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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <grass/gis.h>
#include "cairodriver.h"
static unsigned char *put_2(unsigned char *p, unsigned int n)
{
*p++ = n & 0xFF;
n >>= 8;
*p++ = n & 0xFF;
return p;
}
static unsigned char *put_4(unsigned char *p, unsigned int n)
{
*p++ = n & 0xFF;
n >>= 8;
*p++ = n & 0xFF;
n >>= 8;
*p++ = n & 0xFF;
n >>= 8;
*p++ = n & 0xFF;
return p;
}
static void make_bmp_header(unsigned char *p)
{
*p++ = 'B';
*p++ = 'M';
p = put_4(p, HEADER_SIZE + width * height * 4);
p = put_4(p, 0);
p = put_4(p, HEADER_SIZE);
p = put_4(p, 40);
p = put_4(p, width);
p = put_4(p, -height);
p = put_2(p, 1);
p = put_2(p, 32);
p = put_4(p, 0);
p = put_4(p, width * height * 4);
p = put_4(p, 0);
p = put_4(p, 0);
p = put_4(p, 0);
p = put_4(p, 0);
}
void write_bmp(void)
{
char header[HEADER_SIZE];
FILE *output;
output = fopen(file_name, "wb");
if (!output)
G_fatal_error("cairo: couldn't open output file %s", file_name);
memset(header, 0, sizeof(header));
make_bmp_header(header);
fwrite(header, sizeof(header), 1, output);
fwrite(grid, stride, height, output);
fclose(output);
}
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