/* rgr.c (raster graphics) */
/***********************************************************************
* This code is part of GLPK (GNU Linear Programming Kit).
* Copyright (C) 2004-2018 Free Software Foundation, Inc.
* Written by Andrew Makhorin <mao@gnu.org>.
*
* GLPK 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 3 of the License, or
* (at your option) any later version.
*
* GLPK 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 GLPK. If not, see <http://www.gnu.org/licenses/>.
***********************************************************************/
#include "env.h"
#include "rgr.h"
/***********************************************************************
* NAME
*
* rgr_write_bmp16 - write 16-color raster image in BMP file format
*
* SYNOPSIS
*
* #include "rgr.h"
* int rgr_write_bmp16(const char *fname, int m, int n, const char
* map[]);
*
* DESCRIPTION
*
* The routine rgr_write_bmp16 writes 16-color raster image in
* uncompressed BMP file format (Windows bitmap) to a binary file whose
* name is specified by the character string fname.
*
* The parameters m and n specify, respectively, the number of rows and
* the numbers of columns (i.e. height and width) of the raster image.
*
* The character array map has m*n elements. Elements map[0, ..., n-1]
* correspond to the first (top) scanline, elements map[n, ..., 2*n-1]
* correspond to the second scanline, etc.
*
* Each element of the array map specifies a color of the corresponding
* pixel as 8-bit binary number XXXXIRGB, where four high-order bits (X)
* are ignored, I is high intensity bit, R is red color bit, G is green
* color bit, and B is blue color bit. Thus, all 16 possible colors are
* coded as following hexadecimal numbers:
*
* 0x00 = black 0x08 = dark gray
* 0x01 = blue 0x09 = bright blue
* 0x02 = green 0x0A = bright green
* 0x03 = cyan 0x0B = bright cyan
* 0x04 = red 0x0C = bright red
* 0x05 = magenta 0x0D = bright magenta
* 0x06 = brown 0x0E = yellow
* 0x07 = light gray 0x0F = white
*
* RETURNS
*
* If no error occured, the routine returns zero; otherwise, it prints
* an appropriate error message and returns non-zero. */
static void put_byte(FILE *fp, int c)
{ fputc(c, fp);
return;
}
static void put_word(FILE *fp, int w)
{ /* big endian */
put_byte(fp, w);
put_byte(fp, w >> 8);
return;
}
static void put_dword(FILE *fp, int d)
{ /* big endian */
put_word(fp, d);
put_word(fp, d >> 16);
return;
}
int rgr_write_bmp16(const char *fname, int m, int n, const char map[])
{ FILE *fp;
int offset, bmsize, i, j, b, ret = 0;
if (!(1 <= m && m <= 32767))
xerror("rgr_write_bmp16: m = %d; invalid height\n", m);
if (!(1 <= n && n <= 32767))
xerror("rgr_write_bmp16: n = %d; invalid width\n", n);
fp = fopen(fname, "wb");
if (fp == NULL)
{ xprintf("rgr_write_bmp16: unable to create '%s' - %s\n",
#if 0 /* 29/I-2017 */
fname, strerror(errno));
#else
fname, xstrerr(errno));
#endif
ret = 1;
goto fini;
}
offset = 14 + 40 + 16 * 4;
bmsize = (4 * n + 31) / 32;
/* struct BMPFILEHEADER (14 bytes) */
/* UINT bfType */ put_byte(fp, 'B'), put_byte(fp, 'M');
/* DWORD bfSize */ put_dword(fp, offset + bmsize * 4);
/* UINT bfReserved1 */ put_word(fp, 0);
/* UNIT bfReserved2 */ put_word(fp, 0);
/* DWORD bfOffBits */ put_dword(fp, offset);
/* struct BMPINFOHEADER (40 bytes) */
/* DWORD biSize */ put_dword(fp, 40);
/* LONG biWidth */ put_dword(fp, n);
/* LONG biHeight */ put_dword(fp, m);
/* WORD biPlanes */ put_word(fp, 1);
/* WORD biBitCount */ put_word(fp, 4);
/* DWORD biCompression */ put_dword(fp, 0 /* BI_RGB */);
/* DWORD biSizeImage */ put_dword(fp, 0);
/* LONG biXPelsPerMeter */ put_dword(fp, 2953 /* 75 dpi */);
/* LONG biYPelsPerMeter */ put_dword(fp, 2953 /* 75 dpi */);
/* DWORD biClrUsed */ put_dword(fp, 0);
/* DWORD biClrImportant */ put_dword(fp, 0);
/* struct RGBQUAD (16 * 4 = 64 bytes) */
/* CGA-compatible colors: */
/* 0x00 = black */ put_dword(fp, 0x000000);
/* 0x01 = blue */ put_dword(fp, 0x000080);
/* 0x02 = green */ put_dword(fp, 0x008000);
/* 0x03 = cyan */ put_dword(fp, 0x008080);
/* 0x04 = red */ put_dword(fp, 0x800000);
/* 0x05 = magenta */ put_dword(fp, 0x800080);
/* 0x06 = brown */ put_dword(fp, 0x808000);
/* 0x07 = light gray */ put_dword(fp, 0xC0C0C0);
/* 0x08 = dark gray */ put_dword(fp, 0x808080);
/* 0x09 = bright blue */ put_dword(fp, 0x0000FF);
/* 0x0A = bright green */ put_dword(fp, 0x00FF00);
/* 0x0B = bright cyan */ put_dword(fp, 0x00FFFF);
/* 0x0C = bright red */ put_dword(fp, 0xFF0000);
/* 0x0D = bright magenta */ put_dword(fp, 0xFF00FF);
/* 0x0E = yellow */ put_dword(fp, 0xFFFF00);
/* 0x0F = white */ put_dword(fp, 0xFFFFFF);
/* pixel data bits */
b = 0;
for (i = m - 1; i >= 0; i--)
{ for (j = 0; j < ((n + 7) / 8) * 8; j++)
{ b <<= 4;
b |= (j < n ? map[i * n + j] & 15 : 0);
if (j & 1) put_byte(fp, b);
}
}
fflush(fp);
if (ferror(fp))
{ xprintf("rgr_write_bmp16: write error on '%s' - %s\n",
#if 0 /* 29/I-2017 */
fname, strerror(errno));
#else
fname, xstrerr(errno));
#endif
ret = 1;
}
fini: if (fp != NULL) fclose(fp);
return ret;
}
/* eof */