Split 1 bit LCD code and move appropriate parts to target tree. Only archos code is tested.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@11517 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 860 insertions, 0 deletions

diff --git a/firmware/drivers/lcd-1bit-vert.c b/firmware/drivers/lcd-1bit-vert.c
new file mode 100755
index 0000000000..6ae92af72b
--- /dev/null
+++ b/firmware/drivers/lcd-1bit-vert.c
@@ -0,0 +1,860 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2002 by Alan Korr
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "config.h"
+
+#include "lcd.h"
+#include "kernel.h"
+#include "thread.h"
+#include <string.h>
+#include <stdlib.h>
+#include "file.h"
+#include "debug.h"
+#include "system.h"
+#include "font.h"
+#include "hwcompat.h"
+#include "rbunicode.h"
+#include "bidi.h"
+
+/*** definitions ***/
+
+#define SCROLLABLE_LINES ((LCD_HEIGHT+4)/5 < 32 ? (LCD_HEIGHT+4)/5 : 32)
+
+/*** globals ***/
+
+unsigned char lcd_framebuffer[LCD_HEIGHT/8][LCD_WIDTH];
+
+static int drawmode = DRMODE_SOLID;
+static int xmargin = 0;
+static int ymargin = 0;
+static int curfont = FONT_SYSFIXED;
+
+/* scrolling */
+static volatile int scrolling_lines=0; /* Bitpattern of which lines are scrolling */
+static void scroll_thread(void);
+static char scroll_stack[DEFAULT_STACK_SIZE];
+static const char scroll_name[] = "scroll";
+static int scroll_ticks = 12; /* # of ticks between updates*/
+static int scroll_delay = HZ/2; /* ticks delay before start */
+static int scroll_step = 6;  /* pixels per scroll step */
+static int bidir_limit = 50;  /* percent */
+static struct scrollinfo scroll[SCROLLABLE_LINES];
+
+static const char scroll_tick_table[16] = {
+ /* Hz values:
+    1, 1.25, 1.55, 2, 2.5, 3.12, 4, 5, 6.25, 8.33, 10, 12.5, 16.7, 20, 25, 33 */
+    100, 80, 64, 50, 40, 32, 25, 20, 16, 12, 10, 8, 6, 5, 4, 3
+};
+
+/* LCD init */
+void lcd_init(void)
+{
+    lcd_clear_display();
+    /* Call device specific init */
+    lcd_init_device();
+    create_thread(scroll_thread, scroll_stack,
+                  sizeof(scroll_stack), scroll_name IF_PRIO(, PRIORITY_USER_INTERFACE));
+}
+
+/*** parameter handling ***/
+
+void lcd_set_drawmode(int mode)
+{
+    drawmode = mode & (DRMODE_SOLID|DRMODE_INVERSEVID);
+}
+
+int lcd_get_drawmode(void)
+{
+    return drawmode;
+}
+
+void lcd_setmargins(int x, int y)
+{
+    xmargin = x;
+    ymargin = y;
+}
+
+int lcd_getxmargin(void)
+{
+    return xmargin;
+}
+
+int lcd_getymargin(void)
+{
+    return ymargin;
+}
+
+void lcd_setfont(int newfont)
+{
+    curfont = newfont;
+}
+
+int lcd_getstringsize(const unsigned char *str, int *w, int *h)
+{
+    return font_getstringsize(str, w, h, curfont);
+}
+
+/*** low-level drawing functions ***/
+
+static void setpixel(int x, int y)
+{
+    lcd_framebuffer[y>>3][x] |= 1 << (y & 7);
+}
+
+static void clearpixel(int x, int y)
+{
+    lcd_framebuffer[y>>3][x] &= ~(1 << (y & 7));
+}
+
+static void flippixel(int x, int y)
+{
+    lcd_framebuffer[y>>3][x] ^= 1 << (y & 7);
+}
+
+static void nopixel(int x, int y)
+{
+    (void)x;
+    (void)y;
+}
+
+lcd_pixelfunc_type* const lcd_pixelfuncs[8] = {
+    flippixel, nopixel, setpixel, setpixel,
+    nopixel, clearpixel, nopixel, clearpixel
+};
+                               
+static void flipblock(unsigned char *address, unsigned mask, unsigned bits)
+                      ICODE_ATTR;
+static void flipblock(unsigned char *address, unsigned mask, unsigned bits)
+{
+    *address ^= bits & mask;
+}
+
+static void bgblock(unsigned char *address, unsigned mask, unsigned bits)
+                    ICODE_ATTR;
+static void bgblock(unsigned char *address, unsigned mask, unsigned bits)
+{
+    *address &= bits | ~mask;
+}
+
+static void fgblock(unsigned char *address, unsigned mask, unsigned bits)
+                    ICODE_ATTR;
+static void fgblock(unsigned char *address, unsigned mask, unsigned bits)
+{
+    *address |= bits & mask;
+}
+
+static void solidblock(unsigned char *address, unsigned mask, unsigned bits)
+                       ICODE_ATTR;
+static void solidblock(unsigned char *address, unsigned mask, unsigned bits)
+{
+    unsigned data = *(char*)address;
+
+    bits    ^= data;
+    *address = data ^ (bits & mask);
+}
+
+static void flipinvblock(unsigned char *address, unsigned mask, unsigned bits)
+                         ICODE_ATTR;
+static void flipinvblock(unsigned char *address, unsigned mask, unsigned bits)
+{
+    *address ^= ~bits & mask;
+}
+
+static void bginvblock(unsigned char *address, unsigned mask, unsigned bits)
+                       ICODE_ATTR;
+static void bginvblock(unsigned char *address, unsigned mask, unsigned bits)
+{
+    *address &= ~(bits & mask);
+}
+
+static void fginvblock(unsigned char *address, unsigned mask, unsigned bits)
+                       ICODE_ATTR;
+static void fginvblock(unsigned char *address, unsigned mask, unsigned bits)
+{
+    *address |= ~bits & mask;
+}
+
+static void solidinvblock(unsigned char *address, unsigned mask, unsigned bits)
+                          ICODE_ATTR;
+static void solidinvblock(unsigned char *address, unsigned mask, unsigned bits)
+{
+    unsigned data = *(char *)address;
+    
+    bits     = ~bits ^ data;
+    *address = data ^ (bits & mask);
+}
+
+lcd_blockfunc_type* const lcd_blockfuncs[8] = {
+    flipblock, bgblock, fgblock, solidblock,
+    flipinvblock, bginvblock, fginvblock, solidinvblock
+};
+
+/*** drawing functions ***/
+
+/* Clear the whole display */
+void lcd_clear_display(void)
+{
+    unsigned bits = (drawmode & DRMODE_INVERSEVID) ? 0xFFu : 0;
+
+    memset(lcd_framebuffer, bits, sizeof lcd_framebuffer);
+    scrolling_lines = 0;
+}
+
+/* Set a single pixel */
+void lcd_drawpixel(int x, int y)
+{
+    if (((unsigned)x < LCD_WIDTH) && ((unsigned)y < LCD_HEIGHT))
+        lcd_pixelfuncs[drawmode](x, y);
+}
+
+/* Draw a line */
+void lcd_drawline(int x1, int y1, int x2, int y2)
+{
+    int numpixels;
+    int i;
+    int deltax, deltay;
+    int d, dinc1, dinc2;
+    int x, xinc1, xinc2;
+    int y, yinc1, yinc2;
+    lcd_pixelfunc_type *pfunc = lcd_pixelfuncs[drawmode];
+
+    deltax = abs(x2 - x1);
+    deltay = abs(y2 - y1);
+    xinc2 = 1;
+    yinc2 = 1;
+
+    if (deltax >= deltay)
+    {
+        numpixels = deltax;
+        d = 2 * deltay - deltax;
+        dinc1 = deltay * 2;
+        dinc2 = (deltay - deltax) * 2;
+        xinc1 = 1;
+        yinc1 = 0;
+    }
+    else
+    {
+        numpixels = deltay;
+        d = 2 * deltax - deltay;
+        dinc1 = deltax * 2;
+        dinc2 = (deltax - deltay) * 2;
+        xinc1 = 0;
+        yinc1 = 1;
+    }
+    numpixels++; /* include endpoints */
+
+    if (x1 > x2)
+    {
+        xinc1 = -xinc1;
+        xinc2 = -xinc2;
+    }
+
+    if (y1 > y2)
+    {
+        yinc1 = -yinc1;
+        yinc2 = -yinc2;
+    }
+
+    x = x1;
+    y = y1;
+
+    for (i = 0; i < numpixels; i++)
+    {
+        if (((unsigned)x < LCD_WIDTH) && ((unsigned)y < LCD_HEIGHT))
+            pfunc(x, y);
+
+        if (d < 0)
+        {
+            d += dinc1;
+            x += xinc1;
+            y += yinc1;
+        }
+        else
+        {
+            d += dinc2;
+            x += xinc2;
+            y += yinc2;
+        }
+    }
+}
+
+/* Draw a horizontal line (optimised) */
+void lcd_hline(int x1, int x2, int y)
+{
+    int x;
+    unsigned char *dst, *dst_end;
+    unsigned mask;
+    lcd_blockfunc_type *bfunc;
+
+    /* direction flip */
+    if (x2 < x1)
+    {
+        x = x1;
+        x1 = x2;
+        x2 = x;
+    }
+    
+    /* nothing to draw? */
+    if (((unsigned)y >= LCD_HEIGHT) || (x1 >= LCD_WIDTH) || (x2 < 0))
+        return;  
+    
+    /* clipping */
+    if (x1 < 0)
+        x1 = 0;
+    if (x2 >= LCD_WIDTH)
+        x2 = LCD_WIDTH-1;
+        
+    bfunc = lcd_blockfuncs[drawmode];
+    dst   = &lcd_framebuffer[y>>3][x1];
+    mask  = 1 << (y & 7);
+
+    dst_end = dst + x2 - x1;
+    do
+        bfunc(dst++, mask, 0xFFu);
+    while (dst <= dst_end);
+}
+
+/* Draw a vertical line (optimised) */
+void lcd_vline(int x, int y1, int y2)
+{
+    int ny;
+    unsigned char *dst;
+    unsigned mask, mask_bottom;
+    lcd_blockfunc_type *bfunc;
+
+    /* direction flip */
+    if (y2 < y1)
+    {
+        ny = y1;
+        y1 = y2;
+        y2 = ny;
+    }
+
+    /* nothing to draw? */
+    if (((unsigned)x >= LCD_WIDTH) || (y1 >= LCD_HEIGHT) || (y2 < 0))
+        return;  
+    
+    /* clipping */
+    if (y1 < 0)
+        y1 = 0;
+    if (y2 >= LCD_HEIGHT)
+        y2 = LCD_HEIGHT-1;
+        
+    bfunc = lcd_blockfuncs[drawmode];
+    dst   = &lcd_framebuffer[y1>>3][x];
+    ny    = y2 - (y1 & ~7);
+    mask  = 0xFFu << (y1 & 7);
+    mask_bottom = 0xFFu >> (~ny & 7);
+
+    for (; ny >= 8; ny -= 8)
+    {
+        bfunc(dst, mask, 0xFFu);
+        dst += LCD_WIDTH;
+        mask = 0xFFu;
+    }
+    mask &= mask_bottom;
+    bfunc(dst, mask, 0xFFu);
+}
+
+/* Draw a rectangular box */
+void lcd_drawrect(int x, int y, int width, int height)
+{
+    if ((width <= 0) || (height <= 0))
+        return;
+
+    int x2 = x + width - 1;
+    int y2 = y + height - 1;
+
+    lcd_vline(x, y, y2);
+    lcd_vline(x2, y, y2);
+    lcd_hline(x, x2, y);
+    lcd_hline(x, x2, y2);
+}
+
+/* Fill a rectangular area */
+void lcd_fillrect(int x, int y, int width, int height)
+{
+    int ny;
+    unsigned char *dst, *dst_end;
+    unsigned mask, mask_bottom;
+    unsigned bits = 0;
+    lcd_blockfunc_type *bfunc;
+    bool fillopt = false;
+
+    /* nothing to draw? */
+    if ((width <= 0) || (height <= 0) || (x >= LCD_WIDTH) || (y >= LCD_HEIGHT)
+        || (x + width <= 0) || (y + height <= 0))
+        return;
+
+    /* clipping */
+    if (x < 0)
+    {
+        width += x;
+        x = 0;
+    }
+    if (y < 0)
+    {
+        height += y;
+        y = 0;
+    }
+    if (x + width > LCD_WIDTH)
+        width = LCD_WIDTH - x;
+    if (y + height > LCD_HEIGHT)
+        height = LCD_HEIGHT - y;
+        
+    if (drawmode & DRMODE_INVERSEVID)
+    {
+        if (drawmode & DRMODE_BG)
+        {
+            fillopt = true;
+        }
+    }
+    else
+    {
+        if (drawmode & DRMODE_FG)
+        {
+            fillopt = true;
+            bits = 0xFFu;
+        }
+    }
+    bfunc = lcd_blockfuncs[drawmode];
+    dst   = &lcd_framebuffer[y>>3][x];
+    ny    = height - 1 + (y & 7);
+    mask  = 0xFFu << (y & 7);
+    mask_bottom = 0xFFu >> (~ny & 7);
+
+    for (; ny >= 8; ny -= 8)
+    {
+        if (fillopt && (mask == 0xFFu))
+            memset(dst, bits, width);
+        else
+        {
+            unsigned char *dst_row = dst;
+
+            dst_end = dst_row + width;
+            do
+                bfunc(dst_row++, mask, 0xFFu);
+            while (dst_row < dst_end);
+        }
+
+        dst += LCD_WIDTH;
+        mask = 0xFFu;
+    }
+    mask &= mask_bottom;
+
+    if (fillopt && (mask == 0xFFu))
+        memset(dst, bits, width);
+    else
+    {
+        dst_end = dst + width;
+        do
+            bfunc(dst++, mask, 0xFFu);
+        while (dst < dst_end);
+    }
+}
+
+/* About Rockbox' internal bitmap format:
+ *
+ * A bitmap contains one bit for every pixel that defines if that pixel is
+ * black (1) or white (0). Bits within a byte are arranged vertically, LSB
+ * at top.
+ * The bytes are stored in row-major order, with byte 0 being top left,
+ * byte 1 2nd from left etc. The first row of bytes defines pixel rows
+ * 0..7, the second row defines pixel row 8..15 etc.
+ *
+ * This is the same as the internal lcd hw format. */
+
+/* Draw a partial bitmap */
+void lcd_bitmap_part(const unsigned char *src, int src_x, int src_y,
+                     int stride, int x, int y, int width, int height)
+                     ICODE_ATTR;
+void lcd_bitmap_part(const unsigned char *src, int src_x, int src_y,
+                     int stride, int x, int y, int width, int height)
+{
+    int shift, ny;
+    unsigned char *dst, *dst_end;
+    unsigned mask, mask_bottom;
+    lcd_blockfunc_type *bfunc;
+
+    /* nothing to draw? */
+    if ((width <= 0) || (height <= 0) || (x >= LCD_WIDTH) || (y >= LCD_HEIGHT)
+        || (x + width <= 0) || (y + height <= 0))
+        return;
+        
+    /* clipping */
+    if (x < 0)
+    {
+        width += x;
+        src_x -= x;
+        x = 0;
+    }
+    if (y < 0)
+    {
+        height += y;
+        src_y -= y;
+        y = 0;
+    }
+    if (x + width > LCD_WIDTH)
+        width = LCD_WIDTH - x;
+    if (y + height > LCD_HEIGHT)
+        height = LCD_HEIGHT - y;
+
+    src    += stride * (src_y >> 3) + src_x; /* move starting point */
+    src_y  &= 7;
+    y      -= src_y;
+    dst    = &lcd_framebuffer[y>>3][x];
+    shift  = y & 7;
+    ny     = height - 1 + shift + src_y;
+
+    bfunc  = lcd_blockfuncs[drawmode];
+    mask   = 0xFFu << (shift + src_y);
+    mask_bottom = 0xFFu >> (~ny & 7);
+    
+    if (shift == 0)
+    {
+        bool copyopt = (drawmode == DRMODE_SOLID);
+
+        for (; ny >= 8; ny -= 8)
+        {
+            if (copyopt && (mask == 0xFFu))
+                memcpy(dst, src, width);
+            else
+            {
+                const unsigned char *src_row = src;
+                unsigned char *dst_row = dst;
+                
+                dst_end = dst_row + width;
+                do 
+                    bfunc(dst_row++, mask, *src_row++);
+                while (dst_row < dst_end);
+            }
+
+            src += stride;
+            dst += LCD_WIDTH;
+            mask = 0xFFu;
+        }
+        mask &= mask_bottom;
+
+        if (copyopt && (mask == 0xFFu))
+            memcpy(dst, src, width);
+        else
+        {
+            dst_end = dst + width;
+            do
+                bfunc(dst++, mask, *src++);
+            while (dst < dst_end);
+        }
+    }
+    else
+    {
+        dst_end = dst + width;
+        do
+        {
+            const unsigned char *src_col = src++;
+            unsigned char *dst_col = dst++;
+            unsigned mask_col = mask;
+            unsigned data = 0;
+            
+            for (y = ny; y >= 8; y -= 8)
+            {
+                data |= *src_col << shift;
+
+                if (mask_col & 0xFFu)
+                {
+                    bfunc(dst_col, mask_col, data);
+                    mask_col = 0xFFu;
+                }
+                else
+                    mask_col >>= 8;
+
+                src_col += stride;
+                dst_col += LCD_WIDTH;
+                data >>= 8;
+            }
+            data |= *src_col << shift;
+            bfunc(dst_col, mask_col & mask_bottom, data);
+        }
+        while (dst < dst_end);
+    }
+}
+
+/* Draw a full bitmap */
+void lcd_bitmap(const unsigned char *src, int x, int y, int width, int height)
+{
+    lcd_bitmap_part(src, 0, 0, width, x, y, width, height);
+}
+
+/* put a string at a given pixel position, skipping first ofs pixel columns */
+static void lcd_putsxyofs(int x, int y, int ofs, const unsigned char *str)
+{
+    unsigned short ch;
+    unsigned short *ucs;
+    struct font* pf = font_get(curfont);
+
+    ucs = bidi_l2v(str, 1);
+
+    while ((ch = *ucs++) != 0 && x < LCD_WIDTH)
+    {
+        int width;
+        const unsigned char *bits;
+
+        /* get proportional width and glyph bits */
+        width = font_get_width(pf,ch);
+
+        if (ofs > width)
+        {
+            ofs -= width;
+            continue;
+        }
+
+        bits = font_get_bits(pf, ch);
+
+        lcd_mono_bitmap_part(bits, ofs, 0, width, x, y, width - ofs,
+                             pf->height);
+        
+        x += width - ofs;
+        ofs = 0;
+    }
+}
+/* put a string at a given pixel position */
+void lcd_putsxy(int x, int y, const unsigned char *str)
+{
+    lcd_putsxyofs(x, y, 0, str);
+}
+
+/*** Line oriented text output ***/
+
+/* put a string at a given char position */
+void lcd_puts(int x, int y, const unsigned char *str)
+{
+    lcd_puts_style_offset(x, y, str, STYLE_DEFAULT, 0);
+}
+
+void lcd_puts_style(int x, int y, const unsigned char *str, int style)
+{
+    lcd_puts_style_offset(x, y, str, style, 0);
+}
+
+void lcd_puts_offset(int x, int y, const unsigned char *str, int offset)
+{
+    lcd_puts_style_offset(x, y, str, STYLE_DEFAULT, offset);
+}
+
+/* put a string at a given char position, style, and pixel position,
+ * skipping first offset pixel columns */
+void lcd_puts_style_offset(int x, int y, const unsigned char *str,
+                           int style, int offset)
+{
+    int xpos,ypos,w,h,xrect;
+    int lastmode = drawmode;
+
+    /* make sure scrolling is turned off on the line we are updating */
+    scrolling_lines &= ~(1 << y);
+
+    if(!str || !str[0])
+        return;
+
+    lcd_getstringsize(str, &w, &h);
+    xpos = xmargin + x*w / utf8length(str);
+    ypos = ymargin + y*h;
+    drawmode = (style & STYLE_INVERT) ?
+               (DRMODE_SOLID|DRMODE_INVERSEVID) : DRMODE_SOLID;
+    lcd_putsxyofs(xpos, ypos, offset, str);
+    drawmode ^= DRMODE_INVERSEVID;
+    xrect = xpos + MAX(w - offset, 0);
+    lcd_fillrect(xrect, ypos, LCD_WIDTH - xrect, h);
+    drawmode = lastmode;
+}
+
+/*** scrolling ***/
+
+/* Reverse the invert setting of the scrolling line (if any) at given char
+   position.  Setting will go into affect next time line scrolls. */
+void lcd_invertscroll(int x, int y)
+{
+    struct scrollinfo* s;
+
+    (void)x;
+
+    s = &scroll[y];
+    s->invert = !s->invert;
+}
+
+void lcd_stop_scroll(void)
+{
+    scrolling_lines=0;
+}
+
+void lcd_scroll_speed(int speed)
+{
+    scroll_ticks = scroll_tick_table[speed];
+}
+
+void lcd_scroll_step(int step)
+{
+    scroll_step = step;
+}
+
+void lcd_scroll_delay(int ms)
+{
+    scroll_delay = ms / (HZ / 10);
+}
+
+void lcd_bidir_scroll(int percent)
+{
+    bidir_limit = percent;
+}
+
+void lcd_puts_scroll(int x, int y, const unsigned char *string)
+{
+    lcd_puts_scroll_style(x, y, string, STYLE_DEFAULT);
+}
+
+void lcd_puts_scroll_style(int x, int y, const unsigned char *string, int style)
+{
+     lcd_puts_scroll_style_offset(x, y, string, style, 0);
+}
+
+void lcd_puts_scroll_offset(int x, int y, const unsigned char *string,
+                            int offset)
+{
+     lcd_puts_scroll_style_offset(x, y, string, STYLE_DEFAULT, offset);
+}          
+   
+void lcd_puts_scroll_style_offset(int x, int y, const unsigned char *string,
+                                  int style, int offset)
+{
+    struct scrollinfo* s;
+    int w, h;
+
+    s = &scroll[y];
+
+    s->start_tick = current_tick + scroll_delay;
+    s->invert = false;
+    if (style & STYLE_INVERT) {
+        s->invert = true;
+        lcd_puts_style_offset(x,y,string,STYLE_INVERT,offset);
+    }
+    else
+        lcd_puts_offset(x,y,string,offset);
+
+    lcd_getstringsize(string, &w, &h);
+
+    if (LCD_WIDTH - x * 8 - xmargin < w) {
+        /* prepare scroll line */
+        char *end;
+
+        memset(s->line, 0, sizeof s->line);
+        strcpy(s->line, string);
+
+        /* get width */
+        s->width = lcd_getstringsize(s->line, &w, &h);
+
+        /* scroll bidirectional or forward only depending on the string
+           width */
+        if ( bidir_limit ) {
+            s->bidir = s->width < (LCD_WIDTH - xmargin) *
+                (100 + bidir_limit) / 100;
+        }
+        else
+            s->bidir = false;
+
+        if (!s->bidir) { /* add spaces if scrolling in the round */
+            strcat(s->line, "   ");
+            /* get new width incl. spaces */
+            s->width = lcd_getstringsize(s->line, &w, &h);
+        }
+
+        end = strchr(s->line, '\0');
+        strncpy(end, string, LCD_WIDTH/2);
+
+        s->len = utf8length(string);
+        s->offset = offset;
+        s->startx = xmargin + x * s->width / s->len;;
+        s->backward = false;
+        scrolling_lines |= (1<<y);
+    }
+    else
+        /* force a bit switch-off since it doesn't scroll */
+        scrolling_lines &= ~(1<<y);
+}
+
+static void scroll_thread(void)
+{
+    struct font* pf;
+    struct scrollinfo* s;
+    int index;
+    int xpos, ypos;
+    int lastmode;
+
+    /* initialize scroll struct array */
+    scrolling_lines = 0;
+
+    while ( 1 ) {
+        for ( index = 0; index < SCROLLABLE_LINES; index++ ) {
+            /* really scroll? */
+            if ( !(scrolling_lines&(1<<index)) )
+                continue;
+
+            s = &scroll[index];
+
+            /* check pause */
+            if (TIME_BEFORE(current_tick, s->start_tick))
+                continue;
+
+            if (s->backward)
+                s->offset -= scroll_step;
+            else
+                s->offset += scroll_step;
+
+            pf = font_get(curfont);
+            xpos = s->startx;
+            ypos = ymargin + index * pf->height;
+
+            if (s->bidir) { /* scroll bidirectional */
+                if (s->offset <= 0) {
+                    /* at beginning of line */
+                    s->offset = 0;
+                    s->backward = false;
+                    s->start_tick = current_tick + scroll_delay * 2;
+                }
+                if (s->offset >= s->width - (LCD_WIDTH - xpos)) {
+                    /* at end of line */
+                    s->offset = s->width - (LCD_WIDTH - xpos);
+                    s->backward = true;
+                    s->start_tick = current_tick + scroll_delay * 2;
+                }
+            }
+            else {
+                /* scroll forward the whole time */
+                if (s->offset >= s->width)
+                    s->offset %= s->width;
+            }
+
+            lastmode = drawmode;
+            drawmode = s->invert ?
+                       (DRMODE_SOLID|DRMODE_INVERSEVID) : DRMODE_SOLID;
+            lcd_putsxyofs(xpos, ypos, s->offset, s->line);
+            drawmode = lastmode;
+            lcd_update_rect(xpos, ypos, LCD_WIDTH - xpos, pf->height);
+        }
+
+        sleep(scroll_ticks);
+    }
+}
+