[vte/wip/egmont/bidi: 17/75] explicit rtl, basic painting okay

[Egmont Koblinger <egmontkob src gnome org>]

commit db0e4b9d8fc5bc8f55d13014a14fd5a2087d86e7
Author: Egmont Koblinger <egmont gmail com>
Date:   Sat Aug 18 16:59:59 2018 +0200

    explicit rtl, basic painting okay

 src/vte.cc | 44 ++++++++++++++++++++++++++------------------
 1 file changed, 26 insertions(+), 18 deletions(-)
---
diff --git a/src/vte.cc b/src/vte.cc
index 30e2bfb1..aed22aa4 100644
--- a/src/vte.cc
+++ b/src/vte.cc
@@ -254,6 +254,10 @@ Terminal::invalidate_cells(vte::grid::column_t column_start,
                        n_columns, n_rows);
        _vte_debug_print (VTE_DEBUG_WORK, "?");
 
+        // HACK for BiDi: Always invalidate the entire row
+        column_start = 0;
+        n_columns = m_column_count;
+
        if (n_columns == m_column_count &&
             n_rows == m_row_count) {
                invalidate_all();
@@ -9017,10 +9021,8 @@ Terminal::draw_rows(VteScreen *screen_,
                i = start_column;
                if (row_data != NULL) {
                        cell = _vte_row_data_get_bidi (row_data, i);
-                       if (cell != NULL) {
-                               while (cell->attr.fragment() && i > 0) {
-                                       cell = _vte_row_data_get_bidi (row_data, --i);
-                               }
+                       while (cell != NULL && cell->attr.fragment() && i > 0) {
+                               cell = _vte_row_data_get_bidi (row_data, --i);
                        }
                        /* Walk the line. */
                        do {
@@ -9111,20 +9113,22 @@ Terminal::draw_rows(VteScreen *screen_,
                 * making the drawing area a little wider. */
                i = start_column;
                cell = _vte_row_data_get_bidi (row_data, i);
-               if (cell == NULL) {
-                       goto fg_skip_row;
-               }
-               while (cell->attr.fragment() && i > 0)
+//             if (cell == NULL) {
+//                     goto fg_skip_row;
+//             }
+               while (cell != NULL && cell->attr.fragment() && i > 0)
                        cell = _vte_row_data_get_bidi (row_data, --i);
 
                /* Walk the line. */
                do {
                        /* Get the character cell's contents. */
                        cell = _vte_row_data_get_bidi (row_data, i);
-                       if (cell == NULL) {
-                               goto fg_skip_row;
-                       }
-                       while (cell->c == 0 || cell->attr.invisible() ||
+//                     if (cell == NULL) {
+//                             // goto fg_skip_row;
+//                             i++;
+//                             continue;
+//                     }
+                       while (cell == NULL || cell->c == 0 || cell->attr.invisible() ||
                                        (cell->c == ' ' &&
                                          cell->attr.has_none(VTE_ATTR_UNDERLINE_MASK |
                                                              VTE_ATTR_STRIKETHROUGH_MASK |
@@ -9135,9 +9139,11 @@ Terminal::draw_rows(VteScreen *screen_,
                                        goto fg_skip_row;
                                }
                                cell = _vte_row_data_get_bidi (row_data, i);
-                               if (cell == NULL) {
-                                       goto fg_skip_row;
-                               }
+//                             if (cell == NULL) {
+//                                     // goto fg_skip_row;
+//                                     i++;
+//                                     continue;
+//                             }
                        }
                        /* Find the colors for this cell. */
                        selected = cell_is_selected(i, row);
@@ -9162,7 +9168,9 @@ Terminal::draw_rows(VteScreen *screen_,
                                        /* Retrieve the cell. */
                                        cell = _vte_row_data_get_bidi (row_data, j);
                                        if (cell == NULL) {
-                                               goto fg_next_row;
+                                               // goto fg_next_row;
+                                               j++;
+                                               continue;
                                        }
                                         /* Ignore the attributes on a fragment, the attributes
                                          * of the preceding character cell should apply. */
@@ -9250,8 +9258,8 @@ fg_next_row:
                                         * area a little wider. */
                                        j = start_column;
                                        cell = _vte_row_data_get_bidi (row_data, j);
-                               } while (cell == NULL);
-                               while (cell->attr.fragment() && j > 0) {
+                               } while (FALSE);  // FIXME eliminate loop
+                               while (cell != NULL && cell->attr.fragment() && j > 0) {
                                        cell = _vte_row_data_get_bidi (row_data, --j);
                                }
                        } while (TRUE);