/* Copyright (C) 1998, 1999 artofcode LLC.  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 as published by the
  Free Software Foundation; either version 2 of the License, or (at your
  option) any later version.

  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.

*/

/*$Id: gxmclip.h,v 1.2.6.1.2.1 2003/01/17 00:49:04 giles Exp $ */
/* Mask clipping device and interface */
/* Requires gxdevice.h, gxdevmem.h */

#ifndef gxmclip_INCLUDED
#  define gxmclip_INCLUDED

#include "gxclip.h"

/*
 * ImageType 3 images and Patterns that don't completely fill their
 * bounding box require the ability to clip against a mask.
 * The interface declared here doesn't take a position on whether
 * the mask will be used only in one position (ImageType 3) or in
 * multiple positions for tiling (Patterns).
 *
 * All the information in this file is logically private, but we must expose
 * the structure definition so that clients can allocate instances in the
 * stack frame.
 */

#define tile_clip_buffer_request 300
#define tile_clip_buffer_size\
  ((tile_clip_buffer_request / arch_sizeof_long) * arch_sizeof_long)
typedef struct gx_device_mask_clip_s {
    gx_device_forward_common;	/* target is set by client */
    gx_strip_bitmap tiles;
    gx_device_memory mdev;	/* for tile buffer for copy_mono */
    gs_int_point phase;		/* device space origin relative */
				/* to tile (backwards from gstate phase) */
    /* Ensure that the buffer is long-aligned. */
    union _b {
	byte bytes[tile_clip_buffer_size];
	ulong longs[tile_clip_buffer_size / arch_sizeof_long];
    } buffer;
} gx_device_mask_clip;

extern_st(st_device_mask_clip);
#define public_st_device_mask_clip()	/* in gxmclip.c */\
  gs_public_st_composite_use_final(st_device_mask_clip, gx_device_mask_clip,\
    "gx_device_mask_clip", device_mask_clip_enum_ptrs,\
    device_mask_clip_reloc_ptrs, gx_device_finalize)

/*
 * Internal routine to initialize a mask clipping device.
 * We supply an explicit device space origin or phase.
 * Note that this procedure does not set cdev->tiles.
 */
int gx_mask_clip_initialize(P7(gx_device_mask_clip * cdev,
			       const gx_device_mask_clip * proto,
			       const gx_bitmap * bits, gx_device * tdev,
			       int tx, int ty, gs_memory_t *mem));

/*
 * Prepare colors for a copy_mono operation.
 * The arguments of copy_mono are free variables:
 *   dev, data, sourcex, raster, id, x, y, w, y, color0, color1.
 */
#define setup_mask_copy_mono(cdev, color, mcolor0, mcolor1)\
	BEGIN\
	  if ( cdev->mdev.base == 0 ) {\
	    /*\
	     * The tile was too large for us to buffer even one scan line.\
	     * Punt to the very, very slow default implementation of\
	     * copy_mono.\
	     */\
	    return gx_default_copy_mono(dev, data, sourcex, raster, id,\
					x, y, w, h, color0, color1);\
	  }\
	  if ( color1 != gx_no_color_index ) {\
	    if ( color0 != gx_no_color_index ) {\
	      /* Pre-fill with color0. */\
	      code =\
		(*dev_proc(dev, fill_rectangle))(dev, x, y, w, h, color0);\
	      if ( code < 0 )\
		return code;\
	    }\
	    color = color1;\
	    mcolor0 = 0, mcolor1 = gx_no_color_index;\
	  } else if ( color0 != gx_no_color_index ) {\
	    color = color0;\
	    mcolor0 = gx_no_color_index, mcolor1 = 0;\
	  } else\
	    return 0;\
	END

#endif /* gxmclip_INCLUDED */