/* brushtopbm.c - read a doodle brush file and write a PBM image

**

** Copyright (C) 1988 by Jef Poskanzer.

**

** Permission to use, copy, modify, and distribute this software and its

** documentation for any purpose and without fee is hereby granted, provided

** that the above copyright notice appear in all copies and that both that

** copyright notice and this permission notice appear in supporting

** documentation.  This software is provided "as is" without express or

** implied warranty.

*/

#include "pbm.h"

#define HEADERSIZE 16   /* 16 is just a guess at the header size */

static void

getinit(FILE *         const ifP,

        unsigned int * const colsP,

        unsigned int * const rowsP) {

    unsigned char header[HEADERSIZE];

    size_t bytesRead;

    bytesRead = fread(header, sizeof(header), 1, ifP);

    if (bytesRead !=1)

        pm_error("Error reading header");   

    if (header[0] != 1)

        pm_error("bad magic number 1");

    if (header[1] != 0)

        pm_error("bad magic number 2");

    *colsP =  (header[2] << 8) + header[3];  /* Max 65535 */

    *rowsP =  (header[4] << 8) + header[5];  /* Max 65535 */

}

static void

validateEof(FILE * const ifP) {

    int rc;

    rc = getc(ifP);

    if (rc != EOF)

        pm_message("Extraneous data at end of file");

}

/*

   The routine for converting the raster closely resembles the pbm

   case of pnminvert.  Input is padded up to 16 bit border.

   afu December 2013

 */

int

main(int argc, const char ** argv)  {

    FILE * ifP;

    bit * bitrow;

    unsigned int rows, cols, row;

    pm_proginit(&argc, argv);

    if (argc-1 > 0) {

        ifP = pm_openr(argv[1]);

        if (argc-1 > 1)

            pm_error("Too many arguments (%u).  "

                     "The only argument is the brush file name.", argc-1);

    } else

        ifP = stdin;

    getinit(ifP, &cols, &rows);

    pbm_writepbminit(stdout, cols, rows, 0);

    bitrow = pbm_allocrow_packed(cols + 16);

    for (row = 0; row < rows; ++row) {

        unsigned int const inRowBytes = ((cols + 15) / 16) * 2;

        unsigned int i;

        size_t bytesRead;

        bytesRead = fread (bitrow, 1, inRowBytes, ifP); 

        if (bytesRead != inRowBytes)

            pm_error("Error reading a row of data from brushfile");

        for (i = 0; i < inRowBytes; ++i)

            bitrow[i] = ~bitrow[i];

        /* Clean off remainder of fractional last character */

        pbm_cleanrowend_packed(bitrow, cols);

        pbm_writepbmrow_packed(stdout, bitrow, cols, 0);

    }

    validateEof(ifP);

    pm_close(ifP);

    pm_close(stdout);

    return 0;

}