/extlibs/libmng/libmng_filter.c

https://bitbucket.org/khurley/devil · C · 890 lines · 640 code · 191 blank · 59 comment · 48 complexity · a3c3536036029b406e87f795ca0a5bb7 MD5 · raw file 

    

  1. /* ************************************************************************** */
    2. 

  2. /* *             For conditions of distribution and use,                    * */
    3. 

  3. /* *                see copyright notice in libmng.h                        * */
    4. 

  4. /* ************************************************************************** */
    5. 

  5. /* *                                                                        * */
    6. 

  6. /* * project   : libmng                                                     * */
    7. 

  7. /* * file      : libmng_filter.c           copyright (c) 2000 G.Juyn        * */
    8. 

  8. /* * version   : 1.0.0                                                      * */
    9. 

  9. /* *                                                                        * */
    10. 

  10. /* * purpose   : Filtering routines (implementation)                        * */
    11. 

  11. /* *                                                                        * */
    12. 

  12. /* * author    : G.Juyn                                                     * */
    13. 

  13. /* * web       : http://www.3-t.com                                         * */
    14. 

  14. /* * email     : mailto:info@3-t.com                                        * */
    15. 

  15. /* *                                                                        * */
    16. 

  16. /* * comment   : implementation of the filtering routines                   * */
    17. 

  17. /* *                                                                        * */
    18. 

  18. /* * changes   : 0.5.1 - 05/08/2000 - G.Juyn                                * */
    19. 

  19. /* *             - changed strict-ANSI stuff                                * */
    20. 

  20. /* *             0.5.1 - 05/12/2000 - G.Juyn                                * */
    21. 

  21. /* *             - changed trace to macro for callback error-reporting      * */
    22. 

  22. /* *                                                                        * */
    23. 

  23. /* *             0.9.2 - 08/05/2000 - G.Juyn                                * */
    24. 

  24. /* *             - changed file-prefixes                                    * */
    25. 

  25. /* *                                                                        * */
    26. 

  26. /* *             0.9.3 - 09/07/2000 - G.Juyn                                * */
    27. 

  27. /* *             - added support for new filter_types                       * */
    28. 

  28. /* *                                                                        * */
    29. 

  29. /* ************************************************************************** */
    30. 

  30. 

  31. #include "libmng.h"
    32. 

  32. #include "libmng_data.h"
    33. 

  33. #include "libmng_error.h"
    34. 

  34. #include "libmng_trace.h"
    35. 

  35. #ifdef __BORLANDC__
    36. 

  36. #pragma hdrstop
    37. 

  37. #endif
    38. 

  38. #include "libmng_filter.h"
    39. 

  39. 

  40. #if defined(__BORLANDC__) && defined(MNG_STRICT_ANSI)
    41. 

  41. #pragma option -A                      /* force ANSI-C */
    42. 

  42. #endif
    43. 

  43. 

  44. /* ************************************************************************** */
    45. 

  45. 

  46. #ifdef MNG_INCLUDE_FILTERS
    47. 

  47. 

  48. /* ************************************************************************** */
    49. 

  49. 

  50. mng_retcode filter_a_row (mng_datap pData)
    51. 

  51. {
    52. 

  52.   mng_retcode iRetcode;
    53. 

  53. 

  54. #ifdef MNG_SUPPORT_TRACE
    55. 

  55.   MNG_TRACE (pData, MNG_FN_FILTER_A_ROW, MNG_LC_START)
    56. 

  56. #endif
    57. 

  57. 

  58.   switch (*(pData->pWorkrow + pData->iFilterofs))
    59. 

  59.   {
    60. 

  60.     case 1  : {
    61. 

  61.                 iRetcode = filter_sub     (pData);
    62. 

  62.                 break;
    63. 

  63.               }
    64. 

  64.     case 2  : {
    65. 

  65.                 iRetcode = filter_up      (pData);
    66. 

  66.                 break;
    67. 

  67.               }
    68. 

  68.     case 3  : {
    69. 

  69.                 iRetcode = filter_average (pData);
    70. 

  70.                 break;
    71. 

  71.               }
    72. 

  72.     case 4  : {
    73. 

  73.                 iRetcode = filter_paeth   (pData);
    74. 

  74.                 break;
    75. 

  75.               }
    76. 

  76. 

  77.     default : iRetcode = MNG_INVALIDFILTER;
    78. 

  78.   }
    79. 

  79. 

  80. #ifdef MNG_SUPPORT_TRACE
    81. 

  81.   MNG_TRACE (pData, MNG_FN_FILTER_A_ROW, MNG_LC_END)
    82. 

  82. #endif
    83. 

  83. 

  84.   return iRetcode;
    85. 

  85. }
    86. 

  86. 

  87. /* ************************************************************************** */
    88. 

  88. 

  89. mng_retcode filter_sub (mng_datap pData)
    90. 

  90. {
    91. 

  91.   mng_uint32 iBpp;
    92. 

  92.   mng_uint8p pRawx;
    93. 

  93.   mng_uint8p pRawx_prev;
    94. 

  94.   mng_int32  iX;
    95. 

  95. 

  96. #ifdef MNG_SUPPORT_TRACE
    97. 

  97.   MNG_TRACE (pData, MNG_FN_FILTER_SUB, MNG_LC_START)
    98. 

  98. #endif
    99. 

  99. 

  100.   iBpp       = pData->iFilterbpp;
    101. 

  101.   pRawx      = pData->pWorkrow + pData->iPixelofs + iBpp;
    102. 

  102.   pRawx_prev = pData->pWorkrow + pData->iPixelofs;
    103. 

  103. 

  104.   for (iX = iBpp; iX < pData->iRowsize; iX++)
    105. 

  105.   {
    106. 

  106.     *pRawx = (mng_uint8)(*pRawx + *pRawx_prev);
    107. 

  107.     pRawx++;
    108. 

  108.     pRawx_prev++;
    109. 

  109.   }
    110. 

  110. 

  111. #ifdef MNG_SUPPORT_TRACE
    112. 

  112.   MNG_TRACE (pData, MNG_FN_FILTER_SUB, MNG_LC_END)
    113. 

  113. #endif
    114. 

  114. 

  115.   return MNG_NOERROR;
    116. 

  116. }
    117. 

  117. 

  118. /* ************************************************************************** */
    119. 

  119. 

  120. mng_retcode filter_up (mng_datap pData)
    121. 

  121. {
    122. 

  122.   mng_uint8p pRawx;
    123. 

  123.   mng_uint8p pPriorx;
    124. 

  124.   mng_int32  iX;
    125. 

  125. 

  126. #ifdef MNG_SUPPORT_TRACE
    127. 

  127.   MNG_TRACE (pData, MNG_FN_FILTER_UP, MNG_LC_START)
    128. 

  128. #endif
    129. 

  129. 

  130.   pRawx   = pData->pWorkrow + pData->iPixelofs;
    131. 

  131.   pPriorx = pData->pPrevrow + pData->iPixelofs;
    132. 

  132. 

  133.   for (iX = 0; iX < pData->iRowsize; iX++)
    134. 

  134.   {
    135. 

  135.     *pRawx = (mng_uint8)(*pRawx + *pPriorx);
    136. 

  136.     pRawx++;
    137. 

  137.     pPriorx++;
    138. 

  138.   }
    139. 

  139. 

  140. #ifdef MNG_SUPPORT_TRACE
    141. 

  141.   MNG_TRACE (pData, MNG_FN_FILTER_UP, MNG_LC_END)
    142. 

  142. #endif
    143. 

  143. 

  144.   return MNG_NOERROR;
    145. 

  145. }
    146. 

  146. 

  147. /* ************************************************************************** */
    148. 

  148. 

  149. mng_retcode filter_average (mng_datap pData)
    150. 

  150. {
    151. 

  151.   mng_int32  iBpp;
    152. 

  152.   mng_uint8p pRawx;
    153. 

  153.   mng_uint8p pRawx_prev;
    154. 

  154.   mng_uint8p pPriorx;
    155. 

  155.   mng_int32  iX;
    156. 

  156. 

  157. #ifdef MNG_SUPPORT_TRACE
    158. 

  158.   MNG_TRACE (pData, MNG_FN_FILTER_AVERAGE, MNG_LC_START)
    159. 

  159. #endif
    160. 

  160. 

  161.   iBpp       = pData->iFilterbpp;
    162. 

  162.   pRawx      = pData->pWorkrow + pData->iPixelofs;
    163. 

  163.   pPriorx    = pData->pPrevrow + pData->iPixelofs;
    164. 

  164.   pRawx_prev = pData->pWorkrow + pData->iPixelofs;
    165. 

  165. 

  166.   for (iX = 0; iX < iBpp; iX++)
    167. 

  167.   {
    168. 

  168.     *pRawx = (mng_uint8)(*pRawx + ((*pPriorx) >> 1));
    169. 

  169.     pRawx++;
    170. 

  170.     pPriorx++;
    171. 

  171.   }
    172. 

  172. 

  173.   for (iX = iBpp; iX < pData->iRowsize; iX++)
    174. 

  174.   {
    175. 

  175.     *pRawx = (mng_uint8)(*pRawx + ((*pRawx_prev + *pPriorx) >> 1));
    176. 

  176.     pRawx++;
    177. 

  177.     pPriorx++;
    178. 

  178.     pRawx_prev++;
    179. 

  179.   }
    180. 

  180. 

  181. #ifdef MNG_SUPPORT_TRACE
    182. 

  182.   MNG_TRACE (pData, MNG_FN_FILTER_AVERAGE, MNG_LC_END)
    183. 

  183. #endif
    184. 

  184. 

  185.   return MNG_NOERROR;
    186. 

  186. }
    187. 

  187. 

  188. /* ************************************************************************** */
    189. 

  189. 

  190. mng_retcode filter_paeth (mng_datap pData)
    191. 

  191. {
    192. 

  192.   mng_int32  iBpp;
    193. 

  193.   mng_uint8p pRawx;
    194. 

  194.   mng_uint8p pRawx_prev;
    195. 

  195.   mng_uint8p pPriorx;
    196. 

  196.   mng_uint8p pPriorx_prev;
    197. 

  197.   mng_int32  iX;
    198. 

  198.   mng_uint32 iA, iB, iC;
    199. 

  199.   mng_uint32 iP;
    200. 

  200.   mng_uint32 iPa, iPb, iPc;
    201. 

  201. 

  202. #ifdef MNG_SUPPORT_TRACE
    203. 

  203.   MNG_TRACE (pData, MNG_FN_FILTER_PAETH, MNG_LC_START)
    204. 

  204. #endif
    205. 

  205. 

  206.   iBpp         = pData->iFilterbpp;
    207. 

  207.   pRawx        = pData->pWorkrow + pData->iPixelofs;
    208. 

  208.   pPriorx      = pData->pPrevrow + pData->iPixelofs;
    209. 

  209.   pRawx_prev   = pData->pWorkrow + pData->iPixelofs;
    210. 

  210.   pPriorx_prev = pData->pPrevrow + pData->iPixelofs;
    211. 

  211. 

  212.   for (iX = 0; iX < iBpp; iX++)
    213. 

  213.   {
    214. 

  214.     *pRawx = (mng_uint8)(*pRawx + *pPriorx);
    215. 

  215. 

  216.     pRawx++;
    217. 

  217.     pPriorx++;
    218. 

  218.   }
    219. 

  219. 

  220.   for (iX = iBpp; iX < pData->iRowsize; iX++)
    221. 

  221.   {
    222. 

  222.     iA  = (mng_uint32)*pRawx_prev;
    223. 

  223.     iB  = (mng_uint32)*pPriorx;
    224. 

  224.     iC  = (mng_uint32)*pPriorx_prev;
    225. 

  225.     iP  = iA + iB - iC;
    226. 

  226.     iPa = abs (iP - iA);
    227. 

  227.     iPb = abs (iP - iB);
    228. 

  228.     iPc = abs (iP - iC);
    229. 

  229. 

  230.     if ((iPa <= iPb) && (iPa <= iPc))
    231. 

  231.       *pRawx = (mng_uint8)(*pRawx + iA);
    232. 

  232.     else
    233. 

  233.       if (iPb <= iPc)
    234. 

  234.         *pRawx = (mng_uint8)(*pRawx + iB);
    235. 

  235.       else
    236. 

  236.         *pRawx = (mng_uint8)(*pRawx + iC);
    237. 

  237. 

  238.     pRawx++;
    239. 

  239.     pPriorx++;
    240. 

  240.     pRawx_prev++;
    241. 

  241.     pPriorx_prev++;
    242. 

  242.   }
    243. 

  243. 

  244. #ifdef MNG_SUPPORT_TRACE
    245. 

  245.   MNG_TRACE (pData, MNG_FN_FILTER_PAETH, MNG_LC_END)
    246. 

  246. #endif
    247. 

  247. 

  248.   return MNG_NOERROR;
    249. 

  249. }
    250. 

  250. 

  251. /* ************************************************************************** */
    252. 

  252. /* ************************************************************************** */
    253. 

  253. 

  254. mng_retcode init_rowdiffering (mng_datap pData)
    255. 

  255. {
    256. 

  256.   mng_uint8p pRawi, pRawo;
    257. 

  257.   mng_int32  iX;
    258. 

  258. 

  259. #ifdef MNG_SUPPORT_TRACE
    260. 

  260.   MNG_TRACE (pData, MNG_FN_INIT_ROWDIFFERING, MNG_LC_START)
    261. 

  261. #endif
    262. 

  262. 

  263.   if (pData->iFilter & 0x40)           /* has leveling parameters ? */
    264. 

  264.   {
    265. 

  265.     switch (pData->iColortype)         /* salvage leveling parameters */
    266. 

  266.     {
    267. 

  267.       case 0 : {                       /* gray */
    268. 

  268.                  if (pData->iBitdepth <= 8)
    269. 

  269.                    pData->iLevel0 = (mng_uint16)*pData->pWorkrow;
    270. 

  270.                  else
    271. 

  271.                    pData->iLevel0 = mng_get_uint16 (pData->pWorkrow);
    272. 

  272. 

  273.                  break;
    274. 

  274.                }
    275. 

  275.       case 2 : {                       /* rgb */
    276. 

  276.                  if (pData->iBitdepth <= 8)
    277. 

  277.                  {
    278. 

  278.                    pData->iLevel0 = (mng_uint16)*pData->pWorkrow;
    279. 

  279.                    pData->iLevel1 = (mng_uint16)*(pData->pWorkrow+1);
    280. 

  280.                    pData->iLevel2 = (mng_uint16)*(pData->pWorkrow+2);
    281. 

  281.                  }
    282. 

  282.                  else
    283. 

  283.                  {
    284. 

  284.                    pData->iLevel0 = mng_get_uint16 (pData->pWorkrow);
    285. 

  285.                    pData->iLevel1 = mng_get_uint16 (pData->pWorkrow+2);
    286. 

  286.                    pData->iLevel2 = mng_get_uint16 (pData->pWorkrow+4);
    287. 

  287.                  }
    288. 

  288. 

  289.                  break;
    290. 

  290.                }
    291. 

  291.       case 3 : {                       /* indexed */
    292. 

  292.                  pData->iLevel0 = (mng_uint16)*pData->pWorkrow;
    293. 

  293.                  break;
    294. 

  294.                }
    295. 

  295.       case 4 : {                       /* gray+alpha */
    296. 

  296.                  if (pData->iBitdepth <= 8)
    297. 

  297.                  {
    298. 

  298.                    pData->iLevel0 = (mng_uint16)*pData->pWorkrow;
    299. 

  299.                    pData->iLevel1 = (mng_uint16)*(pData->pWorkrow+1);
    300. 

  300.                  }
    301. 

  301.                  else
    302. 

  302.                  {
    303. 

  303.                    pData->iLevel0 = mng_get_uint16 (pData->pWorkrow);
    304. 

  304.                    pData->iLevel1 = mng_get_uint16 (pData->pWorkrow+2);
    305. 

  305.                  }
    306. 

  306. 

  307.                  break;
    308. 

  308.                }
    309. 

  309.       case 6 : {                       /* rgb+alpha */
    310. 

  310.                  if (pData->iBitdepth <= 8)
    311. 

  311.                  {
    312. 

  312.                    pData->iLevel0 = (mng_uint16)*pData->pWorkrow;
    313. 

  313.                    pData->iLevel1 = (mng_uint16)*(pData->pWorkrow+1);
    314. 

  314.                    pData->iLevel2 = (mng_uint16)*(pData->pWorkrow+2);
    315. 

  315.                    pData->iLevel3 = (mng_uint16)*(pData->pWorkrow+3);
    316. 

  316.                  }
    317. 

  317.                  else
    318. 

  318.                  {
    319. 

  319.                    pData->iLevel0 = mng_get_uint16 (pData->pWorkrow);
    320. 

  320.                    pData->iLevel1 = mng_get_uint16 (pData->pWorkrow+2);
    321. 

  321.                    pData->iLevel2 = mng_get_uint16 (pData->pWorkrow+4);
    322. 

  322.                    pData->iLevel3 = mng_get_uint16 (pData->pWorkrow+6);
    323. 

  323.                  }
    324. 

  324. 

  325.                  break;
    326. 

  326.                }
    327. 

  327.     }
    328. 

  328.   }
    329. 

  329.                                        /* shift the entire row back in place */
    330. 

  330.   pRawi = pData->pWorkrow + pData->iFilterofs;
    331. 

  331.   pRawo = pData->pWorkrow;
    332. 

  332. 

  333.   for (iX = 0; iX < pData->iRowsize + pData->iPixelofs - pData->iFilterofs; iX++)
    334. 

  334.     *pRawo++ = *pRawi++;
    335. 

  335. 

  336.   pData->iFilterofs = 0;               /* indicate so ! */
    337. 

  337. 

  338.   if (pData->iFilter & 0x01)           /* no adaptive filtering ? */
    339. 

  339.     pData->iPixelofs = pData->iFilterofs;
    340. 

  340.   else
    341. 

  341.     pData->iPixelofs = pData->iFilterofs + 1;
    342. 

  342. 

  343. #ifdef MNG_SUPPORT_TRACE
    344. 

  344.   MNG_TRACE (pData, MNG_FN_INIT_ROWDIFFERING, MNG_LC_END)
    345. 

  345. #endif
    346. 

  346. 

  347.   return MNG_NOERROR;
    348. 

  348. }
    349. 

  349. 

  350. /* ************************************************************************** */
    351. 

  351. 

  352. mng_retcode differ_g1 (mng_datap pData)
    353. 

  353. {
    354. 

  354.   mng_uint8p pRawi, pRawo;
    355. 

  355.   mng_int32  iX;
    356. 

  356. 

  357. #ifdef MNG_SUPPORT_TRACE
    358. 

  358.   MNG_TRACE (pData, MNG_FN_DIFFER_G1, MNG_LC_START)
    359. 

  359. #endif
    360. 

  360. 

  361.   if (pData->iLevel0 & 0x01)           /* is it uneven level ? */
    362. 

  362.   {
    363. 

  363.     pRawi = pData->pWorkrow + pData->iPixelofs;
    364. 

  364.     pRawo = pData->pPrevrow + pData->iPixelofs;
    365. 

  365.                                        /* just invert every bit */
    366. 

  366.     for (iX = 0; iX < pData->iRowsize; iX++)
    367. 

  367.       *pRawo++ = (mng_uint8)(~(*pRawi++));
    368. 

  368. 

  369.   }
    370. 

  370. 

  371. #ifdef MNG_SUPPORT_TRACE
    372. 

  372.   MNG_TRACE (pData, MNG_FN_DIFFER_G1, MNG_LC_END)
    373. 

  373. #endif
    374. 

  374. 

  375.   return MNG_NOERROR;
    376. 

  376. }
    377. 

  377. 

  378. /* ************************************************************************** */
    379. 

  379. 

  380. mng_retcode differ_g2 (mng_datap pData)
    381. 

  381. {
    382. 

  382.   mng_uint8p pRawi, pRawo;
    383. 

  383.   mng_int32  iX;
    384. 

  384.   mng_int32  iC, iS;
    385. 

  385.   mng_uint8  iB, iN, iQ;
    386. 

  386. 

  387. #ifdef MNG_SUPPORT_TRACE
    388. 

  388.   MNG_TRACE (pData, MNG_FN_DIFFER_G2, MNG_LC_START)
    389. 

  389. #endif
    390. 

  390. 

  391.   pRawi = pData->pWorkrow + pData->iPixelofs;
    392. 

  392.   pRawo = pData->pPrevrow + pData->iPixelofs;
    393. 

  393.   iC    = 0;
    394. 

  394.   iB    = 0;
    395. 

  395.   iN    = 0;
    396. 

  396.   iS    = 0;
    397. 

  397. 

  398.   for (iX = 0; iX < pData->iRowsamples; iX++)
    399. 

  399.   {
    400. 

  400.     if (!iC)
    401. 

  401.     {
    402. 

  402.       iC = 4;
    403. 

  403.       iB = *pRawi++;
    404. 

  404.       iN = 0;
    405. 

  405.       iS = 8;
    406. 

  406.     }
    407. 

  407. 

  408.     iS -= 2;
    409. 

  409.     iQ = (mng_uint8)(((iB >> iS) + pData->iLevel0) & 0x03);
    410. 

  410.     iN = (mng_uint8)((iN << 2) + iQ);
    411. 

  411.     iC--;
    412. 

  412. 

  413.     if (!iC)
    414. 

  414.       *pRawo++ = iN;
    415. 

  415. 

  416.   }
    417. 

  417. 

  418.   if (iC)
    419. 

  419.     *pRawo = (mng_uint8)(iN << iS);
    420. 

  420. 

  421. #ifdef MNG_SUPPORT_TRACE
    422. 

  422.   MNG_TRACE (pData, MNG_FN_DIFFER_G2, MNG_LC_END)
    423. 

  423. #endif
    424. 

  424. 

  425.   return MNG_NOERROR;
    426. 

  426. }
    427. 

  427. 

  428. /* ************************************************************************** */
    429. 

  429. 

  430. mng_retcode differ_g4 (mng_datap pData)
    431. 

  431. {
    432. 

  432.   mng_uint8p pRawi, pRawo;
    433. 

  433.   mng_int32  iX;
    434. 

  434.   mng_int32  iC, iS;
    435. 

  435.   mng_uint8  iB, iN, iQ;
    436. 

  436. 

  437. #ifdef MNG_SUPPORT_TRACE
    438. 

  438.   MNG_TRACE (pData, MNG_FN_DIFFER_G4, MNG_LC_START)
    439. 

  439. #endif
    440. 

  440. 

  441.   pRawi = pData->pWorkrow + pData->iPixelofs;
    442. 

  442.   pRawo = pData->pPrevrow + pData->iPixelofs;
    443. 

  443.   iC    = 0;
    444. 

  444.   iB    = 0;
    445. 

  445.   iN    = 0;
    446. 

  446.   iS    = 0;
    447. 

  447. 

  448.   for (iX = 0; iX < pData->iRowsamples; iX++)
    449. 

  449.   {
    450. 

  450.     if (!iC)
    451. 

  451.     {
    452. 

  452.       iC = 2;
    453. 

  453.       iB = *pRawi++;
    454. 

  454.       iN = 0;
    455. 

  455.       iS = 8;
    456. 

  456.     }
    457. 

  457. 

  458.     iS -= 4;
    459. 

  459.     iQ = (mng_uint8)(((iB >> iS) + pData->iLevel0) & 0x0F);
    460. 

  460.     iN = (mng_uint8)((iN << 4) + iQ);
    461. 

  461.     iC--;
    462. 

  462. 

  463.     if (!iC)
    464. 

  464.       *pRawo++ = iN;
    465. 

  465. 

  466.   }
    467. 

  467. 

  468.   if (iC)
    469. 

  469.     *pRawo = (mng_uint8)(iN << iS);
    470. 

  470. 

  471. #ifdef MNG_SUPPORT_TRACE
    472. 

  472.   MNG_TRACE (pData, MNG_FN_DIFFER_G4, MNG_LC_END)
    473. 

  473. #endif
    474. 

  474. 

  475.   return MNG_NOERROR;
    476. 

  476. }
    477. 

  477. 

  478. /* ************************************************************************** */
    479. 

  479. 

  480. mng_retcode differ_g8 (mng_datap pData)
    481. 

  481. {
    482. 

  482.   mng_uint8p pRawi, pRawo;
    483. 

  483.   mng_int32  iX;
    484. 

  484. 

  485. #ifdef MNG_SUPPORT_TRACE
    486. 

  486.   MNG_TRACE (pData, MNG_FN_DIFFER_G8, MNG_LC_START)
    487. 

  487. #endif
    488. 

  488. 

  489.   pRawi = pData->pWorkrow + pData->iPixelofs;
    490. 

  490.   pRawo = pData->pPrevrow + pData->iPixelofs;
    491. 

  491. 

  492.   for (iX = 0; iX < pData->iRowsamples; iX++)
    493. 

  493.   {
    494. 

  494.     *pRawo++ = (mng_uint8)(((mng_uint16)*pRawi + pData->iLevel0) & 0xFF);
    495. 

  495. 

  496.     pRawi++;
    497. 

  497.   }
    498. 

  498. 

  499. #ifdef MNG_SUPPORT_TRACE
    500. 

  500.   MNG_TRACE (pData, MNG_FN_DIFFER_G8, MNG_LC_END)
    501. 

  501. #endif
    502. 

  502. 

  503.   return MNG_NOERROR;
    504. 

  504. }
    505. 

  505. 

  506. /* ************************************************************************** */
    507. 

  507. 

  508. mng_retcode differ_g16 (mng_datap pData)
    509. 

  509. {
    510. 

  510.   mng_uint16p pRawi, pRawo;
    511. 

  511.   mng_int32   iX;
    512. 

  512. 

  513. #ifdef MNG_SUPPORT_TRACE
    514. 

  514.   MNG_TRACE (pData, MNG_FN_DIFFER_G16, MNG_LC_START)
    515. 

  515. #endif
    516. 

  516. 

  517.   pRawi = (mng_uint16p)(pData->pWorkrow + pData->iPixelofs);
    518. 

  518.   pRawo = (mng_uint16p)(pData->pPrevrow + pData->iPixelofs);
    519. 

  519. 

  520.   for (iX = 0; iX < pData->iRowsamples; iX++)
    521. 

  521.   {
    522. 

  522.     *pRawo++ = (mng_uint16)(((mng_uint32)*pRawi + (mng_uint32)pData->iLevel0) & 0xFFFF);
    523. 

  523. 

  524.     pRawi++;
    525. 

  525.   }
    526. 

  526. 

  527. #ifdef MNG_SUPPORT_TRACE
    528. 

  528.   MNG_TRACE (pData, MNG_FN_DIFFER_G16, MNG_LC_END)
    529. 

  529. #endif
    530. 

  530. 

  531.   return MNG_NOERROR;
    532. 

  532. }
    533. 

  533. 

  534. /* ************************************************************************** */
    535. 

  535. 

  536. mng_retcode differ_rgb8 (mng_datap pData)
    537. 

  537. {
    538. 

  538.   mng_uint8p pRawi, pRawo;
    539. 

  539.   mng_int32  iX;
    540. 

  540. 

  541. #ifdef MNG_SUPPORT_TRACE
    542. 

  542.   MNG_TRACE (pData, MNG_FN_DIFFER_RGB8, MNG_LC_START)
    543. 

  543. #endif
    544. 

  544. 

  545.   pRawi = pData->pWorkrow + pData->iPixelofs;
    546. 

  546.   pRawo = pData->pPrevrow + pData->iPixelofs;
    547. 

  547. 

  548.   for (iX = 0; iX < pData->iRowsamples; iX++)
    549. 

  549.   {
    550. 

  550.     *(pRawo+1) = (mng_uint8)(((mng_uint16)*(pRawi+1) + pData->iLevel1) & 0xFF);
    551. 

  551.     *pRawo     = (mng_uint8)(((mng_uint16)*pRawi     + pData->iLevel0 +
    552. 

  552.                               (mng_uint16)*(pRawo+1)) & 0xFF);
    553. 

  553.     *(pRawo+2) = (mng_uint8)(((mng_uint16)*(pRawi+2) + pData->iLevel2 +
    554. 

  554.                               (mng_uint16)*(pRawo+1)) & 0xFF);
    555. 

  555. 

  556.     pRawi += 3;
    557. 

  557.     pRawo += 3;
    558. 

  558.   }
    559. 

  559. 

  560. #ifdef MNG_SUPPORT_TRACE
    561. 

  561.   MNG_TRACE (pData, MNG_FN_DIFFER_RGB8, MNG_LC_END)
    562. 

  562. #endif
    563. 

  563. 

  564.   return MNG_NOERROR;
    565. 

  565. }
    566. 

  566. 

  567. /* ************************************************************************** */
    568. 

  568. 

  569. mng_retcode differ_rgb16 (mng_datap pData)
    570. 

  570. {
    571. 

  571.   mng_uint16p pRawi, pRawo;
    572. 

  572.   mng_int32   iX;
    573. 

  573. 

  574. #ifdef MNG_SUPPORT_TRACE
    575. 

  575.   MNG_TRACE (pData, MNG_FN_DIFFER_RGB16, MNG_LC_START)
    576. 

  576. #endif
    577. 

  577. 

  578.   pRawi = (mng_uint16p)(pData->pWorkrow + pData->iPixelofs);
    579. 

  579.   pRawo = (mng_uint16p)(pData->pPrevrow + pData->iPixelofs);
    580. 

  580. 

  581.   for (iX = 0; iX < pData->iRowsamples; iX++)
    582. 

  582.   {
    583. 

  583.     *(pRawo+1) = (mng_uint16)(((mng_uint32)*(pRawi+1) + (mng_uint32)pData->iLevel1) & 0xFFFF);
    584. 

  584.     *pRawo     = (mng_uint16)(((mng_uint32)*pRawi     + (mng_uint32)pData->iLevel0 +
    585. 

  585.                                (mng_uint32)*(pRawo+1)) & 0xFFFF);
    586. 

  586.     *(pRawo+2) = (mng_uint16)(((mng_uint32)*(pRawi+2) + (mng_uint32)pData->iLevel2 +
    587. 

  587.                                (mng_uint32)*(pRawo+1)) & 0xFFFF);
    588. 

  588. 

  589.     pRawi += 3;
    590. 

  590.     pRawo += 3;
    591. 

  591.   }
    592. 

  592. 

  593. #ifdef MNG_SUPPORT_TRACE
    594. 

  594.   MNG_TRACE (pData, MNG_FN_DIFFER_RGB16, MNG_LC_END)
    595. 

  595. #endif
    596. 

  596. 

  597.   return MNG_NOERROR;
    598. 

  598. }
    599. 

  599. 

  600. /* ************************************************************************** */
    601. 

  601. 

  602. mng_retcode differ_idx1 (mng_datap pData)
    603. 

  603. {
    604. 

  604.   mng_uint8p pRawi, pRawo;
    605. 

  605.   mng_int32  iX;
    606. 

  606. 

  607. #ifdef MNG_SUPPORT_TRACE
    608. 

  608.   MNG_TRACE (pData, MNG_FN_DIFFER_IDX1, MNG_LC_START)
    609. 

  609. #endif
    610. 

  610. 

  611.   if (pData->iLevel0 & 0x01)           /* is it uneven level ? */
    612. 

  612.   {
    613. 

  613.     pRawi = pData->pWorkrow + pData->iPixelofs;
    614. 

  614.     pRawo = pData->pPrevrow + pData->iPixelofs;
    615. 

  615.                                        /* just invert every bit */
    616. 

  616.     for (iX = 0; iX < pData->iRowsize; iX++)
    617. 

  617.       *pRawo++ = (mng_uint8)(~(*pRawi++));
    618. 

  618. 

  619.   }
    620. 

  620. 

  621. #ifdef MNG_SUPPORT_TRACE
    622. 

  622.   MNG_TRACE (pData, MNG_FN_DIFFER_IDX1, MNG_LC_END)
    623. 

  623. #endif
    624. 

  624. 

  625.   return MNG_NOERROR;
    626. 

  626. }
    627. 

  627. 

  628. /* ************************************************************************** */
    629. 

  629. 

  630. mng_retcode differ_idx2 (mng_datap pData)
    631. 

  631. {
    632. 

  632.   mng_uint8p pRawi, pRawo;
    633. 

  633.   mng_int32  iX;
    634. 

  634.   mng_int32  iC, iS;
    635. 

  635.   mng_uint8  iB, iN, iQ;
    636. 

  636. 

  637. #ifdef MNG_SUPPORT_TRACE
    638. 

  638.   MNG_TRACE (pData, MNG_FN_DIFFER_IDX2, MNG_LC_START)
    639. 

  639. #endif
    640. 

  640. 

  641.   pRawi = pData->pWorkrow + pData->iPixelofs;
    642. 

  642.   pRawo = pData->pPrevrow + pData->iPixelofs;
    643. 

  643.   iC    = 0;
    644. 

  644.   iB    = 0;
    645. 

  645.   iN    = 0;
    646. 

  646.   iS    = 0;
    647. 

  647. 

  648.   for (iX = 0; iX < pData->iRowsamples; iX++)
    649. 

  649.   {
    650. 

  650.     if (!iC)
    651. 

  651.     {
    652. 

  652.       iC = 4;
    653. 

  653.       iB = *pRawi++;
    654. 

  654.       iN = 0;
    655. 

  655.       iS = 8;
    656. 

  656.     }
    657. 

  657. 

  658.     iS -= 2;
    659. 

  659.     iQ = (mng_uint8)(((iB >> iS) + pData->iLevel0) & 0x03);
    660. 

  660.     iN = (mng_uint8)((iN << 2) + iQ);
    661. 

  661.     iC--;
    662. 

  662. 

  663.     if (!iC)
    664. 

  664.       *pRawo++ = iN;
    665. 

  665. 

  666.   }
    667. 

  667. 

  668.   if (iC)
    669. 

  669.     *pRawo = (mng_uint8)(iN << iS);
    670. 

  670. 

  671. #ifdef MNG_SUPPORT_TRACE
    672. 

  672.   MNG_TRACE (pData, MNG_FN_DIFFER_IDX2, MNG_LC_END)
    673. 

  673. #endif
    674. 

  674. 

  675.   return MNG_NOERROR;
    676. 

  676. }
    677. 

  677. 

  678. /* ************************************************************************** */
    679. 

  679. 

  680. mng_retcode differ_idx4 (mng_datap pData)
    681. 

  681. {
    682. 

  682.   mng_uint8p pRawi, pRawo;
    683. 

  683.   mng_int32  iX;
    684. 

  684.   mng_int32  iC, iS;
    685. 

  685.   mng_uint8  iB, iN, iQ;
    686. 

  686. 

  687. #ifdef MNG_SUPPORT_TRACE
    688. 

  688.   MNG_TRACE (pData, MNG_FN_DIFFER_IDX4, MNG_LC_START)
    689. 

  689. #endif
    690. 

  690. 

  691.   pRawi = pData->pWorkrow + pData->iPixelofs;
    692. 

  692.   pRawo = pData->pPrevrow + pData->iPixelofs;
    693. 

  693.   iC    = 0;
    694. 

  694.   iB    = 0;
    695. 

  695.   iN    = 0;
    696. 

  696.   iS    = 0;
    697. 

  697. 

  698.   for (iX = 0; iX < pData->iRowsamples; iX++)
    699. 

  699.   {
    700. 

  700.     if (!iC)
    701. 

  701.     {
    702. 

  702.       iC = 2;
    703. 

  703.       iB = *pRawi++;
    704. 

  704.       iN = 0;
    705. 

  705.       iS = 8;
    706. 

  706.     }
    707. 

  707. 

  708.     iS -= 4;
    709. 

  709.     iQ = (mng_uint8)(((iB >> iS) + pData->iLevel0) & 0x0F);
    710. 

  710.     iN = (mng_uint8)((iN << 4) + iQ);
    711. 

  711.     iC--;
    712. 

  712. 

  713.     if (!iC)
    714. 

  714.       *pRawo++ = iN;
    715. 

  715. 

  716.   }
    717. 

  717. 

  718.   if (iC)
    719. 

  719.     *pRawo = (mng_uint8)(iN << iS);
    720. 

  720. 

  721. #ifdef MNG_SUPPORT_TRACE
    722. 

  722.   MNG_TRACE (pData, MNG_FN_DIFFER_IDX4, MNG_LC_END)
    723. 

  723. #endif
    724. 

  724. 

  725.   return MNG_NOERROR;
    726. 

  726. }
    727. 

  727. 

  728. /* ************************************************************************** */
    729. 

  729. 

  730. mng_retcode differ_idx8 (mng_datap pData)
    731. 

  731. {
    732. 

  732.   mng_uint8p pRawi, pRawo;
    733. 

  733.   mng_int32  iX;
    734. 

  734. 

  735. #ifdef MNG_SUPPORT_TRACE
    736. 

  736.   MNG_TRACE (pData, MNG_FN_DIFFER_IDX8, MNG_LC_START)
    737. 

  737. #endif
    738. 

  738. 

  739.   pRawi = pData->pWorkrow + pData->iPixelofs;
    740. 

  740.   pRawo = pData->pPrevrow + pData->iPixelofs;
    741. 

  741. 

  742.   for (iX = 0; iX < pData->iRowsamples; iX++)
    743. 

  743.   {
    744. 

  744.     *pRawo++ = (mng_uint8)(((mng_uint16)*pRawi + pData->iLevel0) & 0xFF);
    745. 

  745. 

  746.     pRawi++;
    747. 

  747.   }
    748. 

  748. 

  749. #ifdef MNG_SUPPORT_TRACE
    750. 

  750.   MNG_TRACE (pData, MNG_FN_DIFFER_IDX8, MNG_LC_END)
    751. 

  751. #endif
    752. 

  752. 

  753.   return MNG_NOERROR;
    754. 

  754. }
    755. 

  755. 

  756. /* ************************************************************************** */
    757. 

  757. 

  758. mng_retcode differ_ga8 (mng_datap pData)
    759. 

  759. {
    760. 

  760.   mng_uint8p pRawi, pRawo;
    761. 

  761.   mng_int32  iX;
    762. 

  762. 

  763. #ifdef MNG_SUPPORT_TRACE
    764. 

  764.   MNG_TRACE (pData, MNG_FN_DIFFER_GA8, MNG_LC_START)
    765. 

  765. #endif
    766. 

  766. 

  767.   pRawi = pData->pWorkrow + pData->iPixelofs;
    768. 

  768.   pRawo = pData->pPrevrow + pData->iPixelofs;
    769. 

  769. 

  770.   for (iX = 0; iX < pData->iRowsamples; iX++)
    771. 

  771.   {
    772. 

  772.     *pRawo     = (mng_uint8)(((mng_uint16)*pRawi     + pData->iLevel0) & 0xFF);
    773. 

  773.     *(pRawo+1) = (mng_uint8)(((mng_uint16)*(pRawi+1) + pData->iLevel1) & 0xFF);
    774. 

  774. 

  775.     pRawi += 2;
    776. 

  776.     pRawo += 2;
    777. 

  777.   }
    778. 

  778. 

  779. #ifdef MNG_SUPPORT_TRACE
    780. 

  780.   MNG_TRACE (pData, MNG_FN_DIFFER_GA8, MNG_LC_END)
    781. 

  781. #endif
    782. 

  782. 

  783.   return MNG_NOERROR;
    784. 

  784. }
    785. 

  785. 

  786. /* ************************************************************************** */
    787. 

  787. 

  788. mng_retcode differ_ga16 (mng_datap pData)
    789. 

  789. {
    790. 

  790.   mng_uint16p pRawi, pRawo;
    791. 

  791.   mng_int32   iX;
    792. 

  792. 

  793. #ifdef MNG_SUPPORT_TRACE
    794. 

  794.   MNG_TRACE (pData, MNG_FN_DIFFER_GA16, MNG_LC_START)
    795. 

  795. #endif
    796. 

  796. 

  797.   pRawi = (mng_uint16p)(pData->pWorkrow + pData->iPixelofs);
    798. 

  798.   pRawo = (mng_uint16p)(pData->pPrevrow + pData->iPixelofs);
    799. 

  799. 

  800.   for (iX = 0; iX < pData->iRowsamples; iX++)
    801. 

  801.   {
    802. 

  802.     *pRawo     = (mng_uint16)(((mng_uint32)*pRawi     + (mng_uint32)pData->iLevel0) & 0xFFFF);
    803. 

  803.     *(pRawo+1) = (mng_uint16)(((mng_uint32)*(pRawi+1) + (mng_uint32)pData->iLevel1) & 0xFFFF);
    804. 

  804. 

  805.     pRawi += 2;
    806. 

  806.   }
    807. 

  807. 

  808. #ifdef MNG_SUPPORT_TRACE
    809. 

  809.   MNG_TRACE (pData, MNG_FN_DIFFER_GA16, MNG_LC_END)
    810. 

  810. #endif
    811. 

  811. 

  812.   return MNG_NOERROR;
    813. 

  813. }
    814. 

  814. 

  815. /* ************************************************************************** */
    816. 

  816. 

  817. mng_retcode differ_rgba8 (mng_datap pData)
    818. 

  818. {
    819. 

  819.   mng_uint8p pRawi, pRawo;
    820. 

  820.   mng_int32  iX;
    821. 

  821. 

  822. #ifdef MNG_SUPPORT_TRACE
    823. 

  823.   MNG_TRACE (pData, MNG_FN_DIFFER_RGBA8, MNG_LC_START)
    824. 

  824. #endif
    825. 

  825. 

  826.   pRawi = pData->pWorkrow + pData->iPixelofs;
    827. 

  827.   pRawo = pData->pPrevrow + pData->iPixelofs;
    828. 

  828. 

  829.   for (iX = 0; iX < pData->iRowsamples; iX++)
    830. 

  830.   {
    831. 

  831.     *(pRawo+1) = (mng_uint8)(((mng_uint16)*(pRawi+1) + pData->iLevel1) & 0xFF);
    832. 

  832.     *pRawo     = (mng_uint8)(((mng_uint16)*pRawi     + pData->iLevel0 +
    833. 

  833.                               (mng_uint16)*(pRawo+1)) & 0xFF);
    834. 

  834.     *(pRawo+2) = (mng_uint8)(((mng_uint16)*(pRawi+2) + pData->iLevel2 +
    835. 

  835.                               (mng_uint16)*(pRawo+1)) & 0xFF);
    836. 

  836.     *(pRawo+3) = (mng_uint8)(((mng_uint16)*(pRawi+3) + pData->iLevel3) & 0xFF);
    837. 

  837. 

  838.     pRawi += 4;
    839. 

  839.     pRawo += 4;
    840. 

  840.   }
    841. 

  841. 

  842. #ifdef MNG_SUPPORT_TRACE
    843. 

  843.   MNG_TRACE (pData, MNG_FN_DIFFER_RGBA8, MNG_LC_END)
    844. 

  844. #endif
    845. 

  845. 

  846.   return MNG_NOERROR;
    847. 

  847. }
    848. 

  848. 

  849. /* ************************************************************************** */
    850. 

  850. 

  851. mng_retcode differ_rgba16 (mng_datap pData)
    852. 

  852. {
    853. 

  853.   mng_uint16p pRawi, pRawo;
    854. 

  854.   mng_int32   iX;
    855. 

  855. 

  856. #ifdef MNG_SUPPORT_TRACE
    857. 

  857.   MNG_TRACE (pData, MNG_FN_DIFFER_RGBA16, MNG_LC_START)
    858. 

  858. #endif
    859. 

  859. 

  860.   pRawi = (mng_uint16p)(pData->pWorkrow + pData->iPixelofs);
    861. 

  861.   pRawo = (mng_uint16p)(pData->pPrevrow + pData->iPixelofs);
    862. 

  862. 

  863.   for (iX = 0; iX < pData->iRowsamples; iX++)
    864. 

  864.   {
    865. 

  865.     *(pRawo+1) = (mng_uint16)(((mng_uint32)*(pRawi+1) + (mng_uint32)pData->iLevel1) & 0xFFFF);
    866. 

  866.     *pRawo     = (mng_uint16)(((mng_uint32)*pRawi     + (mng_uint32)pData->iLevel0 +
    867. 

  867.                                (mng_uint32)*(pRawo+1)) & 0xFFFF);
    868. 

  868.     *(pRawo+2) = (mng_uint16)(((mng_uint32)*(pRawi+2) + (mng_uint32)pData->iLevel2 +
    869. 

  869.                                (mng_uint32)*(pRawo+1)) & 0xFFFF);
    870. 

  870.     *(pRawo+3) = (mng_uint16)(((mng_uint32)*(pRawi+3) + (mng_uint32)pData->iLevel3) & 0xFFFF);
    871. 

  871. 

  872.     pRawi += 4;
    873. 

  873.     pRawo += 4;
    874. 

  874.   }
    875. 

  875. 

  876. #ifdef MNG_SUPPORT_TRACE
    877. 

  877.   MNG_TRACE (pData, MNG_FN_DIFFER_RGBA16, MNG_LC_END)
    878. 

  878. #endif
    879. 

  879. 

  880.   return MNG_NOERROR;
    881. 

  881. }
    882. 

  882. 

  883. /* ************************************************************************** */
    884. 

  884. 

  885. #endif /* MNG_INCLUDE_FILTERS */
    886. 

  886. 

  887. /* ************************************************************************** */
    888. 

  888. /* * end of file                                                            * */
    889. 

  889. /* ************************************************************************** */
    890.