/* Copyright (C) 1992, 1993 Aladdin Enterprises.  All rights reserved.
  
  This file is part of Aladdin Ghostscript.
  
  Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author
  or distributor accepts any responsibility for the consequences of using it,
  or for whether it serves any particular purpose or works at all, unless he
  or she says so in writing.  Refer to the Aladdin Ghostscript Free Public
  License (the "License") for full details.
  
  Every copy of Aladdin Ghostscript must include a copy of the License,
  normally in a plain ASCII text file named PUBLIC.  The License grants you
  the right to copy, modify and redistribute Aladdin Ghostscript, but only
  under certain conditions described in the License.  Among other things, the
  License requires that the copyright notice and this notice be preserved on
  all copies.
*/

/* gdevbmp.c */
/* .BMP file format output drivers */
#include "gdevprn.h"
#include "gdevpccm.h"

/* ------ The device descriptors ------ */

/*
 * Default X and Y resolution.
 */
#define X_DPI 72
#define Y_DPI 72

private dev_proc_print_page(bmp_print_page);

/* Monochrome. */

gx_device_printer far_data gs_bmpmono_device =
  prn_device(prn_std_procs, "bmpmono",
	DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
	X_DPI, Y_DPI,
	0,0,0,0,			/* margins */
	1, bmp_print_page);

/* 4-bit planar (EGA/VGA-style) color. */

private gx_device_procs bmp16_procs =
  prn_color_procs(gdev_prn_open, gdev_prn_output_page, gdev_prn_close,
    pc_4bit_map_rgb_color, pc_4bit_map_color_rgb);
gx_device_printer far_data gs_bmp16_device =
  prn_device(bmp16_procs, "bmp16",
	DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
	X_DPI, Y_DPI,
	0,0,0,0,			/* margins */
	4, bmp_print_page);

/* 8-bit (SuperVGA-style) color. */
/* (Uses a fixed palette of 3,3,2 bits.) */

private gx_device_procs bmp256_procs =
  prn_color_procs(gdev_prn_open, gdev_prn_output_page, gdev_prn_close,
    pc_8bit_map_rgb_color, pc_8bit_map_color_rgb);
gx_device_printer far_data gs_bmp256_device =
  prn_device(bmp256_procs, "bmp256",
	DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
	X_DPI, Y_DPI,
	0,0,0,0,			/* margins */
	8, bmp_print_page);

/* 24-bit color. */

private dev_proc_map_rgb_color(map_16m_rgb_color);
private dev_proc_map_color_rgb(map_16m_color_rgb);
private gx_device_procs bmp16m_procs =
  prn_color_procs(gdev_prn_open, gdev_prn_output_page, gdev_prn_close,
    map_16m_rgb_color, map_16m_color_rgb);
gx_device_printer far_data gs_bmp16m_device =
  prn_device(bmp16m_procs, "bmp16m",
	DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
	X_DPI, Y_DPI,
	0,0,0,0,			/* margins */
	24, bmp_print_page);

/* ------ Private definitions ------ */

/* All multi-byte quantities are stored LSB-first! */
typedef ushort word;
#if arch_sizeof_int == 4
typedef uint dword;
#else
#  if arch_sizeof_long == 4
typedef ulong dword;
#  endif
#endif
#if arch_is_big_endian
#  define assign_word(a,v) a = ((v) >> 8) + ((v) << 8)
#  define assign_dword(a,v)\
     a = ((v) >> 24) + (((v) >> 8) & 0xff00L) +\
	 (((dword)(v) << 8) & 0xff0000L) + ((dword)(v) << 24)
#else
#  define assign_word(a,v) a = (v)
#  define assign_dword(a,v) a = (v)
#endif

typedef struct bmp_file_header_s {

	/* BITMAPFILEHEADER */

	/*
	 * This structure actually begins with two bytes
	 * containing the characters 'BM', but we must omit them,
	 * because some compilers would insert padding to force
	 * the size member to a 32- or 64-bit boundary.
	 */

	/*byte	typeB, typeM;*/	/* always 'BM' */
	dword	size;		/* total size of file */
	word	reserved1;
	word	reserved2;
	dword	offBits;	/* offset of bits from start of file */
	
} bmp_file_header;
#define sizeof_bmp_file_header (2 + sizeof(bmp_file_header))

typedef struct bmp_info_header_s {

	/* BITMAPINFOHEADER */

	dword	size;		/* size of info header in bytes */
	dword	width;		/* width in pixels */
	dword	height;		/* height in pixels */
	word	planes;		/* # of planes, always 1 */
	word	bitCount;	/* bits per pixel */
	dword	compression;	/* compression scheme, always 0 */
	dword	sizeImage;	/* size of bits */
	dword	xPelsPerMeter;	/* X pixels per meter */
	dword	yPelsPerMeter;	/* Y pixels per meter */
	dword	clrUsed;	/* # of colors used */
	dword	clrImportant;	/* # of important colors */

	/* This is followed by (1 << bitCount) bmp_quad structures, */
	/* unless bitCount == 24. */

} bmp_info_header;

typedef struct bmp_quad_s {

	/* RGBQUAD */

	byte	blue, green, red, reserved;

} bmp_quad;

/* Write out a page in BMP format. */
/* This routine is used for all formats. */
private int
bmp_print_page(gx_device_printer *pdev, FILE *file)
{	int raster = gdev_prn_raster(pdev);
	/* BMP scan lines are padded to 32 bits. */
	ulong bmp_raster = raster + (-raster & 3);
	int height = pdev->height;
	int depth = pdev->color_info.depth;
	int quads = (depth <= 8 ? sizeof(bmp_quad) << depth : 0);
	byte *row = (byte *)gs_malloc(bmp_raster, 1, "bmp file buffer");
	int y;
	int code = 0;			/* return code */

	if ( row == 0 )			/* can't allocate row buffer */
		return_error(gs_error_VMerror);

	/* Write the file header. */

	fputc('B', file);
	fputc('M', file);
	{	bmp_file_header fhdr;
		assign_dword(fhdr.size,
			sizeof_bmp_file_header +
			sizeof(bmp_info_header) + quads +
			bmp_raster * height);
		assign_word(fhdr.reserved1, 0);
		assign_word(fhdr.reserved2, 0);
		assign_dword(fhdr.offBits,
			sizeof_bmp_file_header +
			sizeof(bmp_info_header) + quads);
		if ( fwrite((const char *)&fhdr, 1, sizeof(fhdr), file) != sizeof(fhdr) )
		{	code = gs_error_ioerror;
			goto bmp_done;
		}
	}
	
	/* Write the info header. */

	{	bmp_info_header ihdr;
		assign_dword(ihdr.size, sizeof(ihdr));
		assign_dword(ihdr.width, pdev->width);
		assign_dword(ihdr.height, height);
		assign_word(ihdr.planes, 1);
		assign_word(ihdr.bitCount, depth);
		assign_dword(ihdr.compression, 0);
		assign_dword(ihdr.sizeImage, bmp_raster * height);
		/* Even though we could compute the resolution correctly, */
		/* the convention seems to be to leave it unspecified. */
		assign_dword(ihdr.xPelsPerMeter, 0);
		    /*(dword)(pdev->x_pixels_per_inch * (1000.0 / 30.48)));*/
		assign_dword(ihdr.yPelsPerMeter, 0);
		    /*(dword)(pdev->y_pixels_per_inch * (1000.0 / 30.48)));*/
		assign_dword(ihdr.clrUsed, 0);
		assign_dword(ihdr.clrImportant, 0);
		if ( fwrite((const char *)&ihdr, 1, sizeof(ihdr), file) != sizeof(ihdr) )
		{	code = gs_error_ioerror;
			goto bmp_done;
		}
	}

	/* Write the palette. */

	if ( depth <= 8 )
	{	int i;
		gx_color_value rgb[3];
		bmp_quad q;
		q.reserved = 0;
		for ( i = 0; i != 1 << depth; i++ )
		{	(*dev_proc(pdev, map_color_rgb))((gx_device *)pdev,
				(gx_color_index)i, rgb);
			q.red = gx_color_value_to_byte(rgb[0]);
			q.green = gx_color_value_to_byte(rgb[1]);
			q.blue = gx_color_value_to_byte(rgb[2]);
			fwrite((const char *)&q, sizeof(q), 1, file);
		}
	}

	/* Write the contents of the image. */
	/* BMP files want the image in bottom-to-top order! */

	for ( y = height - 1; y >= 0; y-- )
	{	gdev_prn_copy_scan_lines(pdev, y, row, raster);
		fwrite((const char *)row, bmp_raster, 1, file);
	}

bmp_done:
	gs_free((char *)row, bmp_raster, 1, "bmp file buffer");

	return code;
}

/* 24-bit color mappers (taken from gdevmem2.c). */
/* Note that Windows expects RGB values in the order B,G,R. */

/* Map a r-g-b color to a color index. */
private gx_color_index
map_16m_rgb_color(gx_device *dev, gx_color_value r, gx_color_value g,
  gx_color_value b)
{	return gx_color_value_to_byte(r) +
	       ((uint)gx_color_value_to_byte(g) << 8) +
	       ((ulong)gx_color_value_to_byte(b) << 16);
}

/* Map a color index to a r-g-b color. */
private int
map_16m_color_rgb(gx_device *dev, gx_color_index color,
  gx_color_value prgb[3])
{	prgb[2] = gx_color_value_from_byte(color >> 16);
	prgb[1] = gx_color_value_from_byte((color >> 8) & 0xff);
	prgb[0] = gx_color_value_from_byte(color & 0xff);
	return 0;
}