/* Copyright (C) 2000-2002 artofcode LLC.  All rights reserved.
  
  This software is provided AS-IS with no warranty, either express or
  implied.
  
  This software is distributed under license and may not be copied,
  modified or distributed except as expressly authorized under the terms
  of the license contained in the file LICENSE in this distribution.
  
  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: ztrans.c,v 1.19.2.1 2003/12/12 22:08:06 giles Exp $ */
/* Transparency operators */
#include "string_.h"
#include "memory_.h"
#include "ghost.h"
#include "oper.h"
#include "gscspace.h"		/* for gscolor2.h */
#include "gscolor2.h"
#include "gsipar3x.h"
#include "gstrans.h"
#include "gxiparam.h"		/* for image enumerator */
#include "idict.h"
#include "idparam.h"
#include "ifunc.h"
#include "igstate.h"
#include "iimage.h"
#include "iname.h"
#include "store.h"
#include "gsdfilt.h"
#include "gdevp14.h"

/* ------ Utilities ------ */

private int
set_float_value(i_ctx_t *i_ctx_p, int (*set_value)(gs_state *, floatp))
{
    os_ptr op = osp;
    double value;
    int code;

    if (real_param(op, &value) < 0)
	return_op_typecheck(op);
    if ((code = set_value(igs, value)) < 0)
	return code;
    pop(1);
    return 0;
}

private int
current_float_value(i_ctx_t *i_ctx_p,
		    float (*current_value)(const gs_state *))
{
    os_ptr op = osp;

    push(1);
    make_real(op, current_value(igs));
    return 0;
}

private int
enum_param(const ref *pnref, const char *const names[])
{
    const char *const *p;
    ref nsref;

    name_string_ref(pnref, &nsref);
    for (p = names; *p; ++p)
	if (r_size(&nsref) == strlen(*p) &&
	    !memcmp(*p, nsref.value.const_bytes, r_size(&nsref))
	    )
	    return p - names;
    return_error(e_rangecheck);
}

/* ------ Graphics state operators ------ */

private const char *const blend_mode_names[] = {
    GS_BLEND_MODE_NAMES, 0
};

/* <modename> .setblendmode - */
private int
zsetblendmode(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    int code;

    check_type(*op, t_name);
    if ((code = enum_param(op, blend_mode_names)) < 0 ||
	(code = gs_setblendmode(igs, code)) < 0
	)
	return code;
    pop(1);
    return 0;
}

/* - .currentblendmode <modename> */
private int
zcurrentblendmode(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    const char *mode_name = blend_mode_names[gs_currentblendmode(igs)];
    ref nref;
    int code = name_enter_string(mode_name, &nref);

    if (code < 0)
	return code;
    push(1);
    *op = nref;
    return 0;
}

/* <0..1> .setopacityalpha - */
private int
zsetopacityalpha(i_ctx_t *i_ctx_p)
{
    return set_float_value(i_ctx_p, gs_setopacityalpha);
}

/* - .currentopacityalpha <0..1> */
private int
zcurrentopacityalpha(i_ctx_t *i_ctx_p)
{
    return current_float_value(i_ctx_p, gs_currentopacityalpha);
}

/* <0..1> .setshapealpha - */
private int
zsetshapealpha(i_ctx_t *i_ctx_p)
{
    return set_float_value(i_ctx_p, gs_setshapealpha);
}

/* - .currentshapealpha <0..1> */
private int
zcurrentshapealpha(i_ctx_t *i_ctx_p)
{
    return current_float_value(i_ctx_p, gs_currentshapealpha);
}

/* <bool> .settextknockout - */
private int
zsettextknockout(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;

    check_type(*op, t_boolean);
    gs_settextknockout(igs, op->value.boolval);
    pop(1);
    return 0;
}

/* - .currenttextknockout <bool> */
private int
zcurrenttextknockout(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;

    push(1);
    make_bool(op, gs_currenttextknockout(igs));
    return 0;
}

/* ------ Rendering stack operators ------ */

private int
rect_param(gs_rect *prect, os_ptr op)
{
    double coords[4];
    int code = num_params(op, 4, coords);

    if (code < 0)
	return code;
    prect->p.x = coords[0], prect->p.y = coords[1];
    prect->q.x = coords[2], prect->q.y = coords[3];
    return 0;
}

private int
mask_op(i_ctx_t *i_ctx_p,
	int (*mask_proc)(gs_state *, gs_transparency_channel_selector_t))
{
    int csel;
    int code = int_param(osp, 1, &csel);

    if (code < 0)
	return code;
    code = mask_proc(igs, csel);
    if (code >= 0)
	pop(1);
    return code;

}

/* <paramdict> <llx> <lly> <urx> <ury> .begintransparencygroup - */
private int
zbegintransparencygroup(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    os_ptr dop = op - 4;
    gs_transparency_group_params_t params;
    gs_rect bbox;
    int code;

    check_type(*dop, t_dictionary);
    check_dict_read(*dop);
    gs_trans_group_params_init(&params);
    if ((code = dict_bool_param(dop, "Isolated", false, &params.Isolated)) < 0 ||
	(code = dict_bool_param(dop, "Knockout", false, &params.Knockout)) < 0
	)
	return code;
    code = rect_param(&bbox, op);
    if (code < 0)
	return code;
    params.ColorSpace = gs_currentcolorspace(igs);
    code = gs_begin_transparency_group(igs, &params, &bbox);
    if (code < 0)
	return code;
    pop(5);
    return code;
}

/* - .discardtransparencygroup - */
private int
zdiscardtransparencygroup(i_ctx_t *i_ctx_p)
{
    if (gs_current_transparency_type(igs) != TRANSPARENCY_STATE_Group)
	return_error(e_rangecheck);
    return gs_discard_transparency_layer(igs);
}

/* - .endtransparencygroup - */
private int
zendtransparencygroup(i_ctx_t *i_ctx_p)
{
    return gs_end_transparency_group(igs);
}

/* <paramdict> <llx> <lly> <urx> <ury> .begintransparencymask - */
private int tf_using_function(floatp, float *, void *);
private int
zbegintransparencymask(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    os_ptr dop = op - 4;
    gs_transparency_mask_params_t params;
    ref *pparam;
    gs_rect bbox;
    int code;
    static const char *const subtype_names[] = {
	GS_TRANSPARENCY_MASK_SUBTYPE_NAMES, 0
    };

    check_type(*dop, t_dictionary);
    check_dict_read(*dop);
    if (dict_find_string(dop, "Subtype", &pparam) <= 0)
	return_error(e_rangecheck);
    if ((code = enum_param(pparam, subtype_names)) < 0)
	return code;
    gs_trans_mask_params_init(&params, code);
    if ((code = dict_floats_param(dop, "Background", 1,
				  params.Background, NULL)) < 0
	)
	return code;
    else if (code > 0)
	params.has_Background = true;
    if (dict_find_string(dop, "TransferFunction", &pparam) >0) {
	gs_function_t *pfn = ref_function(pparam);

	if (pfn == 0 || pfn->params.m != 1 || pfn->params.n != 1)
	    return_error(e_rangecheck);
	params.TransferFunction = tf_using_function;
	params.TransferFunction_data = pfn;
    }
    code = rect_param(&bbox, op);
    if (code < 0)
	return code;
    code = gs_begin_transparency_mask(igs, &params, &bbox);
    if (code < 0)
	return code;
    pop(5);
    return code;
}
/* Implement the TransferFunction using a Function. */
private int
tf_using_function(floatp in_val, float *out, void *proc_data)
{
    float in = in_val;
    gs_function_t *const pfn = proc_data;

    return gs_function_evaluate(pfn, &in, out);
}

/* - .discardtransparencymask - */
private int
zdiscardtransparencymask(i_ctx_t *i_ctx_p)
{
    if (gs_current_transparency_type(igs) != TRANSPARENCY_STATE_Mask)
	return_error(e_rangecheck);
    return gs_discard_transparency_layer(igs);
}

/* <mask#> .endtransparencymask - */
private int
zendtransparencymask(i_ctx_t *i_ctx_p)
{
    return mask_op(i_ctx_p, gs_end_transparency_mask);
}

/* <mask#> .inittransparencymask - */
private int
zinittransparencymask(i_ctx_t *i_ctx_p)
{
    return mask_op(i_ctx_p, gs_init_transparency_mask);
}

/* ------ Soft-mask images ------ */

/* <dict> .image3x - */
private int mask_dict_param(os_ptr, image_params *, const char *, int,
			    gs_image3x_mask_t *);
private int
zimage3x(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_image3x_t image;
    ref *pDataDict;
    image_params ip_data;
    int num_components =
	gs_color_space_num_components(gs_currentcolorspace(igs));
    int ignored;
    int code;

    check_type(*op, t_dictionary);
    check_dict_read(*op);
    gs_image3x_t_init(&image, NULL);
    if (dict_find_string(op, "DataDict", &pDataDict) <= 0)
	return_error(e_rangecheck);
    if ((code = pixel_image_params(i_ctx_p, pDataDict,
				   (gs_pixel_image_t *)&image, &ip_data,
				   12, false)) < 0 ||
	(code = dict_int_param(pDataDict, "ImageType", 1, 1, 0, &ignored)) < 0
	)
	return code;
    /*
     * We have to process the masks in the reverse order, because they
     * insert their DataSource before the one(s) for the DataDict.
     */
    if ((code = mask_dict_param(op, &ip_data, "ShapeMaskDict", num_components,
				&image.Shape)) < 0 ||
	(code = mask_dict_param(op, &ip_data, "OpacityMaskDict", num_components,
				&image.Opacity)) < 0
	)
	return code;
    return zimage_setup(i_ctx_p, (gs_pixel_image_t *)&image,
			&ip_data.DataSource[0],
			image.CombineWithColor, 1);
}    

/* Get one soft-mask dictionary parameter. */
private int
mask_dict_param(os_ptr op, image_params *pip_data, const char *dict_name,
		int num_components, gs_image3x_mask_t *pixm)
{
    ref *pMaskDict;
    image_params ip_mask;
    int ignored;
    int code, mcode;

    if (dict_find_string(op, dict_name, &pMaskDict) <= 0)
	return 1;
    if ((mcode = code = data_image_params(pMaskDict, &pixm->MaskDict,
					  &ip_mask, false, 1, 12, false)) < 0 ||
	(code = dict_int_param(pMaskDict, "ImageType", 1, 1, 0, &ignored)) < 0 ||
	(code = dict_int_param(pMaskDict, "InterleaveType", 1, 3, -1,
			       &pixm->InterleaveType)) < 0 ||
	(code = dict_floats_param(op, "Matte", num_components, pixm->Matte, NULL)) < 0
	)
	return code;
    pixm->has_Matte = code > 0;
    /*
     * The MaskDict must have a DataSource iff InterleaveType == 3.
     */
    if ((pip_data->MultipleDataSources && pixm->InterleaveType != 3) ||
	ip_mask.MultipleDataSources ||
	mcode != (pixm->InterleaveType != 3)
	)
	return_error(e_rangecheck);
    if (pixm->InterleaveType == 3) {
	/* Insert the mask DataSource before the data DataSources. */
	memmove(&pip_data->DataSource[1], &pip_data->DataSource[0],
		(countof(pip_data->DataSource) - 1) *
		sizeof(pip_data->DataSource[0]));
	pip_data->DataSource[0] = ip_mask.DataSource[0];
    }
    return 0;
}

/* depth .pushpdf14devicefilter - */
/* this is a filter operator, but we include it here to maintain
   modularity of the pdf14 transparency support */
private int
zpushpdf14devicefilter(i_ctx_t *i_ctx_p)
{
    gs_device_filter_t *df;
    int code;
    gs_memory_t *mem = gs_memory_stable(imemory);
    os_ptr op = osp;

    check_type(*op, t_integer);
    code = gs_pdf14_device_filter(&df, op->value.intval, mem);
    if (code < 0)
        return code;
    code = gs_push_device_filter(mem, igs, df); 
    if (code < 0)
        return code;
    pop(1);
    return 0;
}

/* ------ Initialization procedure ------ */

/* We need to split the table because of the 16-element limit. */
const op_def ztrans1_op_defs[] = {
    {"1.setblendmode", zsetblendmode},
    {"0.currentblendmode", zcurrentblendmode},
    {"1.setopacityalpha", zsetopacityalpha},
    {"0.currentopacityalpha", zcurrentopacityalpha},
    {"1.setshapealpha", zsetshapealpha},
    {"0.currentshapealpha", zcurrentshapealpha},
    {"1.settextknockout", zsettextknockout},
    {"0.currenttextknockout", zcurrenttextknockout},
    op_def_end(0)
};
const op_def ztrans2_op_defs[] = {
    {"5.begintransparencygroup", zbegintransparencygroup},
    {"0.discardtransparencygroup", zdiscardtransparencygroup},
    {"0.endtransparencygroup", zendtransparencygroup},
    {"5.begintransparencymask", zbegintransparencymask},
    {"0.discardtransparencymask", zdiscardtransparencymask},
    {"1.endtransparencymask", zendtransparencymask},
    {"1.inittransparencymask", zinittransparencymask},
    {"1.image3x", zimage3x},
    {"1.pushpdf14devicefilter", zpushpdf14devicefilter},
    op_def_end(0)
};
