/* Copyright (C) 1995, 1996, 1997, 1998, 1999 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 General Public License for full details.
  
  Everyone is granted permission to copy, modify and redistribute GNU
  Ghostscript, but only under the conditions described in the GNU General
  Public License.  A copy of this license is supposed to have been given
  to you along with GNU Ghostscript so you can know your rights and
  responsibilities.  It should be in a file named COPYING.  Among other
  things, the copyright notice and this notice must be preserved on all
  copies.
*/

/*$RCSfile: gdevmr2n.c,v $ $Revision: 1.2.2.1 $ */
/* RasterOp implementation for 2- and 4-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"

/* 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)

/* ---------------- Fake RasterOp for 2- and 4-bit devices ---------------- */

/*
 * Define patched versions of the driver procedures that may be called
 * by mem_mono_strip_copy_rop (see below).  Currently we just punt to
 * the slow, general case; we could do a lot better.
 */
private int
mem_gray_rop_fill_rectangle(gx_device * dev, int x, int y, int w, int h,
			    gx_color_index color)
{
    return -1;
}
private int
mem_gray_rop_copy_mono(gx_device * dev, const byte * data,
		       int dx, int raster, gx_bitmap_id id,
		       int x, int y, int w, int h,
		       gx_color_index zero, gx_color_index one)
{
    return -1;
}
private int
mem_gray_rop_strip_tile_rectangle(gx_device * dev,
				  const gx_strip_bitmap * tiles,
				  int x, int y, int w, int h,
				  gx_color_index color0, gx_color_index color1,
				  int px, int py)
{
    return -1;
}

int
mem_gray_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_color_index scolors2[2];
    const gx_color_index *real_scolors = scolors;
    gx_color_index tcolors2[2];
    const gx_color_index *real_tcolors = tcolors;
    gx_strip_bitmap texture2;
    const gx_strip_bitmap *real_texture = textures;
    long tdata;
    int depth = dev->color_info.depth;
    int log2_depth = depth >> 1;	/* works for 2, 4 */
    gx_color_index max_pixel = (1 << depth) - 1;
    int code;

#ifdef DEBUG
    if (gs_debug_c('b'))
	trace_copy_rop("mem_gray_strip_copy_rop",
		       dev, sdata, sourcex, sraster,
		       id, scolors, textures, tcolors,
		       x, y, width, height, phase_x, phase_y, lop);
#endif
    if (gx_device_has_color(dev) ||
	(lop & (lop_S_transparent | lop_T_transparent)) ||
	(scolors &&		/* must be (0,0) or (max,max) */
	 ((scolors[0] | scolors[1]) != 0) &&
	 ((scolors[0] & scolors[1]) != max_pixel)) ||
	(tcolors && (tcolors[0] != tcolors[1]))
	) {
	/* We can't fake it: do it the slow, painful way. */
	return mem_default_strip_copy_rop(dev, sdata, sourcex, sraster, id,
					  scolors, textures, tcolors,
					  x, y, width, height,
					  phase_x, phase_y, lop);
    }
    if (scolors) {		/* Must be a solid color: see above. */
	scolors2[0] = scolors2[1] = scolors[0] & 1;
	real_scolors = scolors2;
    }
    if (textures) {
	texture2 = *textures;
	texture2.size.x <<= log2_depth;
	texture2.rep_width <<= log2_depth;
	texture2.shift <<= log2_depth;
	texture2.rep_shift <<= log2_depth;
	real_texture = &texture2;
    }
    if (tcolors) {
	/* For polybit textures with colors other than */
	/* all 0s or all 1s, fabricate the data. */
	if (tcolors[0] != 0 && tcolors[0] != max_pixel) {
	    real_tcolors = 0;
	    *(byte *) & tdata = (byte) tcolors[0] << (8 - depth);
	    texture2.data = (byte *) & tdata;
	    texture2.raster = align_bitmap_mod;
	    texture2.size.x = texture2.rep_width = depth;
	    texture2.size.y = texture2.rep_height = 1;
	    texture2.id = gx_no_bitmap_id;
	    texture2.shift = texture2.rep_shift = 0;
	    real_texture = &texture2;
	} else {
	    tcolors2[0] = tcolors2[1] = tcolors[0] & 1;
	    real_tcolors = tcolors2;
	}
    }
    /*
     * mem_mono_strip_copy_rop may call fill_rectangle, copy_mono, or
     * strip_tile_rectangle for special cases.  Patch those procedures
     * temporarily so they will either do the right thing or return
     * an error.
     */
    {
	dev_proc_fill_rectangle((*fill_rectangle)) =
	    dev_proc(dev, fill_rectangle);
	dev_proc_copy_mono((*copy_mono)) =
	    dev_proc(dev, copy_mono);
	dev_proc_strip_tile_rectangle((*strip_tile_rectangle)) =
	    dev_proc(dev, strip_tile_rectangle);

	set_dev_proc(dev, fill_rectangle, mem_gray_rop_fill_rectangle);
	set_dev_proc(dev, copy_mono, mem_gray_rop_copy_mono);
	set_dev_proc(dev, strip_tile_rectangle,
		     mem_gray_rop_strip_tile_rectangle);
	dev->width <<= log2_depth;
	code = mem_mono_strip_copy_rop(dev, sdata,
				       (real_scolors == NULL ?
					sourcex << log2_depth : sourcex),
				       sraster, id, real_scolors,
				       real_texture, real_tcolors,
				       x << log2_depth, y,
				       width << log2_depth, height,
				       phase_x << log2_depth, phase_y, lop);
	set_dev_proc(dev, fill_rectangle, fill_rectangle);
	set_dev_proc(dev, copy_mono, copy_mono);
	set_dev_proc(dev, strip_tile_rectangle, strip_tile_rectangle);
	dev->width >>= log2_depth;
    }
    /* If we punted, use the general procedure. */
    if (code < 0)
	return mem_default_strip_copy_rop(dev, sdata, sourcex, sraster, id,
					  scolors, textures, tcolors,
					  x, y, width, height,
					  phase_x, phase_y, lop);
    return code;
}
