The R Project SVN R

  free(scanline);

/* 

 * Try to save the content of the device 'd' in 'filename' as Windows BMP.

 * If numbers of colors is less than 256 we use a 'palette' BMP.

 * Return 1 on success, 0 on failure 

*/

#define BMPERROR {R_ShowMessage("Problems writing to 'bmp' file");return 0;} 

#define BMPW(a) {wrd=a;if(fwrite(&wrd,sizeof(unsigned short),1,fp)!=1) BMPERROR}

#define BMPDW(a) {dwrd=a;if(fwrite(&dwrd,sizeof(unsigned long),1,fp)!=1) BMPERROR}

#define BMPLONG(a) {lng=a;if(fwrite(&lng,sizeof(long),1,fp)!=1) BMPERROR}

#define BMPPUTC(a) if(fputc(a,fp)==EOF) BMPERROR;

#define HEADERSIZE 54

int R_SaveAsBmp(void  *d, int width, int height, 

		unsigned long (*gp)(void *, int, int), int bgr, FILE *fp) 

{

  unsigned long  col, palette[256];

  int i, j, r, ncols, mid, high, low, withpalette;

  int bfOffBits, bfSize, biBitCount, biClrUsed , pad;

  unsigned short wrd;

  unsigned long dwrd;

  long lng;

  DECLARESHIFTS;

  /* Have we less than 256 different colors? */

  ncols = mid = 0;

  withpalette = 1;

  for (i=0; i<256 ; i++) palette[i] = 0;

  for (i = 0; (i < height) && withpalette ; i++) {

    for (j = 0; (j < width) && withpalette ; j++) {

      col = gp(d,i,j) & 0xFFFFFFUL ;

      /* binary search the palette: */

      low = 0;  

      high = ncols - 1;

      while (low <= high) {

	mid = (low + high)/2;

	if ( col < palette[mid] ) high = mid - 1;

	else if ( col > palette[mid] ) low  = mid + 1;

	else break;

      }

      if (high < low) {

	/* didn't find colour in palette, insert it: */

	if (ncols >= 256) {

	  withpalette = 0;

	} else {

	  for (r = ncols; r > low; r--)

	    palette[r] = palette[r-1] ;

	  palette[low] = col;

	  ncols ++;

	}

      }

    }

  }

  /* Compute some part of the header */

  if (withpalette) {

    bfOffBits = HEADERSIZE + 4 * 256;

    bfSize = bfOffBits + width * height ;

    biBitCount = 8;

    biClrUsed = 256;

  } else {

    bfOffBits = HEADERSIZE ;

    bfSize = bfOffBits + 3 * width * height ;

    biBitCount = 24;

    biClrUsed = 0;

  }

  /* write the header */

  BMPW(0x4D42); /* bfType must be "BM" */

  BMPDW(bfSize); /*bfSize*/ 

  BMPW(0);BMPW(0); /* bfReserved1 and bfReserved2 must be 0*/

  BMPDW(bfOffBits); /* bfOffBits */

  BMPDW(40);	/* biSize */

  BMPLONG(width); /* biWidth */

  BMPLONG(height); /* biHeight */

  BMPW(1);	/* biPlanes - must be 1 */

  BMPW(biBitCount); /* biBitCount */

  BMPDW(0); /* biCompression=BI_RGB */

  BMPDW(0); /* biSizeImage (with BI_RGB not needed)*/

  BMPLONG(0); /* XPels/M <- used only by Windows?*/

  BMPLONG(0); /* XPels/M */

  BMPDW(biClrUsed); /* biClrUsed */

  BMPDW(0) ; /* biClrImportant All colours are important */

  /* and now the pixels */

  if (withpalette) {

    /* 8 bit image; write the palette */

    for ( i=0; i<256; i++) {

      col = palette[i];

      BMPPUTC(GETBLUE(col));

      BMPPUTC(GETGREEN(col));

      BMPPUTC(GETRED(col));

      BMPPUTC(0);

    }

    /* Rows must be padded to 4-byte boundary */

    for ( pad=0 ; ((width+pad) & 3) != 0; pad++);

    /* and then the pixels */

    for (i=height-1 ; i>=0 ; i--) { 

      for ( j=0 ; j<width ; j++) {

	col = gp(d, i, j)&0xFFFFFFUL;

	/* binary search the palette (the colour must be there): */

	low = 0;  high = ncols - 1;

	while (low <= high) {

	  mid = (low + high)/2;

	  if      (col < palette[mid]) high = mid - 1;

	  else if (col > palette[mid]) low  = mid + 1;

	  else break;

	}

	BMPPUTC(mid);

      }

      for (j=0; j<pad; j++) BMPPUTC(0);

    }

  } else {

    /* 24 bits image */

    BMPDW(0); /* null bmiColors */

    for ( pad=0 ; ((3*width+pad) & 3) != 0; pad++); /*padding*/    

    for (i=height-1 ; i>=0 ; i--) { 

      for ( j=0 ; j<width ; j++) {

	col = gp(d, i, j);

	BMPPUTC(GETBLUE(col));

	BMPPUTC(GETGREEN(col));

	BMPPUTC(GETRED(col));

      }

      for (j=0; j<pad; j++) BMPPUTC(0);

    }

  }

  return 1;

}