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-rw-r--r--src/nvim/grid.c785
1 files changed, 785 insertions, 0 deletions
diff --git a/src/nvim/grid.c b/src/nvim/grid.c
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+++ b/src/nvim/grid.c
@@ -0,0 +1,785 @@
+// This is an open source non-commercial project. Dear PVS-Studio, please check
+// it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+
+#include "nvim/arabic.h"
+#include "nvim/grid.h"
+#include "nvim/highlight.h"
+#include "nvim/screen.h"
+#include "nvim/ui.h"
+#include "nvim/vim.h"
+
+#ifdef INCLUDE_GENERATED_DECLARATIONS
+# include "grid.c.generated.h"
+#endif
+
+// temporary buffer for rendering a single screenline, so it can be
+// compared with previous contents to calculate smallest delta.
+// Per-cell attributes
+static size_t linebuf_size = 0;
+
+/// Determine if dedicated window grid should be used or the default_grid
+///
+/// If UI did not request multigrid support, draw all windows on the
+/// default_grid.
+///
+/// NB: this function can only been used with window grids in a context where
+/// win_grid_alloc already has been called!
+///
+/// If the default_grid is used, adjust window relative positions to global
+/// screen positions.
+void grid_adjust(ScreenGrid **grid, int *row_off, int *col_off)
+{
+ if ((*grid)->target) {
+ *row_off += (*grid)->row_offset;
+ *col_off += (*grid)->col_offset;
+ *grid = (*grid)->target;
+ }
+}
+
+/// Put a unicode char, and up to MAX_MCO composing chars, in a screen cell.
+int schar_from_cc(char_u *p, int c, int u8cc[MAX_MCO])
+{
+ int len = utf_char2bytes(c, (char *)p);
+ for (int i = 0; i < MAX_MCO; i++) {
+ if (u8cc[i] == 0) {
+ break;
+ }
+ len += utf_char2bytes(u8cc[i], (char *)p + len);
+ }
+ p[len] = 0;
+ return len;
+}
+
+/// clear a line in the grid starting at "off" until "width" characters
+/// are cleared.
+void grid_clear_line(ScreenGrid *grid, size_t off, int width, bool valid)
+{
+ for (int col = 0; col < width; col++) {
+ schar_from_ascii(grid->chars[off + (size_t)col], ' ');
+ }
+ int fill = valid ? 0 : -1;
+ (void)memset(grid->attrs + off, fill, (size_t)width * sizeof(sattr_T));
+}
+
+void grid_invalidate(ScreenGrid *grid)
+{
+ (void)memset(grid->attrs, -1, sizeof(sattr_T) * (size_t)grid->rows * (size_t)grid->cols);
+}
+
+bool grid_invalid_row(ScreenGrid *grid, int row)
+{
+ return grid->attrs[grid->line_offset[row]] < 0;
+}
+
+static int line_off2cells(schar_T *line, size_t off, size_t max_off)
+{
+ return (off + 1 < max_off && line[off + 1][0] == 0) ? 2 : 1;
+}
+
+/// Return number of display cells for char at grid->chars[off].
+/// We make sure that the offset used is less than "max_off".
+static int grid_off2cells(ScreenGrid *grid, size_t off, size_t max_off)
+{
+ return line_off2cells(grid->chars, off, max_off);
+}
+
+/// Return true if the character at "row"/"col" on the screen is the left side
+/// of a double-width character.
+///
+/// Caller must make sure "row" and "col" are not invalid!
+bool grid_lefthalve(ScreenGrid *grid, int row, int col)
+{
+ grid_adjust(&grid, &row, &col);
+
+ return grid_off2cells(grid, grid->line_offset[row] + (size_t)col,
+ grid->line_offset[row] + (size_t)grid->cols) > 1;
+}
+
+/// Correct a position on the screen, if it's the right half of a double-wide
+/// char move it to the left half. Returns the corrected column.
+int grid_fix_col(ScreenGrid *grid, int col, int row)
+{
+ int coloff = 0;
+ grid_adjust(&grid, &row, &coloff);
+
+ col += coloff;
+ if (grid->chars != NULL && col > 0
+ && grid->chars[grid->line_offset[row] + (size_t)col][0] == 0) {
+ return col - 1 - coloff;
+ }
+ return col - coloff;
+}
+
+/// output a single character directly to the grid
+void grid_putchar(ScreenGrid *grid, int c, int row, int col, int attr)
+{
+ char buf[MB_MAXBYTES + 1];
+
+ buf[utf_char2bytes(c, buf)] = NUL;
+ grid_puts(grid, (char_u *)buf, row, col, attr);
+}
+
+/// get a single character directly from grid.chars into "bytes[]".
+/// Also return its attribute in *attrp;
+void grid_getbytes(ScreenGrid *grid, int row, int col, char_u *bytes, int *attrp)
+{
+ size_t off;
+
+ grid_adjust(&grid, &row, &col);
+
+ // safety check
+ if (grid->chars != NULL && row < grid->rows && col < grid->cols) {
+ off = grid->line_offset[row] + (size_t)col;
+ *attrp = grid->attrs[off];
+ schar_copy(bytes, grid->chars[off]);
+ }
+}
+
+/// put string '*text' on the window grid at position 'row' and 'col', with
+/// attributes 'attr', and update chars[] and attrs[].
+/// Note: only outputs within one row, message is truncated at grid boundary!
+/// Note: if grid, row and/or col is invalid, nothing is done.
+void grid_puts(ScreenGrid *grid, char_u *text, int row, int col, int attr)
+{
+ grid_puts_len(grid, text, -1, row, col, attr);
+}
+
+static ScreenGrid *put_dirty_grid = NULL;
+static int put_dirty_row = -1;
+static int put_dirty_first = INT_MAX;
+static int put_dirty_last = 0;
+
+/// Start a group of grid_puts_len calls that builds a single grid line.
+///
+/// Must be matched with a grid_puts_line_flush call before moving to
+/// another line.
+void grid_puts_line_start(ScreenGrid *grid, int row)
+{
+ int col = 0; // unused
+ grid_adjust(&grid, &row, &col);
+ assert(put_dirty_row == -1);
+ put_dirty_row = row;
+ put_dirty_grid = grid;
+}
+
+void grid_put_schar(ScreenGrid *grid, int row, int col, char_u *schar, int attr)
+{
+ assert(put_dirty_row == row);
+ size_t off = grid->line_offset[row] + (size_t)col;
+ if (grid->attrs[off] != attr || schar_cmp(grid->chars[off], schar)) {
+ schar_copy(grid->chars[off], schar);
+ grid->attrs[off] = attr;
+
+ put_dirty_first = MIN(put_dirty_first, col);
+ // TODO(bfredl): Y U NO DOUBLEWIDTH?
+ put_dirty_last = MAX(put_dirty_last, col + 1);
+ }
+}
+
+/// like grid_puts(), but output "text[len]". When "len" is -1 output up to
+/// a NUL.
+void grid_puts_len(ScreenGrid *grid, char_u *text, int textlen, int row, int col, int attr)
+{
+ size_t off;
+ char_u *ptr = text;
+ int len = textlen;
+ int c;
+ size_t max_off;
+ int mbyte_blen = 1;
+ int mbyte_cells = 1;
+ int u8c = 0;
+ int u8cc[MAX_MCO];
+ bool clear_next_cell = false;
+ int prev_c = 0; // previous Arabic character
+ int pc, nc, nc1;
+ int pcc[MAX_MCO];
+ int need_redraw;
+ bool do_flush = false;
+
+ grid_adjust(&grid, &row, &col);
+
+ // Safety check. The check for negative row and column is to fix issue
+ // vim/vim#4102. TODO(neovim): find out why row/col could be negative.
+ if (grid->chars == NULL
+ || row >= grid->rows || row < 0
+ || col >= grid->cols || col < 0) {
+ return;
+ }
+
+ if (put_dirty_row == -1) {
+ grid_puts_line_start(grid, row);
+ do_flush = true;
+ } else {
+ if (grid != put_dirty_grid || row != put_dirty_row) {
+ abort();
+ }
+ }
+ off = grid->line_offset[row] + (size_t)col;
+
+ // When drawing over the right half of a double-wide char clear out the
+ // left half. Only needed in a terminal.
+ if (grid != &default_grid && col == 0 && grid_invalid_row(grid, row)) {
+ // redraw the previous cell, make it empty
+ put_dirty_first = -1;
+ put_dirty_last = MAX(put_dirty_last, 1);
+ }
+
+ max_off = grid->line_offset[row] + (size_t)grid->cols;
+ while (col < grid->cols
+ && (len < 0 || (int)(ptr - text) < len)
+ && *ptr != NUL) {
+ c = *ptr;
+ // check if this is the first byte of a multibyte
+ if (len > 0) {
+ mbyte_blen = utfc_ptr2len_len(ptr, (int)((text + len) - ptr));
+ } else {
+ mbyte_blen = utfc_ptr2len((char *)ptr);
+ }
+ if (len >= 0) {
+ u8c = utfc_ptr2char_len(ptr, u8cc, (int)((text + len) - ptr));
+ } else {
+ u8c = utfc_ptr2char(ptr, u8cc);
+ }
+ mbyte_cells = utf_char2cells(u8c);
+ if (p_arshape && !p_tbidi && ARABIC_CHAR(u8c)) {
+ // Do Arabic shaping.
+ if (len >= 0 && (int)(ptr - text) + mbyte_blen >= len) {
+ // Past end of string to be displayed.
+ nc = NUL;
+ nc1 = NUL;
+ } else {
+ nc = utfc_ptr2char_len(ptr + mbyte_blen, pcc,
+ (int)((text + len) - ptr - mbyte_blen));
+ nc1 = pcc[0];
+ }
+ pc = prev_c;
+ prev_c = u8c;
+ u8c = arabic_shape(u8c, &c, &u8cc[0], nc, nc1, pc);
+ } else {
+ prev_c = u8c;
+ }
+ if (col + mbyte_cells > grid->cols) {
+ // Only 1 cell left, but character requires 2 cells:
+ // display a '>' in the last column to avoid wrapping. */
+ c = '>';
+ u8c = '>';
+ u8cc[0] = 0;
+ mbyte_cells = 1;
+ }
+
+ schar_T buf;
+ schar_from_cc(buf, u8c, u8cc);
+
+ need_redraw = schar_cmp(grid->chars[off], buf)
+ || (mbyte_cells == 2 && grid->chars[off + 1][0] != 0)
+ || grid->attrs[off] != attr
+ || exmode_active;
+
+ if (need_redraw) {
+ // When at the end of the text and overwriting a two-cell
+ // character with a one-cell character, need to clear the next
+ // cell. Also when overwriting the left half of a two-cell char
+ // with the right half of a two-cell char. Do this only once
+ // (utf8_off2cells() may return 2 on the right half).
+ if (clear_next_cell) {
+ clear_next_cell = false;
+ } else if ((len < 0 ? ptr[mbyte_blen] == NUL : ptr + mbyte_blen >= text + len)
+ && ((mbyte_cells == 1
+ && grid_off2cells(grid, off, max_off) > 1)
+ || (mbyte_cells == 2
+ && grid_off2cells(grid, off, max_off) == 1
+ && grid_off2cells(grid, off + 1, max_off) > 1))) {
+ clear_next_cell = true;
+ }
+
+ // When at the start of the text and overwriting the right half of a
+ // two-cell character in the same grid, truncate that into a '>'.
+ if (ptr == text && col > 0 && grid->chars[off][0] == 0) {
+ grid->chars[off - 1][0] = '>';
+ grid->chars[off - 1][1] = 0;
+ }
+
+ schar_copy(grid->chars[off], buf);
+ grid->attrs[off] = attr;
+ if (mbyte_cells == 2) {
+ grid->chars[off + 1][0] = 0;
+ grid->attrs[off + 1] = attr;
+ }
+ put_dirty_first = MIN(put_dirty_first, col);
+ put_dirty_last = MAX(put_dirty_last, col + mbyte_cells);
+ }
+
+ off += (size_t)mbyte_cells;
+ col += mbyte_cells;
+ ptr += mbyte_blen;
+ if (clear_next_cell) {
+ // This only happens at the end, display one space next.
+ ptr = (char_u *)" ";
+ len = -1;
+ }
+ }
+
+ if (do_flush) {
+ grid_puts_line_flush(true);
+ }
+}
+
+/// End a group of grid_puts_len calls and send the screen buffer to the UI
+/// layer.
+///
+/// @param set_cursor Move the visible cursor to the end of the changed region.
+/// This is a workaround for not yet refactored code paths
+/// and shouldn't be used in new code.
+void grid_puts_line_flush(bool set_cursor)
+{
+ assert(put_dirty_row != -1);
+ if (put_dirty_first < put_dirty_last) {
+ if (set_cursor) {
+ ui_grid_cursor_goto(put_dirty_grid->handle, put_dirty_row,
+ MIN(put_dirty_last, put_dirty_grid->cols - 1));
+ }
+ if (!put_dirty_grid->throttled) {
+ ui_line(put_dirty_grid, put_dirty_row, put_dirty_first, put_dirty_last,
+ put_dirty_last, 0, false);
+ } else if (put_dirty_grid->dirty_col) {
+ if (put_dirty_last > put_dirty_grid->dirty_col[put_dirty_row]) {
+ put_dirty_grid->dirty_col[put_dirty_row] = put_dirty_last;
+ }
+ }
+ put_dirty_first = INT_MAX;
+ put_dirty_last = 0;
+ }
+ put_dirty_row = -1;
+ put_dirty_grid = NULL;
+}
+
+/// Fill the grid from "start_row" to "end_row" (exclusive), from "start_col"
+/// to "end_col" (exclusive) with character "c1" in first column followed by
+/// "c2" in the other columns. Use attributes "attr".
+void grid_fill(ScreenGrid *grid, int start_row, int end_row, int start_col, int end_col, int c1,
+ int c2, int attr)
+{
+ schar_T sc;
+
+ int row_off = 0, col_off = 0;
+ grid_adjust(&grid, &row_off, &col_off);
+ start_row += row_off;
+ end_row += row_off;
+ start_col += col_off;
+ end_col += col_off;
+
+ // safety check
+ if (end_row > grid->rows) {
+ end_row = grid->rows;
+ }
+ if (end_col > grid->cols) {
+ end_col = grid->cols;
+ }
+
+ // nothing to do
+ if (start_row >= end_row || start_col >= end_col) {
+ return;
+ }
+
+ for (int row = start_row; row < end_row; row++) {
+ // When drawing over the right half of a double-wide char clear
+ // out the left half. When drawing over the left half of a
+ // double wide-char clear out the right half. Only needed in a
+ // terminal.
+ if (start_col > 0 && grid_fix_col(grid, start_col, row) != start_col) {
+ grid_puts_len(grid, (char_u *)" ", 1, row, start_col - 1, 0);
+ }
+ if (end_col < grid->cols
+ && grid_fix_col(grid, end_col, row) != end_col) {
+ grid_puts_len(grid, (char_u *)" ", 1, row, end_col, 0);
+ }
+
+ // if grid was resized (in ext_multigrid mode), the UI has no redraw updates
+ // for the newly resized grid. It is better mark everything as dirty and
+ // send all the updates.
+ int dirty_first = INT_MAX;
+ int dirty_last = 0;
+
+ int col = start_col;
+ schar_from_char(sc, c1);
+ size_t lineoff = grid->line_offset[row];
+ for (col = start_col; col < end_col; col++) {
+ size_t off = lineoff + (size_t)col;
+ if (schar_cmp(grid->chars[off], sc)
+ || grid->attrs[off] != attr) {
+ schar_copy(grid->chars[off], sc);
+ grid->attrs[off] = attr;
+ if (dirty_first == INT_MAX) {
+ dirty_first = col;
+ }
+ dirty_last = col + 1;
+ }
+ if (col == start_col) {
+ schar_from_char(sc, c2);
+ }
+ }
+ if (dirty_last > dirty_first) {
+ // TODO(bfredl): support a cleared suffix even with a batched line?
+ if (put_dirty_row == row) {
+ put_dirty_first = MIN(put_dirty_first, dirty_first);
+ put_dirty_last = MAX(put_dirty_last, dirty_last);
+ } else if (grid->throttled) {
+ // Note: assumes msg_grid is the only throttled grid
+ assert(grid == &msg_grid);
+ int dirty = 0;
+ if (attr != HL_ATTR(HLF_MSG) || c2 != ' ') {
+ dirty = dirty_last;
+ } else if (c1 != ' ') {
+ dirty = dirty_first + 1;
+ }
+ if (grid->dirty_col && dirty > grid->dirty_col[row]) {
+ grid->dirty_col[row] = dirty;
+ }
+ } else {
+ int last = c2 != ' ' ? dirty_last : dirty_first + (c1 != ' ');
+ ui_line(grid, row, dirty_first, last, dirty_last, attr, false);
+ }
+ }
+
+ if (end_col == grid->cols) {
+ grid->line_wraps[row] = false;
+ }
+ }
+}
+
+/// Check whether the given character needs redrawing:
+/// - the (first byte of the) character is different
+/// - the attributes are different
+/// - the character is multi-byte and the next byte is different
+/// - the character is two cells wide and the second cell differs.
+static int grid_char_needs_redraw(ScreenGrid *grid, size_t off_from, size_t off_to, int cols)
+{
+ return (cols > 0
+ && ((schar_cmp(linebuf_char[off_from], grid->chars[off_to])
+ || linebuf_attr[off_from] != grid->attrs[off_to]
+ || (line_off2cells(linebuf_char, off_from, off_from + (size_t)cols) > 1
+ && schar_cmp(linebuf_char[off_from + 1],
+ grid->chars[off_to + 1])))
+ || rdb_flags & RDB_NODELTA));
+}
+
+/// Move one buffered line to the window grid, but only the characters that
+/// have actually changed. Handle insert/delete character.
+/// "coloff" gives the first column on the grid for this line.
+/// "endcol" gives the columns where valid characters are.
+/// "clear_width" is the width of the window. It's > 0 if the rest of the line
+/// needs to be cleared, negative otherwise.
+/// "rlflag" is TRUE in a rightleft window:
+/// When TRUE and "clear_width" > 0, clear columns 0 to "endcol"
+/// When FALSE and "clear_width" > 0, clear columns "endcol" to "clear_width"
+/// If "wrap" is true, then hint to the UI that "row" contains a line
+/// which has wrapped into the next row.
+void grid_put_linebuf(ScreenGrid *grid, int row, int coloff, int endcol, int clear_width,
+ int rlflag, win_T *wp, int bg_attr, bool wrap)
+{
+ size_t max_off_from;
+ size_t max_off_to;
+ int col = 0;
+ bool redraw_this; // Does character need redraw?
+ bool redraw_next; // redraw_this for next character
+ bool clear_next = false;
+ int char_cells; // 1: normal char
+ // 2: occupies two display cells
+ int start_dirty = -1, end_dirty = 0;
+
+ // TODO(bfredl): check all callsites and eliminate
+ // Check for illegal row and col, just in case
+ if (row >= grid->rows) {
+ row = grid->rows - 1;
+ }
+ if (endcol > grid->cols) {
+ endcol = grid->cols;
+ }
+
+ grid_adjust(&grid, &row, &coloff);
+
+ // Safety check. Avoids clang warnings down the call stack.
+ if (grid->chars == NULL || row >= grid->rows || coloff >= grid->cols) {
+ DLOG("invalid state, skipped");
+ return;
+ }
+
+ size_t off_from = 0;
+ size_t off_to = grid->line_offset[row] + (size_t)coloff;
+ max_off_from = linebuf_size;
+ max_off_to = grid->line_offset[row] + (size_t)grid->cols;
+
+ if (rlflag) {
+ // Clear rest first, because it's left of the text.
+ if (clear_width > 0) {
+ while (col <= endcol && grid->chars[off_to][0] == ' '
+ && grid->chars[off_to][1] == NUL
+ && grid->attrs[off_to] == bg_attr) {
+ off_to++;
+ col++;
+ }
+ if (col <= endcol) {
+ grid_fill(grid, row, row + 1, col + coloff, endcol + coloff + 1, ' ', ' ', bg_attr);
+ }
+ }
+ col = endcol + 1;
+ off_to = grid->line_offset[row] + (size_t)col + (size_t)coloff;
+ off_from += (size_t)col;
+ endcol = (clear_width > 0 ? clear_width : -clear_width);
+ }
+
+ if (bg_attr) {
+ for (int c = col; c < endcol; c++) {
+ linebuf_attr[off_from + (size_t)c] =
+ hl_combine_attr(bg_attr, linebuf_attr[off_from + (size_t)c]);
+ }
+ }
+
+ redraw_next = grid_char_needs_redraw(grid, off_from, off_to, endcol - col);
+
+ while (col < endcol) {
+ char_cells = 1;
+ if (col + 1 < endcol) {
+ char_cells = line_off2cells(linebuf_char, off_from, max_off_from);
+ }
+ redraw_this = redraw_next;
+ redraw_next = grid_char_needs_redraw(grid, off_from + (size_t)char_cells,
+ off_to + (size_t)char_cells,
+ endcol - col - char_cells);
+
+ if (redraw_this) {
+ if (start_dirty == -1) {
+ start_dirty = col;
+ }
+ end_dirty = col + char_cells;
+ // When writing a single-width character over a double-width
+ // character and at the end of the redrawn text, need to clear out
+ // the right half of the old character.
+ // Also required when writing the right half of a double-width
+ // char over the left half of an existing one
+ if (col + char_cells == endcol
+ && ((char_cells == 1
+ && grid_off2cells(grid, off_to, max_off_to) > 1)
+ || (char_cells == 2
+ && grid_off2cells(grid, off_to, max_off_to) == 1
+ && grid_off2cells(grid, off_to + 1, max_off_to) > 1))) {
+ clear_next = true;
+ }
+
+ schar_copy(grid->chars[off_to], linebuf_char[off_from]);
+ if (char_cells == 2) {
+ schar_copy(grid->chars[off_to + 1], linebuf_char[off_from + 1]);
+ }
+
+ grid->attrs[off_to] = linebuf_attr[off_from];
+ // For simplicity set the attributes of second half of a
+ // double-wide character equal to the first half.
+ if (char_cells == 2) {
+ grid->attrs[off_to + 1] = linebuf_attr[off_from];
+ }
+ }
+
+ off_to += (size_t)char_cells;
+ off_from += (size_t)char_cells;
+ col += char_cells;
+ }
+
+ if (clear_next) {
+ // Clear the second half of a double-wide character of which the left
+ // half was overwritten with a single-wide character.
+ schar_from_ascii(grid->chars[off_to], ' ');
+ end_dirty++;
+ }
+
+ int clear_end = -1;
+ if (clear_width > 0 && !rlflag) {
+ // blank out the rest of the line
+ // TODO(bfredl): we could cache winline widths
+ while (col < clear_width) {
+ if (grid->chars[off_to][0] != ' '
+ || grid->chars[off_to][1] != NUL
+ || grid->attrs[off_to] != bg_attr) {
+ grid->chars[off_to][0] = ' ';
+ grid->chars[off_to][1] = NUL;
+ grid->attrs[off_to] = bg_attr;
+ if (start_dirty == -1) {
+ start_dirty = col;
+ end_dirty = col;
+ } else if (clear_end == -1) {
+ end_dirty = endcol;
+ }
+ clear_end = col + 1;
+ }
+ col++;
+ off_to++;
+ }
+ }
+
+ if (clear_width > 0 || wp->w_width != grid->cols) {
+ // If we cleared after the end of the line, it did not wrap.
+ // For vsplit, line wrapping is not possible.
+ grid->line_wraps[row] = false;
+ }
+
+ if (clear_end < end_dirty) {
+ clear_end = end_dirty;
+ }
+ if (start_dirty == -1) {
+ start_dirty = end_dirty;
+ }
+ if (clear_end > start_dirty) {
+ ui_line(grid, row, coloff + start_dirty, coloff + end_dirty, coloff + clear_end,
+ bg_attr, wrap);
+ }
+}
+
+void grid_alloc(ScreenGrid *grid, int rows, int columns, bool copy, bool valid)
+{
+ int new_row;
+ ScreenGrid new = *grid;
+ assert(rows >= 0 && columns >= 0);
+ size_t ncells = (size_t)rows * (size_t)columns;
+ new.chars = xmalloc(ncells * sizeof(schar_T));
+ new.attrs = xmalloc(ncells * sizeof(sattr_T));
+ new.line_offset = xmalloc((size_t)rows * sizeof(*new.line_offset));
+ new.line_wraps = xmalloc((size_t)rows * sizeof(*new.line_wraps));
+
+ new.rows = rows;
+ new.cols = columns;
+
+ for (new_row = 0; new_row < new.rows; new_row++) {
+ new.line_offset[new_row] = (size_t)new_row * (size_t)new.cols;
+ new.line_wraps[new_row] = false;
+
+ grid_clear_line(&new, new.line_offset[new_row], columns, valid);
+
+ if (copy) {
+ // If the screen is not going to be cleared, copy as much as
+ // possible from the old screen to the new one and clear the rest
+ // (used when resizing the window at the "--more--" prompt or when
+ // executing an external command, for the GUI).
+ if (new_row < grid->rows && grid->chars != NULL) {
+ int len = MIN(grid->cols, new.cols);
+ memmove(new.chars + new.line_offset[new_row],
+ grid->chars + grid->line_offset[new_row],
+ (size_t)len * sizeof(schar_T));
+ memmove(new.attrs + new.line_offset[new_row],
+ grid->attrs + grid->line_offset[new_row],
+ (size_t)len * sizeof(sattr_T));
+ }
+ }
+ }
+ grid_free(grid);
+ *grid = new;
+
+ // Share a single scratch buffer for all grids, by
+ // ensuring it is as wide as the widest grid.
+ if (linebuf_size < (size_t)columns) {
+ xfree(linebuf_char);
+ xfree(linebuf_attr);
+ linebuf_char = xmalloc((size_t)columns * sizeof(schar_T));
+ linebuf_attr = xmalloc((size_t)columns * sizeof(sattr_T));
+ linebuf_size = (size_t)columns;
+ }
+}
+
+void grid_free(ScreenGrid *grid)
+{
+ xfree(grid->chars);
+ xfree(grid->attrs);
+ xfree(grid->line_offset);
+ xfree(grid->line_wraps);
+
+ grid->chars = NULL;
+ grid->attrs = NULL;
+ grid->line_offset = NULL;
+ grid->line_wraps = NULL;
+}
+
+/// Doesn't allow reinit, so must only be called by free_all_mem!
+void grid_free_all_mem(void)
+{
+ grid_free(&default_grid);
+ xfree(linebuf_char);
+ xfree(linebuf_attr);
+}
+
+/// (Re)allocates a window grid if size changed while in ext_multigrid mode.
+/// Updates size, offsets and handle for the grid regardless.
+///
+/// If "doclear" is true, don't try to copy from the old grid rather clear the
+/// resized grid.
+void win_grid_alloc(win_T *wp)
+{
+ ScreenGrid *grid = &wp->w_grid;
+ ScreenGrid *grid_allocated = &wp->w_grid_alloc;
+
+ int rows = wp->w_height_inner;
+ int cols = wp->w_width_inner;
+ int total_rows = wp->w_height_outer;
+ int total_cols = wp->w_width_outer;
+
+ bool want_allocation = ui_has(kUIMultigrid) || wp->w_floating;
+ bool has_allocation = (grid_allocated->chars != NULL);
+
+ if (grid->rows != rows) {
+ wp->w_lines_valid = 0;
+ xfree(wp->w_lines);
+ wp->w_lines = xcalloc((size_t)rows + 1, sizeof(wline_T));
+ }
+
+ int was_resized = false;
+ if (want_allocation && (!has_allocation
+ || grid_allocated->rows != total_rows
+ || grid_allocated->cols != total_cols)) {
+ grid_alloc(grid_allocated, total_rows, total_cols,
+ wp->w_grid_alloc.valid, false);
+ grid_allocated->valid = true;
+ if (wp->w_floating && wp->w_float_config.border) {
+ wp->w_redr_border = true;
+ }
+ was_resized = true;
+ } else if (!want_allocation && has_allocation) {
+ // Single grid mode, all rendering will be redirected to default_grid.
+ // Only keep track of the size and offset of the window.
+ grid_free(grid_allocated);
+ grid_allocated->valid = false;
+ was_resized = true;
+ } else if (want_allocation && has_allocation && !wp->w_grid_alloc.valid) {
+ grid_invalidate(grid_allocated);
+ grid_allocated->valid = true;
+ }
+
+ grid->rows = rows;
+ grid->cols = cols;
+
+ if (want_allocation) {
+ grid->target = grid_allocated;
+ grid->row_offset = wp->w_winrow_off;
+ grid->col_offset = wp->w_wincol_off;
+ } else {
+ grid->target = &default_grid;
+ grid->row_offset = wp->w_winrow + wp->w_winrow_off;
+ grid->col_offset = wp->w_wincol + wp->w_wincol_off;
+ }
+
+ // send grid resize event if:
+ // - a grid was just resized
+ // - screen_resize was called and all grid sizes must be sent
+ // - the UI wants multigrid event (necessary)
+ if ((resizing_screen || was_resized) && want_allocation) {
+ ui_call_grid_resize(grid_allocated->handle,
+ grid_allocated->cols, grid_allocated->rows);
+ }
+}
+
+/// assign a handle to the grid. The grid need not be allocated.
+void grid_assign_handle(ScreenGrid *grid)
+{
+ static int last_grid_handle = DEFAULT_GRID_HANDLE;
+
+ // only assign a grid handle if not already
+ if (grid->handle == 0) {
+ grid->handle = ++last_grid_handle;
+ }
+}