GUAC-726: Replace overwrite function with much saner function based on character validity checks along column edges.

This commit is contained in:
Michael Jumper 2014-06-05 11:55:21 -07:00
parent 4e16a31600
commit 99cef299f1

View File

@ -63,66 +63,69 @@ static void __guac_terminal_set_columns(guac_terminal* terminal, int row,
}
/**
* Declares that the given range of columns within the given row is about to be
* overwritten, and should be updated as necessary.
* Enforces a character break at the given edge, ensuring that the left side
* of the edge is the final column of a character, and the right side of the
* edge is the initial column of a DIFFERENT character.
*
* For a character in a column N, the left edge number is N, and the right
* edge is N+1.
*/
static void __guac_terminal_overwrite_columns(guac_terminal* terminal, int row, int start_column, int end_column) {
static void __guac_terminal_force_break(guac_terminal* terminal, int row, int edge) {
guac_terminal_buffer_row* buffer_row = guac_terminal_buffer_get_row(terminal->buffer, row, 0);
/* Clear out initial character */
if (start_column > 0) {
/* Ensure character to left of edge is unbroken */
if (edge > 0) {
int aligned_start_column = start_column;
guac_terminal_char* start_char = &(buffer_row->characters[aligned_start_column]);
int end_column = edge - 1;
int start_column = end_column;
/* Determine nearest aligned boundary */
while (aligned_start_column > 0 && start_char->value == GUAC_CHAR_CONTINUATION) {
guac_terminal_char* start_char = &(buffer_row->characters[start_column]);
/* Determine start column */
while (start_column >= 0 && start_char->value == GUAC_CHAR_CONTINUATION) {
start_char--;
aligned_start_column--;
start_column--;
}
/* Clear up to character start */
if (aligned_start_column != start_column) {
/* Clear character if broken */
if (start_char->value == GUAC_CHAR_CONTINUATION || start_char->width != start_column - end_column + 1) {
guac_terminal_char cleared_char;
cleared_char.value = ' ';
cleared_char.attributes = start_char->attributes;
cleared_char.width = 1;
__guac_terminal_set_columns(terminal, row, aligned_start_column, start_column-1, &cleared_char);
__guac_terminal_set_columns(terminal, row, start_column, end_column, &cleared_char);
}
}
/* Clear out final character */
if (end_column >= 0 && end_column < buffer_row->length) {
/* Ensure character to right of edge is unbroken */
if (edge >= 0 && edge < buffer_row->length) {
int aligned_end_column = end_column;
guac_terminal_char* end_char = &(buffer_row->characters[aligned_end_column]);
int start_column = edge;
int end_column = start_column;
/* If we're lucky enough to end on the beginning of a character, just use its defined width */
if (end_char->value != GUAC_CHAR_CONTINUATION)
aligned_end_column += end_char->width - 1;
guac_terminal_char* start_char = &(buffer_row->characters[start_column]);
guac_terminal_char* end_char = &(buffer_row->characters[end_column]);
/* Otherwise, search for nearest aligned boundary */
else {
while (aligned_end_column+1 < buffer_row->length && (end_char+1)->value == GUAC_CHAR_CONTINUATION) {
/* Determine end column */
while (end_column+1 < buffer_row->length && (end_char+1)->value == GUAC_CHAR_CONTINUATION) {
end_char++;
aligned_end_column++;
}
end_column++;
}
/* Clear up to true character end */
if (aligned_end_column != end_column) {
/* Clear character if broken */
if (start_char->value == GUAC_CHAR_CONTINUATION || start_char->width != start_column - end_column + 1) {
guac_terminal_char cleared_char;
cleared_char.value = ' ';
cleared_char.attributes = end_char->attributes;
cleared_char.width = 1;
__guac_terminal_set_columns(terminal, row, end_column+1, aligned_end_column, &cleared_char);
__guac_terminal_set_columns(terminal, row, start_column, end_column, &cleared_char);
}
@ -845,29 +848,6 @@ void guac_terminal_select_end(guac_terminal* terminal, char* string) {
void guac_terminal_copy_columns(guac_terminal* terminal, int row,
int start_column, int end_column, int offset) {
/*
* Handle each resulting overwrite. Note that there are effectively TWO.
* Handling the entire destination region as a single overwrite ignores
* the possibility that the offset may position the source region in
* within part of a multicolumn character.
*
* Consider:
*
* 1) The overwrite which covers only characters OUTSIDE the source region
* 2) The overwrite which coveres only characters WITHIN the source region
*
* The source region does NOT necessarily begin at a character boundary.
*/
if (offset < 0) {
__guac_terminal_overwrite_columns(terminal, row, start_column + offset, start_column-1);
__guac_terminal_overwrite_columns(terminal, row, start_column, end_column + offset);
}
else {
__guac_terminal_overwrite_columns(terminal, row, start_column + offset, end_column-1);
__guac_terminal_overwrite_columns(terminal, row, end_column, end_column + offset);
}
guac_terminal_display_copy_columns(terminal->display, row + terminal->scroll_offset,
start_column, end_column, offset);
@ -880,6 +860,10 @@ void guac_terminal_copy_columns(guac_terminal* terminal, int row,
terminal->visible_cursor_col <= end_column)
terminal->visible_cursor_col += offset;
/* Force breaks around destination region */
__guac_terminal_force_break(terminal, row, start_column + offset);
__guac_terminal_force_break(terminal, row, end_column + offset + 1);
}
void guac_terminal_copy_rows(guac_terminal* terminal,
@ -901,7 +885,6 @@ void guac_terminal_copy_rows(guac_terminal* terminal,
void guac_terminal_set_columns(guac_terminal* terminal, int row,
int start_column, int end_column, guac_terminal_char* character) {
__guac_terminal_overwrite_columns(terminal, row, start_column, end_column);
__guac_terminal_set_columns(terminal, row, start_column, end_column, character);
/* If visible cursor in current row, preserve state */
@ -918,6 +901,10 @@ void guac_terminal_set_columns(guac_terminal* terminal, int row,
}
/* Force breaks around destination region */
__guac_terminal_force_break(terminal, row, start_column);
__guac_terminal_force_break(terminal, row, end_column + 1);
}
static void __guac_terminal_redraw_rect(guac_terminal* term, int start_row, int start_col, int end_row, int end_col) {