/* Copyright (C) 1994, 1996 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.
*/

/* gdevm16.c */
/* 16-bit-per-pixel "memory" (stored bitmap) device */
#include "memory_.h"
#include "gx.h"
#include "gxdevice.h"
#include "gxdevmem.h"			/* semi-public definitions */
#include "gdevmem.h"			/* private definitions */

#undef chunk
#define chunk byte

/* The 16 bits are divided 5 for red, 6 for green, and 5 for blue. */
/* Note that the bits must always be kept in big-endian order. */

/* Procedures */
declare_mem_map_procs(mem_true16_map_rgb_color, mem_true16_map_color_rgb);
declare_mem_procs(mem_true16_copy_mono, mem_true16_copy_color, mem_true16_fill_rectangle);

/* The device descriptor. */
const gx_device_memory far_data mem_true16_device =
  mem_device("image16", 16, 0,
    mem_true16_map_rgb_color, mem_true16_map_color_rgb,
    mem_true16_copy_mono, mem_true16_copy_color, mem_true16_fill_rectangle,
    gx_no_strip_copy_rop);

/* Map a r-g-b color to a color index. */
private gx_color_index
mem_true16_map_rgb_color(gx_device *dev, gx_color_value r, gx_color_value g,
  gx_color_value b)
{	return ((r >> (gx_color_value_bits - 5)) << 11) +
		((g >> (gx_color_value_bits - 6)) << 5) +
		(b >> (gx_color_value_bits - 5));
}

/* Map a color index to a r-g-b color. */
private int
mem_true16_map_color_rgb(gx_device *dev, gx_color_index color,
  gx_color_value prgb[3])
{	ushort value = color >> 11;
	prgb[0] = ((value << 11) + (value << 6) + (value << 1) + (value >> 4)) >> (16 - gx_color_value_bits);
	value = (color >> 6) & 0x7f;
	prgb[1] = ((value << 10) + (value << 4) + (value >> 2)) >> (16 - gx_color_value_bits);
	value = color & 0x3f;
	prgb[2] = ((value << 11) + (value << 6) + (value << 1) + (value >> 4)) >> (16 - gx_color_value_bits);
	return 0;
}

/* Convert x coordinate to byte offset in scan line. */
#undef x_to_byte
#define x_to_byte(x) ((x) << 1)

/* Fill a rectangle with a color. */
private int
mem_true16_fill_rectangle(gx_device *dev,
  int x, int y, int w, int h, gx_color_index color)
{
#if arch_is_big_endian
#  define color16 ((ushort)color)
#else
	ushort color16 = ((uint)(byte)color << 8) + ((ushort)color >> 8);
#endif
	declare_scan_ptr(dest);
	fit_fill(dev, x, y, w, h);
	setup_rect(dest);
	while ( h-- > 0 )
	   {	ushort *pptr = (ushort *)dest;
		int cnt = w;
		do { *pptr++ = color16; } while ( --cnt > 0 );
		inc_ptr(dest, draster);
	   }
	return 0;
#undef color16
}

/* Copy a monochrome bitmap. */
private int
mem_true16_copy_mono(gx_device *dev,
  const byte *base, int sourcex, int sraster, gx_bitmap_id id,
  int x, int y, int w, int h, gx_color_index zero, gx_color_index one)
{
#if arch_is_big_endian
#  define zero16 ((ushort)zero)
#  define one16 ((ushort)one)
#else
	ushort zero16 = ((uint)(byte)zero << 8) + ((ushort)zero >> 8);
	ushort one16 = ((uint)(byte)one << 8) + ((ushort)one >> 8);
#endif
	const byte *line;
	int first_bit;
	declare_scan_ptr(dest);
	fit_copy(dev, base, sourcex, sraster, id, x, y, w, h);
	setup_rect(dest);
	line = base + (sourcex >> 3);
	first_bit = 0x80 >> (sourcex & 7);
	while ( h-- > 0 )
	   {	register ushort *pptr = (ushort *)dest;
		const byte *sptr = line;
		register int sbyte = *sptr++;
		register int bit = first_bit;
		int count = w;
		do
		   {	if ( sbyte & bit )
			   {	if ( one != gx_no_color_index )
				  *pptr = one16;
			   }
			else
			   {	if ( zero != gx_no_color_index )
				  *pptr = zero16;
			   }
			if ( (bit >>= 1) == 0 )
				bit = 0x80, sbyte = *sptr++;
			pptr++;
		   }
		while ( --count > 0 );
		line += sraster;
		inc_ptr(dest, draster);
	   }
	return 0;
#undef zero16
#undef one16
}

/* Copy a color bitmap. */
private int
mem_true16_copy_color(gx_device *dev,
  const byte *base, int sourcex, int sraster, gx_bitmap_id id,
  int x, int y, int w, int h)
{	fit_copy(dev, base, sourcex, sraster, id, x, y, w, h);
	mem_copy_byte_rect(mdev, base, sourcex, sraster, x, y, w, h);
	return 0;
}
