/* Copyright (C) 1995, 1996, 1997, 1998, 1999 Aladdin Enterprises.  All rights reserved.
  
  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License version 2
  as published by the Free Software Foundation.


  This software is provided AS-IS with no warranty, either express or
  implied. That is, this program is distributed in the hope that it will 
  be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  59 Temple Place, Suite 330, Boston, MA, 02111-1307.
  
  For more information about licensing, please refer to
  http://www.ghostscript.com/licensing/. For information on
  commercial licensing, go to http://www.artifex.com/licensing/ or
  contact Artifex Software, Inc., 101 Lucas Valley Road #110,
  San Rafael, CA  94903, U.S.A., +1(415)492-9861.
*/

/* $Id: gdevmr8n.c,v 1.4 2002/02/21 22:24:51 giles Exp $ */
/* RasterOp implementation for 8N-bit memory devices */
#include "memory_.h"
#include "gx.h"
#include "gsbittab.h"
#include "gserrors.h"
#include "gsropt.h"
#include "gxcindex.h"
#include "gxdcolor.h"
#include "gxdevice.h"
#include "gxdevmem.h"
#include "gxdevrop.h"
#include "gdevmem.h"
#include "gdevmrop.h"

/*
 * NOTE: The 16- and 32-bit cases aren't implemented: they just fall back to
 * the default implementation.  This is very slow and will be fixed someday.
 */

#define chunk byte

/* Calculate the X offset for a given Y value, */
/* taking shift into account if necessary. */
#define x_offset(px, ty, textures)\
  ((textures)->shift == 0 ? (px) :\
   (px) + (ty) / (textures)->rep_height * (textures)->rep_shift)

/* ---------------- RasterOp with 8-bit gray / 24-bit RGB ---------------- */

int
mem_gray8_rgb24_strip_copy_rop(gx_device * dev,
	     const byte * sdata, int sourcex, uint sraster, gx_bitmap_id id,
			       const gx_color_index * scolors,
	   const gx_strip_bitmap * textures, const gx_color_index * tcolors,
			       int x, int y, int width, int height,
		       int phase_x, int phase_y, gs_logical_operation_t lop)
{
    gx_device_memory *mdev = (gx_device_memory *) dev;
    gs_rop3_t rop = lop_rop(lop);
    gx_color_index const_source = gx_no_color_index;
    gx_color_index const_texture = gx_no_color_index;
    uint draster = mdev->raster;
    int line_count;
    byte *drow;
    int depth = dev->color_info.depth;
    int bpp = depth >> 3;	/* bytes per pixel, 1 or 3 */
    gx_color_index all_ones = ((gx_color_index) 1 << depth) - 1;
    gx_color_index strans =
	(lop & lop_S_transparent ? all_ones : gx_no_color_index);
    gx_color_index ttrans =
	(lop & lop_T_transparent ? all_ones : gx_no_color_index);

    /* Check for constant source. */
    if (!rop3_uses_S(rop))
	const_source = 0;	/* arbitrary */
    else if (scolors != 0 && scolors[0] == scolors[1]) {
	/* Constant source */
	const_source = scolors[0];
	if (const_source == gx_device_black(dev))
	    rop = rop3_know_S_0(rop);
	else if (const_source == gx_device_white(dev))
	    rop = rop3_know_S_1(rop);
    }

    /* Check for constant texture. */
    if (!rop3_uses_T(rop))
	const_texture = 0;	/* arbitrary */
    else if (tcolors != 0 && tcolors[0] == tcolors[1]) {
	/* Constant texture */
	const_texture = tcolors[0];
	if (const_texture == gx_device_black(dev))
	    rop = rop3_know_T_0(rop);
	else if (const_texture == gx_device_white(dev))
	    rop = rop3_know_T_1(rop);
    }

    if (bpp == 1 &&
	(gx_device_has_color(dev) ||
	 (gx_device_black(dev) != 0 || gx_device_white(dev) != all_ones))
	) {
	/*
	 * This is an 8-bit device but not gray-scale.  Except in a few
	 * simple cases, we have to use the slow algorithm that converts
	 * values to and from RGB.
	 */
	gx_color_index bw_pixel;

	switch (rop) {
	case rop3_0:
	    bw_pixel = gx_device_black(dev);
	    goto bw;
	case rop3_1:
	    bw_pixel = gx_device_white(dev);
bw:	    if (bw_pixel == 0x00)
		rop = rop3_0;
	    else if (bw_pixel == 0xff)
		rop = rop3_1;
	    else
		goto df;
	    break;
	case rop3_D:
	    break;
	case rop3_S:
	    if (lop & lop_S_transparent)
		goto df;
	    break;
	case rop3_T:
	    if (lop & lop_T_transparent)
		goto df;
	    break;
	default:
df:	    return mem_default_strip_copy_rop(dev,
					      sdata, sourcex, sraster, id,
					      scolors, textures, tcolors,
					      x, y, width, height,
					      phase_x, phase_y, lop);
	}
    }

    /* Adjust coordinates to be in bounds. */
    if (const_source == gx_no_color_index) {
	fit_copy(dev, sdata, sourcex, sraster, id,
		 x, y, width, height);
    } else {
	fit_fill(dev, x, y, width, height);
    }

    /* Set up transfer parameters. */
    line_count = height;
    drow = scan_line_base(mdev, y) + x * bpp;

    /*
     * There are 18 cases depending on whether each of the source and
     * texture is constant, 1-bit, or multi-bit, and on whether the
     * depth is 8 or 24 bits.  We divide first according to constant
     * vs. non-constant, and then according to 1- vs. multi-bit, and
     * finally according to pixel depth.  This minimizes source code,
     * but not necessarily time, since we do some of the divisions
     * within 1 or 2 levels of loop.
     */

#define dbit(base, i) ((base)[(i) >> 3] & (0x80 >> ((i) & 7)))
/* 8-bit */
#define cbit8(base, i, colors)\
  (dbit(base, i) ? (byte)colors[1] : (byte)colors[0])
#define rop_body_8(s_pixel, t_pixel)\
  if ( (s_pixel) == strans ||	/* So = 0, s_tr = 1 */\
       (t_pixel) == ttrans	/* Po = 0, p_tr = 1 */\
     )\
    continue;\
  *dptr = (*rop_proc_table[rop])(*dptr, s_pixel, t_pixel)
/* 24-bit */
#define get24(ptr)\
  (((gx_color_index)(ptr)[0] << 16) | ((gx_color_index)(ptr)[1] << 8) | (ptr)[2])
#define put24(ptr, pixel)\
  (ptr)[0] = (byte)((pixel) >> 16),\
  (ptr)[1] = (byte)((uint)(pixel) >> 8),\
  (ptr)[2] = (byte)(pixel)
#define cbit24(base, i, colors)\
  (dbit(base, i) ? colors[1] : colors[0])
#define rop_body_24(s_pixel, t_pixel)\
  if ( (s_pixel) == strans ||	/* So = 0, s_tr = 1 */\
       (t_pixel) == ttrans	/* Po = 0, p_tr = 1 */\
     )\
    continue;\
  { gx_color_index d_pixel = get24(dptr);\
    d_pixel = (*rop_proc_table[rop])(d_pixel, s_pixel, t_pixel);\
    put24(dptr, d_pixel);\
  }

    if (const_texture != gx_no_color_index) {
/**** Constant texture ****/
	if (const_source != gx_no_color_index) {
/**** Constant source & texture ****/
	    for (; line_count-- > 0; drow += draster) {
		byte *dptr = drow;
		int left = width;

		if (bpp == 1)
/**** 8-bit destination ****/
		    for (; left > 0; ++dptr, --left) {
			rop_body_8((byte)const_source, (byte)const_texture);
		    }
		else
/**** 24-bit destination ****/
		    for (; left > 0; dptr += 3, --left) {
			rop_body_24(const_source, const_texture);
		    }
	    }
	} else {
/**** Data source, const texture ****/
	    const byte *srow = sdata;

	    for (; line_count-- > 0; drow += draster, srow += sraster) {
		byte *dptr = drow;
		int left = width;

		if (scolors) {
/**** 1-bit source ****/
		    int sx = sourcex;

		    if (bpp == 1)
/**** 8-bit destination ****/
			for (; left > 0; ++dptr, ++sx, --left) {
			    byte s_pixel = cbit8(srow, sx, scolors);

			    rop_body_8(s_pixel, (byte)const_texture);
			}
		    else
/**** 24-bit destination ****/
			for (; left > 0; dptr += 3, ++sx, --left) {
			    bits32 s_pixel = cbit24(srow, sx, scolors);

			    rop_body_24(s_pixel, const_texture);
			}
		} else if (bpp == 1) {
/**** 8-bit source & dest ****/
		    const byte *sptr = srow + sourcex;

		    for (; left > 0; ++dptr, ++sptr, --left) {
			byte s_pixel = *sptr;

			rop_body_8(s_pixel, (byte)const_texture);
		    }
		} else {
/**** 24-bit source & dest ****/
		    const byte *sptr = srow + sourcex * 3;

		    for (; left > 0; dptr += 3, sptr += 3, --left) {
			bits32 s_pixel = get24(sptr);

			rop_body_24(s_pixel, const_texture);
		    }
		}
	    }
	}
    } else if (const_source != gx_no_color_index) {
/**** Const source, data texture ****/
	uint traster = textures->raster;
	int ty = y + phase_y;

	for (; line_count-- > 0; drow += draster, ++ty) {	/* Loop over copies of the tile. */
	    int dx = x, w = width, nw;
	    byte *dptr = drow;
	    const byte *trow =
	    textures->data + (ty % textures->size.y) * traster;
	    int xoff = x_offset(phase_x, ty, textures);

	    for (; w > 0; dx += nw, w -= nw) {
		int tx = (dx + xoff) % textures->rep_width;
		int left = nw = min(w, textures->size.x - tx);
		const byte *tptr = trow;

		if (tcolors) {
/**** 1-bit texture ****/
		    if (bpp == 1)
/**** 8-bit dest ****/
			for (; left > 0; ++dptr, ++tx, --left) {
			    byte t_pixel = cbit8(tptr, tx, tcolors);

			    rop_body_8((byte)const_source, t_pixel);
			}
		    else
/**** 24-bit dest ****/
			for (; left > 0; dptr += 3, ++tx, --left) {
			    bits32 t_pixel = cbit24(tptr, tx, tcolors);

			    rop_body_24(const_source, t_pixel);
			}
		} else if (bpp == 1) {
/**** 8-bit T & D ****/
		    tptr += tx;
		    for (; left > 0; ++dptr, ++tptr, --left) {
			byte t_pixel = *tptr;

			rop_body_8((byte)const_source, t_pixel);
		    }
		} else {
/**** 24-bit T & D ****/
		    tptr += tx * 3;
		    for (; left > 0; dptr += 3, tptr += 3, --left) {
			bits32 t_pixel = get24(tptr);

			rop_body_24(const_source, t_pixel);
		    }
		}
	    }
	}
    } else {
/**** Data source & texture ****/
	uint traster = textures->raster;
	int ty = y + phase_y;
	const byte *srow = sdata;

	/* Loop over scan lines. */
	for (; line_count-- > 0; drow += draster, srow += sraster, ++ty) {	/* Loop over copies of the tile. */
	    int sx = sourcex;
	    int dx = x;
	    int w = width;
	    int nw;
	    byte *dptr = drow;
	    const byte *trow =
	    textures->data + (ty % textures->size.y) * traster;
	    int xoff = x_offset(phase_x, ty, textures);

	    for (; w > 0; dx += nw, w -= nw) {	/* Loop over individual pixels. */
		int tx = (dx + xoff) % textures->rep_width;
		int left = nw = min(w, textures->size.x - tx);
		const byte *tptr = trow;

		/*
		 * For maximum speed, we should split this loop
		 * into 7 cases depending on source & texture
		 * depth: (1,1), (1,8), (1,24), (8,1), (8,8),
		 * (24,1), (24,24).  But since we expect these
		 * cases to be relatively uncommon, we just
		 * divide on the destination depth.
		 */
		if (bpp == 1) {
/**** 8-bit destination ****/
		    const byte *sptr = srow + sx;

		    tptr += tx;
		    for (; left > 0; ++dptr, ++sptr, ++tptr, ++sx, ++tx, --left) {
			byte s_pixel =
			    (scolors ? cbit8(srow, sx, scolors) : *sptr);
			byte t_pixel =
			    (tcolors ? cbit8(tptr, tx, tcolors) : *tptr);

			rop_body_8(s_pixel, t_pixel);
		    }
		} else {
/**** 24-bit destination ****/
		    const byte *sptr = srow + sx * 3;

		    tptr += tx * 3;
		    for (; left > 0; dptr += 3, sptr += 3, tptr += 3, ++sx, ++tx, --left) {
			bits32 s_pixel =
			    (scolors ? cbit24(srow, sx, scolors) :
			     get24(sptr));
			bits32 t_pixel =
			    (tcolors ? cbit24(tptr, tx, tcolors) :
			     get24(tptr));

			rop_body_24(s_pixel, t_pixel);
		    }
		}
	    }
	}
    }
#undef rop_body_8
#undef rop_body_24
#undef dbit
#undef cbit8
#undef cbit24
    return 0;
}
