/* Copyright (C) 1994, 1995 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU Ghostscript is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility to
  anyone for the consequences of using it or for whether it serves any
  particular purpose or works at all, unless he says so in writing.  Refer
  to the GNU Ghostscript General Public License for full details.
  
*/

/* gdevm24.c */
/* 24-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

/* Procedures */
declare_mem_procs(mem_true24_copy_mono, mem_true24_copy_color, mem_true24_fill_rectangle);

/* The device descriptor. */
const gx_device_memory far_data mem_true24_color_device =
  mem_device("image(24)", 24, 0,
    gx_default_rgb_map_rgb_color, gx_default_rgb_map_color_rgb,
    mem_true24_copy_mono, mem_true24_copy_color, mem_true24_fill_rectangle);

/* Convert x coordinate to byte offset in scan line. */
#undef x_to_byte
#define x_to_byte(x) ((x) * 3)

/* Unpack a color into its bytes. */
#define declare_unpack_color(r, g, b, color)\
	byte r = (byte)(color >> 16);\
	byte g = (byte)((uint)color >> 8);\
	byte b = (byte)color
#if arch_is_big_endian
#  define declare_pack_color(cword, rgb, r, g, b)\
	bits32 cword = (bits32)(rgb) << 8
#else
#  define declare_pack_color(cword, rgb, r, g, b)\
	bits32 cword =\
	  ((bits32)(b) << 16) | ((bits16)(g) << 8) | (r)
#endif
/* Put a 24-bit color into the bitmap. */
#define put3(ptr, r, g, b)\
	(ptr)[0] = r, (ptr)[1] = g, (ptr)[2] = b
/* Put 4 bytes of color into the bitmap. */
#define putw(ptr, wxyz)\
	*(bits32 *)(ptr) = (wxyz)
/* Load the 3-word 24-bit-color cache. */
/* Free variables: [m]dev, rgbr, gbrg, brgb. */
#if arch_is_big_endian
#  define set_color24_cache(crgb, r, g, b)\
	mdev->color24.rgbr = rgbr = ((bits32)(crgb) << 8) | (r),\
	mdev->color24.gbrg = gbrg = (rgbr << 8) | (g),\
	mdev->color24.brgb = brgb = (gbrg << 8) | (b),\
	mdev->color24.rgb = (crgb)
#else
#  define set_color24_cache(crgb, r, g, b)\
	mdev->color24.rgbr = rgbr =\
		((bits32)(r) << 24) | ((bits32)(b) << 16) |\
		((bits16)(g) << 8) | (r),\
	mdev->color24.brgb = brgb = (rgbr << 8) | (b),\
	mdev->color24.gbrg = gbrg = (brgb << 8) | (g),\
	mdev->color24.rgb = (crgb)
#endif

/* Fill a rectangle with a color. */
private int
mem_true24_fill_rectangle(gx_device *dev,
  int x, int y, int w, int h, gx_color_index color)
{	declare_unpack_color(r, g, b, color);
	declare_scan_ptr(dest);
	fit_fill(dev, x, y, w, h);
	setup_rect(dest);
	if ( w >= 5 )
	  { if ( r == g && r == b)
	      {
#if 1
		/* We think we can do better than the library's memset.... */
		int bcntm7 = w * 3 - 7;
		register bits32 cword = color | (color << 24);
		while ( h-- > 0 )
		{	register byte *pptr = dest;
			byte *limit = pptr + bcntm7;
			/* We want to store full words, but we have to */
			/* guarantee that they are word-aligned. */
			switch ( x & 3 )
			  {
			  case 3: *pptr++ = (byte)cword;
			  case 2: *pptr++ = (byte)cword;
			  case 1: *pptr++ = (byte)cword;
			  case 0: ;
			  }
			/* Even with w = 5, we always store at least */
			/* 3 full words, regardless of the starting x. */
			*(bits32 *)pptr =
			  ((bits32 *)pptr)[1] =
			  ((bits32 *)pptr)[2] = cword;
			pptr += 12;
			while ( pptr < limit )
			  { *(bits32 *)pptr =
			      ((bits32 *)pptr)[1] = cword;
			    pptr += 8;
			  }
			switch ( pptr - limit )
			  {
			  case 0: pptr[6] = (byte)cword;
			  case 1: pptr[5] = (byte)cword;
			  case 2: pptr[4] = (byte)cword;
			  case 3: *(bits32 *)pptr = cword;
			    break;
			  case 4: pptr[2] = (byte)cword;
			  case 5: pptr[1] = (byte)cword;
			  case 6: pptr[0] = (byte)cword;
			  case 7: ;
			  }
			inc_ptr(dest, draster);
		}
#else
		int bcnt = w * 3;
		while ( h-- > 0 )
		{	memset(dest, r, bcnt);
			inc_ptr(dest, draster);
		}
#endif
	      }
	    else
	      {	int x3 = -x & 3, ww = w - x3;
		bits32 rgbr, gbrg, brgb;
		if ( mdev->color24.rgb == color )
		  rgbr = mdev->color24.rgbr,
		  gbrg = mdev->color24.gbrg,
		  brgb = mdev->color24.brgb;
		else
		  set_color24_cache(color, r, g, b);
		while ( h-- > 0 )
		  {	register byte *pptr = dest;
			int w1 = ww;
			switch ( x3 )
			  {
			  case 1:
				put3(pptr, r, g, b);
				pptr += 3; break;
			  case 2:
				pptr[0] = r; pptr[1] = g;
				putw(pptr + 2, brgb);
				pptr += 6; break;
			  case 3:
				pptr[0] = r;
				putw(pptr + 1, gbrg);
				putw(pptr + 5, brgb);
				pptr += 9; break;
			  case 0:
				;
			  }
			while ( w1 >= 4 )
			  {	putw(pptr, rgbr);
				putw(pptr + 4, gbrg);
				putw(pptr + 8, brgb);
				pptr += 12;
				w1 -= 4;
			  }
			switch ( w1 )
			  {
			  case 1:
				put3(pptr, r, g, b);
				break;
			  case 2:
				putw(pptr, rgbr);
				pptr[4] = g; pptr[5] = b;
				break;
			  case 3:
				putw(pptr, rgbr);
				putw(pptr + 4, gbrg);
				pptr[8] = b;
				break;
			  case 0:
				;
			  }
			inc_ptr(dest, draster);
		  }
	      }
	  }
	else			/* w < 5 */
	  switch ( w )
	    {
		/* Note that fit_fill guarantees w > 0, h > 0. */
	    case 4:
		do
		  { dest[9] = dest[6] = dest[3] = dest[0] = r;
		    dest[10] = dest[7] = dest[4] = dest[1] = g;
		    dest[11] = dest[8] = dest[5] = dest[2] = b;
		    inc_ptr(dest, draster);
		  }
		while ( --h );
		break;
	    case 3:
		do
		  { dest[6] = dest[3] = dest[0] = r;
		    dest[7] = dest[4] = dest[1] = g;
		    dest[8] = dest[5] = dest[2] = b;
		    inc_ptr(dest, draster);
		  }
		while ( --h );
		break;
	    case 2:
		do
		  { dest[3] = dest[0] = r;
		    dest[4] = dest[1] = g;
		    dest[5] = dest[2] = b;
		    inc_ptr(dest, draster);
		  }
		while ( --h );
		break;
	    case 1:
		do
		  { dest[0] = r, dest[1] = g, dest[2] = b;
		    inc_ptr(dest, draster);
		  }
		while ( --h );
		break;
	    case 0:
	      ;
	    }
	return 0;
}

/* Copy a monochrome bitmap. */
private int
mem_true24_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)
{	const byte *line;
	int sbit;
	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);
	sbit = sourcex & 7;
	first_bit = 0x80 >> sbit;
	if ( zero != gx_no_color_index )
	  {	/* Loop for halftones or inverted masks */
		/* (never used). */
		declare_unpack_color(r0, g0, b0, zero);
		declare_unpack_color(r1, g1, b1, one);
		while ( h-- > 0 )
		   {	register byte *pptr = 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 )
				      put3(pptr, r1, g1, b1);
				  }
				else
				  put3(pptr, r0, g0, b0);
				pptr += 3;
				if ( (bit >>= 1) == 0 )
				  bit = 0x80, sbyte = *sptr++;
			  }
			while ( --count > 0 );
			line += sraster;
			inc_ptr(dest, draster);
		   }
	  }
	else if ( one != gx_no_color_index )
	  {	/* Loop for character and pattern masks. */
		/* This is used heavily. */
		declare_unpack_color(r1, g1, b1, one);
		int first_mask = first_bit << 1;
		int first_count, first_skip;
		if ( sbit + w > 8 )
		  first_mask -= 1,
		  first_count = 8 - sbit;
		else
		  first_mask -= first_mask >> w,
		  first_count = w;
		first_skip = first_count * 3;
		while ( h-- > 0 )
		   {	register byte *pptr = dest;
			const byte *sptr = line;
			register int sbyte = *sptr++ & first_mask;
			int count = w - first_count;
			if ( sbyte )
			  {	register int bit = first_bit;
				do
				  {	if ( sbyte & bit )
					  put3(pptr, r1, g1, b1);
					pptr += 3;
				  }
				while ( (bit >>= 1) & first_mask );
			  }
			else
			  pptr += first_skip;
			while ( count >= 8 )
			  {	sbyte = *sptr++;
				if ( sbyte & 0xf0 )
				  { if ( sbyte & 0x80 )
				      put3(pptr, r1, g1, b1);
				    if ( sbyte & 0x40 )
				      put3(pptr + 3, r1, g1, b1);
				    if ( sbyte & 0x20 )
				      put3(pptr + 6, r1, g1, b1);
				    if ( sbyte & 0x10 )
				      put3(pptr + 9, r1, g1, b1);
				  }
				if ( sbyte & 0xf )
				  { if ( sbyte & 8 )
				      put3(pptr + 12, r1, g1, b1);
				    if ( sbyte & 4 )
				      put3(pptr + 15, r1, g1, b1);
				    if ( sbyte & 2 )
				      put3(pptr + 18, r1, g1, b1);
				    if ( sbyte & 1 )
				      put3(pptr + 21, r1, g1, b1);
				  }
				pptr += 24;
				count -= 8;
			  }
			if ( count > 0 )
			  {	register int bit = 0x80;
				sbyte = *sptr++;
				do
				  {	if ( sbyte & bit )
					  put3(pptr, r1, g1, b1);
					pptr += 3;
					bit >>= 1;
				  }
				while ( --count > 0 );
			  }
			line += sraster;
			inc_ptr(dest, draster);
		   }
	  }
	return 0;
}

/* Copy a color bitmap. */
private int
mem_true24_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;
}