harvey/sys/src/cmd/gs/src/gscsepr.c

/* Copyright (C) 1994, 2000 Aladdin Enterprises.  All rights reserved.
  
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  Every copy of AFPL Ghostscript must include a copy of the License, normally
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  requires that the copyright notice and this notice be preserved on all
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*/

/*$Id: gscsepr.c,v 1.12.2.1 2001/10/21 06:05:44 raph Exp $ */
/* Separation color space and operation definition */
#include "memory_.h"
#include "gx.h"
#include "gserrors.h"
#include "gsfunc.h"
#include "gsrefct.h"
#include "gsmatrix.h"		/* for gscolor2.h */
#include "gscsepr.h"
#include "gxcspace.h"
#include "gxfixed.h"		/* for gxcolor2.h */
#include "gxcolor2.h"		/* for gs_indexed_map */
#include "gzstate.h"		/* for pgs->overprint */

/* ---------------- Color space ---------------- */

gs_private_st_composite(st_color_space_Separation, gs_paint_color_space,
			"gs_color_space_Separation",
			cs_Separation_enum_ptrs, cs_Separation_reloc_ptrs);

/* Define the Separation color space type. */
private cs_proc_base_space(gx_alt_space_Separation);
private cs_proc_equal(gx_equal_Separation);
private cs_proc_init_color(gx_init_Separation);
private cs_proc_concrete_space(gx_concrete_space_Separation);
private cs_proc_concretize_color(gx_concretize_Separation);
private cs_proc_remap_concrete_color(gx_remap_concrete_Separation);
private cs_proc_remap_color(gx_remap_Separation);
private cs_proc_install_cspace(gx_install_Separation);
private cs_proc_adjust_cspace_count(gx_adjust_cspace_Separation);
const gs_color_space_type gs_color_space_type_Separation = {
    gs_color_space_index_Separation, true, false,
    &st_color_space_Separation, gx_num_components_1,
    gx_alt_space_Separation, gx_equal_Separation,
    gx_init_Separation, gx_restrict01_paint_1,
    gx_concrete_space_Separation,
    gx_concretize_Separation, gx_remap_concrete_Separation,
    gx_remap_Separation, gx_install_Separation,
    gx_adjust_cspace_Separation, gx_no_adjust_color_count
};

/* GC procedures */

private 
ENUM_PTRS_WITH(cs_Separation_enum_ptrs, gs_color_space *pcs)
{
    return ENUM_USING(*pcs->params.separation.alt_space.type->stype,
		      &pcs->params.separation.alt_space,
		      sizeof(pcs->params.separation.alt_space), index - 1);
}
ENUM_PTR(0, gs_color_space, params.separation.map);
ENUM_PTRS_END
private RELOC_PTRS_WITH(cs_Separation_reloc_ptrs, gs_color_space *pcs)
{
    RELOC_PTR(gs_color_space, params.separation.map);
    RELOC_USING(*pcs->params.separation.alt_space.type->stype,
		&pcs->params.separation.alt_space,
		sizeof(gs_base_color_space));
}
RELOC_PTRS_END

/* Get the alternate space for a Separation space. */
private const gs_color_space *
gx_alt_space_Separation(const gs_color_space * pcs)
{
    return (const gs_color_space *)&(pcs->params.separation.alt_space);
}

/* Test whether one Separation color space equals another. */
private bool
gx_equal_Separation(const gs_color_space *pcs1, const gs_color_space *pcs2)
{
    return (gs_color_space_equal(gx_alt_space_Separation(pcs1),
				 gx_alt_space_Separation(pcs2)) &&
	    pcs1->params.separation.sname == pcs2->params.separation.sname &&
	    ((pcs1->params.separation.map->proc.tint_transform ==
	        pcs2->params.separation.map->proc.tint_transform &&
	      pcs1->params.separation.map->proc_data ==
	        pcs2->params.separation.map->proc_data) ||
	     !memcmp(pcs1->params.separation.map->values,
		     pcs2->params.separation.map->values,
		     pcs1->params.separation.map->num_values *
		     sizeof(pcs1->params.separation.map->values[0]))));
}

/* Get the concrete space for a Separation space. */
/* (We don't support concrete Separation spaces yet.) */
private const gs_color_space *
gx_concrete_space_Separation(const gs_color_space * pcs,
			     const gs_imager_state * pis)
{
    const gs_color_space *pacs =
	(const gs_color_space *)&pcs->params.separation.alt_space;

    return cs_concrete_space(pacs, pis);
}

/* Install a Separation color space. */
private int
gx_install_Separation(const gs_color_space * pcs, gs_state * pgs)
{
    return (*pcs->params.separation.alt_space.type->install_cspace)
	((const gs_color_space *) & pcs->params.separation.alt_space, pgs);
}

/* Adjust the reference count of a Separation color space. */
private void
gx_adjust_cspace_Separation(const gs_color_space * pcs, int delta)
{
    rc_adjust_const(pcs->params.separation.map, delta,
		    "gx_adjust_Separation");
    (*pcs->params.separation.alt_space.type->adjust_cspace_count)
	((const gs_color_space *)&pcs->params.separation.alt_space, delta);
}

/* ------ Constructors/accessors ------ */

/*
 * The default separation tint transformation function. This will just return
 * the information in the cache or, if the cache is of zero size, set all
 * components in the alternative color space to 0.
 *
 * No special cases are provided for this routine, as the use of separations
 * (particular in this form) is sufficiently rare to not have a significant
 * performance impact.
 */
private int
map_tint_value(const gs_separation_params * pcssepr, floatp in_val,
	       float *out_vals)
{
    int ncomps =
    cs_num_components((const gs_color_space *)&pcssepr->alt_space);
    int nentries = pcssepr->map->num_values / ncomps;
    int indx;
    const float *pv = pcssepr->map->values;
    int i;

    if (nentries == 0) {
	for (i = 0; i < ncomps; i++)
	    out_vals[i] = 0.0;
	return 0;
    }
    if (in_val > 1)
	indx = nentries - 1;
    else if (in_val <= 0)
	indx = 0;
    else
	indx = (int)(in_val * nentries + 0.5);
    pv += indx * ncomps;

    for (i = 0; i < ncomps; i++)
	out_vals[i] = pv[i];
    return 0;
}

/*
 *  Allocate the indexed map required by a separation color space. 
 */
private gs_indexed_map *
alloc_separation_map(const gs_color_space * palt_cspace, int cache_size,
		     gs_memory_t * pmem)
{
    int num_values =
	(cache_size == 0 ? 0 :
	 cache_size * gs_color_space_num_components(palt_cspace));
    gs_indexed_map *pimap;
    int code = alloc_indexed_map(&pimap, num_values, pmem,
				 "gs_cspace_build_Separation");

    if (code < 0)
	return 0;
    pimap->proc.tint_transform = map_tint_value;
    return pimap;
}

/*
 * Build a separation color space.
 *
 * The values array provided with separation color spaces is actually cached
 * information, but filled in by the client. The alternative space is the
 * color space in which the tint procedure will provide alternative colors.
 */
int
gs_cspace_build_Separation(
			      gs_color_space ** ppcspace,
			      gs_separation_name sname,
			      const gs_color_space * palt_cspace,
			      int cache_size,
			      gs_memory_t * pmem
)
{
    gs_color_space *pcspace = 0;
    gs_separation_params *pcssepr = 0;
    int code;

    if (palt_cspace == 0 || !palt_cspace->type->can_be_alt_space)
	return_error(gs_error_rangecheck);

    code = gs_cspace_alloc(&pcspace, &gs_color_space_type_Separation, pmem);
    if (code < 0)
	return code;
    pcssepr = &pcspace->params.separation;
    pcssepr->map = alloc_separation_map(palt_cspace, cache_size, pmem);
    if (pcssepr->map == 0) {
	gs_free_object(pmem, pcspace, "gs_cspace_build_Separation");
	return_error(gs_error_VMerror);
    }
    pcssepr->sname = sname;
    gs_cspace_init_from((gs_color_space *) & pcssepr->alt_space, palt_cspace);
    *ppcspace = pcspace;
    return 0;
}

/*
 * Get the cached value array for a separation color space. This will return
 * a null pointer if the color space is not a separation color space, or if
 * the separation color space has a cache size of 0.
 */
float *
gs_cspace_get_sepr_value_array(const gs_color_space * pcspace)
{
    if (gs_color_space_get_index(pcspace) != gs_color_space_index_Separation)
	return 0;
    return pcspace->params.separation.map->values;
}

/*
 * Set the tint transformation procedure used by a Separation color space.
 */
int
gs_cspace_set_sepr_proc(gs_color_space * pcspace,
	    int (*proc) (P3(const gs_separation_params *, floatp, float *)))
{
    gs_indexed_map *pimap;

    if (gs_color_space_get_index(pcspace) != gs_color_space_index_Separation)
	return_error(gs_error_rangecheck);
    pimap = pcspace->params.separation.map;
    pimap->proc.tint_transform = proc;
    pimap->proc_data = 0;
    return 0;
}

/* Map a Separation tint using a Function. */
private int
map_sepr_using_function(const gs_separation_params * pcssepr,
			floatp in_val, float *out_vals)
{
    float in = in_val;
    gs_function_t *const pfn = pcssepr->map->proc_data;

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

/*
 * Set the Separation tint transformation procedure to a Function.
 */
int
gs_cspace_set_sepr_function(const gs_color_space *pcspace, gs_function_t *pfn)
{
    gs_indexed_map *pimap;

    if (gs_color_space_get_index(pcspace) != gs_color_space_index_Separation ||
	pfn->params.m != 1 ||
	pfn->params.n !=
	  gs_color_space_num_components((const gs_color_space *)
					&pcspace->params.separation.alt_space)
	)
	return_error(gs_error_rangecheck);
    pimap = pcspace->params.separation.map;
    pimap->proc.tint_transform = map_sepr_using_function;
    pimap->proc_data = pfn;
    return 0;
}

/*
 * If the Separation tint transformation procedure is a Function,
 * return the function object, otherwise return 0.
 */
gs_function_t *
gs_cspace_get_sepr_function(const gs_color_space *pcspace)
{
    if (gs_color_space_get_index(pcspace) == gs_color_space_index_Separation &&
	pcspace->params.separation.map->proc.tint_transform ==
	  map_sepr_using_function)
	return pcspace->params.separation.map->proc_data;
    return 0;
}

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

/* setoverprint */
void
gs_setoverprint(gs_state * pgs, bool ovp)
{
    pgs->overprint = ovp;
}

/* currentoverprint */
bool
gs_currentoverprint(const gs_state * pgs)
{
    return pgs->overprint;
}

/* setoverprintmode */
int
gs_setoverprintmode(gs_state * pgs, int mode)
{
    if (mode < 0 || mode > 1)
	return_error(gs_error_rangecheck);
    pgs->overprint_mode = mode;
    return 0;
}

/* currentoverprintmode */
int
gs_currentoverprintmode(const gs_state * pgs)
{
    return pgs->overprint_mode;
}

/* ------ Internal procedures ------ */

/* Initialize a Separation color. */

private void
gx_init_Separation(gs_client_color * pcc, const gs_color_space * pcs)
{
    pcc->paint.values[0] = 1.0;
}

/* Remap a Separation color. */

private int
gx_remap_Separation(const gs_client_color * pcc, const gs_color_space * pcs,
	gx_device_color * pdc, const gs_imager_state * pis, gx_device * dev,
		       gs_color_select_t select)
{
    if (pcs->params.separation.sep_type != SEP_NONE)
	return gx_default_remap_color(pcc, pcs, pdc, pis, dev, select);
    color_set_null(pdc);
    return 0;
}

private int
gx_concretize_Separation(const gs_client_color *pc, const gs_color_space *pcs,
			 frac *pconc, const gs_imager_state *pis)
{
    float tint;
    int code;
    gs_client_color cc;
    const gs_color_space *pacs =
    (const gs_color_space *)&pcs->params.separation.alt_space;

    if (pcs->params.separation.sep_type == SEP_ALL) {
	/* "All" means setting all device components to same value. */
	const gs_color_space *pconcs = cs_concrete_space(pacs, pis);
	int i, n = cs_num_components(pconcs);
	frac conc;
	gs_client_color hack_color = *pc;

	/* Invert the photometric interpretation for additive
         * color spaces because separations are always subtractive.
         * fixme: this code sets all colorants in the alternative
         * color space, not the destination color space. This is
         * wrong.
         */
	if(n==1 || n==3)
	    hack_color.paint.values[0] = 1 - pc->paint.values[0];
	/* hack: using DeviceGray's function to concretize single component color : */
	code = gx_concretize_DeviceGray(&hack_color, pacs, &conc, pis);

	for (i = 0; i < n; i++)
	    pconc[i] = conc;

	return code;
    }

    tint = pc->paint.values[0];
    if (tint < 0)
	tint = 0;
    else if (tint > 1)
	tint = 1;
    /* We always map into the alternate color space. */
    code = (*pcs->params.separation.map->proc.tint_transform) (&pcs->params.separation, tint, &cc.paint.values[0]);
    if (code < 0)
	return code;
    return (*pacs->type->concretize_color) (&cc, pacs, pconc, pis);
}

private int
gx_remap_concrete_Separation(const frac * pconc,
	gx_device_color * pdc, const gs_imager_state * pis, gx_device * dev,
			     gs_color_select_t select)
{				/* We don't support concrete Separation colors yet. */
    return_error(gs_error_rangecheck);
}

/* ---------------- Notes on real Separation colors ---------------- */

typedef ulong gs_separation;	/* BOGUS */

#define gs_no_separation ((gs_separation)(-1L))

#define dev_proc_lookup_separation(proc)\
  gs_separation proc(P4(gx_device *dev, const byte *sname, uint len,\
    gx_color_value *num_levels))

#define dev_proc_map_tint_color(proc)\
  gx_color_index proc(P4(gx_device *dev, gs_separation sepr, bool overprint,\
    gx_color_value tint))

/*
 * In principle, setting a Separation color space, or setting the device
 * when the current color space is a Separation space, calls the
 * lookup_separation device procedure to obtain the separation ID and
 * the number of achievable levels.  Currently, the only hooks for doing
 * this are unsuitable: gx_set_cmap_procs isn't called when the color
 * space changes, and doing it in gx_remap_Separation is inefficient.
 * Probably the best approach is to call gx_set_cmap_procs whenever the
 * color space changes.  In fact, if we do this, we can probably short-cut
 * two levels of procedure call in color remapping (gx_remap_color, by
 * turning it into a macro, and gx_remap_DeviceXXX, by calling the
 * cmap_proc procedure directly).  Some care will be required for the
 * implicit temporary resetting of the color space in [color]image.
 *
 * For actual remapping of Separation colors, we need cmap_separation_direct
 * and cmap_separation_halftoned, just as for the other device color spaces.
 * So we need to break apart gx_render_gray in gxdither.c so it can also
 * do the job for separations.
 */