/* Copyright (C) 1998, 2000 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: gximage4.c,v $ $Revision: 1.3.2.1 $ */
/* ImageType 4 image implementation */
#include "memory_.h"
#include "gx.h"
#include "gserrors.h"
#include "gscspace.h"
#include "gsiparm4.h"
#include "gxiparam.h"
#include "gximage.h"
#include "stream.h"

/* Forward references */
private dev_proc_begin_typed_image(gx_begin_image4);

/* Structure descriptor */
private_st_gs_image4();

/* Define the image type for ImageType 4 images. */
private image_proc_sput(gx_image4_sput);
private image_proc_sget(gx_image4_sget);
private image_proc_release(gx_image4_release);
const gx_image_type_t gs_image_type_4 = {
    &st_gs_image4, gx_begin_image4, gx_data_image_source_size,
    gx_image4_sput, gx_image4_sget, gx_image4_release, 4
};
/*
 * The implementation is shared with ImageType 1, so we don't need our own
 * enum_procs.
 */
/*
  private const gx_image_enum_procs_t image4_enum_procs = {
    gx_image1_plane_data, gx_image1_end_image
  };
*/

/* Initialize an ImageType 4 image. */
void
gs_image4_t_init(gs_image4_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_4;
    pim->MaskColor_is_range = false;
}

/* Start processing an ImageType 4 image. */
private int
gx_begin_image4(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_image_enum *penum;
    const gs_image4_t *pim = (const gs_image4_t *)pic;
    int code = gx_image_enum_alloc(pic, prect, mem, &penum);

    if (code < 0)
	return code;
    penum->alpha = gs_image_alpha_none;
    penum->masked = false;
    penum->adjust = fixed_0;
    /* Check that MaskColor values are within the valid range. */
    {
	bool opaque = false;
	uint max_value = (1 << pim->BitsPerComponent) - 1;
	int spp = cs_num_components(pim->ColorSpace);
	int i;

	for (i = 0; i < spp * 2; i += 2) {
	    uint c0, c1;

	    if (pim->MaskColor_is_range)
		c0 = pim->MaskColor[i], c1 = pim->MaskColor[i + 1];
	    else
		c0 = c1 = pim->MaskColor[i >> 1];

	    if ((c0 | c1) > max_value)
		return_error(gs_error_rangecheck);
	    if (c0 > c1) {
		opaque = true;	/* pixel can never match mask color */
		break;
	    }
	    penum->mask_color.values[i] = c0;
	    penum->mask_color.values[i + 1] = c1;
	}
	penum->use_mask_color = !opaque;
    }
    code = gx_image_enum_begin(dev, pis, pmat, pic, pdcolor, pcpath, mem,
			       penum);
    if (code >= 0)
	*pinfo = (gx_image_enum_common_t *)penum;
    return code;
}

/* Serialization */

private int
gx_image4_sput(const gs_image_common_t *pic, stream *s,
	       const gs_color_space **ppcs)
{
    const gs_image4_t *pim = (const gs_image4_t *)pic;
    bool is_range = pim->MaskColor_is_range;
    int code = gx_pixel_image_sput((const gs_pixel_image_t *)pim, s, ppcs,
				   is_range);
    int num_values =
	gs_color_space_num_components(pim->ColorSpace) * (is_range ? 2 : 1);
    int i;

    if (code < 0)
	return code;
    for (i = 0; i < num_values; ++i)
	sput_variable_uint(s, pim->MaskColor[i]);
    *ppcs = pim->ColorSpace;
    return 0;
}

private int
gx_image4_sget(gs_image_common_t *pic, stream *s,
	       const gs_color_space *pcs)
{
    gs_image4_t *const pim = (gs_image4_t *)pic;
    int num_values;
    int i;
    int code = gx_pixel_image_sget((gs_pixel_image_t *)pim, s, pcs);

    if (code < 0)
	return code;
    pim->type = &gs_image_type_4;
    pim->MaskColor_is_range = code;
    num_values =
	gs_color_space_num_components(pcs) *
	(pim->MaskColor_is_range ? 2 : 1);
    for (i = 0; i < num_values; ++i)
	sget_variable_uint(s, &pim->MaskColor[i]);
    return 0;
}

private void
gx_image4_release(gs_image_common_t *pic, gs_memory_t *mem)
{
    gx_pixel_image_release((gs_pixel_image_t *)pic, mem);
}
