Merge remote-tracking branch 'upstream/master' into mix_20240309HEADrahm

1 files changed, 0 insertions, 1202 deletions

diff --git a/src/vterm/screen.c b/src/vterm/screen.c
deleted file mode 100644
index 1f5bb36114..0000000000
--- a/src/vterm/screen.c
+++ /dev/null
@@ -1,1202 +0,0 @@
-#include "vterm_internal.h"
-
-#include <stdio.h>
-#include <string.h>
-#include "nvim/mbyte.h"
-#include "nvim/tui/termkey/termkey.h"
-
-#include "rect.h"
-
-#define UNICODE_SPACE 0x20
-#define UNICODE_LINEFEED 0x0a
-
-#undef DEBUG_REFLOW
-
-/* State of the pen at some moment in time, also used in a cell */
-typedef struct
-{
-  /* After the bitfield */
-  VTermColor   fg, bg;
-
-  /* Opaque ID that maps to a URI in a set */
-  int uri;
-
-  unsigned int bold      : 1;
-  unsigned int underline : 2;
-  unsigned int italic    : 1;
-  unsigned int blink     : 1;
-  unsigned int reverse   : 1;
-  unsigned int conceal   : 1;
-  unsigned int strike    : 1;
-  unsigned int font      : 4; /* 0 to 9 */
-  unsigned int small     : 1;
-  unsigned int baseline  : 2;
-
-  /* Extra state storage that isn't strictly pen-related */
-  unsigned int protected_cell : 1;
-  unsigned int dwl            : 1; /* on a DECDWL or DECDHL line */
-  unsigned int dhl            : 2; /* on a DECDHL line (1=top 2=bottom) */
-} ScreenPen;
-
-/* Internal representation of a screen cell */
-typedef struct
-{
-  uint32_t chars[VTERM_MAX_CHARS_PER_CELL];
-  ScreenPen pen;
-} ScreenCell;
-
-struct VTermScreen
-{
-  VTerm *vt;
-  VTermState *state;
-
-  const VTermScreenCallbacks *callbacks;
-  void *cbdata;
-
-  VTermDamageSize damage_merge;
-  /* start_row == -1 => no damage */
-  VTermRect damaged;
-  VTermRect pending_scrollrect;
-  int pending_scroll_downward, pending_scroll_rightward;
-
-  int rows;
-  int cols;
-
-  unsigned int global_reverse : 1;
-  unsigned int reflow : 1;
-
-  /* Primary and Altscreen. buffers[1] is lazily allocated as needed */
-  ScreenCell *buffers[2];
-
-  /* buffer will == buffers[0] or buffers[1], depending on altscreen */
-  ScreenCell *buffer;
-
-  /* buffer for a single screen row used in scrollback storage callbacks */
-  VTermScreenCell *sb_buffer;
-
-  ScreenPen pen;
-};
-
-static inline void clearcell(const VTermScreen *screen, ScreenCell *cell)
-{
-  cell->chars[0] = 0;
-  cell->pen = screen->pen;
-}
-
-static inline ScreenCell *getcell(const VTermScreen *screen, int row, int col)
-{
-  if(row < 0 || row >= screen->rows)
-    return NULL;
-  if(col < 0 || col >= screen->cols)
-    return NULL;
-  return screen->buffer + (screen->cols * row) + col;
-}
-
-static ScreenCell *alloc_buffer(VTermScreen *screen, int rows, int cols)
-{
-  ScreenCell *new_buffer = vterm_allocator_malloc(screen->vt, sizeof(ScreenCell) * rows * cols);
-
-  for(int row = 0; row < rows; row++) {
-    for(int col = 0; col < cols; col++) {
-      clearcell(screen, &new_buffer[row * cols + col]);
-    }
-  }
-
-  return new_buffer;
-}
-
-static void damagerect(VTermScreen *screen, VTermRect rect)
-{
-  VTermRect emit;
-
-  switch(screen->damage_merge) {
-  case VTERM_DAMAGE_CELL:
-    /* Always emit damage event */
-    emit = rect;
-    break;
-
-  case VTERM_DAMAGE_ROW:
-    /* Emit damage longer than one row. Try to merge with existing damage in
-     * the same row */
-    if(rect.end_row > rect.start_row + 1) {
-      // Bigger than 1 line - flush existing, emit this
-      vterm_screen_flush_damage(screen);
-      emit = rect;
-    }
-    else if(screen->damaged.start_row == -1) {
-      // None stored yet
-      screen->damaged = rect;
-      return;
-    }
-    else if(rect.start_row == screen->damaged.start_row) {
-      // Merge with the stored line
-      if(screen->damaged.start_col > rect.start_col)
-        screen->damaged.start_col = rect.start_col;
-      if(screen->damaged.end_col < rect.end_col)
-        screen->damaged.end_col = rect.end_col;
-      return;
-    }
-    else {
-      // Emit the currently stored line, store a new one
-      emit = screen->damaged;
-      screen->damaged = rect;
-    }
-    break;
-
-  case VTERM_DAMAGE_SCREEN:
-  case VTERM_DAMAGE_SCROLL:
-    /* Never emit damage event */
-    if(screen->damaged.start_row == -1)
-      screen->damaged = rect;
-    else {
-      rect_expand(&screen->damaged, &rect);
-    }
-    return;
-
-  default:
-    DEBUG_LOG("TODO: Maybe merge damage for level %d\n", screen->damage_merge);
-    return;
-  }
-
-  if(screen->callbacks && screen->callbacks->damage)
-    (*screen->callbacks->damage)(emit, screen->cbdata);
-}
-
-static void damagescreen(VTermScreen *screen)
-{
-  VTermRect rect = {
-    .start_row = 0,
-    .end_row   = screen->rows,
-    .start_col = 0,
-    .end_col   = screen->cols,
-  };
-
-  damagerect(screen, rect);
-}
-
-static int putglyph(VTermGlyphInfo *info, VTermPos pos, void *user)
-{
-  VTermScreen *screen = user;
-  ScreenCell *cell = getcell(screen, pos.row, pos.col);
-
-  if(!cell)
-    return 0;
-
-  int i;
-  for(i = 0; i < VTERM_MAX_CHARS_PER_CELL && info->chars[i]; i++) {
-    cell->chars[i] = info->chars[i];
-    cell->pen = screen->pen;
-  }
-  if(i < VTERM_MAX_CHARS_PER_CELL)
-    cell->chars[i] = 0;
-
-  for(int col = 1; col < info->width; col++)
-    getcell(screen, pos.row, pos.col + col)->chars[0] = (uint32_t)-1;
-
-  VTermRect rect = {
-    .start_row = pos.row,
-    .end_row   = pos.row+1,
-    .start_col = pos.col,
-    .end_col   = pos.col+info->width,
-  };
-
-  cell->pen.protected_cell = info->protected_cell;
-  cell->pen.dwl            = info->dwl;
-  cell->pen.dhl            = info->dhl;
-
-  damagerect(screen, rect);
-
-  return 1;
-}
-
-static void sb_pushline_from_row(VTermScreen *screen, int row)
-{
-  VTermPos pos = { .row = row };
-  for(pos.col = 0; pos.col < screen->cols; pos.col++)
-    vterm_screen_get_cell(screen, pos, screen->sb_buffer + pos.col);
-
-  (screen->callbacks->sb_pushline)(screen->cols, screen->sb_buffer, screen->cbdata);
-}
-
-static int moverect_internal(VTermRect dest, VTermRect src, void *user)
-{
-  VTermScreen *screen = user;
-
-  if(screen->callbacks && screen->callbacks->sb_pushline &&
-     dest.start_row == 0 && dest.start_col == 0 &&        // starts top-left corner
-     dest.end_col == screen->cols &&                      // full width
-     screen->buffer == screen->buffers[BUFIDX_PRIMARY]) { // not altscreen
-    for(int row = 0; row < src.start_row; row++)
-      sb_pushline_from_row(screen, row);
-  }
-
-  int cols = src.end_col - src.start_col;
-  int downward = src.start_row - dest.start_row;
-
-  int init_row, test_row, inc_row;
-  if(downward < 0) {
-    init_row = dest.end_row - 1;
-    test_row = dest.start_row - 1;
-    inc_row  = -1;
-  }
-  else {
-    init_row = dest.start_row;
-    test_row = dest.end_row;
-    inc_row  = +1;
-  }
-
-  for(int row = init_row; row != test_row; row += inc_row)
-    memmove(getcell(screen, row, dest.start_col),
-            getcell(screen, row + downward, src.start_col),
-            cols * sizeof(ScreenCell));
-
-  return 1;
-}
-
-static int moverect_user(VTermRect dest, VTermRect src, void *user)
-{
-  VTermScreen *screen = user;
-
-  if(screen->callbacks && screen->callbacks->moverect) {
-    if(screen->damage_merge != VTERM_DAMAGE_SCROLL)
-      // Avoid an infinite loop
-      vterm_screen_flush_damage(screen);
-
-    if((*screen->callbacks->moverect)(dest, src, screen->cbdata))
-      return 1;
-  }
-
-  damagerect(screen, dest);
-
-  return 1;
-}
-
-static int erase_internal(VTermRect rect, int selective, void *user)
-{
-  VTermScreen *screen = user;
-
-  for(int row = rect.start_row; row < screen->state->rows && row < rect.end_row; row++) {
-    const VTermLineInfo *info = vterm_state_get_lineinfo(screen->state, row);
-
-    for(int col = rect.start_col; col < rect.end_col; col++) {
-      ScreenCell *cell = getcell(screen, row, col);
-
-      if(selective && cell->pen.protected_cell)
-        continue;
-
-      cell->chars[0] = 0;
-      cell->pen = (ScreenPen){
-        /* Only copy .fg and .bg; leave things like rv in reset state */
-        .fg = screen->pen.fg,
-        .bg = screen->pen.bg,
-      };
-      cell->pen.dwl = info->doublewidth;
-      cell->pen.dhl = info->doubleheight;
-    }
-  }
-
-  return 1;
-}
-
-static int erase_user(VTermRect rect, int selective, void *user)
-{
-  VTermScreen *screen = user;
-
-  damagerect(screen, rect);
-
-  return 1;
-}
-
-static int erase(VTermRect rect, int selective, void *user)
-{
-  erase_internal(rect, selective, user);
-  return erase_user(rect, 0, user);
-}
-
-static int scrollrect(VTermRect rect, int downward, int rightward, void *user)
-{
-  VTermScreen *screen = user;
-
-  if(screen->damage_merge != VTERM_DAMAGE_SCROLL) {
-    vterm_scroll_rect(rect, downward, rightward,
-        moverect_internal, erase_internal, screen);
-
-    vterm_screen_flush_damage(screen);
-
-    vterm_scroll_rect(rect, downward, rightward,
-        moverect_user, erase_user, screen);
-
-    return 1;
-  }
-
-  if(screen->damaged.start_row != -1 &&
-     !rect_intersects(&rect, &screen->damaged)) {
-    vterm_screen_flush_damage(screen);
-  }
-
-  if(screen->pending_scrollrect.start_row == -1) {
-    screen->pending_scrollrect = rect;
-    screen->pending_scroll_downward  = downward;
-    screen->pending_scroll_rightward = rightward;
-  }
-  else if(rect_equal(&screen->pending_scrollrect, &rect) &&
-     ((screen->pending_scroll_downward  == 0 && downward  == 0) ||
-      (screen->pending_scroll_rightward == 0 && rightward == 0))) {
-    screen->pending_scroll_downward  += downward;
-    screen->pending_scroll_rightward += rightward;
-  }
-  else {
-    vterm_screen_flush_damage(screen);
-
-    screen->pending_scrollrect = rect;
-    screen->pending_scroll_downward  = downward;
-    screen->pending_scroll_rightward = rightward;
-  }
-
-  vterm_scroll_rect(rect, downward, rightward,
-      moverect_internal, erase_internal, screen);
-
-  if(screen->damaged.start_row == -1)
-    return 1;
-
-  if(rect_contains(&rect, &screen->damaged)) {
-    /* Scroll region entirely contains the damage; just move it */
-    vterm_rect_move(&screen->damaged, -downward, -rightward);
-    rect_clip(&screen->damaged, &rect);
-  }
-  /* There are a number of possible cases here, but lets restrict this to only
-   * the common case where we might actually gain some performance by
-   * optimising it. Namely, a vertical scroll that neatly cuts the damage
-   * region in half.
-   */
-  else if(rect.start_col <= screen->damaged.start_col &&
-          rect.end_col   >= screen->damaged.end_col &&
-          rightward == 0) {
-    if(screen->damaged.start_row >= rect.start_row &&
-       screen->damaged.start_row  < rect.end_row) {
-      screen->damaged.start_row -= downward;
-      if(screen->damaged.start_row < rect.start_row)
-        screen->damaged.start_row = rect.start_row;
-      if(screen->damaged.start_row > rect.end_row)
-        screen->damaged.start_row = rect.end_row;
-    }
-    if(screen->damaged.end_row >= rect.start_row &&
-       screen->damaged.end_row  < rect.end_row) {
-      screen->damaged.end_row -= downward;
-      if(screen->damaged.end_row < rect.start_row)
-        screen->damaged.end_row = rect.start_row;
-      if(screen->damaged.end_row > rect.end_row)
-        screen->damaged.end_row = rect.end_row;
-    }
-  }
-  else {
-    DEBUG_LOG("TODO: Just flush and redo damaged=" STRFrect " rect=" STRFrect "\n",
-        ARGSrect(screen->damaged), ARGSrect(rect));
-  }
-
-  return 1;
-}
-
-static int movecursor(VTermPos pos, VTermPos oldpos, int visible, void *user)
-{
-  VTermScreen *screen = user;
-
-  if(screen->callbacks && screen->callbacks->movecursor)
-    return (*screen->callbacks->movecursor)(pos, oldpos, visible, screen->cbdata);
-
-  return 0;
-}
-
-static int setpenattr(VTermAttr attr, VTermValue *val, void *user)
-{
-  VTermScreen *screen = user;
-
-  switch(attr) {
-  case VTERM_ATTR_BOLD:
-    screen->pen.bold = val->boolean;
-    return 1;
-  case VTERM_ATTR_UNDERLINE:
-    screen->pen.underline = val->number;
-    return 1;
-  case VTERM_ATTR_ITALIC:
-    screen->pen.italic = val->boolean;
-    return 1;
-  case VTERM_ATTR_BLINK:
-    screen->pen.blink = val->boolean;
-    return 1;
-  case VTERM_ATTR_REVERSE:
-    screen->pen.reverse = val->boolean;
-    return 1;
-  case VTERM_ATTR_CONCEAL:
-    screen->pen.conceal = val->boolean;
-    return 1;
-  case VTERM_ATTR_STRIKE:
-    screen->pen.strike = val->boolean;
-    return 1;
-  case VTERM_ATTR_FONT:
-    screen->pen.font = val->number;
-    return 1;
-  case VTERM_ATTR_FOREGROUND:
-    screen->pen.fg = val->color;
-    return 1;
-  case VTERM_ATTR_BACKGROUND:
-    screen->pen.bg = val->color;
-    return 1;
-  case VTERM_ATTR_SMALL:
-    screen->pen.small = val->boolean;
-    return 1;
-  case VTERM_ATTR_BASELINE:
-    screen->pen.baseline = val->number;
-    return 1;
-  case VTERM_ATTR_URI:
-    screen->pen.uri = val->number;
-    return 1;
-
-  case VTERM_N_ATTRS:
-    return 0;
-  }
-
-  return 0;
-}
-
-static int settermprop(VTermProp prop, VTermValue *val, void *user)
-{
-  VTermScreen *screen = user;
-
-  switch(prop) {
-  case VTERM_PROP_ALTSCREEN:
-    if(val->boolean && !screen->buffers[BUFIDX_ALTSCREEN])
-      return 0;
-
-    screen->buffer = val->boolean ? screen->buffers[BUFIDX_ALTSCREEN] : screen->buffers[BUFIDX_PRIMARY];
-    /* only send a damage event on disable; because during enable there's an
-     * erase that sends a damage anyway
-     */
-    if(!val->boolean)
-      damagescreen(screen);
-    break;
-  case VTERM_PROP_REVERSE:
-    screen->global_reverse = val->boolean;
-    damagescreen(screen);
-    break;
-  default:
-    ; /* ignore */
-  }
-
-  if(screen->callbacks && screen->callbacks->settermprop)
-    return (*screen->callbacks->settermprop)(prop, val, screen->cbdata);
-
-  return 1;
-}
-
-static int bell(void *user)
-{
-  VTermScreen *screen = user;
-
-  if(screen->callbacks && screen->callbacks->bell)
-    return (*screen->callbacks->bell)(screen->cbdata);
-
-  return 0;
-}
-
-/* How many cells are non-blank
- * Returns the position of the first blank cell in the trailing blank end */
-static int line_popcount(ScreenCell *buffer, int row, int rows, int cols)
-{
-  int col = cols - 1;
-  while(col >= 0 && buffer[row * cols + col].chars[0] == 0)
-    col--;
-  return col + 1;
-}
-
-static void resize_buffer(VTermScreen *screen, int bufidx, int new_rows, int new_cols, bool active, VTermStateFields *statefields)
-{
-  int old_rows = screen->rows;
-  int old_cols = screen->cols;
-
-  ScreenCell *old_buffer = screen->buffers[bufidx];
-  VTermLineInfo *old_lineinfo = statefields->lineinfos[bufidx];
-
-  ScreenCell *new_buffer = vterm_allocator_malloc(screen->vt, sizeof(ScreenCell) * new_rows * new_cols);
-  VTermLineInfo *new_lineinfo = vterm_allocator_malloc(screen->vt, sizeof(new_lineinfo[0]) * new_rows);
-
-  int old_row = old_rows - 1;
-  int new_row = new_rows - 1;
-
-  VTermPos old_cursor = statefields->pos;
-  VTermPos new_cursor = { -1, -1 };
-
-#ifdef DEBUG_REFLOW
-  fprintf(stderr, "Resizing from %dx%d to %dx%d; cursor was at (%d,%d)\n",
-      old_cols, old_rows, new_cols, new_rows, old_cursor.col, old_cursor.row);
-#endif
-
-  /* Keep track of the final row that is knonw to be blank, so we know what
-   * spare space we have for scrolling into
-   */
-  int final_blank_row = new_rows;
-
-  while(old_row >= 0) {
-    int old_row_end = old_row;
-    /* TODO: Stop if dwl or dhl */
-    while(screen->reflow && old_lineinfo && old_row > 0 && old_lineinfo[old_row].continuation)
-      old_row--;
-    int old_row_start = old_row;
-
-    int width = 0;
-    for(int row = old_row_start; row <= old_row_end; row++) {
-      if(screen->reflow && row < (old_rows - 1) && old_lineinfo[row + 1].continuation)
-        width += old_cols;
-      else
-        width += line_popcount(old_buffer, row, old_rows, old_cols);
-    }
-
-    if(final_blank_row == (new_row + 1) && width == 0)
-      final_blank_row = new_row;
-
-    int new_height = screen->reflow
-      ? width ? (width + new_cols - 1) / new_cols : 1
-      : 1;
-
-    int new_row_end = new_row;
-    int new_row_start = new_row - new_height + 1;
-
-    old_row = old_row_start;
-    int old_col = 0;
-
-    int spare_rows = new_rows - final_blank_row;
-
-    if(new_row_start < 0 && /* we'd fall off the top */
-        spare_rows >= 0 && /* we actually have spare rows */
-        (!active || new_cursor.row == -1 || (new_cursor.row - new_row_start) < new_rows))
-    {
-      /* Attempt to scroll content down into the blank rows at the bottom to
-       * make it fit
-       */
-      int downwards = -new_row_start;
-      if(downwards > spare_rows)
-        downwards = spare_rows;
-      int rowcount = new_rows - downwards;
-
-#ifdef DEBUG_REFLOW
-      fprintf(stderr, "  scroll %d rows +%d downwards\n", rowcount, downwards);
-#endif
-
-      memmove(&new_buffer[downwards * new_cols], &new_buffer[0],  (unsigned long) rowcount * new_cols * sizeof(ScreenCell));
-      memmove(&new_lineinfo[downwards],          &new_lineinfo[0], rowcount * sizeof(new_lineinfo[0]));
-
-      new_row += downwards;
-      new_row_start += downwards;
-      new_row_end += downwards;
-
-      if(new_cursor.row >= 0)
-        new_cursor.row += downwards;
-
-      final_blank_row += downwards;
-    }
-
-#ifdef DEBUG_REFLOW
-    fprintf(stderr, "  rows [%d..%d] <- [%d..%d] width=%d\n",
-        new_row_start, new_row_end, old_row_start, old_row_end, width);
-#endif
-
-    if(new_row_start < 0) {
-      if(old_row_start <= old_cursor.row && old_cursor.row <= old_row_end) {
-        new_cursor.row = 0;
-        new_cursor.col = old_cursor.col;
-        if(new_cursor.col >= new_cols)
-          new_cursor.col = new_cols-1;
-      }
-      break;
-    }
-
-    for(new_row = new_row_start, old_row = old_row_start; new_row <= new_row_end; new_row++) {
-      int count = width >= new_cols ? new_cols : width;
-      width -= count;
-
-      int new_col = 0;
-
-      while(count) {
-        /* TODO: This could surely be done a lot faster by memcpy()'ing the entire range */
-        new_buffer[new_row * new_cols + new_col] = old_buffer[old_row * old_cols + old_col];
-
-        if(old_cursor.row == old_row && old_cursor.col == old_col)
-          new_cursor.row = new_row, new_cursor.col = new_col;
-
-        old_col++;
-        if(old_col == old_cols) {
-          old_row++;
-
-          if(!screen->reflow) {
-            new_col++;
-            break;
-          }
-          old_col = 0;
-        }
-
-        new_col++;
-        count--;
-      }
-
-      if(old_cursor.row == old_row && old_cursor.col >= old_col) {
-        new_cursor.row = new_row, new_cursor.col = (old_cursor.col - old_col + new_col);
-        if(new_cursor.col >= new_cols)
-          new_cursor.col = new_cols-1;
-      }
-
-      while(new_col < new_cols) {
-        clearcell(screen, &new_buffer[new_row * new_cols + new_col]);
-        new_col++;
-      }
-
-      new_lineinfo[new_row].continuation = (new_row > new_row_start);
-    }
-
-    old_row = old_row_start - 1;
-    new_row = new_row_start - 1;
-  }
-
-  if(old_cursor.row <= old_row) {
-    /* cursor would have moved entirely off the top of the screen; lets just
-     * bring it within range */
-    new_cursor.row = 0, new_cursor.col = old_cursor.col;
-    if(new_cursor.col >= new_cols)
-      new_cursor.col = new_cols-1;
-  }
-
-  /* We really expect the cursor position to be set by now */
-  if(active && (new_cursor.row == -1 || new_cursor.col == -1)) {
-    fprintf(stderr, "screen_resize failed to update cursor position\n");
-    abort();
-  }
-
-  if(old_row >= 0 && bufidx == BUFIDX_PRIMARY) {
-    /* Push spare lines to scrollback buffer */
-    if(screen->callbacks && screen->callbacks->sb_pushline)
-      for(int row = 0; row <= old_row; row++)
-        sb_pushline_from_row(screen, row);
-    if(active)
-      statefields->pos.row -= (old_row + 1);
-  }
-  if(new_row >= 0 && bufidx == BUFIDX_PRIMARY &&
-      screen->callbacks && screen->callbacks->sb_popline) {
-    /* Try to backfill rows by popping scrollback buffer */
-    while(new_row >= 0) {
-      if(!(screen->callbacks->sb_popline(old_cols, screen->sb_buffer, screen->cbdata)))
-        break;
-
-      VTermPos pos = { .row = new_row };
-      for(pos.col = 0; pos.col < old_cols && pos.col < new_cols; pos.col += screen->sb_buffer[pos.col].width) {
-        VTermScreenCell *src = &screen->sb_buffer[pos.col];
-        ScreenCell *dst = &new_buffer[pos.row * new_cols + pos.col];
-
-        for(int i = 0; i < VTERM_MAX_CHARS_PER_CELL; i++) {
-          dst->chars[i] = src->chars[i];
-          if(!src->chars[i])
-            break;
-        }
-
-        dst->pen.bold      = src->attrs.bold;
-        dst->pen.underline = src->attrs.underline;
-        dst->pen.italic    = src->attrs.italic;
-        dst->pen.blink     = src->attrs.blink;
-        dst->pen.reverse   = src->attrs.reverse ^ screen->global_reverse;
-        dst->pen.conceal   = src->attrs.conceal;
-        dst->pen.strike    = src->attrs.strike;
-        dst->pen.font      = src->attrs.font;
-        dst->pen.small     = src->attrs.small;
-        dst->pen.baseline  = src->attrs.baseline;
-
-        dst->pen.fg = src->fg;
-        dst->pen.bg = src->bg;
-
-        dst->pen.uri = src->uri;
-
-        if(src->width == 2 && pos.col < (new_cols-1))
-          (dst + 1)->chars[0] = (uint32_t) -1;
-      }
-      for( ; pos.col < new_cols; pos.col++)
-        clearcell(screen, &new_buffer[pos.row * new_cols + pos.col]);
-      new_row--;
-
-      if(active)
-        statefields->pos.row++;
-    }
-  }
-  if(new_row >= 0) {
-    /* Scroll new rows back up to the top and fill in blanks at the bottom */
-    int moverows = new_rows - new_row - 1;
-    memmove(&new_buffer[0], &new_buffer[(new_row + 1) * new_cols], (unsigned long) moverows * new_cols * sizeof(ScreenCell));
-    memmove(&new_lineinfo[0], &new_lineinfo[new_row + 1], moverows * sizeof(new_lineinfo[0]));
-
-    new_cursor.row -= (new_row + 1);
-
-    for(new_row = moverows; new_row < new_rows; new_row++) {
-      for(int col = 0; col < new_cols; col++)
-        clearcell(screen, &new_buffer[new_row * new_cols + col]);
-      new_lineinfo[new_row] = (VTermLineInfo){ 0 };
-    }
-  }
-
-  vterm_allocator_free(screen->vt, old_buffer);
-  screen->buffers[bufidx] = new_buffer;
-
-  vterm_allocator_free(screen->vt, old_lineinfo);
-  statefields->lineinfos[bufidx] = new_lineinfo;
-
-  if(active)
-    statefields->pos = new_cursor;
-
-  return;
-}
-
-static int resize(int new_rows, int new_cols, VTermStateFields *fields, void *user)
-{
-  VTermScreen *screen = user;
-
-  int altscreen_active = (screen->buffers[BUFIDX_ALTSCREEN] && screen->buffer == screen->buffers[BUFIDX_ALTSCREEN]);
-
-  int old_rows = screen->rows;
-  int old_cols = screen->cols;
-
-  if(new_cols > old_cols) {
-    /* Ensure that ->sb_buffer is large enough for a new or and old row */
-    if(screen->sb_buffer)
-      vterm_allocator_free(screen->vt, screen->sb_buffer);
-
-    screen->sb_buffer = vterm_allocator_malloc(screen->vt, sizeof(VTermScreenCell) * new_cols);
-  }
-
-  resize_buffer(screen, 0, new_rows, new_cols, !altscreen_active, fields);
-  if(screen->buffers[BUFIDX_ALTSCREEN])
-    resize_buffer(screen, 1, new_rows, new_cols, altscreen_active, fields);
-  else if(new_rows != old_rows) {
-    /* We don't need a full resize of the altscreen because it isn't enabled
-     * but we should at least keep the lineinfo the right size */
-    vterm_allocator_free(screen->vt, fields->lineinfos[BUFIDX_ALTSCREEN]);
-
-    VTermLineInfo *new_lineinfo = vterm_allocator_malloc(screen->vt, sizeof(new_lineinfo[0]) * new_rows);
-    for(int row = 0; row < new_rows; row++)
-      new_lineinfo[row] = (VTermLineInfo){ 0 };
-
-    fields->lineinfos[BUFIDX_ALTSCREEN] = new_lineinfo;
-  }
-
-  screen->buffer = altscreen_active ? screen->buffers[BUFIDX_ALTSCREEN] : screen->buffers[BUFIDX_PRIMARY];
-
-  screen->rows = new_rows;
-  screen->cols = new_cols;
-
-  if(new_cols <= old_cols) {
-    if(screen->sb_buffer)
-      vterm_allocator_free(screen->vt, screen->sb_buffer);
-
-    screen->sb_buffer = vterm_allocator_malloc(screen->vt, sizeof(VTermScreenCell) * new_cols);
-  }
-
-  /* TODO: Maaaaybe we can optimise this if there's no reflow happening */
-  damagescreen(screen);
-
-  if(screen->callbacks && screen->callbacks->resize)
-    return (*screen->callbacks->resize)(new_rows, new_cols, screen->cbdata);
-
-  return 1;
-}
-
-static int setlineinfo(int row, const VTermLineInfo *newinfo, const VTermLineInfo *oldinfo, void *user)
-{
-  VTermScreen *screen = user;
-
-  if(newinfo->doublewidth != oldinfo->doublewidth ||
-     newinfo->doubleheight != oldinfo->doubleheight) {
-    for(int col = 0; col < screen->cols; col++) {
-      ScreenCell *cell = getcell(screen, row, col);
-      cell->pen.dwl = newinfo->doublewidth;
-      cell->pen.dhl = newinfo->doubleheight;
-    }
-
-    VTermRect rect = {
-      .start_row = row,
-      .end_row   = row + 1,
-      .start_col = 0,
-      .end_col   = newinfo->doublewidth ? screen->cols / 2 : screen->cols,
-    };
-    damagerect(screen, rect);
-
-    if(newinfo->doublewidth) {
-      rect.start_col = screen->cols / 2;
-      rect.end_col   = screen->cols;
-
-      erase_internal(rect, 0, user);
-    }
-  }
-
-  return 1;
-}
-
-static int sb_clear(void *user) {
-  VTermScreen *screen = user;
-
-  if(screen->callbacks && screen->callbacks->sb_clear)
-    if((*screen->callbacks->sb_clear)(screen->cbdata))
-      return 1;
-
-  return 0;
-}
-
-static VTermStateCallbacks state_cbs = {
-  .putglyph    = &putglyph,
-  .movecursor  = &movecursor,
-  .scrollrect  = &scrollrect,
-  .erase       = &erase,
-  .setpenattr  = &setpenattr,
-  .settermprop = &settermprop,
-  .bell        = &bell,
-  .resize      = &resize,
-  .setlineinfo = &setlineinfo,
-  .sb_clear    = &sb_clear,
-};
-
-static VTermScreen *screen_new(VTerm *vt)
-{
-  VTermState *state = vterm_obtain_state(vt);
-  if(!state)
-    return NULL;
-
-  VTermScreen *screen = vterm_allocator_malloc(vt, sizeof(VTermScreen));
-  int rows, cols;
-
-  vterm_get_size(vt, &rows, &cols);
-
-  screen->vt = vt;
-  screen->state = state;
-
-  screen->damage_merge = VTERM_DAMAGE_CELL;
-  screen->damaged.start_row = -1;
-  screen->pending_scrollrect.start_row = -1;
-
-  screen->rows = rows;
-  screen->cols = cols;
-
-  screen->global_reverse = false;
-  screen->reflow = false;
-
-  screen->callbacks = NULL;
-  screen->cbdata    = NULL;
-
-  screen->buffers[BUFIDX_PRIMARY] = alloc_buffer(screen, rows, cols);
-
-  screen->buffer = screen->buffers[BUFIDX_PRIMARY];
-
-  screen->sb_buffer = vterm_allocator_malloc(screen->vt, sizeof(VTermScreenCell) * cols);
-
-  vterm_state_set_callbacks(screen->state, &state_cbs, screen);
-
-  return screen;
-}
-
-INTERNAL void vterm_screen_free(VTermScreen *screen)
-{
-  vterm_allocator_free(screen->vt, screen->buffers[BUFIDX_PRIMARY]);
-  if(screen->buffers[BUFIDX_ALTSCREEN])
-    vterm_allocator_free(screen->vt, screen->buffers[BUFIDX_ALTSCREEN]);
-
-  vterm_allocator_free(screen->vt, screen->sb_buffer);
-
-  vterm_allocator_free(screen->vt, screen);
-}
-
-void vterm_screen_reset(VTermScreen *screen, int hard)
-{
-  screen->damaged.start_row = -1;
-  screen->pending_scrollrect.start_row = -1;
-  vterm_state_reset(screen->state, hard);
-  vterm_screen_flush_damage(screen);
-}
-
-static size_t _get_chars(const VTermScreen *screen, const int utf8, void *buffer, size_t len, const VTermRect rect)
-{
-  size_t outpos = 0;
-  int padding = 0;
-
-#define PUT(c)                                             \
-  if(utf8) {                                               \
-    size_t thislen = utf_char2len(c);                      \
-    if(buffer && outpos + thislen <= len)                  \
-      outpos += fill_utf8((c), (char *)buffer + outpos);   \
-    else                                                   \
-      outpos += thislen;                                   \
-  }                                                        \
-  else {                                                   \
-    if(buffer && outpos + 1 <= len)                        \
-      ((uint32_t*)buffer)[outpos++] = (c);                 \
-    else                                                   \
-      outpos++;                                            \
-  }
-
-  for(int row = rect.start_row; row < rect.end_row; row++) {
-    for(int col = rect.start_col; col < rect.end_col; col++) {
-      ScreenCell *cell = getcell(screen, row, col);
-
-      if(cell->chars[0] == 0)
-        // Erased cell, might need a space
-        padding++;
-      else if(cell->chars[0] == (uint32_t)-1)
-        // Gap behind a double-width char, do nothing
-        ;
-      else {
-        while(padding) {
-          PUT(UNICODE_SPACE);
-          padding--;
-        }
-        for(int i = 0; i < VTERM_MAX_CHARS_PER_CELL && cell->chars[i]; i++) {
-          PUT(cell->chars[i]);
-        }
-      }
-    }
-
-    if(row < rect.end_row - 1) {
-      PUT(UNICODE_LINEFEED);
-      padding = 0;
-    }
-  }
-
-  return outpos;
-}
-
-size_t vterm_screen_get_chars(const VTermScreen *screen, uint32_t *chars, size_t len, const VTermRect rect)
-{
-  return _get_chars(screen, 0, chars, len, rect);
-}
-
-size_t vterm_screen_get_text(const VTermScreen *screen, char *str, size_t len, const VTermRect rect)
-{
-  return _get_chars(screen, 1, str, len, rect);
-}
-
-/* Copy internal to external representation of a screen cell */
-int vterm_screen_get_cell(const VTermScreen *screen, VTermPos pos, VTermScreenCell *cell)
-{
-  ScreenCell *intcell = getcell(screen, pos.row, pos.col);
-  if(!intcell)
-    return 0;
-
-  for(int i = 0; i < VTERM_MAX_CHARS_PER_CELL; i++) {
-    cell->chars[i] = intcell->chars[i];
-    if(!intcell->chars[i])
-      break;
-  }
-
-  cell->attrs.bold      = intcell->pen.bold;
-  cell->attrs.underline = intcell->pen.underline;
-  cell->attrs.italic    = intcell->pen.italic;
-  cell->attrs.blink     = intcell->pen.blink;
-  cell->attrs.reverse   = intcell->pen.reverse ^ screen->global_reverse;
-  cell->attrs.conceal   = intcell->pen.conceal;
-  cell->attrs.strike    = intcell->pen.strike;
-  cell->attrs.font      = intcell->pen.font;
-  cell->attrs.small     = intcell->pen.small;
-  cell->attrs.baseline  = intcell->pen.baseline;
-
-  cell->attrs.dwl = intcell->pen.dwl;
-  cell->attrs.dhl = intcell->pen.dhl;
-
-  cell->fg = intcell->pen.fg;
-  cell->bg = intcell->pen.bg;
-
-  cell->uri = intcell->pen.uri;
-
-  if(pos.col < (screen->cols - 1) &&
-     getcell(screen, pos.row, pos.col + 1)->chars[0] == (uint32_t)-1)
-    cell->width = 2;
-  else
-    cell->width = 1;
-
-  return 1;
-}
-
-int vterm_screen_is_eol(const VTermScreen *screen, VTermPos pos)
-{
-  /* This cell is EOL if this and every cell to the right is black */
-  for(; pos.col < screen->cols; pos.col++) {
-    ScreenCell *cell = getcell(screen, pos.row, pos.col);
-    if(cell->chars[0] != 0)
-      return 0;
-  }
-
-  return 1;
-}
-
-VTermScreen *vterm_obtain_screen(VTerm *vt)
-{
-  if(vt->screen)
-    return vt->screen;
-
-  VTermScreen *screen = screen_new(vt);
-  vt->screen = screen;
-
-  return screen;
-}
-
-void vterm_screen_enable_reflow(VTermScreen *screen, bool reflow)
-{
-  screen->reflow = reflow;
-}
-
-#undef vterm_screen_set_reflow
-void vterm_screen_set_reflow(VTermScreen *screen, bool reflow)
-{
-  vterm_screen_enable_reflow(screen, reflow);
-}
-
-void vterm_screen_enable_altscreen(VTermScreen *screen, int altscreen)
-{
-  if(!screen->buffers[BUFIDX_ALTSCREEN] && altscreen) {
-    int rows, cols;
-    vterm_get_size(screen->vt, &rows, &cols);
-
-    screen->buffers[BUFIDX_ALTSCREEN] = alloc_buffer(screen, rows, cols);
-  }
-}
-
-void vterm_screen_set_callbacks(VTermScreen *screen, const VTermScreenCallbacks *callbacks, void *user)
-{
-  screen->callbacks = callbacks;
-  screen->cbdata = user;
-}
-
-void *vterm_screen_get_cbdata(VTermScreen *screen)
-{
-  return screen->cbdata;
-}
-
-void vterm_screen_set_unrecognised_fallbacks(VTermScreen *screen, const VTermStateFallbacks *fallbacks, void *user)
-{
-  vterm_state_set_unrecognised_fallbacks(screen->state, fallbacks, user);
-}
-
-void *vterm_screen_get_unrecognised_fbdata(VTermScreen *screen)
-{
-  return vterm_state_get_unrecognised_fbdata(screen->state);
-}
-
-void vterm_screen_flush_damage(VTermScreen *screen)
-{
-  if(screen->pending_scrollrect.start_row != -1) {
-    vterm_scroll_rect(screen->pending_scrollrect, screen->pending_scroll_downward, screen->pending_scroll_rightward,
-        moverect_user, erase_user, screen);
-
-    screen->pending_scrollrect.start_row = -1;
-  }
-
-  if(screen->damaged.start_row != -1) {
-    if(screen->callbacks && screen->callbacks->damage)
-      (*screen->callbacks->damage)(screen->damaged, screen->cbdata);
-
-    screen->damaged.start_row = -1;
-  }
-}
-
-void vterm_screen_set_damage_merge(VTermScreen *screen, VTermDamageSize size)
-{
-  vterm_screen_flush_damage(screen);
-  screen->damage_merge = size;
-}
-
-static int attrs_differ(VTermAttrMask attrs, ScreenCell *a, ScreenCell *b)
-{
-  if((attrs & VTERM_ATTR_BOLD_MASK)       && (a->pen.bold != b->pen.bold))
-    return 1;
-  if((attrs & VTERM_ATTR_UNDERLINE_MASK)  && (a->pen.underline != b->pen.underline))
-    return 1;
-  if((attrs & VTERM_ATTR_ITALIC_MASK)     && (a->pen.italic != b->pen.italic))
-    return 1;
-  if((attrs & VTERM_ATTR_BLINK_MASK)      && (a->pen.blink != b->pen.blink))
-    return 1;
-  if((attrs & VTERM_ATTR_REVERSE_MASK)    && (a->pen.reverse != b->pen.reverse))
-    return 1;
-  if((attrs & VTERM_ATTR_CONCEAL_MASK)    && (a->pen.conceal != b->pen.conceal))
-    return 1;
-  if((attrs & VTERM_ATTR_STRIKE_MASK)     && (a->pen.strike != b->pen.strike))
-    return 1;
-  if((attrs & VTERM_ATTR_FONT_MASK)       && (a->pen.font != b->pen.font))
-    return 1;
-  if((attrs & VTERM_ATTR_FOREGROUND_MASK) && !vterm_color_is_equal(&a->pen.fg, &b->pen.fg))
-    return 1;
-  if((attrs & VTERM_ATTR_BACKGROUND_MASK) && !vterm_color_is_equal(&a->pen.bg, &b->pen.bg))
-    return 1;
-  if((attrs & VTERM_ATTR_SMALL_MASK)      && (a->pen.small != b->pen.small))
-    return 1;
-  if((attrs & VTERM_ATTR_BASELINE_MASK)   && (a->pen.baseline != b->pen.baseline))
-    return 1;
-  if((attrs & VTERM_ATTR_URI_MASK)        && (a->pen.uri != b->pen.uri))
-    return 1;
-
-  return 0;
-}
-
-int vterm_screen_get_attrs_extent(const VTermScreen *screen, VTermRect *extent, VTermPos pos, VTermAttrMask attrs)
-{
-  ScreenCell *target = getcell(screen, pos.row, pos.col);
-
-  // TODO: bounds check
-  extent->start_row = pos.row;
-  extent->end_row   = pos.row + 1;
-
-  if(extent->start_col < 0)
-    extent->start_col = 0;
-  if(extent->end_col < 0)
-    extent->end_col = screen->cols;
-
-  int col;
-
-  for(col = pos.col - 1; col >= extent->start_col; col--)
-    if(attrs_differ(attrs, target, getcell(screen, pos.row, col)))
-      break;
-  extent->start_col = col + 1;
-
-  for(col = pos.col + 1; col < extent->end_col; col++)
-    if(attrs_differ(attrs, target, getcell(screen, pos.row, col)))
-      break;
-  extent->end_col = col - 1;
-
-  return 1;
-}
-
-void vterm_screen_convert_color_to_rgb(const VTermScreen *screen, VTermColor *col)
-{
-  vterm_state_convert_color_to_rgb(screen->state, col);
-}
-
-static void reset_default_colours(VTermScreen *screen, ScreenCell *buffer)
-{
-  for(int row = 0; row <= screen->rows - 1; row++)
-    for(int col = 0; col <= screen->cols - 1; col++) {
-      ScreenCell *cell = &buffer[row * screen->cols + col];
-      if(VTERM_COLOR_IS_DEFAULT_FG(&cell->pen.fg))
-        cell->pen.fg = screen->pen.fg;
-      if(VTERM_COLOR_IS_DEFAULT_BG(&cell->pen.bg))
-        cell->pen.bg = screen->pen.bg;
-    }
-}
-
-void vterm_screen_set_default_colors(VTermScreen *screen, const VTermColor *default_fg, const VTermColor *default_bg)
-{
-  vterm_state_set_default_colors(screen->state, default_fg, default_bg);
-
-  if(default_fg && VTERM_COLOR_IS_DEFAULT_FG(&screen->pen.fg)) {
-    screen->pen.fg = *default_fg;
-    screen->pen.fg.type = (screen->pen.fg.type & ~VTERM_COLOR_DEFAULT_MASK)
-                        | VTERM_COLOR_DEFAULT_FG;
-  }
-
-  if(default_bg && VTERM_COLOR_IS_DEFAULT_BG(&screen->pen.bg)) {
-    screen->pen.bg = *default_bg;
-    screen->pen.bg.type = (screen->pen.bg.type & ~VTERM_COLOR_DEFAULT_MASK)
-                        | VTERM_COLOR_DEFAULT_BG;
-  }
-
-  reset_default_colours(screen, screen->buffers[0]);
-  if(screen->buffers[1])
-    reset_default_colours(screen, screen->buffers[1]);
-}