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/* Copyright (C) 1999, 2000, 2001 Aladdin Enterprises.  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: gdevpdfg.c,v 1.68 2005/09/12 11:34:50 leonardo Exp $ */

/* Graphics state management for pdfwrite driver */

#include "math_.h"

#include "string_.h"

#include "memory_.h"

#include "gx.h"

#include "gserrors.h"

#include "gsfunc0.h"

#include "gsstate.h"

#include "gxbitmap.h"		/* for gxhttile.h in gzht.h */

#include "gxdht.h"

#include "gxfarith.h"		/* for gs_sin/cos_degrees */

#include "gxfmap.h"

#include "gxht.h"

#include "gxistate.h"

#include "gxdcolor.h"

#include "gxpcolor.h"

#include "gsptype2.h"

#include "gzht.h"

#include "gdevpdfx.h"

#include "gdevpdfg.h"

#include "gdevpdfo.h"

#include "szlibx.h"

/* ---------------- Miscellaneous ---------------- */

/* Save the viewer's graphic state. */

int

pdf_save_viewer_state(gx_device_pdf *pdev, stream *s)

{

    const int i = pdev->vgstack_depth;

    if (pdev->vgstack_depth >= count_of(pdev->vgstack))

	return_error(gs_error_unregistered); /* Must not happen. */

    pdev->vgstack[i].transfer_ids[0] = pdev->transfer_ids[0];

    pdev->vgstack[i].transfer_ids[1] = pdev->transfer_ids[1];

    pdev->vgstack[i].transfer_ids[2] = pdev->transfer_ids[2];

    pdev->vgstack[i].transfer_ids[3] = pdev->transfer_ids[3];

    pdev->vgstack[i].transfer_not_identity = pdev->transfer_not_identity;

    pdev->vgstack[i].opacity_alpha = pdev->state.opacity.alpha;

    pdev->vgstack[i].shape_alpha = pdev->state.shape.alpha;

    pdev->vgstack[i].blend_mode = pdev->state.blend_mode;

    pdev->vgstack[i].halftone_id = pdev->halftone_id;

    pdev->vgstack[i].black_generation_id = pdev->black_generation_id;

    pdev->vgstack[i].undercolor_removal_id = pdev->undercolor_removal_id;

    pdev->vgstack[i].overprint_mode = pdev->overprint_mode;

    pdev->vgstack[i].smoothness = pdev->state.smoothness;

    pdev->vgstack[i].flatness = pdev->state.flatness;

    pdev->vgstack[i].text_knockout = pdev->state.text_knockout;

    pdev->vgstack[i].fill_overprint = pdev->fill_overprint;

    pdev->vgstack[i].stroke_overprint = pdev->stroke_overprint;

    pdev->vgstack[i].stroke_adjust = pdev->state.stroke_adjust;

    pdev->vgstack[i].fill_used_process_color = pdev->fill_used_process_color;

    pdev->vgstack[i].stroke_used_process_color = pdev->stroke_used_process_color;

    pdev->vgstack[i].saved_fill_color = pdev->saved_fill_color;

    pdev->vgstack[i].saved_stroke_color = pdev->saved_stroke_color;

    pdev->vgstack[i].line_params = pdev->state.line_params;

    pdev->vgstack[i].line_params.dash.pattern = 0; /* Use pdev->dash_pattern instead. */

    memcpy(pdev->vgstack[i].dash_pattern, pdev->dash_pattern, 

		sizeof(pdev->vgstack[i].dash_pattern));

    pdev->vgstack_depth++;

    if (s)

	stream_puts(s, "q\n");

    return 0;

}

/* Load the viewer's graphic state. */

private void

pdf_load_viewer_state(gx_device_pdf *pdev, pdf_viewer_state *s)

{   

    pdev->transfer_ids[0] = s->transfer_ids[0];

    pdev->transfer_ids[1] = s->transfer_ids[1];

    pdev->transfer_ids[2] = s->transfer_ids[2];

    pdev->transfer_ids[3] = s->transfer_ids[3];

    pdev->transfer_not_identity = s->transfer_not_identity;

    pdev->state.opacity.alpha = s->opacity_alpha;

    pdev->state.shape.alpha = s->shape_alpha;

    pdev->state.blend_mode = s->blend_mode;

    pdev->halftone_id = s->halftone_id;

    pdev->black_generation_id = s->black_generation_id;

    pdev->undercolor_removal_id = s->undercolor_removal_id;

    pdev->overprint_mode = s->overprint_mode;

    pdev->state.smoothness = s->smoothness;

    pdev->state.flatness = s->flatness;

    pdev->state.text_knockout = s->text_knockout;

    pdev->fill_overprint = s->fill_overprint;

    pdev->stroke_overprint = s->stroke_overprint;

    pdev->state.stroke_adjust = s->stroke_adjust;

    pdev->fill_used_process_color = s->fill_used_process_color;

    pdev->stroke_used_process_color = s->stroke_used_process_color;

    pdev->saved_fill_color = s->saved_fill_color;

    pdev->saved_stroke_color = s->saved_stroke_color;

    pdev->state.line_params = s->line_params;

    memcpy(pdev->dash_pattern, s->dash_pattern,

		sizeof(s->dash_pattern));

}

/* Restore the viewer's graphic state. */

int

pdf_restore_viewer_state(gx_device_pdf *pdev, stream *s)

{   const int i = --pdev->vgstack_depth;

    if (i < pdev->vgstack_bottom || i < 0)

	return_error(gs_error_unregistered); /* Must not happen. */

    if (s)

	stream_puts(s, "Q\n");

    pdf_load_viewer_state(pdev, pdev->vgstack + i);

    return 0;

}

/* Set initial color. */

void

pdf_set_initial_color(gx_device_pdf * pdev, gx_hl_saved_color *saved_fill_color,

		    gx_hl_saved_color *saved_stroke_color,

		    bool *fill_used_process_color, bool *stroke_used_process_color)

{

    gx_device_color black;

    pdev->black = gx_device_black((gx_device *)pdev);

    pdev->white = gx_device_white((gx_device *)pdev);

    set_nonclient_dev_color(&black, pdev->black);

    gx_hld_save_color(NULL, &black, saved_fill_color);

    gx_hld_save_color(NULL, &black, saved_stroke_color);

    *fill_used_process_color = true;

    *stroke_used_process_color = true;

}

/* Prepare intitial values for viewer's graphics state parameters. */

private void

pdf_viewer_state_from_imager_state_aux(pdf_viewer_state *pvs, const gs_imager_state *pis)

{

    pvs->transfer_not_identity = 

	    (pis->set_transfer.red   != NULL ? pis->set_transfer.red->proc   != gs_identity_transfer : 0) * 1 +

	    (pis->set_transfer.green != NULL ? pis->set_transfer.green->proc != gs_identity_transfer : 0) * 2 +

	    (pis->set_transfer.blue  != NULL ? pis->set_transfer.blue->proc  != gs_identity_transfer : 0) * 4 +

	    (pis->set_transfer.gray  != NULL ? pis->set_transfer.gray->proc  != gs_identity_transfer : 0) * 8;

    pvs->transfer_ids[0] = (pis->set_transfer.red != NULL ? pis->set_transfer.red->id : 0);

    pvs->transfer_ids[1] = (pis->set_transfer.green != NULL ? pis->set_transfer.green->id : 0);

    pvs->transfer_ids[2] = (pis->set_transfer.blue != NULL ? pis->set_transfer.blue->id : 0);

    pvs->transfer_ids[3] = (pis->set_transfer.gray != NULL ? pis->set_transfer.gray->id : 0);

    pvs->opacity_alpha = pis->opacity.alpha;

    pvs->shape_alpha = pis->shape.alpha;

    pvs->blend_mode = pis->blend_mode;

    pvs->halftone_id = (pis->dev_ht != 0 ? pis->dev_ht->id : 0);

    pvs->black_generation_id = (pis->black_generation != 0 ? pis->black_generation->id : 0);

    pvs->undercolor_removal_id = (pis->undercolor_removal != 0 ? pis->undercolor_removal->id : 0);

    pvs->overprint_mode = 0;

    pvs->smoothness = pis->smoothness;

    pvs->text_knockout = pis->text_knockout;

    pvs->fill_overprint = false;

    pvs->stroke_overprint = false;

    pvs->stroke_adjust = false;

    pvs->line_params.half_width = 0.5;

    pvs->line_params.cap = 0;

    pvs->line_params.join = 0;

    pvs->line_params.curve_join = 0;

    pvs->line_params.miter_limit = 10.0;

    pvs->line_params.miter_check = 0;

    pvs->line_params.dot_length = pis->line_params.dot_length;

    pvs->line_params.dot_length_absolute = pis->line_params.dot_length_absolute;

    pvs->line_params.dot_orientation = pis->line_params.dot_orientation;

    memset(&pvs->line_params.dash, 0 , sizeof(pvs->line_params.dash));

    memset(pvs->dash_pattern, 0, sizeof(pvs->dash_pattern));

}

/* Copy viewer state from images state. */

void

pdf_viewer_state_from_imager_state(gx_device_pdf * pdev, 

	const gs_imager_state *pis, const gx_device_color *pdevc)

{

    pdf_viewer_state vs;

    pdf_viewer_state_from_imager_state_aux(&vs, pis);

    gx_hld_save_color(pis, pdevc, &vs.saved_fill_color);

    gx_hld_save_color(pis, pdevc, &vs.saved_stroke_color);

    pdf_load_viewer_state(pdev, &vs);

}

/* Prepare intitial values for viewer's graphics state parameters. */

void

pdf_prepare_initial_viewer_state(gx_device_pdf * pdev, const gs_imager_state *pis)

{

    /* Parameter values, which are specified in PDF spec, are set here.

     * Parameter values, which are specified in PDF spec as "installation dependent",

     * are set here to intial values used with PS interpreter.

     * This allows to write differences to the output file

     * and skip initial values.

     */

    pdf_set_initial_color(pdev, &pdev->vg_initial.saved_fill_color, &pdev->vg_initial.saved_stroke_color,

	    &pdev->vg_initial.fill_used_process_color, &pdev->vg_initial.stroke_used_process_color);

    pdf_viewer_state_from_imager_state_aux(&pdev->vg_initial, pis);

    pdev->vg_initial_set = true;

    /*

     * Some parameters listed in PDF spec are missed here :

     * text state - it is initialized per page.

     * rendering intent - not sure why, fixme.

     */

}

/* Reset the graphics state parameters to initial values. */

/* Used if pdf_prepare_initial_viewer_state was not callad. */

private void

pdf_reset_graphics_old(gx_device_pdf * pdev)

{

    pdf_set_initial_color(pdev, &pdev->saved_fill_color, &pdev->saved_stroke_color, 

				&pdev->fill_used_process_color, &pdev->stroke_used_process_color);

    pdev->state.flatness = -1;

    {

	static const gx_line_params lp_initial = {

	    gx_line_params_initial

	};

	pdev->state.line_params = lp_initial;

    }

    pdev->fill_overprint = false;

    pdev->stroke_overprint = false;

    pdf_reset_text(pdev);

}

/* Reset the graphics state parameters to initial values. */

void

pdf_reset_graphics(gx_device_pdf * pdev)

{

    if (pdev->vg_initial_set)

	pdf_load_viewer_state(pdev, &pdev->vg_initial);

    else

	pdf_reset_graphics_old(pdev);

    pdf_reset_text(pdev);

}

/* Write client color. */

private int

pdf_write_ccolor(gx_device_pdf * pdev, const gs_imager_state * pis, 

	        const gs_client_color *pcc)

{   

    int i, n = gx_hld_get_number_color_components(pis);

    pprintg1(pdev->strm, "%g", psdf_round(pcc->paint.values[0], 255, 8));

    for (i = 1; i < n; i++) {

	pprintg1(pdev->strm, " %g", psdf_round(pcc->paint.values[i], 255, 8));

    }

    return 0;

}

/* Set the fill or stroke color. */

private int

pdf_reset_color(gx_device_pdf * pdev, const gs_imager_state * pis, 

	        const gx_drawing_color *pdc, gx_hl_saved_color * psc,

		bool *used_process_color,

		const psdf_set_color_commands_t *ppscc)

{

    int code;

    gx_hl_saved_color temp;

    bool process_color;

    const gs_color_space *pcs, *pcs2;

    const gs_client_color *pcc; /* fixme: not needed due to gx_hld_get_color_component. */

    cos_value_t cs_value;

    const char *command;

    int code1 = 0;

    gs_color_space_index csi;

    if (pdev->skip_colors)

	return 0;

    process_color = !gx_hld_save_color(pis, pdc, &temp);

    /* Since pdfwrite never applies halftones and patterns, but monitors

     * halftone/pattern IDs separately, we don't need to compare

     * halftone/pattern bodies here.

     */

    if (gx_hld_saved_color_equal(&temp, psc))

	return 0;

    /*

     * In principle, we can set colors in either stream or text

     * context.  However, since we currently enclose all text

     * strings inside a gsave/grestore, this causes us to lose

     * track of the color when we leave text context.  Therefore,

     * we require stream context for setting colors.

     */

    code = pdf_open_page(pdev, PDF_IN_STREAM);

    if (code < 0)

	return code;

    switch (gx_hld_get_color_space_and_ccolor(pis, pdc, &pcs, &pcc)) {

	case non_pattern_color_space:

	    switch (gs_color_space_get_index(pcs)) {

		case gs_color_space_index_DeviceGray:

		    command = ppscc->setgray; 

		    break;

		case gs_color_space_index_DeviceRGB:

		    command = ppscc->setrgbcolor; 

		    break;

		case gs_color_space_index_DeviceCMYK:

		    command = ppscc->setcmykcolor; 

		    break;

		case gs_color_space_index_Indexed:

		    if (pdev->CompatibilityLevel <= 1.2) {

			pcs2 = (const gs_color_space *)&pcs->params.indexed.base_space;

			csi = gs_color_space_get_index(pcs2);

			if (csi == gs_color_space_index_Separation) {

			    pcs2 = (const gs_color_space *)&pcs2->params.separation.alt_space;

			    goto check_pcs2;

			}

			goto check_pcs2;

		    }

		    goto scn;

		case gs_color_space_index_Separation:

		    if (pdev->CompatibilityLevel <= 1.2) {

			pcs2 = (const gs_color_space *)&pcs->params.separation.alt_space;

			check_pcs2:

			csi = gs_color_space_get_index(pcs2);

			switch(gs_color_space_get_index(pcs2)) {

			    case gs_color_space_index_DevicePixel :

			    case gs_color_space_index_DeviceN:

			    case gs_color_space_index_CIEICC:

				goto write_process_color;

			    default: 

				DO_NOTHING;

			}

		    }

		    goto scn;

		case gs_color_space_index_CIEICC:

		case gs_color_space_index_DevicePixel:

		case gs_color_space_index_DeviceN:

		    if (pdev->CompatibilityLevel <= 1.2)

	    		goto write_process_color;

		    goto scn;

		default :

	        scn:

		    command = ppscc->setcolorn;

		    if (!gx_hld_saved_color_same_cspace(&temp, psc)) {

			code = pdf_color_space(pdev, &cs_value, NULL, pcs,

					&pdf_color_space_names, true);

			/* fixme : creates redundant PDF objects. */

			if (code == gs_error_rangecheck) {

			    /* The color space can't write to PDF. */

			    goto write_process_color;

			}

			if (code < 0)

			    return code;

			code = cos_value_write(&cs_value, pdev);

			if (code < 0)

			    return code;

			pprints1(pdev->strm, " %s\n", ppscc->setcolorspace);

		    } else if (*used_process_color)

			goto write_process_color;

		    break;

	    }

	    *used_process_color = false;

	    code = pdf_write_ccolor(pdev, pis, pcc);

	    if (code < 0)

		return code;

	    pprints1(pdev->strm, " %s\n", command);

	    break;

	case pattern_color_sapce:

	    {	pdf_resource_t *pres;

		if (pdc->type == gx_dc_type_pattern)

		    code = pdf_put_colored_pattern(pdev, pdc, pcs,

				ppscc, pis->have_pattern_streams, &pres);

		else if (pdc->type == &gx_dc_pure_masked) {

		    code = pdf_put_uncolored_pattern(pdev, pdc, pcs, 

				ppscc, pis->have_pattern_streams, &pres);

		    if (code < 0 || pres == 0)

			return code;

		    if (pis->have_pattern_streams)

			code = pdf_write_ccolor(pdev, pis, pcc);

		} else if (pdc->type == &gx_dc_pattern2) {

		    if (pdev->CompatibilityLevel <= 1.2)

	    		return_error(gs_error_rangecheck);

		    code1 = pdf_put_pattern2(pdev, pdc, ppscc, &pres);

		} else

		    return_error(gs_error_rangecheck);

		if (code < 0)

		    return code;

		cos_value_write(cos_resource_value(&cs_value, pres->object), pdev);

		pprints1(pdev->strm, " %s\n", ppscc->setcolorn);

		code = pdf_add_resource(pdev, pdev->substream_Resources, "/Pattern", pres);

		if (code < 0)

		    return code;

	    }

	    *used_process_color = false;

	    break;

	default: /* must not happen. */

	case use_process_color:

	write_process_color:

	    code = psdf_set_color((gx_device_vector *)pdev, pdc, ppscc);

	    if (code < 0)

		return code;

	    *used_process_color = true;

    }

    *psc = temp;

    return code1;

}

int

pdf_set_drawing_color(gx_device_pdf * pdev, const gs_imager_state * pis,

		      const gx_drawing_color *pdc,

		      gx_hl_saved_color * psc,

		      bool *used_process_color,

		      const psdf_set_color_commands_t *ppscc)

{

    return pdf_reset_color(pdev, pis, pdc, psc, used_process_color, ppscc);

}

int

pdf_set_pure_color(gx_device_pdf * pdev, gx_color_index color,

		   gx_hl_saved_color * psc,

    		   bool *used_process_color,

		   const psdf_set_color_commands_t *ppscc)

{

    gx_drawing_color dcolor;

    set_nonclient_dev_color(&dcolor, color);

    return pdf_reset_color(pdev, NULL, &dcolor, psc, used_process_color, ppscc);

}

/*

 * Convert a string into cos name.

 */

int

pdf_string_to_cos_name(gx_device_pdf *pdev, const byte *str, uint len, 

		       cos_value_t *pvalue)

{

    byte *chars = gs_alloc_string(pdev->pdf_memory, len + 1, 

                                  "pdf_string_to_cos_name");

    if (chars == 0)

	return_error(gs_error_VMerror);

    chars[0] = '/';

    memcpy(chars + 1, str, len);

    cos_string_value(pvalue, chars, len + 1);

    return 0;

}

/* ---------------- Graphics state updating ---------------- */

/* ------ Functions ------ */

/* Define the maximum size of a Function reference. */

#define MAX_FN_NAME_CHARS 9	/* /Default, /Identity */

#define MAX_FN_CHARS max(MAX_REF_CHARS + 4, MAX_FN_NAME_CHARS)

/*

 * Create and write a Function for a gx_transfer_map.  We use this for

 * transfer, BG, and UCR functions.  If check_identity is true, check for

 * an identity map.  Return 1 if the map is the identity map, otherwise

 * return 0.

 */

private data_source_proc_access(transfer_map_access); /* check prototype */

private int

transfer_map_access(const gs_data_source_t *psrc, ulong start, uint length,

		    byte *buf, const byte **ptr)

{

    const gx_transfer_map *map = (const gx_transfer_map *)psrc->data.str.data;

    uint i;

    if (ptr)

	*ptr = buf;

    for (i = 0; i < length; ++i)

	buf[i] = frac2byte(map->values[(uint)start + i]);

    return 0;

}

private int

transfer_map_access_signed(const gs_data_source_t *psrc,

			   ulong start, uint length,

			   byte *buf, const byte **ptr)

{

    /* To prevent numeric errors, we need to map 0 to an integer. 

     * We can't apply a general expression, because Decode isn't accessible here.

     * Assuming this works for UCR only.

     * Assuming the range of UCR is always [-1, 1].

     * Assuming BitsPerSample = 8.

     */

    const gx_transfer_map *map = (const gx_transfer_map *)psrc->data.str.data;

    uint i;

    *ptr = buf;

    for (i = 0; i < length; ++i)

	buf[i] = (byte)

	    ((frac2float(map->values[(uint)start + i]) + 1) * 127);

    return 0;

}

private int

pdf_write_transfer_map(gx_device_pdf *pdev, const gx_transfer_map *map,

		       int range0, bool check_identity,

		       const char *key, char *ids)

{

    gs_memory_t *mem = pdev->pdf_memory;

    gs_function_Sd_params_t params;

    static const float domain01[2] = { 0, 1 };

    static const int size = transfer_map_size;

    float range01[2], decode[2];

    gs_function_t *pfn;

    long id;

    int code;

    if (map == 0) {

	*ids = 0;		/* no map */

	return 1;

    }

    if (check_identity) {

	/* Check for an identity map. */

	int i;

	if (map->proc == gs_identity_transfer)

	    i = transfer_map_size;

	else

 	    for (i = 0; i < transfer_map_size; ++i) {

 		fixed d = map->values[i] - bits2frac(i, log2_transfer_map_size);

 		if (any_abs(d) > fixed_epsilon) /* ignore small noise */

  		    break;

 	    }

	if (i == transfer_map_size) {

	    strcpy(ids, key);

	    strcat(ids, "/Identity");

	    return 1;

	}

    }

    params.m = 1;

    params.Domain = domain01;

    params.n = 1;

    range01[0] = (float)range0, range01[1] = 1.0;

    params.Range = range01;

    params.Order = 1;

    params.DataSource.access =

	(range0 < 0 ? transfer_map_access_signed : transfer_map_access);

    params.DataSource.data.str.data = (const byte *)map; /* bogus */

    /* DataSource */

    params.BitsPerSample = 8;	/* could be 16 */

    params.Encode = 0;

    if (range01[0] < 0 && range01[1] > 0) {

	/* This works for UCR only.

	 * Map 0 to an integer. 

	 * Rather the range of UCR is always [-1, 1], 

	 * we prefer a general expression. 

	 */

	int r0 = (int)( -range01[0] * ((1 << params.BitsPerSample) - 1) 

			/ (range01[1] - range01[0]) ); /* Round down. */

	float r1 = r0 * range01[1] / -range01[0]; /* r0 + r1 <= (1 << params.BitsPerSample) - 1 */

	decode[0] = range01[0];

	decode[1] = range01[0] + (range01[1] - range01[0]) * ((1 << params.BitsPerSample) - 1) 

				    / (r0 + r1);

	params.Decode = decode;

    } else

    	params.Decode = 0;

    params.Size = &size;

    code = gs_function_Sd_init(&pfn, &params, mem);

    if (code < 0)

	return code;

    code = pdf_write_function(pdev, pfn, &id);

    gs_function_free(pfn, false, mem);

    if (code < 0)

	return code;

    sprintf(ids, "%s%s%ld 0 R", key, (key[0] && key[0] != ' ' ? " " : ""), id);

    return 0;

}

private int

pdf_write_transfer(gx_device_pdf *pdev, const gx_transfer_map *map,

		   const char *key, char *ids)

{

    return pdf_write_transfer_map(pdev, map, 0, true, key, ids);

}

/* ------ Halftones ------ */

/*

 * Recognize the predefined PDF halftone functions.  Note that because the

 * corresponding PostScript functions use single-precision floats, the

 * functions used for testing must do the same in order to get identical

 * results.  Currently we only do this for a few of the functions.

 */

#define HT_FUNC(name, expr)\

  private floatp name(floatp xd, floatp yd) {\

    float x = (float)xd, y = (float)yd;\

    return d2f(expr);\

  }

/*

 * In most versions of gcc (e.g., 2.7.2.3, 2.95.4), return (float)xxx

 * doesn't actually do the coercion.  Force this here.  Note that if we

 * use 'inline', it doesn't work.

 */

private float

d2f(floatp d)

{

    float f = (float)d;

    return f;

}

private floatp

ht_Round(floatp xf, floatp yf)

{

    float x = (float)xf, y = (float)yf;

    float xabs = fabs(x), yabs = fabs(y);

    if (d2f(xabs + yabs) <= 1)

	return d2f(1 - d2f(d2f(x * x) + d2f(y * y)));

    xabs -= 1, yabs -= 1;

    return d2f(d2f(d2f(xabs * xabs) + d2f(yabs * yabs)) - 1);

}

private floatp

ht_Diamond(floatp xf, floatp yf)

{

    float x = (float)xf, y = (float)yf;

    float xabs = fabs(x), yabs = fabs(y);

    if (d2f(xabs + yabs) <= 0.75)

	return d2f(1 - d2f(d2f(x * x) + d2f(y * y)));

    if (d2f(xabs + yabs) <= d2f(1.23))

	return d2f(1 - d2f(d2f(d2f(0.85) * xabs) + yabs));

    xabs -= 1, yabs -= 1;

    return d2f(d2f(d2f(xabs * xabs) + d2f(yabs * yabs)) - 1);

}

private floatp

ht_Ellipse(floatp xf, floatp yf)

{

    float x = (float)xf, y = (float)yf;

    float xabs = fabs(x), yabs = fabs(y);

    /*

     * The PDF Reference, 2nd edition, incorrectly specifies the

     * computation w = 4 * |x| + 3 * |y| - 3.  The PostScript code in the

     * same book correctly implements w = 3 * |x| + 4 * |y| - 3.

     */

    float w = (float)(d2f(d2f(3 * xabs) + d2f(4 * yabs)) - 3);

    if (w < 0) {

	yabs /= 0.75;

	return d2f(1 - d2f((d2f(x * x) + d2f(yabs * yabs)) / 4));

    }

    if (w > 1) {

	xabs = 1 - xabs, yabs = d2f(1 - yabs) / 0.75;

	return d2f(d2f((d2f(xabs * xabs) + d2f(yabs * yabs)) / 4) - 1);

    }

    return d2f(0.5 - w);

}

/*

 * Most of these are recognized properly even without d2f.  We've only

 * added d2f where it apparently makes a difference.

 */

private float

d2fsin_d(double x) {

    return d2f(gs_sin_degrees(d2f(x)));

}

private float

d2fcos_d(double x) {

    return d2f(gs_cos_degrees(d2f(x)));

}

HT_FUNC(ht_EllipseA, 1 - (x * x + 0.9 * y * y))

HT_FUNC(ht_InvertedEllipseA, x * x + 0.9 * y * y - 1)

HT_FUNC(ht_EllipseB, 1 - sqrt(x * x + 0.625 * y * y))

HT_FUNC(ht_EllipseC, 1 - (0.9 * x * x + y * y))

HT_FUNC(ht_InvertedEllipseC, 0.9 * x * x + y * y - 1)

HT_FUNC(ht_Line, -fabs((x - x) + y)) /* quiet compiler (unused variable x) */

HT_FUNC(ht_LineX, (y - y) + x) /* quiet compiler (unused variable y) */

HT_FUNC(ht_LineY, (x - x) + y) /* quiet compiler (unused variable x) */

HT_FUNC(ht_Square, -max(fabs(x), fabs(y)))

HT_FUNC(ht_Cross, -min(fabs(x), fabs(y)))

HT_FUNC(ht_Rhomboid, (0.9 * fabs(x) + fabs(y)) / 2)

HT_FUNC(ht_DoubleDot, (d2fsin_d(x * 360) + d2fsin_d(y * 360)) / 2)

HT_FUNC(ht_InvertedDoubleDot, -(d2fsin_d(x * 360) + d2fsin_d(y * 360)) / 2)

HT_FUNC(ht_SimpleDot, 1 - d2f(d2f(x * x) + d2f(y * y)))

HT_FUNC(ht_InvertedSimpleDot, d2f(d2f(x * x) + d2f(y * y)) - 1)

HT_FUNC(ht_CosineDot, (d2fcos_d(x * 180) + d2fcos_d(y * 180)) / 2)

HT_FUNC(ht_Double, (d2fsin_d(x * 180) + d2fsin_d(y * 360)) / 2)

HT_FUNC(ht_InvertedDouble, -(d2fsin_d(x * 180) + d2fsin_d(y * 360)) / 2)

typedef struct ht_function_s {

    const char *fname;

    floatp (*proc)(floatp, floatp);

} ht_function_t;

private const ht_function_t ht_functions[] = {

    {"Round", ht_Round},

    {"Diamond", ht_Diamond},

    {"Ellipse", ht_Ellipse},

    {"EllipseA", ht_EllipseA},

    {"InvertedEllipseA", ht_InvertedEllipseA},

    {"EllipseB", ht_EllipseB},

    {"EllipseC", ht_EllipseC},

    {"InvertedEllipseC", ht_InvertedEllipseC},

    {"Line", ht_Line},

    {"LineX", ht_LineX},

    {"LineY", ht_LineY},

    {"Square", ht_Square},

    {"Cross", ht_Cross},

    {"Rhomboid", ht_Rhomboid},

    {"DoubleDot", ht_DoubleDot},

    {"InvertedDoubleDot", ht_InvertedDoubleDot},

    {"SimpleDot", ht_SimpleDot},

    {"InvertedSimpleDot", ht_InvertedSimpleDot},

    {"CosineDot", ht_CosineDot},

    {"Double", ht_Double},

    {"InvertedDouble", ht_InvertedDouble}

};

/* Write each kind of halftone. */

private int

pdf_write_spot_function(gx_device_pdf *pdev, const gx_ht_order *porder,

			long *pid)

{

    /****** DOESN'T HANDLE STRIP HALFTONES ******/

    int w = porder->width, h = porder->height;

    uint num_bits = porder->num_bits;

    gs_function_Sd_params_t params;

    static const float domain_spot[4] = { -1, 1, -1, 1 };

    static const float range_spot[4] = { -1, 1 };

    int size[2];

    gs_memory_t *mem = pdev->pdf_memory;

    /*

     * Even though the values are logically ushort, we must always store

     * them in big-endian order, so we access them as bytes.

     */

    byte *values;

    gs_function_t *pfn;

    uint i;

    int code = 0;

    params.m = 2;

    params.Domain = domain_spot;

    params.n = 1;

    params.Range = range_spot;

    params.Order = 0;		/* default */

    /*

     * We could use 8, 16, or 32 bits per sample to save space, but for

     * simplicity, we always use 16.

     */

    if (num_bits > 0x10000)

	return_error(gs_error_rangecheck);

    params.BitsPerSample = 16;

    params.Encode = 0;

    /*

     * The default Decode array maps the actual data values [1 .. w*h] to a

     * sub-interval of the Range, but that's OK, since all that matters is

     * the relative values, not the absolute values.

     */

    params.Decode = 0;

    size[0] = w;

    size[1] = h;

    params.Size = size;

    /* Create the (temporary) threshold array. */

    values = gs_alloc_byte_array(mem, num_bits, 2, "pdf_write_spot_function");

    if (values == 0)

	return_error(gs_error_VMerror);

    for (i = 0; i < num_bits; ++i) {

	gs_int_point pt;

	int value;

	if ((code = porder->procs->bit_index(porder, i, &pt)) < 0)

	    break;

	value = pt.y * w + pt.x;

	/* Always store the values in big-endian order. */

	values[i * 2] = (byte)(value >> 8);

	values[i * 2 + 1] = (byte)value;

    }

    data_source_init_bytes(&params.DataSource, (const byte *)values,

			   sizeof(*values) * num_bits);

    if (code >= 0 &&

	(code = gs_function_Sd_init(&pfn, &params, mem)) >= 0

	) {

	code = pdf_write_function(pdev, pfn, pid);

	gs_function_free(pfn, false, mem);

    }

    gs_free_object(mem, values, "pdf_write_spot_function");

    return code;

}

private int

pdf_write_spot_halftone(gx_device_pdf *pdev, const gs_spot_halftone *psht,

			const gx_ht_order *porder, long *pid)

{

    char trs[17 + MAX_FN_CHARS + 1];

    int code = pdf_write_transfer(pdev, porder->transfer, "/TransferFunction",

				  trs);

    long id, spot_id;

    stream *s;

    int i = countof(ht_functions);

    gs_memory_t *mem = pdev->pdf_memory;

    if (code < 0)

	return code;

    /*

     * See if we can recognize the spot function, by comparing its sampled

     * values against those in the order.

     */

    {	gs_screen_enum senum;

	gx_ht_order order;

	int code;

	order = *porder;

	code = gs_screen_order_alloc(&order, mem);

	if (code < 0)

	    goto notrec;

	for (i = 0; i < countof(ht_functions); ++i) {

	    floatp (*spot_proc)(floatp, floatp) = ht_functions[i].proc;

	    gs_point pt;

	    gs_screen_enum_init_memory(&senum, &order, NULL, &psht->screen,

				       mem);

	    while ((code = gs_screen_currentpoint(&senum, &pt)) == 0 &&

		   gs_screen_next(&senum, spot_proc(pt.x, pt.y)) >= 0)

		DO_NOTHING;

	    if (code < 0)

		continue;

	    /* Compare the bits and levels arrays. */

	    if (memcmp(order.levels, porder->levels,

		       order.num_levels * sizeof(*order.levels)))

		continue;

	    if (memcmp(order.bit_data, porder->bit_data,

		       order.num_bits * porder->procs->bit_data_elt_size))

		continue;

	    /* We have a match. */

	    break;

	}

	gx_ht_order_release(&order, mem, false);

    }

 notrec:

    if (i == countof(ht_functions)) {

	/* Create and write a Function for the spot function. */

	pdf_write_spot_function(pdev, porder, &spot_id);

    }	

    *pid = id = pdf_begin_separate(pdev);

    s = pdev->strm;

    /* Use the original, requested frequency and angle. */

    pprintg2(s, "<</Type/Halftone/HalftoneType 1/Frequency %g/Angle %g",

	     psht->screen.frequency, psht->screen.angle);

    if (i < countof(ht_functions))

	pprints1(s, "/SpotFunction/%s", ht_functions[i].fname);

    else

	pprintld1(s, "/SpotFunction %ld 0 R", spot_id);

    stream_puts(s, trs);

    if (psht->accurate_screens)

	stream_puts(s, "/AccurateScreens true");

    stream_puts(s, ">>\n");