+/* Copyright (C) 1992 Aladdin Enterprises. All rights reserved.
+ Distributed by Free Software Foundation, Inc.
+
+This file is part of Ghostscript.
+
+Ghostscript is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY. No author or distributor accepts responsibility
+to anyone for the consequences of using it or for whether it serves any
+particular purpose or works at all, unless he says so in writing. Refer
+to the Ghostscript General Public License for full details.
+
+Everyone is granted permission to copy, modify and redistribute
+Ghostscript, but only under the conditions described in the Ghostscript
+General Public License. A copy of this license is supposed to have been
+given to you along with Ghostscript so you can know your rights and
+responsibilities. It should be in a file named COPYING. Among other
+things, the copyright notice and this notice must be preserved on all
+copies. */
+
+/* gp_dosfb.c */
+/* MS-DOS frame buffer swapping routines for Ghostscript */
+#include <conio.h>
+#include "memory_.h"
+#include "gx.h"
+#include "gp.h"
+#include "gserrors.h"
+#include "gxdevice.h"
+
+/* On MS-DOS machines, we maintain a console image in memory, */
+/* and swap screens on request. */
+#define cw_width 80
+#define cw_height 25
+typedef struct text_line_s {
+ int end;
+ char text[cw_width + 1];
+} text_line;
+typedef struct {
+ text_line _ds *line;
+ text_line lines[cw_height];
+} ds_text_screen;
+
+private ds_text_screen console;
+
+private int console_is_current;
+
+/* Buffer one scan line of graphics. */
+#define row_buf_size 1280
+private char graphics_file_name[] = "_temp_.gfb";
+
+/* Forward references */
+private int save_graphics(P1(gx_device *));
+private int restore_graphics(P1(gx_device *));
+
+/* Initialize the console buffer. */
+void
+gp_init_console()
+{ memset(&console.lines, 0, sizeof(console.lines));
+ console.line = &console.lines[0];
+ console_is_current = 0;
+}
+
+/* Write a string to the console. */
+void
+gp_console_puts(const char *str, uint size)
+{ register ds_text_screen _ds *cop = &console;
+ register text_line _ds *lip = cop->line;
+ for ( ; size ; str++, size-- )
+ switch ( *str )
+ {
+ case '\n':
+ if ( lip == &cop->lines[cw_height - 1] )
+ { /* Scroll up */
+ memcpy(&cop->lines[0], &cop->lines[1],
+ sizeof(text_line) * (cw_height - 1));
+ }
+ else
+ cop->line = ++lip;
+ lip->end = 0;
+ break;
+ case '\t':
+ gp_console_puts(" ", 8 - (lip->end & 7));
+ lip = cop->line;
+ break;
+ default:
+ if ( lip->end == cw_width )
+ { gp_console_puts("\n", 1);
+ lip = cop->line;
+ }
+ lip->text[lip->end++] = *str;
+ }
+}
+
+/* Make the console current on the screen. */
+int
+gp_make_console_current(gx_device *dev)
+{ int code = 0;
+ if ( !console_is_current )
+ code = save_graphics(dev);
+ /* Transfer the console buffer to the screen. */
+ /* Unfortunately, there is no standard way to clear the screen. */
+ /* Output the ANSI sequence and hope for the best. */
+ cputs("\r\033[2J\r \r");
+ { int i;
+ register text_line _ds *lip;
+ for ( i = 0, lip = &console.lines[0]; i < cw_height; i++, lip++ )
+ { if ( i != 0 ) cputs("\r\n");
+ lip->text[lip->end] = 0;
+ cputs(lip->text);
+ }
+ }
+ console_is_current = 1;
+ return code;
+}
+
+/* Make the graphics current on the screen. */
+int
+gp_make_graphics_current(gx_device *dev)
+{ if ( console_is_current )
+ { int code = restore_graphics(dev);
+ if ( code < 0 ) return code;
+ console_is_current = 0;
+ }
+ return 0;
+}
+
+/* ------ Internal routines ------ */
+
+/* We compress the pixmap just a little, by noting */
+/* replicated bytes at the beginning and end of a line. */
+typedef struct { ushort pre, post; } row_head;
+
+/* Save the graphics screen on a file. */
+private int
+save_graphics(gx_device *dev)
+{ uint row_size = gx_device_bytes_per_scan_line(dev, 0);
+ char row_buf[row_buf_size];
+ int count = row_buf_size / row_size;
+ FILE *gfile;
+ int y;
+ if ( count == 0 ) return -1;
+ gfile = fopen(graphics_file_name, "wb");
+ if ( gfile == 0 ) return gs_error_ioerror;
+ for ( y = 0; y < dev->height; y += count )
+ { char _ss *row = row_buf;
+ int n = count;
+ (*dev->procs->get_bits)(dev, y, row, row_buf_size, 0);
+ while ( n-- )
+ { row_head head;
+ char _ss *beg = row, *end = row + row_size - 1;
+ while ( end > beg && *end == end[-1] ) end--;
+ if ( beg < end )
+ while ( *beg == beg[1] ) beg++;
+ head.pre = beg - row;
+ head.post = end + 1 - row;
+ fwrite((char *)&head, 1, sizeof(head), gfile);
+ fwrite(beg, head.post - head.pre, 1, gfile);
+ row += row_size;
+ }
+ }
+ fclose(gfile);
+ return 0;
+}
+
+/* Restore the graphics screen from a file. */
+private int
+restore_graphics(gx_device *dev)
+{ FILE *gfile;
+ uint row_size = gx_device_bytes_per_scan_line(dev, 0);
+ char row_buf[row_buf_size];
+ int y;
+ if ( row_size > row_buf_size ) return -1;
+ gfile = fopen(graphics_file_name, "rb");
+ if ( gfile == 0 ) return gs_error_ioerror;
+ for ( y = 0; y < dev->height; y ++ )
+ { row_head head;
+ char _ss *beg, *end;
+ fread((char *)&head, 1, sizeof(head), gfile);
+ beg = row_buf + head.pre;
+ end = row_buf + head.post;
+ fread(beg, 1, end - beg, gfile);
+ if ( head.pre )
+ memset(row_buf, *beg, head.pre);
+ if ( head.post < row_size )
+ memset(end, end[-1], row_size - head.post);
+ (*dev->procs->copy_color)(dev, row_buf, 0, row_size, gx_no_bitmap_id, 0, y, dev->width, 1);
+ }
+ fclose(gfile);
+ return 0;
+}
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