quakeforge/libs/console/buffer.c
Bill Currie d6d45bf07c [console] Add a function to clear the scroll-back buffer
Needed for when the console display is cleared.
2022-09-20 12:14:01 +09:00

136 lines
3.1 KiB
C

/*
buffer.c
console buffer support
Copyright (C) 2001 BillCurrie <bill@taniwha.org>
Author: BillCurrie <bill@taniwha.org>
Date: 2001/09/28
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to:
Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_STRING_H
# include "string.h"
#endif
#ifdef HAVE_STRINGS_H
# include "strings.h"
#endif
#include <stdlib.h>
#include "QF/console.h"
VISIBLE con_buffer_t *
Con_CreateBuffer (size_t buffer_size, int max_lines)
{
con_buffer_t *buffer;
if (!(buffer = malloc (sizeof (con_buffer_t))))
return 0;
if (!(buffer->buffer = malloc (buffer_size)))
goto err;
buffer->buffer_size = buffer_size;
if (!(buffer->lines = calloc (max_lines, sizeof (con_line_t))))
goto err;
buffer->max_lines = max_lines;
buffer->line_head = 1;
buffer->line_tail = 0;
return buffer;
err:
if (buffer->buffer)
free (buffer->buffer);
free (buffer);
return 0;
}
VISIBLE void
Con_DestroyBuffer (con_buffer_t *buffer)
{
free (buffer->buffer);
free (buffer->lines);
free (buffer);
}
VISIBLE void
Con_BufferAddText (con_buffer_t *buf, const char *text)
{
con_line_t *cur_line = &buf->lines[(buf->line_head - 1 + buf->max_lines)
% buf->max_lines];
con_line_t *tail_line = &buf->lines[buf->line_tail];
uint32_t text_head = (cur_line->text + cur_line->len) % buf->buffer_size;
byte c;
while ((c = *text++)) {
cur_line->len++;
buf->buffer[text_head++] = c;
if (text_head >= buf->buffer_size) {
text_head -= buf->buffer_size;
}
if (text_head == tail_line->text) {
tail_line->len--;
buf->buffer[tail_line->text++] = 0;
if (tail_line->text >= buf->buffer_size) {
tail_line->text -= buf->buffer_size;
}
if (!tail_line->len) {
buf->line_tail++;
buf->line_tail %= buf->max_lines;
tail_line = &buf->lines[buf->line_tail];
}
}
if (c == '\n') {
cur_line++;
if ((uint32_t) (cur_line - buf->lines) >= buf->max_lines) {
cur_line -= buf->max_lines;
}
cur_line->text = text_head;
cur_line->len = 0;
buf->line_head++;
if (buf->line_head >= buf->max_lines) {
buf->line_head -= buf->max_lines;
}
if (buf->line_head == buf->line_tail) {
buf->lines[buf->line_tail].text = 0;
buf->lines[buf->line_tail].len = 0;
buf->line_tail++;
if (buf->line_tail >= buf->max_lines) {
buf->line_tail -= buf->max_lines;
}
}
}
}
}
VISIBLE void
Con_ClearBuffer (con_buffer_t *buffer)
{
buffer->line_head = 1;
buffer->line_tail = 0;
buffer->lines[0].text = 0;
buffer->lines[0].len = 0;
}