path: root/drv_generic_text.c

/* $Id: drv_generic_text.c,v 1.34 2006/02/27 08:12:34 reinelt Exp $
 *
 * generic driver helper for text-based displays
 *
 * Copyright (C) 1999, 2000 Michael Reinelt <reinelt@eunet.at>
 * Copyright (C) 2004 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net>
 *
 * This file is part of LCD4Linux.
 *
 * LCD4Linux 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, or (at your option)
 * any later version.
 *
 * LCD4Linux 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 the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *
 * $Log: drv_generic_text.c,v $
 * Revision 1.34  2006/02/27 08:12:34  reinelt
 * use serdisplib's full color support
 *
 * Revision 1.33  2006/02/27 06:15:55  reinelt
 * indent...
 *
 * Revision 1.32  2006/02/25 13:36:33  geronet
 * updated indent.sh, applied coding style
 *
 * Revision 1.31  2006/01/30 05:47:38  reinelt
 * graphic subsystem changed to full-color RGBA
 *
 * Revision 1.30  2006/01/03 06:13:46  reinelt
 * GPIO's for MatrixOrbital
 *
 * Revision 1.29  2005/11/06 09:54:43  reinelt
 * fixed icon size removed, uses XRES & YRES (I hope this doesn't lead to problemes...)
 *
 * Revision 1.28  2005/08/22 05:44:43  reinelt
 * new driver 'WincorNixdorf'
 * some fixes to the bar code
 *
 * Revision 1.27  2005/05/08 04:32:44  reinelt
 * CodingStyle added and applied
 *
 * Revision 1.26  2005/05/06 06:37:34  reinelt
 * hollow bar patch from geronet
 *
 * Revision 1.25  2005/02/24 07:06:48  reinelt
 * SimpleLCD driver added
 *
 * Revision 1.24  2005/01/18 06:30:23  reinelt
 * added (C) to all copyright statements
 *
 * Revision 1.23  2005/01/09 10:53:24  reinelt
 * small type in plugin_uname fixed
 * new homepage lcd4linux.bulix.org
 *
 * Revision 1.22  2004/11/28 15:50:24  reinelt
 * Cwlinux fixes (invalidation of user-defined chars)
 *
 * Revision 1.21  2004/06/26 12:04:59  reinelt
 *
 * uh-oh... the last CVS log message messed up things a lot...
 *
 * Revision 1.20  2004/06/26 09:27:21  reinelt
 *
 * added '-W' to CFLAGS
 * changed all C++ comments to C ones
 * cleaned up a lot of signed/unsigned mistakes
 *
 * Revision 1.19  2004/06/26 06:12:15  reinelt
 *
 * support for Beckmann+Egle Compact Terminals
 * some mostly cosmetic changes in the MatrixOrbital and USBLCD driver
 * added debugging to the generic serial driver
 * fixed a bug in the generic text driver where icons could be drawn outside
 * the display bounds
 *
 * Revision 1.18  2004/06/20 10:09:55  reinelt
 *
 * 'const'ified the whole source
 *
 * Revision 1.17  2004/06/05 06:41:40  reinelt
 *
 * chancged splash screen again
 *
 * Revision 1.16  2004/06/02 10:09:22  reinelt
 *
 * splash screen for HD44780
 *
 * Revision 1.15  2004/06/01 06:45:30  reinelt
 *
 * some Fixme's processed
 * documented some code
 *
 * Revision 1.14  2004/05/26 11:37:36  reinelt
 *
 * Curses driver ported.
 *
 * Revision 1.13  2004/03/19 09:17:46  reinelt
 *
 * removed the extra 'goto' function, row and col are additional parameters
 * of the write() function now.
 *
 * Revision 1.12  2004/03/03 03:47:04  reinelt
 * big patch from Martin Hejl:
 * - use qprintf() where appropriate
 * - save CPU cycles on gettimeofday()
 * - add quit() functions to free allocated memory
 * - fixed lots of memory leaks
 *
 * Revision 1.11  2004/02/15 21:43:43  reinelt
 * T6963 driver nearly finished
 * framework for graphic displays done
 * i2c_sensors patch from Xavier
 * some more old generation files removed
 *
 * Revision 1.10  2004/02/14 11:56:17  reinelt
 * M50530 driver ported
 * changed lots of 'char' to 'unsigned char'
 *
 * Revision 1.9  2004/02/07 13:45:23  reinelt
 * icon visibility patch #2 from Xavier
 *
 * Revision 1.8  2004/01/30 20:57:56  reinelt
 * HD44780 patch from Martin Hejl
 * dmalloc integrated
 *
 * Revision 1.7  2004/01/29 04:40:02  reinelt
 * every .c file includes "config.h" now
 *
 * Revision 1.6  2004/01/23 07:04:23  reinelt
 * icons finished!
 *
 * Revision 1.5  2004/01/23 04:53:54  reinelt
 * icon widget added (not finished yet!)
 *
 * Revision 1.4  2004/01/22 07:57:45  reinelt
 * several bugs fixed where segfaulting on layout>display
 * Crystalfontz driver optimized, 632 display already works
 *
 * Revision 1.3  2004/01/20 14:25:12  reinelt
 * some reorganization
 * moved drv_generic to drv_generic_serial
 * moved port locking stuff to drv_generic_serial
 *
 * Revision 1.2  2004/01/20 12:45:47  reinelt
 * "Default screen" working with MatrixOrbital
 *
 * Revision 1.1  2004/01/20 05:36:59  reinelt
 * moved text-display-specific stuff to drv_generic_text
 * moved all the bar stuff from drv_generic_bar to generic_text
 *
 */

/* 
 *
 * exported variables:
 *
 * extern int DROWS, DCOLS;    display size
 * extern int XRES,  YRES;     pixel width/height of one char
 * extern int CHARS, CHAR0;    number of user-defineable characters, ASCII of first char
 * extern int ICONS;           number of user-defineable characters reserved for icons
 * extern int GOTO_COST;       number of bytes a goto command requires
 * extern int INVALIDATE;      re-send a modified userdefined char?
 *
 *
 * these functions must be implemented by the real driver:
 *
 * void (*drv_generic_text_real_write)(int row, int col, unsigned char *data, int len);
 *  writes a text of specified length at position (row, col)
 *
 * void (*drv_generic_text_real_defchar)(int ascii, unsigned char *buffer);
 *  defines the bitmap of a user-defined character
 *
 *
 * exported fuctions:
 *
 * int drv_generic_text_init (char *section, char *driver);
 *   initializes the generic text driver
 *
 * int drv_generic_text_draw (WIDGET *W);
 *   renders Text widget into framebuffer
 *   calls drv_generic_text_real_write()
 *
 * int drv_generic_text_icon_init (void);
 *   initializes the generic icon driver
 *   
 * int drv_generic_text_icon_draw (WIDGET *W);
 *   renders Icon widget into framebuffer
 *   calls drv_generic_text_real_write() and drv_generic_text_real_defchar()
 *
 * int drv_generic_text_bar_init (int single_segments);
 *   initializes the generic icon driver
 *
 * void drv_generic_text_bar_add_segment (int val1, int val2, DIRECTION dir, int ascii);
 *   adds a 'fixed' character to the bar-renderer
 *
 * int drv_generic_text_bar_draw (WIDGET *W);
 *   renders Bar widget into framebuffer
 *   calls drv_generic_text_real_write() and drv_generic_text_real_defchar()
 *
 * int drv_generic_text_quit (void);
 *   closes the generic text driver
 *
 */

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <termios.h>
#include <fcntl.h>

#include "debug.h"
#include "cfg.h"
#include "plugin.h"
#include "widget.h"
#include "widget_text.h"
#include "widget_icon.h"
#include "widget_bar.h"
#include "drv.h"
#include "drv_generic_text.h"

#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif


typedef struct {
    int val1;
    int val2;
    DIRECTION dir;
    STYLE style;
    int segment;
    int invalid;
} BAR;

typedef struct {
    int val1;
    int val2;
    DIRECTION dir;
    STYLE style;
    int used;
    int ascii;
} SEGMENT;

static char *Section = NULL;
static char *Driver = NULL;


int DROWS = 20;			/* display size: rows */
int DCOLS = 4;			/* display size: columns */
int XRES = 6;			/* pixels of one char cell */
int YRES = 8;			/* pixels of one char cell */
int CHARS = 0;			/* number of user-defineable characters */
int CHAR0 = 0;			/* ASCII of first user-defineable char */
int ICONS = 0;			/* number of user-defineable characters reserved for icons */

int GOTO_COST = 0;		/* number of bytes a goto command requires */
int INVALIDATE = 0;		/* re-send a modified userdefined char? */


void (*drv_generic_text_real_write) () = NULL;
void (*drv_generic_text_real_defchar) () = NULL;


static int LROWS = 20;		/* layout size: rows */
static int LCOLS = 4;		/* layout size: columns */

static char *LayoutFB = NULL;
static char *DisplayFB = NULL;

static int Single_Segments = 0;

static int nSegment = 0;
static int fSegment = 0;
static SEGMENT Segment[128];
static BAR *BarFB = NULL;



/****************************************/
/*** generic Framebuffer stuff        ***/
/****************************************/

static void drv_generic_text_resizeFB(int rows, int cols)
{
    char *newFB;
    BAR *newBar;
    int i, row, col;

    /* Layout FB is large enough */
    if (rows <= LROWS && cols <= LCOLS)
	return;

    /* get maximum values */
    if (rows < LROWS)
	rows = LROWS;
    if (cols < LCOLS)
	cols = LCOLS;

    /* allocate new Layout FB */
    newFB = malloc(cols * rows * sizeof(char));
    memset(newFB, ' ', rows * cols * sizeof(char));

    /* transfer contents */
    if (LayoutFB != NULL) {
	for (row = 0; row < LROWS; row++) {
	    for (col = 0; col < LCOLS; col++) {
		newFB[row * cols + col] = LayoutFB[row * LCOLS + col];
	    }
	}
	free(LayoutFB);
    }
    LayoutFB = newFB;


    /* resize Bar buffer */
    if (BarFB) {

	newBar = malloc(rows * cols * sizeof(BAR));

	for (i = 0; i < rows * cols; i++) {
	    newBar[i].val1 = -1;
	    newBar[i].val2 = -1;
	    newBar[i].dir = 0;
	    newBar[i].segment = -1;
	    newBar[i].invalid = 0;
	}

	/* transfer contents */
	for (row = 0; row < LROWS; row++) {
	    for (col = 0; col < LCOLS; col++) {
		newBar[row * cols + col] = BarFB[row * LCOLS + col];
	    }
	}

	free(BarFB);
	BarFB = newBar;
    }

    LCOLS = cols;
    LROWS = rows;
}


/****************************************/
/*** generic text handling            ***/
/****************************************/

int drv_generic_text_init(const char *section, const char *driver)
{

    Section = (char *) section;
    Driver = (char *) driver;

    /* init display framebuffer */
    DisplayFB = (char *) malloc(DCOLS * DROWS * sizeof(char));
    memset(DisplayFB, ' ', DROWS * DCOLS * sizeof(char));

    /* init layout framebuffer */
    LROWS = 0;
    LCOLS = 0;
    LayoutFB = NULL;
    drv_generic_text_resizeFB(DROWS, DCOLS);

    /* sanity check */
    if (LayoutFB == NULL || DisplayFB == NULL) {
	error("%s: framebuffer could not be allocated: malloc() failed", Driver);
	return -1;
    }

    return 0;
}


/* say hello to the user */
int drv_generic_text_greet(const char *msg1, const char *msg2)
{
    int i;
    int flag = 0;

    char *line1[] = { "* LCD4Linux " VERSION " *",
	"LCD4Linux " VERSION,
	"* LCD4Linux *",
	"LCD4Linux",
	"L4Linux",
	NULL
    };

    char *line2[] = { "http://lcd4linux.bulix.org",
	"lcd4linux.bulix.org",
	NULL
    };


    for (i = 0; line1[i]; i++) {
	if (strlen(line1[i]) <= (unsigned) DCOLS) {
	    if (drv_generic_text_real_write)
		drv_generic_text_real_write(0, (DCOLS - strlen(line1[i])) / 2, line1[i], strlen(line1[i]));
	    flag = 1;
	    break;
	}
    }

    if (DROWS >= 2) {
	for (i = 0; line2[i]; i++) {
	    if (strlen(line2[i]) <= (unsigned) DCOLS) {
		if (drv_generic_text_real_write)
		    drv_generic_text_real_write(1, (DCOLS - strlen(line2[i])) / 2, line2[i], strlen(line2[i]));
		flag = 1;
		break;
	    }
	}
    }

    if (msg1 && DROWS >= 3) {
	int len = strlen(msg1);
	if (len <= DCOLS) {
	    if (drv_generic_text_real_write)
		drv_generic_text_real_write(2, (DCOLS - len) / 2, msg1, len);
	    flag = 1;
	}
    }

    if (msg2 && DROWS >= 4) {
	int len = strlen(msg2);
	if (len <= DCOLS) {
	    if (drv_generic_text_real_write)
		drv_generic_text_real_write(3, (DCOLS - len) / 2, msg2, len);
	    flag = 1;
	}
    }

    return flag;
}


int drv_generic_text_draw(WIDGET * W)
{
    WIDGET_TEXT *Text = W->data;
    char *txt, *fb1, *fb2;
    int row, col, col0, len, end;

    row = W->row;
    col = W->col;
    txt = Text->buffer;
    len = strlen(txt);
    end = col + len;

    /* maybe grow layout framebuffer */
    drv_generic_text_resizeFB(row + 1, col + len);

    fb1 = LayoutFB + row * LCOLS;
    fb2 = DisplayFB + row * DCOLS;

    /* transfer new text into layout buffer */
    memcpy(fb1 + col, txt, len);

    if (row < DROWS) {
	for (; col <= end && col < DCOLS; col++) {
	    int pos1, pos2, equal;
	    if (fb1[col] == fb2[col])
		continue;
	    col0 = col;
	    for (pos1 = col, pos2 = pos1, col++, equal = 0; col <= end && col < DCOLS; col++) {
		if (fb1[col] == fb2[col]) {
		    /* If we find just one equal byte, we don't break, because this  */
		    /* would require a goto, which takes several bytes, too. */
		    if (GOTO_COST >= 0 && ++equal > GOTO_COST)
			break;
		} else {
		    pos2 = col;
		    equal = 0;
		}
	    }
	    memcpy(fb2 + pos1, fb1 + pos1, pos2 - pos1 + 1);
	    if (drv_generic_text_real_write)
		drv_generic_text_real_write(row, col0, fb2 + pos1, pos2 - pos1 + 1);
	}
    }

    return 0;
}


int drv_generic_text_quit(void)
{

    if (LayoutFB) {
	free(LayoutFB);
	LayoutFB = NULL;
    }

    if (DisplayFB) {
	free(DisplayFB);
	DisplayFB = NULL;
    }

    if (BarFB) {
	free(BarFB);
	BarFB = NULL;
    }
    widget_unregister();

    return (0);
}


/****************************************/
/*** generic icon handling            ***/
/****************************************/

int drv_generic_text_icon_init(void)
{
    if (cfg_number(Section, "Icons", 0, 0, CHARS, &ICONS) < 0)
	return -1;
    if (ICONS > 0) {
	info("%s: reserving %d of %d user-defined characters for icons", Driver, ICONS, CHARS);
    }
    return 0;
}


int drv_generic_text_icon_draw(WIDGET * W)
{
    static int icon_counter = 0;
    WIDGET_ICON *Icon = W->data;
    int row, col;
    int l_idx, d_idx;
    int invalidate = 0;
    unsigned char ascii;

    row = W->row;
    col = W->col;

    /* maybe grow layout framebuffer */
    drv_generic_text_resizeFB(row + 1, col + 1);

    /* icon deactivated? */
    if (Icon->ascii == -2)
	return 0;

    /* ASCII already assigned? */
    if (Icon->ascii == -1) {
	if (icon_counter >= ICONS) {
	    error("cannot process icon '%s': out of icons", W->name);
	    Icon->ascii = -2;
	    return -1;
	}
	icon_counter++;
	Icon->ascii = CHAR0 + CHARS - icon_counter;
    }

    /* maybe redefine icon */
    if (Icon->curmap != Icon->prvmap && Icon->visible) {
	Icon->prvmap = Icon->curmap;
	if (drv_generic_text_real_defchar)
	    drv_generic_text_real_defchar(Icon->ascii, Icon->bitmap + YRES * Icon->curmap);
	invalidate = INVALIDATE;
    }

    /* use blank if invisible */
    ascii = Icon->visible ? Icon->ascii : ' ';

    /* index into the two framebuffers */
    l_idx = row * LCOLS + col;
    d_idx = row * DCOLS + col;

    /* transfer icon into layout buffer */
    LayoutFB[l_idx] = ascii;

    /* maybe send icon to the display */
    if (row < DROWS && col < DCOLS && (DisplayFB[d_idx] != ascii || invalidate)) {
	DisplayFB[d_idx] = ascii;
	if (drv_generic_text_real_write)
	    drv_generic_text_real_write(row, col, DisplayFB + d_idx, 1);
    }

    return 0;

}


/****************************************/
/*** generic bar handling             ***/
/****************************************/

static void drv_generic_text_bar_clear(void)
{
    int i;

    for (i = 0; i < LROWS * LCOLS; i++) {
	BarFB[i].val1 = -1;
	BarFB[i].val2 = -1;
	BarFB[i].dir = 0;
	BarFB[i].style = 0;
	BarFB[i].segment = -1;
	BarFB[i].invalid = 0;
    }

    for (i = 0; i < nSegment; i++) {
	Segment[i].used = 0;
    }
}


int drv_generic_text_bar_init(const int single_segments)
{
    if (BarFB)
	free(BarFB);

    if ((BarFB = malloc(LROWS * LCOLS * sizeof(BAR))) == NULL) {
	error("bar buffer allocation failed: out of memory");
	return -1;
    }

    Single_Segments = single_segments;

    nSegment = 0;
    fSegment = 0;

    drv_generic_text_bar_clear();

    return 0;
}


void drv_generic_text_bar_add_segment(const int val1, const int val2, const DIRECTION dir, const int ascii)
{
    Segment[fSegment].val1 = val1;
    Segment[fSegment].val2 = val2;
    Segment[fSegment].dir = dir;
    if (val1 == 0 && val2 == 0)
	Segment[fSegment].style = 0;
    else
	Segment[fSegment].style = 255;
    Segment[fSegment].used = 0;
    Segment[fSegment].ascii = ascii;

    fSegment++;
    nSegment = fSegment;
}


static void drv_generic_text_bar_create_bar(int row, int col, const DIRECTION dir, STYLE style, int len, int val1,
					    int val2)
{
    int rev = 0, max;
    if (style)
	BarFB[row * LCOLS + col].style = STYLE_FIRST;

    switch (dir) {
    case DIR_WEST:
	max = len * XRES;
	val1 = max - val1;
	val2 = max - val2;
	rev = 1;

    case DIR_EAST:
	while (len > 0 && col < LCOLS) {
	    BarFB[row * LCOLS + col].dir = dir;
	    BarFB[row * LCOLS + col].segment = -1;
	    if (style && BarFB[row * LCOLS + col].style == 0)
		BarFB[row * LCOLS + col].style = style;
	    if (val1 >= XRES) {
		BarFB[row * LCOLS + col].val1 = rev ? 0 : XRES;
		val1 -= XRES;
	    } else {
		BarFB[row * LCOLS + col].val1 = rev ? XRES - val1 : val1;
		val1 = 0;
	    }
	    if (val2 >= XRES) {
		BarFB[row * LCOLS + col].val2 = rev ? 0 : XRES;
		val2 -= XRES;
	    } else {
		BarFB[row * LCOLS + col].val2 = rev ? XRES - val2 : val2;
		val2 = 0;
	    }
	    len--;
	    col++;
	}
	if (style)
	    BarFB[row * LCOLS + col - 1].style = STYLE_LAST;
	break;

    case DIR_SOUTH:
	max = len * YRES;
	val1 = max - val1;
	val2 = max - val2;
	rev = 1;

    case DIR_NORTH:
	while (len > 0 && row < LROWS) {
	    BarFB[row * LCOLS + col].dir = dir;
	    BarFB[row * LCOLS + col].segment = -1;
	    if (val1 >= YRES) {
		BarFB[row * LCOLS + col].val1 = rev ? 0 : YRES;
		val1 -= YRES;
	    } else {
		BarFB[row * LCOLS + col].val1 = rev ? YRES - val1 : val1;
		val1 = 0;
	    }
	    if (val2 >= YRES) {
		BarFB[row * LCOLS + col].val2 = rev ? 0 : YRES;
		val2 -= YRES;
	    } else {
		BarFB[row * LCOLS + col].val2 = rev ? YRES - val2 : val2;
		val2 = 0;
	    }
	    len--;
	    row++;
	}
	break;
    }
}


static void drv_generic_text_bar_create_segments(void)
{
    int i, j, n;
    int res, l1, l2;

    /* find first unused segment */
    for (i = fSegment; i < nSegment && Segment[i].used; i++);

    /* pack unused segments */
    for (j = i + 1; j < nSegment; j++) {
	if (Segment[j].used)
	    Segment[i++] = Segment[j];
    }
    nSegment = i;

    /* create needed segments */
    for (n = 0; n < LROWS * LCOLS; n++) {
	if (BarFB[n].dir == 0)
	    continue;
	res = BarFB[n].dir & (DIR_EAST | DIR_WEST) ? XRES : YRES;
	for (i = 0; i < nSegment; i++) {
	    l1 = Segment[i].val1;
	    if (l1 > res)
		l1 = res;
	    l2 = Segment[i].val2;
	    if (l2 > res)
		l2 = res;

	    /* same value */
	    if (l1 == BarFB[n].val1 && l2 == BarFB[n].val2) {
		/* empty block, only style is interesting */
		if (l1 == 0 && l2 == 0 && Segment[i].style == BarFB[n].style)
		    break;
		/* full block, style doesn't matter */
		if (l1 == res && l2 == res)
		    break;
		/* half upper block */
		if (l1 == res && l2 == 0 && Segment[i].style == BarFB[n].style)
		    break;
		/* half lower block */
		if (l1 == 0 && l2 == res && Segment[i].style == BarFB[n].style)
		    break;
		/* same style, same direction */
		if (Segment[i].style == BarFB[n].style && Segment[i].dir & BarFB[n].dir)
		    break;
#if 0
		/* hollow style, val(1,2) == 1, like '[' */
		if (l1 == 1 && l2 == 1 && Segment[i].style == STYLE_FIRST && BarFB[n].style == STYLE_HOLLOW)
		    break;
		/* hollow style, val(1,2) == 1, like ']' */
		if (l1 == 1 && l2 == 1 && Segment[i].style == STYLE_LAST && BarFB[n].style == STYLE_HOLLOW)
		    break;
#endif
	    }
	}
	if (i == nSegment) {
	    nSegment++;
	    Segment[i].val1 = BarFB[n].val1;
	    Segment[i].val2 = BarFB[n].val2;
	    Segment[i].dir = BarFB[n].dir;
	    Segment[i].style = BarFB[n].style;
	    Segment[i].used = 0;
	    Segment[i].ascii = -1;
	}
	BarFB[n].segment = i;
    }
}


static int drv_generic_text_bar_segment_error(const int i, const int j)
{
    int res;
    int i1, i2, j1, j2;

    if (i == j)
	return 65535;
    if (!(Segment[i].dir & Segment[j].dir))
	return 65535;
    if (Segment[i].style != Segment[j].style)
	return 65535;

    res = Segment[i].dir & (DIR_EAST | DIR_WEST) ? XRES : YRES;

    i1 = Segment[i].val1;
    if (i1 > res)
	i1 = res;
    i2 = Segment[i].val2;
    if (i2 > res)
	i2 = res;
    j1 = Segment[j].val1;
    if (j1 > res)
	j1 = res;
    j2 = Segment[j].val2;
    if (j2 > res)
	j2 = res;

    /* do not replace empty with non-empty */
    if (i1 == 0 && j1 != 0)
	return 65535;
    if (i2 == 0 && j2 != 0)
	return 65535;

    /* do not replace full with non-full */
    if (i1 == res && j1 < res)
	return 65535;
    if (i2 == res && j2 < res)
	return 65535;

    /* do not replace start line */
    /* but only if there are at least some chars available */
    if (CHARS - ICONS > 0) {
	if (i1 == 1 && j1 != 1 && i2 > 0)
	    return 65535;
	if (i2 == 1 && j2 != 1 && j1 > 0)
	    return 65535;
    }

    /* do not replace equal length with non-equal length */
    if (i1 == i2 && j1 != j2)
	return 65535;

    return (i1 - j1) * (i1 - j1) + (i2 - j2) * (i2 - j2);
}


static void drv_generic_text_bar_pack_segments(void)
{
    int i, j, n, min;
    int pack_i, pack_j;
    int pass1 = 1;
    int error[nSegment][nSegment];

    if (nSegment <= fSegment + CHARS - ICONS) {
	return;
    }

    for (i = 0; i < nSegment; i++) {
	for (j = 0; j < nSegment; j++) {
	    error[i][j] = drv_generic_text_bar_segment_error(i, j);
	    // debug ("[%d][%d] = %d", i, j, error[i][j]);
	}
    }

    while (nSegment > fSegment + CHARS - ICONS) {

	min = 65535;
	pack_i = -1;
	pack_j = -1;
	for (i = fSegment; i < nSegment; i++) {
	    if (pass1 && Segment[i].used)
		continue;
	    for (j = 0; j < nSegment; j++) {
		if (error[i][j] < min) {
		    min = error[i][j];
		    pack_i = i;
		    pack_j = j;
		}
	    }
	}
	if (pack_i == -1) {
	    if (pass1) {
		pass1 = 0;
		continue;
	    } else {
		error("unable to compact bar characters");
		error("nSegment=%d fSegment=%d CHARS=%d ICONS=%d", nSegment, fSegment, CHARS, ICONS);
		error("Segment[0].val1=%d val2=%d", Segment[0].val1, Segment[0].val2);
		error("Segment[1].val1=%d val2=%d", Segment[1].val1, Segment[1].val2);
		error("Segment[2].val1=%d val2=%d", Segment[2].val1, Segment[2].val2);
		nSegment = CHARS - ICONS;
		break;
	    }
	}
#if 0
	debug("pack_segment: n=%d i=%d j=%d min=%d", nSegment, pack_i, pack_j, min);
	debug("Pack_segment: i1=%d i2=%d j1=%d j2=%d\n", Segment[pack_i].val1, Segment[pack_i].val2,
	      Segment[pack_j].val1, Segment[pack_j].val2);
#endif

	nSegment--;
	Segment[pack_i] = Segment[nSegment];

	for (i = 0; i < nSegment; i++) {
	    error[pack_i][i] = error[nSegment][i];
	    error[i][pack_i] = error[i][nSegment];
	}

	for (n = 0; n < LROWS * LCOLS; n++) {
	    if (BarFB[n].segment == pack_i)
		BarFB[n].segment = pack_j;
	    if (BarFB[n].segment == nSegment)
		BarFB[n].segment = pack_i;
	}
    }
}


static void drv_generic_text_bar_define_chars(void)
{
    int c, i, j;
    unsigned char buffer[8];

    for (i = fSegment; i < nSegment; i++) {
	if (Segment[i].used)
	    continue;
	if (Segment[i].ascii != -1)
	    continue;
	for (c = 0; c < CHARS - ICONS; c++) {
	    for (j = fSegment; j < nSegment; j++) {
		if (Segment[j].ascii == c)
		    break;
	    }
	    if (j == nSegment)
		break;
	}
	Segment[i].ascii = c;
	switch (Segment[i].dir) {
	case DIR_WEST:
	    if (Segment[i].style) {
		buffer[0] = 255;
		buffer[7] = 255;
		if (Segment[i].style & (STYLE_FIRST | STYLE_LAST))
		    for (j = 1; j < 7; j++) {
			buffer[j] |= Segment[i].style & STYLE_FIRST ? 16 : 1;
		    }
	    }
	    break;
	case DIR_EAST:
	    for (j = 0; j < 4; j++) {
		buffer[j] = 255 << (XRES - Segment[i].val1);
		buffer[j + 4] = 255 << (XRES - Segment[i].val2);
	    }
	    if (Segment[i].style) {
		buffer[0] = 255;
		buffer[7] = 255;
		if (Segment[i].style & (STYLE_FIRST | STYLE_LAST))
		    for (j = 1; j < 7; j++) {
			buffer[j] |= Segment[i].style & STYLE_FIRST ? 16 : 1;
		    }
	    }
	    break;
	case DIR_NORTH:
	    for (j = 0; j < Segment[i].val1; j++) {
		buffer[7 - j] = (1 << XRES) - 1;
	    }
	    for (; j < YRES; j++) {
		buffer[7 - j] = 0;
	    }
	    break;
	case DIR_SOUTH:
	    for (j = 0; j < Segment[i].val1; j++) {
		buffer[j] = (1 << XRES) - 1;
	    }
	    for (; j < YRES; j++) {
		buffer[j] = 0;
	    }
	    break;
	}
	if (drv_generic_text_real_defchar)
	    drv_generic_text_real_defchar(CHAR0 + c, buffer);

	/* maybe invalidate framebuffer */
	if (INVALIDATE) {
	    for (j = 0; j < LROWS * LCOLS; j++) {
		if (BarFB[j].segment == i) {
		    BarFB[j].invalid = 1;
		}
	    }
	}
    }
}


int drv_generic_text_bar_draw(WIDGET * W)
{
    WIDGET_BAR *Bar = W->data;
    int row, col, col0, len, res, max, val1, val2;
    int c, n, s;
    DIRECTION dir;
    STYLE style;

    row = W->row;
    col = W->col;
    dir = Bar->direction;
    style = Bar->style;
    len = Bar->length;

    /* maybe grow layout framebuffer */
    /* bars *always* grow heading North or East! */
    if (dir & (DIR_EAST | DIR_WEST)) {
	drv_generic_text_resizeFB(row + 1, col + len);
    } else {
	drv_generic_text_resizeFB(row + 1, col + 1);
    }

    res = dir & (DIR_EAST | DIR_WEST) ? XRES : YRES;
    max = len * res;
    val1 = Bar->val1 * (double) (max);
    val2 = Bar->val2 * (double) (max);

    if (val1 < 1)
	val1 = 1;
    else if (val1 > max)
	val1 = max;

    if (val2 < 1)
	val2 = 1;
    else if (val2 > max)
	val2 = max;

    if (Single_Segments)
	val2 = val1;

    /* create this bar */
    drv_generic_text_bar_create_bar(row, col, dir, style, len, val1, val2);

    /* process all bars */
    drv_generic_text_bar_create_segments();
    drv_generic_text_bar_pack_segments();
    drv_generic_text_bar_define_chars();

    /* reset usage flags */
    for (s = 0; s < nSegment; s++) {
	Segment[s].used = 0;
    }

    /* set usage flags */
    for (n = 0; n < LROWS * LCOLS; n++) {
	if ((s = BarFB[n].segment) != -1)
	    Segment[s].used = 1;
    }

    /* transfer bars into layout buffer */
    for (row = 0; row < LROWS; row++) {
	for (col = 0; col < LCOLS; col++) {
	    n = row * LCOLS + col;
	    s = BarFB[n].segment;
	    if (s == -1)
		continue;
	    c = Segment[s].ascii;
	    if (c == -1)
		continue;
	    if (s >= fSegment)
		c += CHAR0;	/* ascii offset for user-defineable chars */
	    LayoutFB[n] = c;
	    /* maybe invalidate display framebuffer */
	    if (BarFB[n].invalid) {
		BarFB[n].invalid = 0;
		DisplayFB[row * DCOLS + col] = ~LayoutFB[n];
	    }
	}
    }

    /* transfer differences to the display */
    for (row = 0; row < DROWS; row++) {
	for (col = 0; col < DCOLS; col++) {
	    int pos1, pos2, equal;
	    if (LayoutFB[row * LCOLS + col] == DisplayFB[row * DCOLS + col])
		continue;
	    col0 = col;
	    for (pos1 = col, pos2 = pos1, col++, equal = 0; col < DCOLS; col++) {
		if (LayoutFB[row * LCOLS + col] == DisplayFB[row * DCOLS + col]) {
		    /* If we find just one equal byte, we don't break, because this  */
		    /* would require a goto, which takes several bytes, too. */
		    if (++equal > GOTO_COST)
			break;
		} else {
		    pos2 = col;
		    equal = 0;
		}
	    }
	    memcpy(DisplayFB + row * DCOLS + pos1, LayoutFB + row * LCOLS + pos1, pos2 - pos1 + 1);
	    if (drv_generic_text_real_write)
		drv_generic_text_real_write(row, col0, DisplayFB + row * DCOLS + pos1, pos2 - pos1 + 1);
	}
    }

    return 0;

}