/* atlc - arbitrary transmission line calculator, for the analysis of transmission lines are directional couplers. Copyright (C) 2002. Dr. David Kirkby, PhD (G8WRB). 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 package_version 2 of the License, or (at your option) any later package_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. Dr. David Kirkby, e-mail drkirkby at ntlworld.com */ #include "config.h" #ifdef HAVE_STRING_H #include #endif #ifdef HAVE_STRINGS_H #include #endif #ifdef HAVE_STDLIB_H #include #endif #include "definitions.h" #include "exit_codes.h" unsigned char *bmp_buff; /* We make the bitmap header public, as we write it back later, when saving bmp files. It saves a lot of hassle, just writing what we read back, rather than correctly calculating all the data in the header correctly */ /* #define DEBUG */ #define BITMAP_HEADER_SIZE 0x36 /* 54 */ void read_bitmap_file_headers(char *filename, int *offset, size_t *size, int *width, int *height) { FILE *fp; struct Bitmap_File_Head_Struct Bitmap_File_Head; struct Bitmap_Head_Struct Bitmap_Head; int ColormapSize, Maps; int length_of_file; /* Appently Photoshop versions < 7.01 don't write this into Bitmap_Head.biSizeIm so it causes a problem. So we will work out the length by seeking to the end of the file and finding the position of the file pointer */ bmp_buff=ustring(0,BITMAP_HEADER_SIZE); if(strcmp(filename,"-")==0) { fp=stdin; } else fp=fopen(filename,"rb"); if(fp==NULL) { fprintf(stderr,"cannot open %s\n", filename); exit_with_msg_and_exit_code("",CANT_OPEN_FILE_FOR_READING); } /* deternine the length of the file, as its not always written into the bitmap. I thought it needed to be, but apparently it does not and photoshop versions < 7.01 don't do it. */ if( fseek(fp, 0, SEEK_END) == -1) { fprintf(stderr," Can't seek to the end of the file in read_bitmap_file_headers.c\n"); exit(FSEEK_FAILURE); } if( (length_of_file=ftell(fp)) == -1) exit_with_msg_and_exit_code("Can't find length of file in read_bitmap_file_headers.c",FTELL_FAILURE); if( (fseek(fp, 0, SEEK_SET) ) == -1) { fprintf(stderr," Can't seek to the beggining of the file in read_bitmap_file_headers.c\n"); exit(FSEEK_FAILURE); } /* Read the .bmp file header into a bmp_buff */ if (!(fread(bmp_buff, 1,BITMAP_HEADER_SIZE,fp))||(strncmp((char *) bmp_buff,"BM",2))) { fprintf(stderr,"%s is not a valid BMP file\n", filename); exit_with_msg_and_exit_code("",NOT_A_VALID_BITMAP_FILE); } /* On most machines, sizeof(short)==2 and sizeof(int)==4. This is so no matter if the machine is 32 or 64 bis. An exception is the Cray Y-MP, which has sizeof(short)=8 sizeof(int)=8 sizeof(long)=8. In this case, it is much more difficult to write the header for the bitmap. But in the aid of portability, this is done. So these is a section of code that will work even if sizeof(short)=8 and sizeof(int)=8. See below for that. */ /* Read the bmp_buff into the two structures we want */ Bitmap_File_Head.zzMagic[0x0] = bmp_buff[0]; Bitmap_File_Head.zzMagic[0x1] = bmp_buff[1]; Bitmap_File_Head.bfSize = bmp_buff[0x2] + ((bmp_buff[3] + ((bmp_buff[4] + (bmp_buff[5] << 8)) << 8)) <<8); Bitmap_File_Head.zzHotX = bmp_buff[0x6] + (bmp_buff[7] << 8); Bitmap_File_Head.zzHotY = bmp_buff[0x8] + (bmp_buff[0x09] << 8); Bitmap_File_Head.bfOffs = bmp_buff[0x0a] + ((bmp_buff[0xb] + ((bmp_buff[0xc] + (bmp_buff[0x0d] << 8)) << 8)) <<8); Bitmap_File_Head.biSize = bmp_buff[0x0E] + ((bmp_buff[0x0f] + ((bmp_buff[0x10] + (bmp_buff[0x11] << 8)) << 8)) <<8); #ifdef DEBUG printf("Bitmap_File_Head.bfSize = %d \n",Bitmap_File_Head.bfSize); printf("Bitmap_File_Head.zzHotX = %d\n",Bitmap_File_Head.zzHotX); printf("Bitmap_File_Head.zzHotY = %d\n",Bitmap_File_Head.zzHotY); printf("Bitmap_File_Head.bfOffs = %d\n",Bitmap_File_Head.bfOffs); printf("Bitmap_File_Head.biSize = %d\n\n",Bitmap_File_Head.biSize); #endif Bitmap_Head.biWidth=bmp_buff[0x12] + ((bmp_buff[0x13] + ((bmp_buff[0x14] + (bmp_buff[0x15] << 8)) << 8)) <<8); Bitmap_Head.biHeight=bmp_buff[0x16] + ((bmp_buff[0x17] + ((bmp_buff[0x18] + (bmp_buff[0x19] << 8)) << 8)) <<8); Bitmap_Head.biPlanes = bmp_buff[0x1A] + (bmp_buff[0x1b] << 8); Bitmap_Head.biBitCnt = bmp_buff[0x1C] + (bmp_buff[0x1d] << 8); Bitmap_Head.biCompr= bmp_buff[0x1E] + ((bmp_buff[0x1f] + ((bmp_buff[0x20] + (bmp_buff[0x21] << 8)) << 8)) <<8); Bitmap_Head.biSizeIm=bmp_buff[0x22] + ((bmp_buff[0x23] + ((bmp_buff[0x24] + (bmp_buff[0x25] << 8)) << 8)) <<8); /* I thought the length of the image was always stored in Bitmap_Head.biSizeIm, but this appears not to be so. Hence it is now calculated from the length of the file */ Bitmap_Head.biSizeIm=length_of_file-BITMAP_HEADER_SIZE; Bitmap_Head.biXPels = bmp_buff[0x26] + ((bmp_buff[0x27] + ((bmp_buff[0x28] + (bmp_buff[0x29] << 8)) << 8)) <<8); Bitmap_Head.biYPels= bmp_buff[0x2A] + ((bmp_buff[0x2b] + ((bmp_buff[0x2c] + (bmp_buff[0x2d] << 8)) << 8)) <<8); Bitmap_Head.biClrUsed = bmp_buff[0x2E] + ((bmp_buff[0x2f] + ((bmp_buff[0x30] + (bmp_buff[0x31] << 8)) << 8)) <<8); Bitmap_Head.biClrImp = bmp_buff[0x32] + ((bmp_buff[0x33] + ((bmp_buff[0x34] + (bmp_buff[0x35] << 8)) << 8)) <<8); Maps=4; if(Bitmap_Head.biBitCnt!=24) { fprintf(stderr,"Sorry, the .bmp bitmap must have 24 bits per colour,\n"); fprintf(stderr,"but it has %d bits. Resave the \n",Bitmap_Head.biBitCnt); fprintf(stderr,"image using 24-bit colour\n"); exit_with_msg_and_exit_code("mage using 24-bit colour",BITMAP_NOT_24_BIT); } #ifdef DEBUG printf("Bitmap_Head.biWidth =%d =0x%x\n",Bitmap_Head.biWidth,Bitmap_Head.biWidth); printf("Bitmap_Head.biHeight =%d =0x%x\n",Bitmap_Head.biHeight,Bitmap_Head.biHeight); printf("Bitmap_Head.biPlanes =%d =0x%x\n",Bitmap_Head.biPlanes,Bitmap_Head.biPlanes); printf("Bitmap_Head.biBitCnt =%d =0x%x\n",Bitmap_Head.biBitCnt,Bitmap_Head.biBitCnt); printf("Bitmap_Head.biCompr =%d =0x%x\n",Bitmap_Head.biCompr,Bitmap_Head.biCompr ); printf("Bitmap_Head.biSizeIm =%d =0x%x\n",Bitmap_Head.biSizeIm,Bitmap_Head.biSizeIm); printf("size by ftell=%d\n", length_of_file); printf("Bitmap_Head.biXPels =%d =0x%x\n",Bitmap_Head.biXPels,Bitmap_Head.biXPels); printf("Bitmap_Head.biYPels =%d =0x%x\n",Bitmap_Head.biYPels,Bitmap_Head.biYPels); printf("Bitmap_Head.biClrUsed =%d =0x%x\n",Bitmap_Head.biClrUsed,Bitmap_Head.biClrUsed); printf("Bitmap_Head.biClrImp =%d =0x%x\n",Bitmap_Head.biClrImp,Bitmap_Head.biClrImp); #endif ColormapSize = (Bitmap_File_Head.bfOffs - Bitmap_File_Head.biSize - 14) / Maps; if ((Bitmap_Head.biClrUsed == 0) && (Bitmap_Head.biBitCnt <= 8)) Bitmap_Head.biClrUsed = ColormapSize; /* Sanity checks */ if (Bitmap_Head.biHeight == 0 || Bitmap_Head.biWidth == 0) { fprintf(stderr,"error reading BMP file header of %s - width or height is zero\n",filename); exit_with_msg_and_exit_code("",WIDTH_OR_HEIGHT_ZERO_IN_BITMAP); } if (Bitmap_Head.biPlanes != 1) { fprintf(stderr,"error reading BMP file header of %s - bitplanes not equal to 1\n",filename); exit_with_msg_and_exit_code("",BITPLANES_NOT_1_IN_BITMAP); } if (ColormapSize > 256 || Bitmap_Head.biClrUsed > 256) { fprintf(stderr,"error reading BMP file header of %s - colourmap size error\n",filename); exit_with_msg_and_exit_code("",COLOURMAP_GREATER_THAN_256); } /* Windows and OS/2 declare filler so that rows are a multiple of word length (32 bits == 4 bytes) */ /*fclose(fp); I'm not sure if this should be closed or not. Why did I ??? */ *width=Bitmap_Head.biWidth; *height=Bitmap_Head.biHeight; *offset=Bitmap_File_Head.bfOffs; *size=Bitmap_Head.biSizeIm; if( *size < 3 * (*width) * (*height) ) { fprintf(stderr,"Internal error in read_bitmap_file_headers.c\n"); exit(1); } }