 1);
+@@ -1809,9 +1979,11 @@ csihandle(void)
+ tdeleteline(csiescseq.arg[0]);
+ break;
+ case 'X': /* ECH -- Erase <n> char */
++ if (csiescseq.arg[0] < 0)
++ return;
+ DEFAULT(csiescseq.arg[0], 1);
+- tclearregion(term.c.x, term.c.y,
+- term.c.x + csiescseq.arg[0] - 1, term.c.y);
++ x = MIN(term.c.x + csiescseq.arg[0], term.col) - 1;
++ tclearregion(term.c.x, term.c.y, x, term.c.y, 1);
+ break;
+ case 'P': /* DCH -- Delete <n> char */
+ DEFAULT(csiescseq.arg[0], 1);
+@@ -1833,9 +2005,9 @@ csihandle(void)
+ break;
+ case 'n': /* DSR – Device Status Report (cursor position) */
+ if (csiescseq.arg[0] == 6) {
+- len = snprintf(buf, sizeof(buf), "\033[%i;%iR",
++ n = snprintf(buf, sizeof(buf), "\033[%i;%iR",
+ term.c.y+1, term.c.x+1);
+- ttywrite(buf, len, 0);
++ ttywrite(buf, n, 0);
+ }
+ break;
+ case 'r': /* DECSTBM -- Set Scrolling Region */
+@@ -2128,16 +2300,8 @@ tdumpsel(void)
+ void
+ tdumpline(int n)
+ {
+- char buf[UTF_SIZ];
+- const Glyph *bp, *end;
+-
+- bp = &term.line[n][0];
+- end = &bp[MIN(tlinelen(n), term.col) - 1];
+- if (bp != end || bp->u != ' ') {
+- for ( ; bp <= end; ++bp)
+- tprinter(buf, utf8encode(bp->u, buf));
+- }
+- tprinter("\n", 1);
++ char str[(term.col + 1) * UTF_SIZ];
++ tprinter(str, tgetline(str, &term.line[n][0]));
+ }
+
+ void
+@@ -2358,7 +2522,7 @@ eschandle(uchar ascii)
+ return 0;
+ case 'D': /* IND -- Linefeed */
+ if (term.c.y == term.bot) {
+- tscrollup(term.top, 1, 1);
++ tscrollup(term.top, term.bot, 1, SCROLL_SAVEHIST);
+ } else {
+ tmoveto(term.c.x, term.c.y+1);
+ }
+@@ -2371,7 +2535,7 @@ eschandle(uchar ascii)
+ break;
+ case 'M': /* RI -- Reverse index */
+ if (term.c.y == term.top) {
+- tscrolldown(term.top, 1, 1);
++ tscrolldown(term.top, 1);
+ } else {
+ tmoveto(term.c.x, term.c.y-1);
+ }
+@@ -2511,7 +2675,8 @@ check_control_code:
+ */
+ return;
+ }
+- if (selected(term.c.x, term.c.y))
++ /* selected() takes relative coordinates */
++ if (selected(term.c.x + term.scr, term.c.y + term.scr))
+ selclear();
+
+ gp = &term.line[term.c.y][term.c.x];
+@@ -2546,6 +2711,7 @@ check_control_code:
+ if (term.c.x+width < term.col) {
+ tmoveto(term.c.x+width, term.c.y);
+ } else {
++ term.wrapcwidth[IS_SET(MODE_ALTSCREEN)] = width;
+ term.c.state |= CURSOR_WRAPNEXT;
+ }
+ }
+@@ -2583,93 +2749,275 @@ twrite(const char *buf, int buflen, int show_ctrl)
+ }
+
+ void
+-tresize(int col, int row)
++treflow(int col, int row)
+ {
+ int i, j;
+- int minrow = MIN(row, term.row);
+- int mincol = MIN(col, term.col);
+- int *bp;
+- TCursor c;
+-
+- if (col < 1 || row < 1) {
+- fprintf(stderr,
+- "tresize: error resizing to %dx%d\n", col, row);
+- return;
++ int oce, nce, bot, scr;
++ int ox = 0, oy = -term.histf, nx = 0, ny = -1, len;
++ int cy = -1; /* proxy for new y coordinate of cursor */
++ int nlines;
++ Line *buf, line;
++
++ /* y coordinate of cursor line end */
++ for (oce = term.c.y; oce < term.row - 1 &&
++ tiswrapped(term.line[oce]); oce++);
++
++ nlines = term.histf + oce + 1;
++ if (col < term.col) {
++ /* each line can take this many lines after reflow */
++ j = (term.col + col - 1) / col;
++ nlines = j * nlines;
++ if (nlines > HISTSIZE + RESIZEBUFFER + row) {
++ nlines = HISTSIZE + RESIZEBUFFER + row;
++ oy = -(nlines / j - oce - 1);
++ }
+ }
++ buf = xmalloc(nlines * sizeof(Line));
++ do {
++ if (!nx)
++ buf[++ny] = xmalloc(col * sizeof(Glyph));
++ if (!ox) {
++ line = TLINEABS(oy);
++ len = tlinelen(line);
++ }
++ if (oy == term.c.y) {
++ if (!ox)
++ len = MAX(len, term.c.x + 1);
++ /* update cursor */
++ if (cy < 0 && term.c.x - ox < col - nx) {
++ term.c.x = nx + term.c.x - ox, cy = ny;
++ UPDATEWRAPNEXT(0, col);
++ }
++ }
++ /* get reflowed lines in buf */
++ if (col - nx > len - ox) {
++ memcpy(&buf[ny][nx], &line[ox], (len-ox) * sizeof(Glyph));
++ nx += len - ox;
++ if (len == 0 || !(line[len - 1].mode & ATTR_WRAP)) {
++ for (j = nx; j < col; j++)
++ tclearglyph(&buf[ny][j], 0);
++ nx = 0;
++ } else if (nx > 0) {
++ buf[ny][nx - 1].mode &= ~ATTR_WRAP;
++ }
++ ox = 0, oy++;
++ } else if (col - nx == len - ox) {
++ memcpy(&buf[ny][nx], &line[ox], (col-nx) * sizeof(Glyph));
++ ox = 0, oy++, nx = 0;
++ } else/* if (col - nx < len - ox) */ {
++ memcpy(&buf[ny][nx], &line[ox], (col-nx) * sizeof(Glyph));
++ ox += col - nx;
++ buf[ny][col - 1].mode |= ATTR_WRAP;
++ nx = 0;
++ }
++ } while (oy <= oce);
++ if (nx)
++ for (j = nx; j < col; j++)
++ tclearglyph(&buf[ny][j], 0);
+
+- /*
+- * 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 extra lines */
++ for (i = row; i < term.row; i++)
+ free(term.line[i]);
+- free(term.alt[i]);
++ /* resize to new height */
++ term.line = xrealloc(term.line, row * sizeof(Line));
++
++ bot = MIN(ny, row - 1);
++ scr = MAX(row - term.row, 0);
++ /* update y coordinate of cursor line end */
++ nce = MIN(oce + scr, bot);
++ /* update cursor y coordinate */
++ term.c.y = nce - (ny - cy);
++ if (term.c.y < 0) {
++ j = nce, nce = MIN(nce + -term.c.y, bot);
++ term.c.y += nce - j;
++ while (term.c.y < 0) {
++ free(buf[ny--]);
++ term.c.y++;
++ }
+ }
+- /* 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 new rows */
++ for (i = row - 1; i > nce; i--) {
++ term.line[i] = xmalloc(col * sizeof(Glyph));
++ for (j = 0; j < col; j++)
++ tclearglyph(&term.line[i][j], 0);
+ }
+- for (i += row; i < term.row; i++) {
++ /* fill visible area */
++ for (/*i = nce */; i >= term.row; i--, ny--)
++ term.line[i] = buf[ny];
++ for (/*i = term.row - 1 */; i >= 0; i--, ny--) {
+ free(term.line[i]);
+- free(term.alt[i]);
++ term.line[i] = buf[ny];
++ }
++ /* fill lines in history buffer and update term.histf */
++ for (/*i = -1 */; ny >= 0 && i >= -HISTSIZE; i--, ny--) {
++ j = (term.histi + i + 1 + HISTSIZE) % HISTSIZE;
++ free(term.hist[j]);
++ term.hist[j] = buf[ny];
+ }
++ term.histf = -i - 1;
++ term.scr = MIN(term.scr, term.histf);
++ /* resize rest of the history lines */
++ for (/*i = -term.histf - 1 */; i >= -HISTSIZE; i--) {
++ j = (term.histi + i + 1 + HISTSIZE) % HISTSIZE;
++ term.hist[j] = xrealloc(term.hist[j], col * sizeof(Glyph));
++ }
++ free(buf);
++}
+
+- /* 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));
++void
++rscrolldown(int n)
++{
++ int i;
++ Line temp;
+
+- for (i = 0; i < HISTSIZE; i++) {
+- term.hist[i] = xrealloc(term.hist[i], col * sizeof(Glyph));
+- for (j = mincol; j < col; j++) {
+- term.hist[i][j] = term.c.attr;
+- term.hist[i][j].u = ' ';
+- }
+- }
++ /* can never be true as of now
++ if (IS_SET(MODE_ALTSCREEN))
++ return; */
+
+- /* 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));
+- }
++ if ((n = MIN(n, term.histf)) <= 0)
++ return;
+
+- /* allocate any new rows */
+- for (/* i = minrow */; i < row; i++) {
+- term.line[i] = xmalloc(col * sizeof(Glyph));
+- term.alt[i] = xmalloc(col * sizeof(Glyph));
++ for (i = term.c.y + n; i >= n; i--) {
++ temp = term.line[i];
++ term.line[i] = term.line[i-n];
++ term.line[i-n] = temp;
+ }
++ for (/*i = n - 1 */; i >= 0; i--) {
++ temp = term.line[i];
++ term.line[i] = term.hist[term.histi];
++ term.hist[term.histi] = temp;
++ term.histi = (term.histi - 1 + HISTSIZE) % HISTSIZE;
++ }
++ term.c.y += n;
++ term.histf -= n;
++ if ((i = term.scr - n) >= 0) {
++ term.scr = i;
++ } else {
++ term.scr = 0;
++ if (sel.ob.x != -1 && !sel.alt)
++ selmove(-i);
++ }
++}
++
++void
++tresize(int col, int row)
++{
++ int *bp;
++
++ /* col and row are always MAX(_, 1)
++ if (col < 1 || row < 1) {
++ fprintf(stderr, "tresize: error resizing to %dx%d\n", col, row);
++ return;
++ } */
++
++ term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
++ term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
+ if (col > term.col) {
+ bp = term.tabs + term.col;
+-
+ memset(bp, 0, sizeof(*term.tabs) * (col - term.col));
+ while (--bp > term.tabs && !*bp)
+ /* nothing */ ;
+ for (bp += tabspaces; bp < term.tabs + col; bp += tabspaces)
+ *bp = 1;
+ }
+- /* update terminal size */
+- term.col = col;
+- term.row = row;
+- /* 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 (IS_SET(MODE_ALTSCREEN))
++ tresizealt(col, row);
++ else
++ tresizedef(col, row);
++}
++
++void
++tresizedef(int col, int row)
++{
++ int i, j;
++
++ /* return if dimensions haven't changed */
++ if (term.col == col && term.row == row) {
++ tfulldirt();
++ return;
++ }
++ if (col != term.col) {
++ if (!sel.alt)
++ selremove();
++ treflow(col, row);
++ } else {
++ /* slide screen up if otherwise cursor would get out of the screen */
++ if (term.c.y >= row) {
++ tscrollup(0, term.row - 1, term.c.y - row + 1, SCROLL_RESIZE);
++ term.c.y = row - 1;
+ }
+- if (0 < col && minrow < row) {
+- tclearregion(0, minrow, col - 1, row - 1);
++ for (i = row; i < term.row; i++)
++ free(term.line[i]);
++
++ /* resize to new height */
++ term.line = xrealloc(term.line, row * sizeof(Line));
++ /* allocate any new rows */
++ for (i = term.row; i < row; i++) {
++ term.line[i] = xmalloc(col * sizeof(Glyph));
++ for (j = 0; j < col; j++)
++ tclearglyph(&term.line[i][j], 0);
+ }
+- tswapscreen();
+- tcursor(CURSOR_LOAD);
++ /* scroll down as much as height has increased */
++ rscrolldown(row - term.row);
++ }
++ /* update terminal size */
++ term.col = col, term.row = row;
++ /* reset scrolling region */
++ term.top = 0, term.bot = row - 1;
++ /* dirty all lines */
++ tfulldirt();
++}
++
++void
++tresizealt(int col, int row)
++{
++ int i, j;
++
++ /* return if dimensions haven't changed */
++ if (term.col == col && term.row == row) {
++ tfulldirt();
++ return;
+ }
+- term.c = c;
++ if (sel.alt)
++ selremove();
++ /* slide screen up if otherwise cursor would get out of the screen */
++ for (i = 0; i <= term.c.y - row; i++)
++ free(term.line[i]);
++ if (i > 0) {
++ /* ensure that both src and dst are not NULL */
++ memmove(term.line, term.line + i, row * sizeof(Line));
++ term.c.y = row - 1;
++ }
++ for (i += row; i < term.row; i++)
++ free(term.line[i]);
++ /* resize to new height */
++ term.line = xrealloc(term.line, row * sizeof(Line));
++ /* resize to new width */
++ for (i = 0; i < MIN(row, term.row); i++) {
++ term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
++ for (j = term.col; j < col; j++)
++ tclearglyph(&term.line[i][j], 0);
++ }
++ /* allocate any new rows */
++ for (/*i = MIN(row, term.row) */; i < row; i++) {
++ term.line[i] = xmalloc(col * sizeof(Glyph));
++ for (j = 0; j < col; j++)
++ tclearglyph(&term.line[i][j], 0);
++ }
++ /* update cursor */
++ if (term.c.x >= col) {
++ term.c.state &= ~CURSOR_WRAPNEXT;
++ term.c.x = col - 1;
++ } else {
++ UPDATEWRAPNEXT(1, col);
++ }
++ /* update terminal size */
++ term.col = col, term.row = row;
++ /* reset scrolling region */
++ term.top = 0, term.bot = row - 1;
++ /* dirty all lines */
++ tfulldirt();
+ }
+
+ void
+@@ -2709,9 +3057,8 @@ draw(void)
+ cx--;
+
+ drawregion(0, 0, term.col, term.row);
+- if (term.scr == 0)
+- xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+- term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
++ xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
++ term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
+ term.ocx = cx;
+ term.ocy = term.c.y;
+ xfinishdraw();
+diff --git a/st.h b/st.h
+index 818a6f8..514ec08 100644
+--- a/st.h
++++ b/st.h
+@@ -22,17 +22,19 @@
+
+ enum glyph_attribute {
+ ATTR_NULL = 0,
+- ATTR_BOLD = 1 << 0,
+- ATTR_FAINT = 1 << 1,
+- ATTR_ITALIC = 1 << 2,
+- ATTR_UNDERLINE = 1 << 3,
+- ATTR_BLINK = 1 << 4,
+- ATTR_REVERSE = 1 << 5,
+- ATTR_INVISIBLE = 1 << 6,
+- ATTR_STRUCK = 1 << 7,
+- ATTR_WRAP = 1 << 8,
+- ATTR_WIDE = 1 << 9,
+- ATTR_WDUMMY = 1 << 10,
++ ATTR_SET = 1 << 0,
++ ATTR_BOLD = 1 << 1,
++ ATTR_FAINT = 1 << 2,
++ ATTR_ITALIC = 1 << 3,
++ ATTR_UNDERLINE = 1 << 4,
++ ATTR_BLINK = 1 << 5,
++ ATTR_REVERSE = 1 << 6,
++ ATTR_INVISIBLE = 1 << 7,
++ ATTR_STRUCK = 1 << 8,
++ ATTR_WRAP = 1 << 9,
++ ATTR_WIDE = 1 << 10,
++ ATTR_WDUMMY = 1 << 11,
++ ATTR_SELECTED = 1 << 12,
+ ATTR_BOLD_FAINT = ATTR_BOLD | ATTR_FAINT,
+ };
+
+@@ -90,6 +92,7 @@ void toggleprinter(const Arg *);
+
+ int tattrset(int);
+ void tnew(int, int);
++int tisaltscreen(void);
+ void tresize(int, int);
+ void tsetdirtattr(int);
+ void ttyhangup(void);
