/*** $Id: lbm.c,v 1.7 2003/09/04 06:02:53 weiym Exp $** ** pcx.c: Low-level LBM/PBM bitmap file read/save routines.** ** Copyright (C) 2003 Feynman Software.** Copyright (C) 2000 ~ 2002 Wei Yongming.**** Some code comes from lbm.c of Allegro by Shawn Hargreaves.** ** Current maintainer:  Wei Yongming.*//*** This program 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 of the License, or** (at your option) any later version.**** This program 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA*//*         ______   ___    ___**        /\  _  \ /\_ \  /\_ \**        \ \ \L\ \\//\ \ \//\ \      __     __   _ __   ___**         \ \  __ \ \ \ \  \ \ \   /'__`\ /'_ `\/\`'__\/ __`\**          \ \ \/\ \ \_\ \_ \_\ \_/\  __//\ \L\ \ \ \//\ \L\ \**           \ \_\ \_\/\____\/\____\ \____\ \____ \ \_\\ \____/**            \/_/\/_/\/____/\/____/\/____/\/___L\ \/_/ \/___/**                                           /\____/**                                           \_/__/*/#include <stdio.h>#include <stdlib.h>#include <string.h>#include "common.h"#include "gdi.h"#include "readbmp.h"#if 1 /* def _LBM_FILE_SUPPORT */static void bmpSetBitsInLine (int bpp, BYTE* bits, int pos, BYTE* value){    int offset, shift;    switch (bpp) {    case 1:        offset = pos / 8;        shift = 8 - (pos % 8);        bits [offset] |= (*value & 0x01) << shift;        break;    case 4:        offset = pos / 2;        shift = 4 - ((pos % 2) << 2);        bits [offset] |= (*value & 0x0F) << shift;        break;    case 8:        offset = pos;        bits [offset] |= *value;        break;    case 15:    case 16:        offset = pos * 2;        bits [offset] |= value [0];        bits [offset + 1] |= value [1];        break;    case 24:        offset = pos * 3;        bits [offset] |= value [0];        bits [offset + 1] |= value [1];        bits [offset + 2] |= value [2];        break;    case 32:        offset = pos * 4;        bits [offset] |= value [0];        bits [offset + 1] |= value [1];        bits [offset + 2] |= value [2];        bits [offset + 3] |= value [3];        break;    }}/* load_lbm: *  Loads IFF ILBM/PBM files with up to 8 bits per pixel, returning *  in a bitmap structure and storing the palette data in the specified *  palette (this should be an array of at least 256 RGB structures). */int load_lbm (MG_RWops* f, MYBITMAP* bmp, RGB *pal){   #define IFF_FORM     0x4D524F46     /* 'FORM' - IFF FORM structure  */   #define IFF_ILBM     0x4D424C49     /* 'ILBM' - interleaved bitmap  */   #define IFF_PBM      0x204D4250     /* 'PBM ' - new DP2e format     */   #define IFF_BMHD     0x44484D42     /* 'BMHD' - bitmap header       */   #define IFF_CMAP     0x50414D43     /* 'CMAP' - color map (palette) */   #define IFF_BODY     0x59444F42     /* 'BODY' - bitmap data         */   BYTE* bits;   int w, h, i, x, y, bpl, ppl, pbm_mode;   char ch, cmp_type, bit_plane, color_depth;   unsigned char uc, check_flags, bit_mask, *line_buf;   long id, len, l;   unsigned long size;   id = fp_igetl(f);              /* read file header    */   if (id != IFF_FORM) {            /* check for 'FORM' id */      return ERR_BMP_IMAGE_TYPE;   }   fp_igetl(f);                   /* skip FORM length    */   id = fp_igetl(f);              /* read id             */   /* check image type ('ILBM' or 'PBM ') */   if ((id != IFF_ILBM) && (id != IFF_PBM)) {      return ERR_BMP_IMAGE_TYPE;   }   pbm_mode = id == IFF_PBM;   id = fp_igetl(f);              /* read id               */   if (id != IFF_BMHD) {            /* check for header      */      return ERR_BMP_IMAGE_TYPE;   }   len = fp_mgetl(f);             /* read header length    */   if (len != 20) {                 /* check, if it is right */      return ERR_BMP_IMAGE_TYPE;   }   w = fp_mgetw(f);               /* read screen width  */   h = fp_mgetw(f);               /* read screen height */   fp_igetw(f);                   /* skip initial x position  */   fp_igetw(f);                   /* skip initial y position  */   color_depth = fp_getc(f);      /* get image depth   */   if (color_depth > 8) {      return ERR_BMP_NOT_SUPPORTED;   }   fp_getc(f);                    /* skip masking type */   cmp_type = fp_getc(f);         /* get compression type */   if ((cmp_type != 0) && (cmp_type != 1)) {      return ERR_BMP_NOT_SUPPORTED;   }   fp_getc(f);                    /* skip unused field        */   fp_igetw(f);                   /* skip transparent color   */   fp_getc(f);                    /* skip x aspect ratio      */   fp_getc(f);                    /* skip y aspect ratio      */   fp_igetw(f);                   /* skip default page width  */   fp_igetw(f);                   /* skip default page height */   check_flags = 0;   do {  /* We'll use cycle to skip possible junk      */         /*  chunks: ANNO, CAMG, GRAB, DEST, TEXT etc. */      id = fp_igetl(f);      switch(id) {         case IFF_CMAP:            memset(pal, 0, 256 * 3);            len = fp_mgetl(f) / 3;            for (i=0; i<len; i++) {               pal[i].r = fp_getc(f);               pal[i].g = fp_getc(f);               pal[i].b = fp_getc(f);            }            check_flags |= 1;       /* flag "palette read" */            break;         case IFF_BODY:            fp_igetl(f);          /* skip BODY size */            if (pbm_mode)               bpl = w;            else {               bpl = w >> 3;        /* calc bytes per line  */               if (w & 7)           /* for finish bits      */                  bpl++;            }            if (bpl & 1)            /* alignment            */               bpl++;            size = bpl * w * h;            if (!(bits = malloc (size))) {                return ERR_BMP_MEM;            }            memset (bits, 0, size);            bmp->bits = bits;            bmp->pitch = bpl;            bmp->size  = size;            line_buf = malloc (bpl);            if (!line_buf) {                return ERR_BMP_MEM;            }            if (pbm_mode) {               for (y = 0; y < h; y++) {                  if (cmp_type) {                     i = 0;                     while (i < bpl) {                        uc = fp_getc(f);                        if (uc < 128) {                           uc++;                           MGUI_RWread (f, &line_buf[i], 1, uc);                           i += uc;                        }                        else if (uc > 128) {                           uc = 257 - uc;                           ch = fp_getc(f);                           memset (&line_buf[i], ch, uc);                           i += uc;                        }                        /* 128 (0x80) means NOP - no operation  */                     }                  }                  else  /* pure theoretical situation */                     MGUI_RWread (f, line_buf, 1, bpl);                                    for (i = 0; i < bpl; i++)                    bmpSetBitsInLine (color_depth, bits, i, line_buf + i);                  bits += bpl;               }            }            else {               for (y = 0; y < h; y++) {                  for (bit_plane = 0; bit_plane < color_depth; bit_plane++) {                     if (cmp_type) {                        i = 0;                        while (i < bpl) {                           uc = fp_getc(f);                           if (uc < 128) {                              uc++;                              MGUI_RWread (f, &line_buf[i], 1, uc);                              i += uc;                           }                           else if (uc > 128) {                              uc = 257 - uc;                              ch = fp_getc(f);                              memset (&line_buf[i], ch, uc);                              i += uc;                           }                           /* 128 (0x80) means NOP - no operation  */                        }                     }                     else                        MGUI_RWread (f, line_buf, 1, bpl);                     bit_mask = 1 << bit_plane;                     ppl = bpl;     /* for all pixel blocks */                     if (w & 7)     /*  may be, except the  */                        ppl--;      /*  the last            */                     for (x = 0; x < ppl; x++) {                        if (line_buf[x] & 128)                           bmpSetBitsInLine (color_depth, bits, x * 8, &bit_mask);                        if (line_buf[x] & 64)                           bmpSetBitsInLine (color_depth, bits, x * 8 + 1, &bit_mask);                        if (line_buf[x] & 32)                           bmpSetBitsInLine (color_depth, bits, x * 8 + 2, &bit_mask);                        if (line_buf[x] & 16)                           bmpSetBitsInLine (color_depth, bits, x * 8 + 3, &bit_mask);                        if (line_buf[x] & 8)                           bmpSetBitsInLine (color_depth, bits, x * 8 + 4, &bit_mask);                        if (line_buf[x] & 4)                           bmpSetBitsInLine (color_depth, bits, x * 8 + 5, &bit_mask);                        if (line_buf[x] & 2)                           bmpSetBitsInLine (color_depth, bits, x * 8 + 6, &bit_mask);                        if (line_buf[x] & 1)                           bmpSetBitsInLine (color_depth, bits, x * 8 + 7, &bit_mask);                     }                     /* last pixel block */                     if (w & 7) {                        x = bpl - 1;                        /* no necessary to check if (w & 7) > 0 in */                        /* first condition, because (w & 7) != 0   */                        if (line_buf[x] & 128)                           bmpSetBitsInLine (color_depth, bits, x * 8, &bit_mask);                        if ((line_buf[x] & 64) && ((w & 7) > 1))                           bmpSetBitsInLine (color_depth, bits, x * 8 + 1, &bit_mask);                        if ((line_buf[x] & 32) && ((w & 7) > 2))                           bmpSetBitsInLine (color_depth, bits, x * 8 + 2, &bit_mask);                        if ((line_buf[x] & 16) && ((w & 7) > 3))                           bmpSetBitsInLine (color_depth, bits, x * 8 + 3, &bit_mask);                        if ((line_buf[x] & 8)  && ((w & 7) > 4))                           bmpSetBitsInLine (color_depth, bits, x * 8 + 4, &bit_mask);                        if ((line_buf[x] & 4)  && ((w & 7) > 5))                           bmpSetBitsInLine (color_depth, bits, x * 8 + 5, &bit_mask);                        if ((line_buf[x] & 2)  && ((w & 7) > 6))                           bmpSetBitsInLine (color_depth, bits, x * 8 + 6, &bit_mask);                        if ((line_buf[x] & 1)  && ((w & 7) > 7))                           bmpSetBitsInLine (color_depth, bits, x * 8 + 7, &bit_mask);                     }                  }                  bits += bpl;               }            }            free (line_buf);            check_flags |= 2;       /* flag "bitmap read" */            break;         default:                   /* skip useless chunks  */            len = fp_mgetl (f);            if (len & 1)               len++;            for (l=0; l < (len >> 1); l++)               fp_igetw (f);      }      /* Exit from loop if we are at the end of file, */      /* or if we loaded both bitmap and palette      */   } while ((check_flags != 3) && (!MGUI_RWeof (f)));   if (check_flags != 3) {      if (check_flags & 2)         return ERR_BMP_LOAD;   }       bmp->flags = MYBMP_FLOW_DOWN;    bmp->depth = color_depth;    bmp->w     = w;    bmp->h     = h;    bmp->frames = 1;   return ERR_BMP_OK;}BOOL check_lbm (MG_RWops* fp){   long id, len;   id = fp_igetl(fp);              /* read file header    */   if (id != IFF_FORM) {           /* check for 'FORM' id */      return FALSE;   }   fp_igetl(fp);                   /* skip FORM length    */   id = fp_igetl(fp);              /* read id             */   /* check image type ('ILBM' or 'PBM ') */   if ((id != IFF_ILBM) && (id != IFF_PBM)) {      return FALSE;   }   id = fp_igetl(fp);              /* read id               */   if (id != IFF_BMHD) {            /* check for header      */      return FALSE;   }   len = fp_mgetl(fp);             /* read header length    */   if (len != 20) {                 /* check, if it is right */      return FALSE;   }    return TRUE;}#endif /* _LBM_FILE_SUPPORT */