/* Copyright (C) 2000 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: gximag3x.c,v 1.7.6.1.2.1 2003/01/17 00:49:04 giles Exp $ */
/* ImageType 3x image implementation */
/****** THE REAL WORK IS NYI ******/
#include "math_.h"		/* for ceil, floor */
#include "memory_.h"
#include "gx.h"
#include "gserrors.h"
#include "gsbitops.h"
#include "gscspace.h"
#include "gscpixel.h"
#include "gsstruct.h"
#include "gxdevice.h"
#include "gxdevmem.h"
#include "gximag3x.h"
#include "gxistate.h"
#include "gdevbbox.h"

extern_st(st_color_space);

/* Forward references */
private dev_proc_begin_typed_image(gx_begin_image3x);
private image_enum_proc_plane_data(gx_image3x_plane_data);
private image_enum_proc_end_image(gx_image3x_end_image);
private image_enum_proc_flush(gx_image3x_flush);
private image_enum_proc_planes_wanted(gx_image3x_planes_wanted);

/* GC descriptor */
private_st_gs_image3x();

/* Define the image type for ImageType 3x images. */
const gx_image_type_t gs_image_type_3x = {
    &st_gs_image3x, gx_begin_image3x, gx_data_image_source_size,
    gx_image_no_sput, gx_image_no_sget, gx_image_default_release,
    IMAGE3X_IMAGETYPE
};
private const gx_image_enum_procs_t image3x_enum_procs = {
    gx_image3x_plane_data, gx_image3x_end_image,
    gx_image3x_flush, gx_image3x_planes_wanted
};

/* Initialize an ImageType 3x image. */
private void
gs_image3x_mask_init(gs_image3x_mask_t *pimm)
{
    pimm->InterleaveType = 0;	/* not a valid type */
    pimm->has_Matte = false;
    gs_data_image_t_init(&pimm->MaskDict, 1);
    pimm->MaskDict.BitsPerComponent = 0;	/* not supplied */
}
void
gs_image3x_t_init(gs_image3x_t * pim, const gs_color_space * color_space)
{
    gs_pixel_image_t_init((gs_pixel_image_t *) pim, color_space);
    pim->type = &gs_image_type_3x;
    gs_image3x_mask_init(&pim->Opacity);
    gs_image3x_mask_init(&pim->Shape);
}

/*
 * We implement ImageType 3 images by interposing a mask clipper in
 * front of an ordinary ImageType 1 image.  Note that we build up the
 * mask row-by-row as we are processing the image.
 *
 * We export a generalized form of the begin_image procedure for use by
 * the PDF and PostScript writers.
 */

typedef struct image3x_channel_state_s {
    gx_image_enum_common_t *info;
    gx_device *mdev;		/* gx_device_memory in default impl. */
				/* (only for masks) */
    gs_image3_interleave_type_t InterleaveType;
    int width, height, full_height, depth;
    byte *data;			/* (if chunky) */
    /* Only the following change dynamically. */
    int y;
    int skip;			/* only for masks, # of rows to skip, */
				/* see below */
} image3x_channel_state_t;
typedef struct gx_image3x_enum_s {
    gx_image_enum_common;
    gx_device *pcdev;		/* gx_device_mask_clip in default impl. */
    int num_components;		/* (not counting masks) */
    int bpc;			/* pixel BitsPerComponent */
    gs_memory_t *memory;
#define NUM_MASKS 2		/* opacity, shape */
    image3x_channel_state_t mask[NUM_MASKS], pixel;
} gx_image3x_enum_t;

extern_st(st_gx_image_enum_common);
gs_private_st_suffix_add9(st_image3x_enum, gx_image3x_enum_t,
  "gx_image3x_enum_t", image3x_enum_enum_ptrs, image3x_enum_reloc_ptrs,
  st_gx_image_enum_common, pcdev, mask[0].info, mask[0].mdev, mask[0].data,
  mask[1].info, mask[1].mdev, mask[1].data, pixel.info, pixel.data);

/*
 * Begin a generic ImageType 3x image, with client handling the creation of
 * the mask image and mask clip devices.
 */
typedef struct image3x_channel_values_s {
    gs_matrix matrix;
    gs_point corner;
    gs_int_rect rect;
    gs_image_t image;
} image3x_channel_values_t;
private bool is_multiple(P2(int x, int y));
private int check_image3x_mask(P6(const gs_image3x_t *pim,
				  const gs_image3x_mask_t *pimm,
				  const image3x_channel_values_t *ppcv,
				  image3x_channel_values_t *pmcv,
				  image3x_channel_state_t *pmcs,
				  gs_memory_t *mem));
int
gx_begin_image3x_generic(gx_device * dev,
			const gs_imager_state *pis, const gs_matrix *pmat,
			const gs_image_common_t *pic, const gs_int_rect *prect,
			const gx_drawing_color *pdcolor,
			const gx_clip_path *pcpath, gs_memory_t *mem,
			image3x_make_mid_proc_t make_mid,
			image3x_make_mcde_proc_t make_mcde,
			gx_image_enum_common_t **pinfo)
{
    const gs_image3x_t *pim = (const gs_image3x_t *)pic;
    gx_image3x_enum_t *penum;
    gx_device *pcdev = 0;
    image3x_channel_values_t mask[2], pixel;
    gs_matrix mat;
    gx_device *midev[2];
    gx_image_enum_common_t *minfo[2];
    gs_int_point origin[2];
    int code;
    int i;

    /* Validate the parameters. */
    if (pim->Height <= 0)
	return_error(gs_error_rangecheck);
    penum = gs_alloc_struct(mem, gx_image3x_enum_t, &st_image3x_enum,
			    "gx_begin_image3x");
    if (penum == 0)
	return_error(gs_error_VMerror);
    /* Initialize pointers now in case we bail out. */
    penum->mask[0].info = 0, penum->mask[0].mdev = 0, penum->mask[0].data = 0;
    penum->mask[1].info = 0, penum->mask[1].mdev = 0, penum->mask[1].data = 0;
    penum->pixel.info = 0, penum->pixel.data = 0;
    if (prect)
	pixel.rect = *prect;
    else {
	pixel.rect.p.x = pixel.rect.p.y = 0;
	pixel.rect.q.x = pim->Width;
	pixel.rect.q.y = pim->Height;
    }
    if ((code = gs_matrix_invert(&pim->ImageMatrix, &pixel.matrix)) < 0 ||
	(code = gs_point_transform(pim->Width, pim->Height, &pixel.matrix,
				   &pixel.corner)) < 0 ||
	(code = check_image3x_mask(pim, &pim->Opacity, &pixel, &mask[0],
				   &penum->mask[0], mem)) < 0 ||
	(code = check_image3x_mask(pim, &pim->Shape, &pixel, &mask[1],
				   &penum->mask[1], mem)) < 0
	) {
	goto out0;
    }
    penum->num_components =
	gs_color_space_num_components(pim->ColorSpace);
    gx_image_enum_common_init((gx_image_enum_common_t *) penum,
			      (const gs_data_image_t *)pim,
			      &image3x_enum_procs, dev,
			      1 + penum->num_components,
			      pim->format);
    penum->pixel.width = pixel.rect.q.x - pixel.rect.p.x;
    penum->pixel.height = pixel.rect.q.y - pixel.rect.p.y;
    penum->pixel.full_height = pim->Height;
    penum->pixel.y = 0;
    if (penum->mask[0].data || penum->mask[1].data) {
	/* Also allocate a row buffer for the pixel data. */
	penum->pixel.data =
	    gs_alloc_bytes(mem,
			   (penum->pixel.width * pim->BitsPerComponent *
			    penum->num_components + 7) >> 3,
			   "gx_begin_image3x(pixel.data)");
	if (penum->pixel.data == 0) {
	    code = gs_note_error(gs_error_VMerror);
	    goto out1;
	}
    }
    penum->bpc = pim->BitsPerComponent;
    penum->memory = mem;
    if (pmat == 0)
	pmat = &ctm_only(pis);
    for (i = 0; i < NUM_MASKS; ++i) {
	gs_rect mrect;
	gx_device *mdev;
	/*
	 * The mask data has to be defined in a DevicePixel color space
	 * of the correct depth so that no color mapping will occur.
	 */
	/****** FREE COLOR SPACE ON ERROR OR AT END ******/
	gs_color_space *pmcs;

	if (penum->mask[i].depth == 0) {	/* mask not supplied */
	    midev[0] = 0;
	    minfo[0] = 0;
	    continue;
	}
	pmcs =  gs_alloc_struct(mem, gs_color_space, &st_color_space,
				"gx_begin_image3x_generic");
	if (pmcs == 0)
	    return_error(gs_error_VMerror);
	gs_cspace_init_DevicePixel(pmcs, penum->mask[i].depth);
	mrect.p.x = mrect.p.y = 0;
	mrect.q.x = penum->mask[i].width;
	mrect.q.y = penum->mask[i].height;
	if ((code = gs_matrix_multiply(&mask[i].matrix, pmat, &mat)) < 0 ||
	    (code = gs_bbox_transform(&mrect, &mat, &mrect)) < 0
	    )
	    return code;
	origin[i].x = floor(mrect.p.x);
	origin[i].y = floor(mrect.p.y);
	code = make_mid(&mdev, dev,
			(int)ceil(mrect.q.x) - origin[i].x,
			(int)ceil(mrect.q.y) - origin[i].y,
			penum->mask[i].depth, mem);
	if (code < 0)
	    goto out1;
	penum->mask[i].mdev = mdev;
	gs_image_t_init_gray(&mask[i].image, pis); /* gray is bogus */
	mask[i].image.ColorSpace = pmcs;
	mask[i].image.adjust = false;
	{
	    const gx_image_type_t *type1 = mask[i].image.type;
	    const gs_image3x_mask_t *pixm =
		(i == 0 ? &pim->Opacity : &pim->Shape);

	    *(gs_data_image_t *)&mask[i].image = pixm->MaskDict;
	    mask[i].image.type = type1;
	    mask[i].image.BitsPerComponent = pixm->MaskDict.BitsPerComponent;
	}
	{
	    gs_matrix m_mat;

	    /*
	     * Adjust the translation for rendering the mask to include a
	     * negative translation by origin.{x,y} in device space.
	     */
	    m_mat = *pmat;
	    m_mat.tx -= origin[i].x;
	    m_mat.ty -= origin[i].y;
	    /*
	     * Note that pis = NULL here, since we don't want to have to
	     * create another imager state with default log_op, etc.
	     * dcolor = NULL is OK because this is an opaque image with
	     * CombineWithColor = false.
	     */
	    code = gx_device_begin_typed_image(mdev, NULL, &m_mat,
			       (const gs_image_common_t *)&mask[i].image,
					       &mask[i].rect, NULL, NULL,
					       mem, &penum->mask[i].info);
	    if (code < 0)
		goto out2;
	}
	midev[i] = mdev;
	minfo[i] = penum->mask[i].info;
    }
    gs_image_t_init(&pixel.image, pim->ColorSpace);
    {
	const gx_image_type_t *type1 = pixel.image.type;

	*(gs_pixel_image_t *)&pixel.image = *(const gs_pixel_image_t *)pim;
	pixel.image.type = type1;
    }
    code = make_mcde(dev, pis, pmat, (const gs_image_common_t *)&pixel.image,
		     prect, pdcolor, pcpath, mem, &penum->pixel.info,
		     &pcdev, midev, minfo, origin, pim);
    if (code < 0)
	goto out3;
    penum->pcdev = pcdev;
    /*
     * Set num_planes, plane_widths, and plane_depths from the values in the
     * enumerators for the mask(s) and the image data.
     */
    {
	int added_depth = 0;
	int pi = 0;

	for (i = 0; i < NUM_MASKS; ++i) {
	    if (penum->mask[i].depth == 0)	/* no mask */
		continue;
	    switch (penum->mask[i].InterleaveType) {
	    case interleave_chunky:
		/* Add the mask data to the depth of the image data. */
		added_depth += pim->BitsPerComponent;
		break;
	    case interleave_separate_source:
		/* Insert the mask as a separate plane. */
		penum->plane_widths[pi] = penum->mask[i].width;
		penum->plane_depths[pi] = penum->mask[i].depth;
		++pi;
		break;
	    default:		/* can't happen */
		code = gs_note_error(gs_error_Fatal);
		goto out3;
	    }
	}
	memcpy(&penum->plane_widths[pi], &penum->pixel.info->plane_widths[0],
	       penum->pixel.info->num_planes * sizeof(penum->plane_widths[0]));
	memcpy(&penum->plane_depths[pi], &penum->pixel.info->plane_depths[0],
	       penum->pixel.info->num_planes * sizeof(penum->plane_depths[0]));
	penum->plane_depths[pi] += added_depth;
	penum->num_planes = pi + penum->pixel.info->num_planes;
    }
    if (midev[0])
	gx_device_retain(midev[0], true); /* will free explicitly */
    if (midev[1])
	gx_device_retain(midev[1], true); /* ditto */
    gx_device_retain(pcdev, true); /* ditto */
    *pinfo = (gx_image_enum_common_t *) penum;
    return 0;
  out3:
    if (penum->mask[1].info)
	gx_image_end(penum->mask[1].info, false);
    if (penum->mask[0].info)
	gx_image_end(penum->mask[0].info, false);
  out2:
    if (penum->mask[1].mdev) {
	gs_closedevice(penum->mask[1].mdev);
	gs_free_object(mem, penum->mask[1].mdev,
		       "gx_begin_image3x(mask[1].mdev)");
    }
    if (penum->mask[0].mdev) {
	gs_closedevice(penum->mask[0].mdev);
	gs_free_object(mem, penum->mask[0].mdev,
		       "gx_begin_image3x(mask[0].mdev)");
    }
  out1:
    gs_free_object(mem, penum->mask[0].data, "gx_begin_image3x(mask[0].data)");
    gs_free_object(mem, penum->mask[1].data, "gx_begin_image3x(mask[1].data)");
    gs_free_object(mem, penum->pixel.data, "gx_begin_image3x(pixel.data)");
  out0:
    gs_free_object(mem, penum, "gx_begin_image3x");
    return code;
}
private bool
is_multiple(int x, int y)
{
    return (x % y == 0 || y % x == 0);
}
private bool
check_image3x_extent(floatp mask_coeff, floatp data_coeff)
{
    if (mask_coeff == 0)
	return data_coeff == 0;
    if (data_coeff == 0 || (mask_coeff > 0) != (data_coeff > 0))
	return false;
    return true;
}
/* Check mask parameters. */
/* Reads ppcv->{matrix,corner,rect}, sets pmcv->{matrix,corner,rect} and */
/* pmcs->{InterleaveType,width,height,full_height,data,y,skip}. */
private bool
check_image3x_mask(const gs_image3x_t *pim, const gs_image3x_mask_t *pimm,
		   const image3x_channel_values_t *ppcv,
		   image3x_channel_values_t *pmcv,
		   image3x_channel_state_t *pmcs, gs_memory_t *mem)
{
    int mask_width = pimm->MaskDict.Width, mask_height = pimm->MaskDict.Height;
    int code;

    if (pimm->MaskDict.BitsPerComponent == 0) /* mask missing */
	return 0;
    if (mask_height <= 0)
	return_error(gs_error_rangecheck);
    switch (pimm->InterleaveType) {
	/*case interleave_scan_lines:*/	/* not supported */
	default:
	    return_error(gs_error_rangecheck);
	case interleave_chunky:
	    if (mask_width != pim->Width ||
		mask_height != pim->Height ||
		pimm->MaskDict.BitsPerComponent != pim->BitsPerComponent ||
		pim->format != gs_image_format_chunky
		)
		return_error(gs_error_rangecheck);
	    break;
	    if (!is_multiple(mask_height, pim->Height))
		return_error(gs_error_rangecheck);
	    /* falls through */
	case interleave_separate_source:
	    switch (pimm->MaskDict.BitsPerComponent) {
	    case 1: case 2: case 4: case 8:
		break;
	    default:
		return_error(gs_error_rangecheck);
	    }
    }
    if (!check_image3x_extent(pim->ImageMatrix.xx,
			      pimm->MaskDict.ImageMatrix.xx) ||
	!check_image3x_extent(pim->ImageMatrix.xy,
			      pimm->MaskDict.ImageMatrix.xy) ||
	!check_image3x_extent(pim->ImageMatrix.yx,
			      pimm->MaskDict.ImageMatrix.yx) ||
	!check_image3x_extent(pim->ImageMatrix.yy,
			      pimm->MaskDict.ImageMatrix.yy)
	)
	return_error(gs_error_rangecheck);
    if ((code = gs_matrix_invert(&pimm->MaskDict.ImageMatrix, &pmcv->matrix)) < 0 ||
	(code = gs_point_transform(mask_width, mask_height,
				   &pmcv->matrix, &pmcv->corner)) < 0
	)
	return code;
    if (fabs(ppcv->matrix.tx - pmcv->matrix.tx) >= 0.5 ||
	fabs(ppcv->matrix.ty - pmcv->matrix.ty) >= 0.5 ||
	fabs(ppcv->corner.x - pmcv->corner.x) >= 0.5 ||
	fabs(ppcv->corner.y - pmcv->corner.y) >= 0.5
	)
	return_error(gs_error_rangecheck);
    pmcv->rect.p.x = ppcv->rect.p.x * mask_width / pim->Width;
    pmcv->rect.p.y = ppcv->rect.p.y * mask_height / pim->Height;
    pmcv->rect.q.x = (ppcv->rect.q.x * mask_width + pim->Width - 1) /
	pim->Width;
    pmcv->rect.q.y = (ppcv->rect.q.y * mask_height + pim->Height - 1) /
	pim->Height;
    /* Initialize the channel state in the enumerator. */
    pmcs->InterleaveType = pimm->InterleaveType;
    pmcs->width = pmcv->rect.q.x - pmcv->rect.p.x;
    pmcs->height = pmcv->rect.q.y - pmcv->rect.p.y;
    pmcs->full_height = pimm->MaskDict.Height;
    pmcs->depth = pimm->MaskDict.BitsPerComponent;
    if (pmcs->InterleaveType == interleave_chunky) {
	/* Allocate a buffer for the data. */
	pmcs->data =
	    gs_alloc_bytes(mem,
			   (pmcs->width * pimm->MaskDict.BitsPerComponent + 7) >> 3,
			   "gx_begin_image3x(mask data)");
	if (pmcs->data == 0)
	    return_error(gs_error_VMerror);
    }
    pmcs->y = pmcs->skip = 0;
    return 0;
}

/*
 * Return > 0 if we want more data from channel 1 now, < 0 if we want more
 * from channel 2 now, 0 if we want both.
 */
private int
channel_next(const image3x_channel_state_t *pics1,
	     const image3x_channel_state_t *pics2)
{
    /*
     * The invariant we need to maintain is that we always have at least as
     * much channel N as channel N+1 data, where N = 0 = opacity, 1 = shape,
     * and 2 = pixel.  I.e., for any two consecutive channels c1 and c2, we
     * require c1.y / c1.full_height >= c2.y / c2.full_height, or, to avoid
     * floating point, c1.y * c2.full_height >= c2.y * c1.full_height.  We
     * know this condition is true now; return a value that indicates how to
     * maintain it.
     */
    int h1 = pics1->full_height;
    int h2 = pics2->full_height;
    long current = pics1->y * (long)h2 - pics2->y * (long)h1;

#ifdef DEBUG
    if (current < 0)
	lprintf4("channel_next invariant fails: %d/%d < %d/%d\n",
		 pics1->y, pics1->full_height,
		 pics2->y, pics2->full_height);
#endif
    return ((current -= h1) >= 0 ? -1 :
	    current + h2 >= 0 ? 0 : 1);
}

/* Define the default implementation of ImageType 3 processing. */
private IMAGE3X_MAKE_MID_PROC(make_midx_default); /* check prototype */
private int
make_midx_default(gx_device **pmidev, gx_device *dev, int width, int height,
		 int depth, gs_memory_t *mem)
{
    const gx_device_memory *mdproto = gdev_mem_device_for_bits(depth);
    gx_device_memory *midev;
    int code;

    if (mdproto == 0)
	return_error(gs_error_rangecheck);
    midev = gs_alloc_struct(mem, gx_device_memory, &st_device_memory,
			    "make_mid_default");
    if (midev == 0)
	return_error(gs_error_VMerror);
    gs_make_mem_device(midev, mdproto, mem, 0, NULL);
    midev->bitmap_memory = mem;
    midev->width = width;
    midev->height = height;
    gx_device_fill_in_procs((gx_device *)midev);
    code = dev_proc(midev, open_device)((gx_device *)midev);
    if (code < 0) {
	gs_free_object(mem, midev, "make_midx_default");
	return code;
    }
    midev->is_open = true;
    dev_proc(midev, fill_rectangle)
	((gx_device *)midev, 0, 0, width, height, (gx_color_index)0);
    *pmidev = (gx_device *)midev;
    return 0;
}
private IMAGE3X_MAKE_MCDE_PROC(make_mcdex_default);  /* check prototype */
private int
make_mcdex_default(gx_device *dev, const gs_imager_state *pis,
		   const gs_matrix *pmat, const gs_image_common_t *pic,
		   const gs_int_rect *prect, const gx_drawing_color *pdcolor,
		   const gx_clip_path *pcpath, gs_memory_t *mem,
		   gx_image_enum_common_t **pinfo,
		   gx_device **pmcdev, gx_device *midev[2],
		   gx_image_enum_common_t *pminfo[2],
		   const gs_int_point origin[2],
		   const gs_image3x_t *pim)
{
    /**************** NYI ****************/
    /*
     * There is no soft-mask analogue of make_mcde_default, because
     * soft-mask clipping is a more complicated operation, implemented
     * by the general transparency code.  As a default, we simply ignore
     * the soft mask.  However, we have to create an intermediate device
     * that can be freed at the end and that simply forwards all calls.
     * The most convenient device for this purpose is the bbox device.
     */
    gx_device_bbox *bbdev =
	gs_alloc_struct_immovable(mem, gx_device_bbox, &st_device_bbox,
				  "make_mcdex_default");
    int code;

    if (bbdev == 0)
	return_error(gs_error_VMerror);
    gx_device_bbox_init(bbdev, dev);
    gx_device_bbox_fwd_open_close(bbdev, false);
    code = dev_proc(bbdev, begin_typed_image)
	((gx_device *)bbdev, pis, pmat, pic, prect, pdcolor, pcpath, mem,
	 pinfo);
    if (code < 0) {
	gs_free_object(mem, bbdev, "make_mcdex_default");
	return code;
    }
    *pmcdev = (gx_device *)bbdev;
    return 0;
}
private int
gx_begin_image3x(gx_device * dev,
		const gs_imager_state * pis, const gs_matrix * pmat,
		const gs_image_common_t * pic, const gs_int_rect * prect,
		const gx_drawing_color * pdcolor, const gx_clip_path * pcpath,
		gs_memory_t * mem, gx_image_enum_common_t ** pinfo)
{
    return gx_begin_image3x_generic(dev, pis, pmat, pic, prect, pdcolor,
				    pcpath, mem, make_midx_default,
				    make_mcdex_default, pinfo);
}

/* Process the next piece of an ImageType 3 image. */
private int
gx_image3x_plane_data(gx_image_enum_common_t * info,
		     const gx_image_plane_t * planes, int height,
		     int *rows_used)
{
    gx_image3x_enum_t *penum = (gx_image3x_enum_t *) info;
    int pixel_height = penum->pixel.height;
    int pixel_used = 0;
    int mask_height[2];
    int mask_used[2];
    int h1 = pixel_height - penum->pixel.y;
    int h;
    const gx_image_plane_t *pixel_planes;
    gx_image_plane_t pixel_plane, mask_plane[2];
    int code = 0;
    int i, pi = 0;
    int num_chunky = 0;

    for (i = 0; i < NUM_MASKS; ++i) {
	int mh = mask_height[i] = penum->mask[i].height;

	mask_plane[i].data = 0;
	mask_used[i] = 0;
	if (!penum->mask[i].depth)
	    continue;
	h1 = min(h1, mh - penum->mask[i].y);
	if (penum->mask[i].InterleaveType == interleave_chunky)
	    ++num_chunky;
    }
    h = min(height, h1);
    /* Initialized rows_used in case we get an error. */
    *rows_used = 0;
    if (h <= 0)
	return 0;

    /* Handle masks from separate sources. */
    for (i = 0; i < NUM_MASKS; ++i)
	if (penum->mask[i].InterleaveType == interleave_separate_source) {
	    /*
	     * In order to be able to recover from interruptions, we must
	     * limit separate-source processing to 1 scan line at a time.
	     */
	    if (h > 1)
		h = 1;
	    mask_plane[i] = planes[pi++];
	}
    pixel_planes = &planes[pi];

    /* Handle chunky masks. */
    if (num_chunky) {
	int bpc = penum->bpc;
	int num_components = penum->num_components;
	int width = penum->pixel.width;
	/* Pull apart the source data and the mask data. */
	/* We do this in the simplest (not fastest) way for now. */
	uint bit_x = bpc * (num_components + num_chunky) * planes[pi].data_x;
	sample_load_declare_setup(sptr, sbit, planes[0].data + (bit_x >> 3),
				  bit_x & 7, bpc);
	sample_store_declare_setup(pptr, pbit, pbbyte,
				   penum->pixel.data, 0, bpc);
	sample_store_declare(dptr[NUM_MASKS], dbit[NUM_MASKS],
			     dbbyte[NUM_MASKS]);
	int depth[NUM_MASKS];
	int x;

	if (h > 1) {
	    /* Do the operation one row at a time. */
	    h = 1;
	}
	for (i = 0; i < NUM_MASKS; ++i)
	    if (penum->mask[i].data) {
		depth[i] = penum->mask[i].depth;
		mask_plane[i].data = dptr[i] = penum->mask[i].data;
		mask_plane[i].data_x = 0;
		/* raster doesn't matter */
		sample_store_setup(dbit[i], 0, depth[i]);
		sample_store_preload(dbbyte[i], dptr[i], 0, depth[i]);
	    } else
		depth[i] = 0;
	pixel_plane.data = pptr;
	pixel_plane.data_x = 0;
	/* raster doesn't matter */
	pixel_planes = &pixel_plane;
	for (x = 0; x < width; ++x) {
	    uint value;

	    for (i = 0; i < NUM_MASKS; ++i)
		if (depth[i]) {
		    sample_load_next12(value, sptr, sbit, bpc);
		    sample_store_next12(value, dptr[i], dbit[i], depth[i],
					dbbyte[i]);
		}
	    for (i = 0; i < num_components; ++i) {
		sample_load_next12(value, sptr, sbit, bpc);
		sample_store_next12(value, pptr, pbit, bpc, pbbyte);
	    }
	}
	for (i = 0; i < NUM_MASKS; ++i)
	    if (penum->mask[i].data)
		sample_store_flush(dptr[i], dbit[i], depth[i], dbbyte[i]);
	sample_store_flush(pptr, pbit, bpc, pbbyte);
	}
    /*
     * Process the mask data first, so it will set up the mask
     * device for clipping the pixel data.
     */
    for (i = 0; i < NUM_MASKS; ++i)
	if (mask_plane[i].data) {
	    /*
	     * If, on the last call, we processed some mask rows
	     * successfully but processing the pixel rows was interrupted,
	     * we set rows_used to indicate the number of pixel rows
	     * processed (since there is no way to return two rows_used
	     * values).  If this happened, some mask rows may get presented
	     * again.  We must skip over them rather than processing them
	     * again.
	     */
	    int skip = penum->mask[i].skip;

	    if (skip >= h) {
		penum->mask[i].skip = skip - (mask_used[i] = h);
	    } else {
		int mask_h = h - skip;

		mask_plane[i].data += skip * mask_plane[i].raster;
		penum->mask[i].skip = 0;
		code = gx_image_plane_data_rows(penum->mask[i].info,
						&mask_plane[i],
						mask_h, &mask_used[i]);
		mask_used[i] += skip;
	    }
	    *rows_used = mask_used[i];
	    penum->mask[i].y += mask_used[i];
	    if (code < 0)
		return code;
	}
    if (pixel_planes[0].data) {
	/*
	 * If necessary, flush any buffered mask data to the mask clipping
	 * device.
	 */
	for (i = 0; i < NUM_MASKS; ++i)
	    if (penum->mask[i].info)
		gx_image_flush(penum->mask[i].info);
	code = gx_image_plane_data_rows(penum->pixel.info, pixel_planes, h,
					&pixel_used);
	/*
	 * There isn't any way to set rows_used if different amounts of
	 * the mask and pixel data were used.  Fake it.
	 */
	*rows_used = pixel_used;
	/*
	 * Don't return code yet: we must account for the fact that
	 * some mask data may have been processed.
	 */
	penum->pixel.y += pixel_used;
	if (code < 0) {
	    /*
	     * We must prevent the mask data from being processed again.
	     * We rely on the fact that h > 1 is only possible if the
	     * mask and pixel data have the same Y scaling.
	     */
	    for (i = 0; i < NUM_MASKS; ++i)
		if (mask_used[i] > pixel_used) {
		    int skip = mask_used[i] - pixel_used;

		    penum->mask[i].skip = skip;
		    penum->mask[i].y -= skip;
		    mask_used[i] = pixel_used;
		}
	}
    }
    if_debug7('b', "[b]image3x h=%d %sopacity.y=%d %sopacity.y=%d %spixel.y=%d\n",
	      h, (mask_plane[0].data ? "+" : ""), penum->mask[0].y,
	      (mask_plane[1].data ? "+" : ""), penum->mask[1].y,
	      (pixel_planes[0].data ? "+" : ""), penum->pixel.y);
    if (penum->mask[0].y >= penum->mask[0].height &&
	penum->mask[1].y >= penum->mask[1].height &&
	penum->pixel.y >= penum->pixel.height)
	return 1;
    /*
     * The mask may be complete (gx_image_plane_data_rows returned 1),
     * but there may still be pixel rows to go, so don't return 1 here.
     */
    return (code < 0 ? code : 0);
}

/* Flush buffered data. */
private int
gx_image3x_flush(gx_image_enum_common_t * info)
{
    gx_image3x_enum_t * const penum = (gx_image3x_enum_t *) info;
    int code = gx_image_flush(penum->mask[0].info);

    if (code >= 0)
	code = gx_image_flush(penum->mask[1].info);
    if (code >= 0)
	code = gx_image_flush(penum->pixel.info);
    return code;
}

/* Determine which data planes are wanted. */
private bool
gx_image3x_planes_wanted(const gx_image_enum_common_t * info, byte *wanted)
{
    const gx_image3x_enum_t * const penum = (const gx_image3x_enum_t *) info;
    /*
     * We always want at least as much of the mask(s) to be filled as the
     * pixel data.
     */
    bool
	sso = penum->mask[0].InterleaveType == interleave_separate_source,
	sss = penum->mask[1].InterleaveType == interleave_separate_source;

    if (sso & sss) {
	/* Both masks have separate sources. */
	int mask_next = channel_next(&penum->mask[1], &penum->pixel);

	memset(wanted + 2, (mask_next <= 0 ? 0xff : 0), info->num_planes - 2);
	wanted[1] = (mask_next >= 0 ? 0xff : 0);
	if (wanted[1]) {
	    mask_next = channel_next(&penum->mask[0], &penum->mask[1]);
	    wanted[0] = mask_next >= 0;
	} else
	    wanted[0] = 0;
	return false;		/* see below */
    } else if (sso | sss) {
	/* Only one separate source. */
	const image3x_channel_state_t *pics =
	    (sso ? &penum->mask[0] : &penum->mask[1]);
	int mask_next = channel_next(pics, &penum->pixel);

	wanted[0] = (mask_next >= 0 ? 0xff : 0);
	memset(wanted + 1, (mask_next <= 0 ? 0xff : 0), info->num_planes - 1);
	/*
	 * In principle, wanted will always be true for both mask and pixel
	 * data if the full_heights are equal.  Unfortunately, even in this
	 * case, processing may be interrupted after a mask row has been
	 * passed to the underlying image processor but before the data row
	 * has been passed, in which case pixel data will be 'wanted', but
	 * not mask data, for the next call.  Therefore, we must return
	 * false.
	 */
	return false
	    /*(next == 0 &&
	      pics->full_height == penum->pixel.full_height)*/;
    } else {
	/* Everything is chunky, only 1 plane. */
	wanted[0] = 0xff;
	return true;
    }
}

/* Clean up after processing an ImageType 3x image. */
private int
gx_image3x_end_image(gx_image_enum_common_t * info, bool draw_last)
{
    gx_image3x_enum_t *penum = (gx_image3x_enum_t *) info;
    gs_memory_t *mem = penum->memory;
    gx_device *mdev0 = penum->mask[0].mdev;
    int ocode =
	(penum->mask[0].info ? gx_image_end(penum->mask[0].info, draw_last) :
	 0);
    gx_device *mdev1 = penum->mask[1].mdev;
    int scode =
	(penum->mask[1].info ? gx_image_end(penum->mask[1].info, draw_last) :
	 0);
    gx_device *pcdev = penum->pcdev;
    int pcode = gx_image_end(penum->pixel.info, draw_last);

    gs_closedevice(pcdev);
    if (mdev0)
	gs_closedevice(mdev0);
    if (mdev1)
	gs_closedevice(mdev1);
    gs_free_object(mem, penum->mask[0].data,
		   "gx_image3x_end_image(mask[0].data)");
    gs_free_object(mem, penum->mask[1].data,
		   "gx_image3x_end_image(mask[1].data)");
    gs_free_object(mem, penum->pixel.data,
		   "gx_image3x_end_image(pixel.data)");
    gs_free_object(mem, pcdev, "gx_image3x_end_image(pcdev)");
    gs_free_object(mem, mdev0, "gx_image3x_end_image(mask[0].mdev)");
    gs_free_object(mem, mdev1, "gx_image3x_end_image(mask[1].mdev)");
    gs_free_object(mem, penum, "gx_image3x_end_image");
    return (pcode < 0 ? pcode : scode < 0 ? scode : ocode);
}