firmware/drivers/lcd-1bit-vert.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2002 by Alan Korr
  11  *
  12  * All files in this archive are subject to the GNU General Public License.
  13  * See the file COPYING in the source tree root for full license agreement.
  14  *
  15  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  16  * KIND, either express or implied.
  17  *
  18  ****************************************************************************/
  19 #include "config.h"
  20
  21 #include "lcd.h"
  22 #include "kernel.h"
  23 #include "thread.h"
  24 #include <string.h>
  25 #include <stdlib.h>
  26 #include "file.h"
  27 #include "debug.h"
  28 #include "system.h"
  29 #include "font.h"
  30 #include "rbunicode.h"
  31 #include "bidi.h"
  32 #include "scroll_engine.h"
  33
  34 /*** globals ***/
  35
  36 unsigned char lcd_framebuffer[LCD_FBHEIGHT][LCD_FBWIDTH];
  37
  38 static int drawmode = DRMODE_SOLID;
  39 static int xmargin = 0;
  40 static int ymargin = 0;
  41 static int curfont = FONT_SYSFIXED;
  42
  43 /* LCD init */
  44 void lcd_init(void)
  45 {
  46     lcd_clear_display();
  47     /* Call device specific init */
  48     lcd_init_device();
  49     scroll_init();
  50 }
  51
  52 /*** parameter handling ***/
  53
  54 void lcd_set_drawmode(int mode)
  55 {
  56     drawmode = mode & (DRMODE_SOLID|DRMODE_INVERSEVID);
  57 }
  58
  59 int lcd_get_drawmode(void)
  60 {
  61     return drawmode;
  62 }
  63
  64 void lcd_setmargins(int x, int y)
  65 {
  66     xmargin = x;
  67     ymargin = y;
  68 }
  69
  70 int lcd_getxmargin(void)
  71 {
  72     return xmargin;
  73 }
  74
  75 int lcd_getymargin(void)
  76 {
  77     return ymargin;
  78 }
  79
  80 void lcd_setfont(int newfont)
  81 {
  82     curfont = newfont;
  83 }
  84
  85 int lcd_getstringsize(const unsigned char *str, int *w, int *h)
  86 {
  87     return font_getstringsize(str, w, h, curfont);
  88 }
  89
  90 /*** low-level drawing functions ***/
  91
  92 static void setpixel(int x, int y)
  93 {
  94     lcd_framebuffer[y>>3][x] |= 1 << (y & 7);
  95 }
  96
  97 static void clearpixel(int x, int y)
  98 {
  99     lcd_framebuffer[y>>3][x] &= ~(1 << (y & 7));
 100 }
 101
 102 static void flippixel(int x, int y)
 103 {
 104     lcd_framebuffer[y>>3][x] ^= 1 << (y & 7);
 105 }
 106
 107 static void nopixel(int x, int y)
 108 {
 109     (void)x;
 110     (void)y;
 111 }
 112
 113 lcd_pixelfunc_type* const lcd_pixelfuncs[8] = {
 114     flippixel, nopixel, setpixel, setpixel,
 115     nopixel, clearpixel, nopixel, clearpixel
 116 };
 117
 118 static void flipblock(unsigned char *address, unsigned mask, unsigned bits)
 119                       ICODE_ATTR;
 120 static void flipblock(unsigned char *address, unsigned mask, unsigned bits)
 121 {
 122     *address ^= bits & mask;
 123 }
 124
 125 static void bgblock(unsigned char *address, unsigned mask, unsigned bits)
 126                     ICODE_ATTR;
 127 static void bgblock(unsigned char *address, unsigned mask, unsigned bits)
 128 {
 129     *address &= bits | ~mask;
 130 }
 131
 132 static void fgblock(unsigned char *address, unsigned mask, unsigned bits)
 133                     ICODE_ATTR;
 134 static void fgblock(unsigned char *address, unsigned mask, unsigned bits)
 135 {
 136     *address |= bits & mask;
 137 }
 138
 139 static void solidblock(unsigned char *address, unsigned mask, unsigned bits)
 140                        ICODE_ATTR;
 141 static void solidblock(unsigned char *address, unsigned mask, unsigned bits)
 142 {
 143     unsigned data = *(char*)address;
 144
 145     bits    ^= data;
 146     *address = data ^ (bits & mask);
 147 }
 148
 149 static void flipinvblock(unsigned char *address, unsigned mask, unsigned bits)
 150                          ICODE_ATTR;
 151 static void flipinvblock(unsigned char *address, unsigned mask, unsigned bits)
 152 {
 153     *address ^= ~bits & mask;
 154 }
 155
 156 static void bginvblock(unsigned char *address, unsigned mask, unsigned bits)
 157                        ICODE_ATTR;
 158 static void bginvblock(unsigned char *address, unsigned mask, unsigned bits)
 159 {
 160     *address &= ~(bits & mask);
 161 }
 162
 163 static void fginvblock(unsigned char *address, unsigned mask, unsigned bits)
 164                        ICODE_ATTR;
 165 static void fginvblock(unsigned char *address, unsigned mask, unsigned bits)
 166 {
 167     *address |= ~bits & mask;
 168 }
 169
 170 static void solidinvblock(unsigned char *address, unsigned mask, unsigned bits)
 171                           ICODE_ATTR;
 172 static void solidinvblock(unsigned char *address, unsigned mask, unsigned bits)
 173 {
 174     unsigned data = *(char *)address;
 175
 176     bits     = ~bits ^ data;
 177     *address = data ^ (bits & mask);
 178 }
 179
 180 lcd_blockfunc_type* const lcd_blockfuncs[8] = {
 181     flipblock, bgblock, fgblock, solidblock,
 182     flipinvblock, bginvblock, fginvblock, solidinvblock
 183 };
 184
 185 /*** drawing functions ***/
 186
 187 /* Clear the whole display */
 188 void lcd_clear_display(void)
 189 {
 190     unsigned bits = (drawmode & DRMODE_INVERSEVID) ? 0xFFu : 0;
 191
 192     memset(lcd_framebuffer, bits, sizeof lcd_framebuffer);
 193     lcd_scroll_info.lines = 0;
 194 }
 195
 196 /* Set a single pixel */
 197 void lcd_drawpixel(int x, int y)
 198 {
 199     if (((unsigned)x < LCD_WIDTH) && ((unsigned)y < LCD_HEIGHT))
 200         lcd_pixelfuncs[drawmode](x, y);
 201 }
 202
 203 /* Draw a line */
 204 void lcd_drawline(int x1, int y1, int x2, int y2)
 205 {
 206     int numpixels;
 207     int i;
 208     int deltax, deltay;
 209     int d, dinc1, dinc2;
 210     int x, xinc1, xinc2;
 211     int y, yinc1, yinc2;
 212     lcd_pixelfunc_type *pfunc = lcd_pixelfuncs[drawmode];
 213
 214     deltax = abs(x2 - x1);
 215     deltay = abs(y2 - y1);
 216     xinc2 = 1;
 217     yinc2 = 1;
 218
 219     if (deltax >= deltay)
 220     {
 221         numpixels = deltax;
 222         d = 2 * deltay - deltax;
 223         dinc1 = deltay * 2;
 224         dinc2 = (deltay - deltax) * 2;
 225         xinc1 = 1;
 226         yinc1 = 0;
 227     }
 228     else
 229     {
 230         numpixels = deltay;
 231         d = 2 * deltax - deltay;
 232         dinc1 = deltax * 2;
 233         dinc2 = (deltax - deltay) * 2;
 234         xinc1 = 0;
 235         yinc1 = 1;
 236     }
 237     numpixels++; /* include endpoints */
 238
 239     if (x1 > x2)
 240     {
 241         xinc1 = -xinc1;
 242         xinc2 = -xinc2;
 243     }
 244
 245     if (y1 > y2)
 246     {
 247         yinc1 = -yinc1;
 248         yinc2 = -yinc2;
 249     }
 250
 251     x = x1;
 252     y = y1;
 253
 254     for (i = 0; i < numpixels; i++)
 255     {
 256         if (((unsigned)x < LCD_WIDTH) && ((unsigned)y < LCD_HEIGHT))
 257             pfunc(x, y);
 258
 259         if (d < 0)
 260         {
 261             d += dinc1;
 262             x += xinc1;
 263             y += yinc1;
 264         }
 265         else
 266         {
 267             d += dinc2;
 268             x += xinc2;
 269             y += yinc2;
 270         }
 271     }
 272 }
 273
 274 /* Draw a horizontal line (optimised) */
 275 void lcd_hline(int x1, int x2, int y)
 276 {
 277     int x;
 278     unsigned char *dst, *dst_end;
 279     unsigned mask;
 280     lcd_blockfunc_type *bfunc;
 281
 282     /* direction flip */
 283     if (x2 < x1)
 284     {
 285         x = x1;
 286         x1 = x2;
 287         x2 = x;
 288     }
 289
 290     /* nothing to draw? */
 291     if (((unsigned)y >= LCD_HEIGHT) || (x1 >= LCD_WIDTH) || (x2 < 0))
 292         return;
 293
 294     /* clipping */
 295     if (x1 < 0)
 296         x1 = 0;
 297     if (x2 >= LCD_WIDTH)
 298         x2 = LCD_WIDTH-1;
 299
 300     bfunc = lcd_blockfuncs[drawmode];
 301     dst   = &lcd_framebuffer[y>>3][x1];
 302     mask  = 1 << (y & 7);
 303
 304     dst_end = dst + x2 - x1;
 305     do
 306         bfunc(dst++, mask, 0xFFu);
 307     while (dst <= dst_end);
 308 }
 309
 310 /* Draw a vertical line (optimised) */
 311 void lcd_vline(int x, int y1, int y2)
 312 {
 313     int ny;
 314     unsigned char *dst;
 315     unsigned mask, mask_bottom;
 316     lcd_blockfunc_type *bfunc;
 317
 318     /* direction flip */
 319     if (y2 < y1)
 320     {
 321         ny = y1;
 322         y1 = y2;
 323         y2 = ny;
 324     }
 325
 326     /* nothing to draw? */
 327     if (((unsigned)x >= LCD_WIDTH) || (y1 >= LCD_HEIGHT) || (y2 < 0))
 328         return;
 329
 330     /* clipping */
 331     if (y1 < 0)
 332         y1 = 0;
 333     if (y2 >= LCD_HEIGHT)
 334         y2 = LCD_HEIGHT-1;
 335
 336     bfunc = lcd_blockfuncs[drawmode];
 337     dst   = &lcd_framebuffer[y1>>3][x];
 338     ny    = y2 - (y1 & ~7);
 339     mask  = 0xFFu << (y1 & 7);
 340     mask_bottom = 0xFFu >> (~ny & 7);
 341
 342     for (; ny >= 8; ny -= 8)
 343     {
 344         bfunc(dst, mask, 0xFFu);
 345         dst += LCD_WIDTH;
 346         mask = 0xFFu;
 347     }
 348     mask &= mask_bottom;
 349     bfunc(dst, mask, 0xFFu);
 350 }
 351
 352 /* Draw a rectangular box */
 353 void lcd_drawrect(int x, int y, int width, int height)
 354 {
 355     if ((width <= 0) || (height <= 0))
 356         return;
 357
 358     int x2 = x + width - 1;
 359     int y2 = y + height - 1;
 360
 361     lcd_vline(x, y, y2);
 362     lcd_vline(x2, y, y2);
 363     lcd_hline(x, x2, y);
 364     lcd_hline(x, x2, y2);
 365 }
 366
 367 /* Fill a rectangular area */
 368 void lcd_fillrect(int x, int y, int width, int height)
 369 {
 370     int ny;
 371     unsigned char *dst, *dst_end;
 372     unsigned mask, mask_bottom;
 373     unsigned bits = 0;
 374     lcd_blockfunc_type *bfunc;
 375     bool fillopt = false;
 376
 377     /* nothing to draw? */
 378     if ((width <= 0) || (height <= 0) || (x >= LCD_WIDTH) || (y >= LCD_HEIGHT)
 379         || (x + width <= 0) || (y + height <= 0))
 380         return;
 381
 382     /* clipping */
 383     if (x < 0)
 384     {
 385         width += x;
 386         x = 0;
 387     }
 388     if (y < 0)
 389     {
 390         height += y;
 391         y = 0;
 392     }
 393     if (x + width > LCD_WIDTH)
 394         width = LCD_WIDTH - x;
 395     if (y + height > LCD_HEIGHT)
 396         height = LCD_HEIGHT - y;
 397
 398     if (drawmode & DRMODE_INVERSEVID)
 399     {
 400         if (drawmode & DRMODE_BG)
 401         {
 402             fillopt = true;
 403         }
 404     }
 405     else
 406     {
 407         if (drawmode & DRMODE_FG)
 408         {
 409             fillopt = true;
 410             bits = 0xFFu;
 411         }
 412     }
 413     bfunc = lcd_blockfuncs[drawmode];
 414     dst   = &lcd_framebuffer[y>>3][x];
 415     ny    = height - 1 + (y & 7);
 416     mask  = 0xFFu << (y & 7);
 417     mask_bottom = 0xFFu >> (~ny & 7);
 418
 419     for (; ny >= 8; ny -= 8)
 420     {
 421         if (fillopt && (mask == 0xFFu))
 422             memset(dst, bits, width);
 423         else
 424         {
 425             unsigned char *dst_row = dst;
 426
 427             dst_end = dst_row + width;
 428             do
 429                 bfunc(dst_row++, mask, 0xFFu);
 430             while (dst_row < dst_end);
 431         }
 432
 433         dst += LCD_WIDTH;
 434         mask = 0xFFu;
 435     }
 436     mask &= mask_bottom;
 437
 438     if (fillopt && (mask == 0xFFu))
 439         memset(dst, bits, width);
 440     else
 441     {
 442         dst_end = dst + width;
 443         do
 444             bfunc(dst++, mask, 0xFFu);
 445         while (dst < dst_end);
 446     }
 447 }
 448
 449 /* About Rockbox' internal bitmap format:
 450  *
 451  * A bitmap contains one bit for every pixel that defines if that pixel is
 452  * black (1) or white (0). Bits within a byte are arranged vertically, LSB
 453  * at top.
 454  * The bytes are stored in row-major order, with byte 0 being top left,
 455  * byte 1 2nd from left etc. The first row of bytes defines pixel rows
 456  * 0..7, the second row defines pixel row 8..15 etc.
 457  *
 458  * This is the same as the internal lcd hw format. */
 459
 460 /* Draw a partial bitmap */
 461 void lcd_bitmap_part(const unsigned char *src, int src_x, int src_y,
 462                      int stride, int x, int y, int width, int height)
 463                      ICODE_ATTR;
 464 void lcd_bitmap_part(const unsigned char *src, int src_x, int src_y,
 465                      int stride, int x, int y, int width, int height)
 466 {
 467     int shift, ny;
 468     unsigned char *dst, *dst_end;
 469     unsigned mask, mask_bottom;
 470     lcd_blockfunc_type *bfunc;
 471
 472     /* nothing to draw? */
 473     if ((width <= 0) || (height <= 0) || (x >= LCD_WIDTH) || (y >= LCD_HEIGHT)
 474         || (x + width <= 0) || (y + height <= 0))
 475         return;
 476
 477     /* clipping */
 478     if (x < 0)
 479     {
 480         width += x;
 481         src_x -= x;
 482         x = 0;
 483     }
 484     if (y < 0)
 485     {
 486         height += y;
 487         src_y -= y;
 488         y = 0;
 489     }
 490     if (x + width > LCD_WIDTH)
 491         width = LCD_WIDTH - x;
 492     if (y + height > LCD_HEIGHT)
 493         height = LCD_HEIGHT - y;
 494
 495     src    += stride * (src_y >> 3) + src_x; /* move starting point */
 496     src_y  &= 7;
 497     y      -= src_y;
 498     dst    = &lcd_framebuffer[y>>3][x];
 499     shift  = y & 7;
 500     ny     = height - 1 + shift + src_y;
 501
 502     bfunc  = lcd_blockfuncs[drawmode];
 503     mask   = 0xFFu << (shift + src_y);
 504     mask_bottom = 0xFFu >> (~ny & 7);
 505
 506     if (shift == 0)
 507     {
 508         bool copyopt = (drawmode == DRMODE_SOLID);
 509
 510         for (; ny >= 8; ny -= 8)
 511         {
 512             if (copyopt && (mask == 0xFFu))
 513                 memcpy(dst, src, width);
 514             else
 515             {
 516                 const unsigned char *src_row = src;
 517                 unsigned char *dst_row = dst;
 518
 519                 dst_end = dst_row + width;
 520                 do
 521                     bfunc(dst_row++, mask, *src_row++);
 522                 while (dst_row < dst_end);
 523             }
 524
 525             src += stride;
 526             dst += LCD_WIDTH;
 527             mask = 0xFFu;
 528         }
 529         mask &= mask_bottom;
 530
 531         if (copyopt && (mask == 0xFFu))
 532             memcpy(dst, src, width);
 533         else
 534         {
 535             dst_end = dst + width;
 536             do
 537                 bfunc(dst++, mask, *src++);
 538             while (dst < dst_end);
 539         }
 540     }
 541     else
 542     {
 543         dst_end = dst + width;
 544         do
 545         {
 546             const unsigned char *src_col = src++;
 547             unsigned char *dst_col = dst++;
 548             unsigned mask_col = mask;
 549             unsigned data = 0;
 550
 551             for (y = ny; y >= 8; y -= 8)
 552             {
 553                 data |= *src_col << shift;
 554
 555                 if (mask_col & 0xFFu)
 556                 {
 557                     bfunc(dst_col, mask_col, data);
 558                     mask_col = 0xFFu;
 559                 }
 560                 else
 561                     mask_col >>= 8;
 562
 563                 src_col += stride;
 564                 dst_col += LCD_WIDTH;
 565                 data >>= 8;
 566             }
 567             data |= *src_col << shift;
 568             bfunc(dst_col, mask_col & mask_bottom, data);
 569         }
 570         while (dst < dst_end);
 571     }
 572 }
 573
 574 /* Draw a full bitmap */
 575 void lcd_bitmap(const unsigned char *src, int x, int y, int width, int height)
 576 {
 577     lcd_bitmap_part(src, 0, 0, width, x, y, width, height);
 578 }
 579
 580 /* put a string at a given pixel position, skipping first ofs pixel columns */
 581 static void lcd_putsxyofs(int x, int y, int ofs, const unsigned char *str)
 582 {
 583     unsigned short ch;
 584     unsigned short *ucs;
 585     struct font* pf = font_get(curfont);
 586
 587     ucs = bidi_l2v(str, 1);
 588
 589     while ((ch = *ucs++) != 0 && x < LCD_WIDTH)
 590     {
 591         int width;
 592         const unsigned char *bits;
 593
 594         /* get proportional width and glyph bits */
 595         width = font_get_width(pf,ch);
 596
 597         if (ofs > width)
 598         {
 599             ofs -= width;
 600             continue;
 601         }
 602
 603         bits = font_get_bits(pf, ch);
 604
 605         lcd_mono_bitmap_part(bits, ofs, 0, width, x, y, width - ofs,
 606                              pf->height);
 607
 608         x += width - ofs;
 609         ofs = 0;
 610     }
 611 }
 612 /* put a string at a given pixel position */
 613 void lcd_putsxy(int x, int y, const unsigned char *str)
 614 {
 615     lcd_putsxyofs(x, y, 0, str);
 616 }
 617
 618 /*** Line oriented text output ***/
 619
 620 /* put a string at a given char position */
 621 void lcd_puts(int x, int y, const unsigned char *str)
 622 {
 623     lcd_puts_style_offset(x, y, str, STYLE_DEFAULT, 0);
 624 }
 625
 626 void lcd_puts_style(int x, int y, const unsigned char *str, int style)
 627 {
 628     lcd_puts_style_offset(x, y, str, style, 0);
 629 }
 630
 631 void lcd_puts_offset(int x, int y, const unsigned char *str, int offset)
 632 {
 633     lcd_puts_style_offset(x, y, str, STYLE_DEFAULT, offset);
 634 }
 635
 636 /* put a string at a given char position, style, and pixel position,
 637  * skipping first offset pixel columns */
 638 void lcd_puts_style_offset(int x, int y, const unsigned char *str,
 639                            int style, int offset)
 640 {
 641     int xpos,ypos,w,h,xrect;
 642     int lastmode = drawmode;
 643
 644     /* make sure scrolling is turned off on the line we are updating */
 645     lcd_scroll_info.lines &= ~(1 << y);
 646
 647     if(!str || !str[0])
 648         return;
 649
 650     lcd_getstringsize(str, &w, &h);
 651     xpos = xmargin + x*w / utf8length(str);
 652     ypos = ymargin + y*h;
 653     drawmode = (style & STYLE_INVERT) ?
 654                (DRMODE_SOLID|DRMODE_INVERSEVID) : DRMODE_SOLID;
 655     lcd_putsxyofs(xpos, ypos, offset, str);
 656     drawmode ^= DRMODE_INVERSEVID;
 657     xrect = xpos + MAX(w - offset, 0);
 658     lcd_fillrect(xrect, ypos, LCD_WIDTH - xrect, h);
 659     drawmode = lastmode;
 660 }
 661
 662 /*** scrolling ***/
 663 void lcd_puts_scroll(int x, int y, const unsigned char *string)
 664 {
 665     lcd_puts_scroll_style(x, y, string, STYLE_DEFAULT);
 666 }
 667
 668 void lcd_puts_scroll_style(int x, int y, const unsigned char *string, int style)
 669 {
 670      lcd_puts_scroll_style_offset(x, y, string, style, 0);
 671 }
 672
 673 void lcd_puts_scroll_offset(int x, int y, const unsigned char *string,
 674                             int offset)
 675 {
 676      lcd_puts_scroll_style_offset(x, y, string, STYLE_DEFAULT, offset);
 677 }
 678
 679 void lcd_puts_scroll_style_offset(int x, int y, const unsigned char *string,
 680                                   int style, int offset)
 681 {
 682     struct scrollinfo* s;
 683     int w, h;
 684
 685     if(y>=LCD_SCROLLABLE_LINES) return;
 686
 687     s = &lcd_scroll_info.scroll[y];
 688
 689     s->start_tick = current_tick + lcd_scroll_info.delay;
 690     s->style = style;
 691     if (style & STYLE_INVERT) {
 692         lcd_puts_style_offset(x,y,string,STYLE_INVERT,offset);
 693     }
 694     else
 695         lcd_puts_offset(x,y,string,offset);
 696
 697     lcd_getstringsize(string, &w, &h);
 698
 699     if (LCD_WIDTH - x * 8 - xmargin < w) {
 700         /* prepare scroll line */
 701         char *end;
 702
 703         memset(s->line, 0, sizeof s->line);
 704         strcpy(s->line, string);
 705
 706         /* get width */
 707         s->width = lcd_getstringsize(s->line, &w, &h);
 708
 709         /* scroll bidirectional or forward only depending on the string
 710            width */
 711         if ( lcd_scroll_info.bidir_limit ) {
 712             s->bidir = s->width < (LCD_WIDTH - xmargin) *
 713                 (100 + lcd_scroll_info.bidir_limit) / 100;
 714         }
 715         else
 716             s->bidir = false;
 717
 718         if (!s->bidir) { /* add spaces if scrolling in the round */
 719             strcat(s->line, "   ");
 720             /* get new width incl. spaces */
 721             s->width = lcd_getstringsize(s->line, &w, &h);
 722         }
 723
 724         end = strchr(s->line, '\0');
 725         strncpy(end, string, LCD_WIDTH/2);
 726
 727         s->len = utf8length(string);
 728         s->offset = offset;
 729         s->startx = xmargin + x * s->width / s->len;;
 730         s->backward = false;
 731         lcd_scroll_info.lines |= (1<<y);
 732     }
 733     else
 734         /* force a bit switch-off since it doesn't scroll */
 735         lcd_scroll_info.lines &= ~(1<<y);
 736 }
 737
 738 void lcd_scroll_fn(void)
 739 {
 740     struct font* pf;
 741     struct scrollinfo* s;
 742     int index;
 743     int xpos, ypos;
 744     int lastmode;
 745
 746     for ( index = 0; index < LCD_SCROLLABLE_LINES; index++ ) {
 747         /* really scroll? */
 748         if ((lcd_scroll_info.lines & (1 << index)) == 0)
 749             continue;
 750
 751         s = &lcd_scroll_info.scroll[index];
 752
 753         /* check pause */
 754         if (TIME_BEFORE(current_tick, s->start_tick))
 755             continue;
 756
 757         if (s->backward)
 758             s->offset -= lcd_scroll_info.step;
 759         else
 760             s->offset += lcd_scroll_info.step;
 761
 762         pf = font_get(curfont);
 763         xpos = s->startx;
 764         ypos = ymargin + index * pf->height;
 765
 766         if (s->bidir) { /* scroll bidirectional */
 767             if (s->offset <= 0) {
 768                 /* at beginning of line */
 769                 s->offset = 0;
 770                 s->backward = false;
 771                 s->start_tick = current_tick + lcd_scroll_info.delay * 2;
 772             }
 773             if (s->offset >= s->width - (LCD_WIDTH - xpos)) {
 774                 /* at end of line */
 775                 s->offset = s->width - (LCD_WIDTH - xpos);
 776                 s->backward = true;
 777                 s->start_tick = current_tick + lcd_scroll_info.delay * 2;
 778             }
 779         }
 780         else {
 781             /* scroll forward the whole time */
 782             if (s->offset >= s->width)
 783                 s->offset %= s->width;
 784         }
 785
 786         lastmode = drawmode;
 787         drawmode = (s->style&STYLE_INVERT) ?
 788             (DRMODE_SOLID|DRMODE_INVERSEVID) : DRMODE_SOLID;
 789         lcd_putsxyofs(xpos, ypos, s->offset, s->line);
 790         drawmode = lastmode;
 791         lcd_update_rect(xpos, ypos, LCD_WIDTH - xpos, pf->height);
 792     }
 793 }