/* Hello, Emacs, this is -*-C-*-
 * $Id: linux.trm,v 1.31 2012/01/30 19:31:01 sfeam Exp $
 *
 */

/* GNUPLOT - linux.trm */

/*[
 * Copyright 1993, 1998, 2004
 *
 * Permission to use, copy, and distribute this software and its
 * documentation for any purpose with or without fee is hereby granted,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.
 *
 * Permission to modify the software is granted, but not the right to
 * distribute the complete modified source code.  Modifications are to
 * be distributed as patches to the released version.  Permission to
 * distribute binaries produced by compiling modified sources is granted,
 * provided you
 *   1. distribute the corresponding source modifications from the
 *    released version in the form of a patch file along with the binaries,
 *   2. add special version identification to distinguish your version
 *    in addition to the base release version number,
 *   3. provide your name and address as the primary contact for the
 *    support of your modified version, and
 *   4. retain our contact information in regard to use of the base
 *    software.
 * Permission to distribute the released version of the source code along
 * with corresponding source modifications in the form of a patch file is
 * granted with same provisions 2 through 4 for binary distributions.
 *
 * This software is provided "as is" without express or implied warranty
 * to the extent permitted by applicable law.
]*/

/*
 * This file is included by ../term.c.
 *
 * This terminal driver supports:
 *  SVGA up to 1024x768x256 for PC's running the Linux Operating System
 *  (also VGA 640x480x16, and SVGA 800x600x256)
 *
 * AUTHOR
 *  Scott Heavner (sdh@po.cwru.edu)
 *  based on original linux.trm by Tommy Frandsen (frandsen@diku.dk)
 *  patched by David J. Liu (liu@molecule.phri.nyu.edu)
 *  to increase perfomance and safety based on the features of SVGALib/GL.
 *  send your comments or suggestions to (pixar!info-gnuplot@sun.com).
 */

/*
 * Compile with Linux SVGAlib 0.95 currently maintained by
 * Harm Hanemaayer (hhanemaa@cs.ruu.nl).
 * supports Trident, Tseng, Cirrus, Oak and generic vga.
 */

#include "driver.h"

/*
 * January 2012 (Gnuplot version 4.6)
 * This font used to be imported from bitmap.c, which is no longer built
 * by default.
 */
#ifndef FNT5X9
#define FNT5X9 0
#define FNT5X9_VCHAR 11		/* vertical spacing between characters */
#define FNT5X9_VBITS 9		/* actual number of rows of bits per char */
#define FNT5X9_HCHAR 7		/* horizontal spacing between characters */
#define FNT5X9_HBITS 5		/* actual number of bits per row per char */
#ifndef TERM_HELP
/* 5x9 font, bottom row first, left pixel in lsb */
const unsigned int fnt5x9[96][FNT5X9_VBITS] = {
  /* */  {000000,000000,000000,000000,000000,000000,000000,000000,000000},
  /*!*/  {000000,000000,0x0004,000000,0x0004,0x0004,0x0004,0x0004,0x0004},
  /*"*/  {000000,000000,000000,000000,000000,000000,0x000a,0x000a,0x000a},
  /*#*/  {000000,000000,0x000a,0x000a,0x001f,0x000a,0x001f,0x000a,0x000a},
  /*$*/  {000000,000000,0x0004,0x000f,0x0014,0x000e,0x0005,0x001e,0x0004},
  /*%*/  {000000,000000,0x0018,0x0019,0x0002,0x0004,0x0008,0x0013,0x0003},
  /*&*/  {000000,000000,0x0016,0x0009,0x0015,0x0002,0x0005,0x0005,0x0002},
  /*'*/  {000000,000000,000000,000000,000000,0x0002,0x0004,0x0006,0x0006},
  /*(*/  {000000,000000,0x0008,0x0004,0x0002,0x0002,0x0002,0x0004,0x0008},
  /*)*/  {000000,000000,0x0002,0x0004,0x0008,0x0008,0x0008,0x0004,0x0002},
  /***/  {000000,000000,0x0004,0x0015,0x000e,0x001f,0x000e,0x0015,0x0004},
  /*+*/  {000000,000000,000000,0x0004,0x0004,0x001f,0x0004,0x0004,000000},
  /*,*/  {000000,0x0002,0x0004,0x0006,0x0006,000000,000000,000000,000000},
  /*-*/  {000000,000000,000000,000000,000000,0x001f,000000,000000,000000},
  /*.*/  {000000,000000,0x0006,0x0006,000000,000000,000000,000000,000000},
  /*-/-*/{000000,000000,000000,0x0001,0x0002,0x0004,0x0008,0x0010,000000},
  /*0*/  {000000,000000,0x000e,0x0011,0x0013,0x0015,0x0019,0x0011,0x000e},
  /*1*/  {000000,000000,0x000e,0x0004,0x0004,0x0004,0x0004,0x0006,0x0004},
  /*2*/  {000000,000000,0x001f,0x0001,0x0001,0x000e,0x0010,0x0011,0x000e},
  /*3*/  {000000,000000,0x000e,0x0011,0x0010,0x000c,0x0010,0x0011,0x000e},
  /*4*/  {000000,000000,0x0008,0x0008,0x001f,0x0009,0x000a,0x000c,0x0008},
  /*5*/  {000000,000000,0x000e,0x0011,0x0010,0x0010,0x000f,0x0001,0x001f},
  /*6*/  {000000,000000,0x000e,0x0011,0x0011,0x000f,0x0001,0x0002,0x000c},
  /*7*/  {000000,000000,0x0001,0x0001,0x0002,0x0004,0x0008,0x0010,0x001f},
  /*8*/  {000000,000000,0x000e,0x0011,0x0011,0x000e,0x0011,0x0011,0x000e},
  /*9*/  {000000,000000,0x0006,0x0008,0x0010,0x001e,0x0011,0x0011,0x000e},
  /*:*/  {000000,000000,000000,0x0006,0x0006,000000,0x0006,0x0006,000000},
  /*;*/  {000000,0x0001,0x0002,0x0006,0x0006,000000,0x0006,0x0006,000000},
  /*<*/  {000000,000000,0x0008,0x0004,0x0002,0x0001,0x0002,0x0004,0x0008},
  /*=*/  {000000,000000,000000,000000,0x001f,000000,0x001f,000000,000000},
  /*>*/  {000000,000000,0x0002,0x0004,0x0008,0x0010,0x0008,0x0004,0x0002},
  /*?*/  {000000,000000,0x0004,000000,0x0004,0x0008,0x0010,0x0011,0x000e},
  /*@*/  {000000,000000,0x000e,0x0015,0x0015,0x0016,0x0010,0x0011,0x000e},
  /*A*/  {000000,000000,0x0011,0x0011,0x001f,0x0011,0x0011,0x000a,0x0004},
  /*B*/  {000000,000000,0x000f,0x0012,0x0012,0x000e,0x0012,0x0012,0x000f},
  /*C*/  {000000,000000,0x000e,0x0011,0x0001,0x0001,0x0001,0x0011,0x000e},
  /*D*/  {000000,000000,0x000f,0x0012,0x0012,0x0012,0x0012,0x0012,0x000f},
  /*E*/  {000000,000000,0x001f,0x0001,0x0001,0x0007,0x0001,0x0001,0x001f},
  /*F*/  {000000,000000,0x0001,0x0001,0x0001,0x0007,0x0001,0x0001,0x001f},
  /*G*/  {000000,000000,0x001e,0x0011,0x0011,0x0019,0x0001,0x0001,0x001e},
  /*H*/  {000000,000000,0x0011,0x0011,0x0011,0x001f,0x0011,0x0011,0x0011},
  /*I*/  {000000,000000,0x000e,0x0004,0x0004,0x0004,0x0004,0x0004,0x000e},
  /*J*/  {000000,000000,0x000e,0x0011,0x0010,0x0010,0x0010,0x0010,0x0010},
  /*K*/  {000000,000000,0x0011,0x0009,0x0005,0x0003,0x0005,0x0009,0x0011},
  /*L*/  {000000,000000,0x001f,0x0001,0x0001,0x0001,0x0001,0x0001,0x0001},
  /*M*/  {000000,000000,0x0011,0x0011,0x0011,0x0015,0x0015,0x001b,0x0011},
  /*N*/  {000000,000000,0x0011,0x0011,0x0011,0x0019,0x0015,0x0013,0x0011},
  /*O*/  {000000,000000,0x000e,0x0011,0x0011,0x0011,0x0011,0x0011,0x000e},
  /*P*/  {000000,000000,0x0001,0x0001,0x0001,0x000f,0x0011,0x0011,0x000f},
  /*Q*/  {000000,0x0018,0x000e,0x0015,0x0011,0x0011,0x0011,0x0011,0x000e},
  /*R*/  {000000,000000,0x0011,0x0009,0x0005,0x000f,0x0011,0x0011,0x000f},
  /*S*/  {000000,000000,0x000e,0x0011,0x0010,0x000e,0x0001,0x0011,0x000e},
  /*T*/  {000000,000000,0x0004,0x0004,0x0004,0x0004,0x0004,0x0004,0x001f},
  /*U*/  {000000,000000,0x000e,0x0011,0x0011,0x0011,0x0011,0x0011,0x0011},
  /*V*/  {000000,000000,0x0004,0x0004,0x000a,0x000a,0x0011,0x0011,0x0011},
  /*W*/  {000000,000000,0x0011,0x001b,0x0015,0x0011,0x0011,0x0011,0x0011},
  /*X*/  {000000,000000,0x0011,0x0011,0x000a,0x0004,0x000a,0x0011,0x0011},
  /*Y*/  {000000,000000,0x0004,0x0004,0x0004,0x0004,0x000a,0x0011,0x0011},
  /*Z*/  {000000,000000,0x001f,0x0001,0x0002,0x0004,0x0008,0x0010,0x001f},
  /*[*/  {000000,000000,0x000e,0x0002,0x0002,0x0002,0x0002,0x0002,0x000e},
  /*\ */ {000000,000000,000000,0x0010,0x0008,0x0004,0x0002,0x0001,000000},
  /*]*/  {000000,000000,0x000e,0x0008,0x0008,0x0008,0x0008,0x0008,0x000e},
  /*^*/  {000000,000000,000000,000000,000000,000000,0x0011,0x000a,0x0004},
  /*_*/  {000000,000000,0x001f,000000,000000,000000,000000,000000,000000},
  /*`*/  {000000,000000,000000,000000,000000,0x0008,0x0004,0x000c,0x000c},
  /*a*/  {000000,000000,0x001e,0x0011,0x001e,0x0010,0x000e,000000,000000},
  /*b*/  {000000,000000,0x000d,0x0013,0x0011,0x0013,0x000d,0x0001,0x0001},
  /*c*/  {000000,000000,0x000e,0x0011,0x0001,0x0011,0x000e,000000,000000},
  /*d*/  {000000,000000,0x0016,0x0019,0x0011,0x0019,0x0016,0x0010,0x0010},
  /*e*/  {000000,000000,0x000e,0x0001,0x001f,0x0011,0x000e,000000,000000},
  /*f*/  {000000,000000,0x0004,0x0004,0x0004,0x000e,0x0004,0x0014,0x0008},
  /*g*/  {0x000e,0x0011,0x0016,0x0019,0x0011,0x0019,0x0016,000000,000000},
  /*h*/  {000000,000000,0x0011,0x0011,0x0011,0x0013,0x000d,0x0001,0x0001},
  /*i*/  {000000,000000,0x000e,0x0004,0x0004,0x0004,0x0006,000000,0x0004},
  /*j*/  {0x0006,0x0009,0x0008,0x0008,0x0008,0x0008,0x000c,000000,0x0008},
  /*k*/  {000000,000000,0x0009,0x0005,0x0003,0x0005,0x0009,0x0001,0x0001},
  /*l*/  {000000,000000,0x000e,0x0004,0x0004,0x0004,0x0004,0x0004,0x0006},
  /*m*/  {000000,000000,0x0015,0x0015,0x0015,0x0015,0x000b,000000,000000},
  /*n*/  {000000,000000,0x0011,0x0011,0x0011,0x0013,0x000d,000000,000000},
  /*o*/  {000000,000000,0x000e,0x0011,0x0011,0x0011,0x000e,000000,000000},
  /*p*/  {0x0001,0x0001,0x000d,0x0013,0x0011,0x0013,0x000d,000000,000000},
  /*q*/  {0x0010,0x0010,0x0016,0x0019,0x0011,0x0019,0x0016,000000,000000},
  /*r*/  {000000,000000,0x0001,0x0001,0x0001,0x0013,0x000d,000000,000000},
  /*s*/  {000000,000000,0x000f,0x0010,0x000e,0x0001,0x001e,000000,000000},
  /*t*/  {000000,000000,0x0008,0x0014,0x0004,0x0004,0x001f,0x0004,0x0004},
  /*u*/  {000000,000000,0x0016,0x0019,0x0011,0x0011,0x0011,000000,000000},
  /*v*/  {000000,000000,0x0004,0x000a,0x0011,0x0011,0x0011,000000,000000},
  /*w*/  {000000,000000,0x000a,0x0015,0x0015,0x0011,0x0011,000000,000000},
  /*x*/  {000000,000000,0x0011,0x000a,0x0004,0x000a,0x0011,000000,000000},
  /*y*/  {0x000e,0x0010,0x001e,0x0011,0x0011,0x0011,0x0011,000000,000000},
  /*z*/  {000000,000000,0x001f,0x0002,0x0004,0x0008,0x001f,000000,000000},
  /*{*/  {000000,000000,0x0008,0x0004,0x0004,0x0002,0x0004,0x0004,0x0008},
  /*|*/  {000000,000000,0x0004,0x0004,0x0004,000000,0x0004,0x0004,0x0004},
  /*}*/  {000000,000000,0x0002,0x0004,0x0004,0x0008,0x0004,0x0004,0x0002},
  /*~*/  {000000,000000,000000,000000,000000,000000,0x0008,0x0015,0x0002},
  /*DEL*/{000000,000000,0x001f,0x001f,0x001f,0x001f,0x001f,0x001f,0x001f},
};
#endif /* TERM_HELP */
#endif /* local copy of 5x9 font */


#ifdef TERM_REGISTER
register_term(linux)
#endif

#ifdef TERM_PROTO

#define LINUX_VCHAR FNT5X9_VCHAR
#define LINUX_HCHAR FNT5X9_HCHAR
#define LINUX_VTIC 5
#define LINUX_HTIC 5
#define LINUX_XMAX 0		/* These two entries are just place holders. */
#define LINUX_YMAX 0		/* The actual values will be filled in init. */

TERM_PUBLIC void LINUX_options __PROTO((void));
TERM_PUBLIC void LINUX_init __PROTO((void));
TERM_PUBLIC void LINUX_reset __PROTO((void));
TERM_PUBLIC void LINUX_text __PROTO((void));
TERM_PUBLIC void LINUX_graphics __PROTO((void));
TERM_PUBLIC void LINUX_linetype __PROTO((int linetype));
TERM_PUBLIC void LINUX_move __PROTO((unsigned int x, unsigned int y));
TERM_PUBLIC void LINUX_vector __PROTO((unsigned int x, unsigned int y));
TERM_PUBLIC int LINUX_text_angle __PROTO((int ang));
TERM_PUBLIC void LINUX_put_text __PROTO((unsigned int x, unsigned int y, const char *str));
TERM_PUBLIC void LINUX_suspend __PROTO((void));
TERM_PUBLIC void LINUX_resume __PROTO((void));

/* also used in vgagl.trm, so export it: */
TERM_PUBLIC int LINUX_graphics_allowed;

#endif

#ifdef TERM_BODY

#define _STRING_H_
#include <vga.h>

static int linux_vmode = G1024x768x256;		/* default mode */
static int vgacolor[] = { 7, 8, 2, 3, 4, 5, 9, 14, 12, 15, 13, 10, 11, 1, 6 };
static int graphics_on = FALSE;
static vga_modeinfo *modeinfo;
static int linux_startx, linux_starty, linux_lasty;
static int linux_angle;
TERM_PUBLIC int LINUX_graphics_allowed = FALSE; /* also used in vgagl.trm */
extern void drop_privilege __PROTO((void));
extern void take_privilege __PROTO((void));

typedef int (*linux_line_func_ptr) __PROTO((int x1, int y1, int x2, int y2));

static void LINUX_putc __PROTO((unsigned int x, unsigned int y, int c, int ang,
				linux_line_func_ptr line_func));

/* this function is called at the very beginning of main() to initialize
 *  the vgalib and to revoke suid privileges.
 * /dev/console and /dev/tty\d and /dev/vc/\d are considered graphic terminals, all other
 * don't support the linux terminal */

void
LINUX_setup()
{
    char line[256];
    FILE *pipe;

    LINUX_graphics_allowed = FALSE;

    if (geteuid() != 0)
	return;			/* if we aren't root, we cannot init graphics */

    if ((pipe = popen("/usr/bin/tty", "r")) != NULL) {
	line[0] = 0;
	fgets(line, 256, pipe);
	pclose(pipe);
	line[strlen(line) - 1] = '\0';
	if (
	    strcmp(line, "/dev/console") == 0 ||

	    ( ( strncmp(line, "/dev/tty", 8) == 0 || strncmp(line, "/dev/vc/", 8) == 0 )
	     && isdigit((unsigned char) line[8]))

	     ) {
	    LINUX_graphics_allowed = TRUE;
	} else {
	    /* check for socket name as set for example by `screen' */
	    char* sty = getenv("STY");
	    if (sty) {
		int n1, n2;
		if (3 == sscanf(sty, "%d.tty%d.%s", &n1, &n2, line)) {
		    /* we could check here, if host is the
		     * same as gethostname() returns. */
		    LINUX_graphics_allowed = TRUE;
		}
	    }
	}
    }
    if (LINUX_graphics_allowed) {
	take_privilege();
	vga_init();
	drop_privilege();
    } else {
	/* err - shouldn't we give up root uid whatever happens ?
	 * or perhaps vga_init() does it ?
	 */
	setuid(getuid());
    }
}

TERM_PUBLIC
void LINUX_options()
{
    if (!LINUX_graphics_allowed) {
	int_error(NO_CARET, "Linux terminal driver not available");
    }
    fprintf(stderr, "%s\n", vga_getmodename(linux_vmode));
}

TERM_PUBLIC
void LINUX_init()
{
    /* vga_init () has been moved to immediately after main () for security */
    if (vga_getdefaultmode() != -1)
	linux_vmode = vga_getdefaultmode();
    /* get the default mode from GSVGAMODE, if available */
    if (!vga_hasmode(linux_vmode))
	linux_vmode = G640x480x16;
    /* test default mode first */
    if (!vga_hasmode(linux_vmode)) {
	fputs("Error, unable to initiate graphics.\n", stderr);
	return;
    }				/* this mode is the bottom line */
    modeinfo = vga_getmodeinfo(linux_vmode);
    term->xmax = modeinfo->width;
    term->ymax = modeinfo->height;
    linux_lasty = modeinfo->height - 1;
}

TERM_PUBLIC void
LINUX_reset()
{
    if (graphics_on) {
	vga_setmode(TEXT);
	graphics_on = FALSE;
    }
}

TERM_PUBLIC void
LINUX_text()
{
    if (graphics_on) {
	vga_getch();
	vga_setmode(TEXT);
	graphics_on = FALSE;
    }
}

TERM_PUBLIC void
LINUX_graphics()
{
    if (!graphics_on) {
	vga_setmode(linux_vmode);
	graphics_on = TRUE;
    }
}

TERM_PUBLIC void
LINUX_suspend()
{
    vga_flip();
}

TERM_PUBLIC void
LINUX_resume()
{
    vga_flip();
}

TERM_PUBLIC void
LINUX_linetype(int linetype)
{
    if (linetype < -2)
	linetype = LT_BLACK;
    if (linetype >= 13)
	linetype %= 13;
    vga_setegacolor(vgacolor[linetype + 2]);
}

TERM_PUBLIC void
LINUX_move(unsigned int x, unsigned int y)
{
    linux_startx = x;
    linux_starty = y;
}

TERM_PUBLIC void
LINUX_vector(unsigned int x, unsigned int y)
{
    vga_drawline(linux_startx, linux_lasty - linux_starty, x, linux_lasty - y);
    linux_startx = x;
    linux_starty = y;
}

TERM_PUBLIC int
LINUX_text_angle(int ang)
{
    linux_angle = (ang ? 1 : 0);
    return TRUE;
}

static void
LINUX_putc(
    unsigned int x, unsigned int y,
    int c,
    int ang,
    linux_line_func_ptr line_func)
{
    int i, j, k;
    unsigned int pixelon;

    i = (int) (c) - 32;
    for (j = 0; j < FNT5X9_VBITS; j++) {
	for (k = 0; k < FNT5X9_HBITS; k++) {
	    pixelon = (((unsigned int) (fnt5x9[i][j])) >> k & 1);
	    if (pixelon) {
		switch (ang) {
		case 0:
		    (*line_func) (x + k + 1, y - j, x + k + 1, y - j);
		    break;
		case 1:
		    (*line_func) (x - j, y - k - 1, x - j, y - k - 1);
		    break;
		}
	    }
	}
    }
}

TERM_PUBLIC void
LINUX_put_text(unsigned int x, unsigned int y, const char *str)
{
    int i;
    switch (linux_angle) {
    case 0:
	y -= LINUX_VCHAR / 2;
	break;
    case 1:
	x += LINUX_VCHAR / 2;
	break;
    }
    for (i = 0; str[i]; i++) {
	LINUX_putc(x, linux_lasty - y, str[i], linux_angle, vga_drawline);
	switch (linux_angle) {
	case 0:
	    x += LINUX_HCHAR;
	    break;
	case 1:
	    y += LINUX_HCHAR;
	    break;
	}
    }
}

#endif

#ifdef TERM_TABLE
TERM_TABLE_START(linux_driver)
    "linux", "Linux PC with (s)vgalib",
    LINUX_XMAX, LINUX_YMAX, LINUX_VCHAR, LINUX_HCHAR,
    LINUX_VTIC, LINUX_HTIC, LINUX_options, LINUX_init, LINUX_reset,
    LINUX_text, null_scale, LINUX_graphics, LINUX_move, LINUX_vector,
    LINUX_linetype, LINUX_put_text, LINUX_text_angle,
    null_justify_text, do_point, do_arrow, set_font_null,
    0,				/* pointsize */
    TERM_CAN_MULTIPLOT, LINUX_suspend, LINUX_resume
TERM_TABLE_END(linux_driver)
#undef LAST_TERM
#define LAST_TERM linux_driver
#endif

#ifdef TERM_HELP
START_HELP(linux)
"1 linux",
"?commands set terminal linux",
"?set terminal linux",
"?set term linux",
"?terminal linux",
"?term linux",
"?linux",
" The `linux` driver has no additional options to specify.  It looks at the",
" environment variable GSVGAMODE for the default mode; if not set, it uses",
" 1024x768x256 as default mode or, if that is not possible, 640x480x16",
" (standard VGA)."
END_HELP(linux)
#endif