ghostscript-8.71/psi/zdpnext.c

/* Copyright (C) 2001-2006 Artifex Software, Inc.
   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 that
   license.  Refer to licensing information at http://www.artifex.com/
   or contact Artifex Software, Inc.,  7 Mt. Lassen Drive - Suite A-134,
   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
*/

/* $Id: zdpnext.c 9043 2008-08-28 22:48:19Z giles $ */
/* NeXT Display PostScript extensions */
#include "math_.h"
#include "ghost.h"
#include "oper.h"
#include "gscoord.h"
#include "gscspace.h"		/* for iimage.h */
#include "gsdpnext.h"
#include "gsmatrix.h"
#include "gsiparam.h"		/* for iimage.h */
#include "gsiparm2.h"
#include "gspath2.h"
#include "gxcvalue.h"
#include "gxdevice.h"
#include "gxsample.h"
#include "ialloc.h"
#include "igstate.h"
#include "iimage.h"
#include "iimage2.h"
#include "store.h"

/* ------ alpha channel ------ */

/* - currentalpha <alpha> */
static int
zcurrentalpha(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;

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

/* <alpha> setalpha - */
static int
zsetalpha(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    double alpha;
    int code;

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

/* ------ Imaging/compositing ------ */

/*
 * Miscellaneous notes:
 *
 * composite / dissolve respect destination clipping (both clip & viewclip),
 *   but ignore source clipping.
 * composite / dissolve must handle overlapping source/destination correctly.
 * compositing converts the source to the destination's color model
 *   (including halftoning if needed).
 */

/*
 * Define the operand and bookeeping structure for a compositing operation.
 */
typedef struct alpha_composite_state_s {
    /* Compositing parameters */
    gs_composite_alpha_params_t params;
    /* Temporary structures */
    gs_composite_t *pcte;
    gx_device *cdev;
    gx_device *orig_dev;
} alpha_composite_state_t;

/* Forward references */
static int begin_composite(i_ctx_t *, alpha_composite_state_t *);
static void end_composite(i_ctx_t *, alpha_composite_state_t *);
static int xywh_param(os_ptr, double[4]);

/* <dict> .alphaimage - */
/* This is the dictionary version of the alphaimage operator, which is */
/* now a pseudo-operator (see gs_dpnxt.ps). */
static int
zalphaimage(i_ctx_t *i_ctx_p)
{
    return image1_setup(i_ctx_p, true);
}

/* <destx> <desty> <width> <height> <op> compositerect - */
static int
zcompositerect(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    double dest_rect[4];
    alpha_composite_state_t cstate;
    int code = xywh_param(op - 1, dest_rect);

    if (code < 0)
	return code;
    check_int_leu(*op, compositerect_last);
    cstate.params.op = (gs_composite_op_t) op->value.intval;
    code = begin_composite(i_ctx_p, &cstate);
    if (code < 0)
	return code;
    {
	gs_rect rect;

	rect.q.x = (rect.p.x = dest_rect[0]) + dest_rect[2];
	rect.q.y = (rect.p.y = dest_rect[1]) + dest_rect[3];
	code = gs_rectfill(igs, &rect, 1);
    }
    end_composite(i_ctx_p, &cstate);
    if (code >= 0)
	pop(5);
    return code;
}

/* Common code for composite and dissolve. */
static int
composite_image(i_ctx_t *i_ctx_p, const gs_composite_alpha_params_t * params)
{
    os_ptr op = osp;
    alpha_composite_state_t cstate;
    gs_image2_t image;
    double src_rect[4];
    double dest_pt[2];
    gs_matrix save_ctm;
    int code = xywh_param(op - 4, src_rect);

    cstate.params = *params;
    gs_image2_t_init(&image);
    if (code < 0 ||
	(code = num_params(op - 1, 2, dest_pt)) < 0
	)
	return code;
    if (r_has_type(op - 3, t_null))
	image.DataSource = igs;
    else {
	check_stype(op[-3], st_igstate_obj);
	check_read(op[-3]);
	image.DataSource = igstate_ptr(op - 3);
    }
    image.XOrigin = src_rect[0];
    image.YOrigin = src_rect[1];
    image.Width = src_rect[2];
    image.Height = src_rect[3];
    image.PixelCopy = true;
    /* Compute appropriate transformations. */
    gs_currentmatrix(igs, &save_ctm);
    gs_translate(igs, dest_pt[0], dest_pt[1]);
    gs_make_identity(&image.ImageMatrix);
    if (image.DataSource == igs) {
	image.XOrigin -= dest_pt[0];
	image.YOrigin -= dest_pt[1];
    }
    code = begin_composite(i_ctx_p, &cstate);
    if (code >= 0) {
	code = process_non_source_image(i_ctx_p,
					(const gs_image_common_t *)&image,
					"composite_image");
	end_composite(i_ctx_p, &cstate);
	if (code >= 0)
	    pop(8);
    }
    gs_setmatrix(igs, &save_ctm);
    return code;
}

/* <srcx> <srcy> <width> <height> <srcgstate|null> <destx> <desty> <op> */
/*   composite - */
static int
zcomposite(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_composite_alpha_params_t params;

    check_int_leu(*op, composite_last);
    params.op = (gs_composite_op_t) op->value.intval;
    return composite_image(i_ctx_p, &params);
}

/* <srcx> <srcy> <width> <height> <srcgstate|null> <destx> <desty> <delta> */
/*   dissolve - */
static int
zdissolve(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_composite_alpha_params_t params;
    double delta;
    int code = real_param(op, &delta);

    if (code < 0)
	return code;
    if (delta < 0 || delta > 1)
	return_error(e_rangecheck);
    params.op = composite_Dissolve;
    params.delta = delta;
    return composite_image(i_ctx_p, &params);
}

/* ------ Image reading ------ */

static int device_is_true_color(gx_device * dev);

/* <x> <y> <width> <height> <matrix> .sizeimagebox */
/*   <dev_x> <dev_y> <dev_width> <dev_height> <matrix> */
static void box_confine(int *pp, int *pq, int wh);
static int
zsizeimagebox(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    const gx_device *dev = gs_currentdevice(igs);
    gs_rect srect, drect;
    gs_matrix mat;
    gs_int_rect rect;
    int w, h;
    int code;

    check_type(op[-4], t_integer);
    check_type(op[-3], t_integer);
    check_type(op[-2], t_integer);
    check_type(op[-1], t_integer);
    srect.p.x = op[-4].value.intval;
    srect.p.y = op[-3].value.intval;
    srect.q.x = srect.p.x + op[-2].value.intval;
    srect.q.y = srect.p.y + op[-1].value.intval;
    gs_currentmatrix(igs, &mat);
    gs_bbox_transform(&srect, &mat, &drect);
    /*
     * We want the dimensions of the image as a source, not a
     * destination, so we need to expand it rather than pixround.
     */
    rect.p.x = (int)floor(drect.p.x);
    rect.p.y = (int)floor(drect.p.y);
    rect.q.x = (int)ceil(drect.q.x);
    rect.q.y = (int)ceil(drect.q.y);
    /*
     * Clip the rectangle to the device boundaries, since that's what
     * the NeXT implementation does.
     */
    box_confine(&rect.p.x, &rect.q.x, dev->width);
    box_confine(&rect.p.y, &rect.q.y, dev->height);
    w = rect.q.x - rect.p.x;
    h = rect.q.y - rect.p.y;
    /*
     * The NeXT documentation doesn't specify very clearly what is
     * supposed to be in the matrix: the following produces results
     * that match testing on an actual NeXT system.
     */
    mat.tx -= rect.p.x;
    mat.ty -= rect.p.y;
    code = write_matrix(op, &mat);
    if (code < 0)
	return code;
    make_int(op - 4, rect.p.x);
    make_int(op - 3, rect.p.y);
    make_int(op - 2, w);
    make_int(op - 1, h);
    return 0;
}
static void
box_confine(int *pp, int *pq, int wh)
{
    if ( *pq <= 0 )
	*pp = *pq = 0;
    else if ( *pp >= wh )
	*pp = *pq = wh;
    else {
	if ( *pp < 0 )
	    *pp = 0;
	if ( *pq > wh )
	    *pq = wh;
    }
}

/* - .sizeimageparams <bits/sample> <multiproc> <ncolors> */
static int
zsizeimageparams(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gx_device *dev = gs_currentdevice(igs);
    int ncomp = dev->color_info.num_components;
    int bps;

    push(3);
    if (device_is_true_color(dev))
	bps = dev->color_info.depth / ncomp;
    else {
	/*
	 * Set bps to the smallest allowable number of bits that is
	 * sufficient to represent the number of different colors.
	 */
	gx_color_value max_value =
	    (dev->color_info.num_components == 1 ?
	     dev->color_info.max_gray :
	     max(dev->color_info.max_gray, dev->color_info.max_color));
	static const gx_color_value sizes[] = {
	    1, 2, 4, 8, 12, sizeof(gx_max_color_value) * 8
	};
	int i;

	for (i = 0;; ++i)
	    if (max_value <= ((ulong) 1 << sizes[i]) - 1)
		break;
	bps = sizes[i];
    }
    make_int(op - 2, bps);
    make_false(op - 1);
    make_int(op, ncomp);
    return 0;
}

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

const op_def zdpnext_op_defs[] =
{
    {"0currentalpha", zcurrentalpha},
    {"1setalpha", zsetalpha},
    {"1.alphaimage", zalphaimage},
    {"8composite", zcomposite},
    {"5compositerect", zcompositerect},
    {"8dissolve", zdissolve},
    {"5.sizeimagebox", zsizeimagebox},
    {"0.sizeimageparams", zsizeimageparams},
    op_def_end(0)
};

/* ------ Internal routines ------ */

/* Collect a rect operand. */
static int
xywh_param(os_ptr op, double rect[4])
{
    int code = num_params(op, 4, rect);

    if (code < 0)
	return code;
    if (rect[2] < 0)
	rect[0] += rect[2], rect[2] = -rect[2];
    if (rect[3] < 0)
	rect[1] += rect[3], rect[3] = -rect[3];
    return code;
}

/* Begin a compositing operation. */
static int
begin_composite(i_ctx_t *i_ctx_p, alpha_composite_state_t * pcp)
{
    gx_device *dev = gs_currentdevice(igs);
    int code =
	gs_create_composite_alpha(&pcp->pcte, &pcp->params, imemory);

    if (code < 0)
	return code;
    pcp->orig_dev = pcp->cdev = dev;	/* for end_composite */
    code = (*dev_proc(dev, create_compositor))
	(dev, &pcp->cdev, pcp->pcte, (gs_imager_state *)igs, imemory);
    if (code < 0) {
	end_composite(i_ctx_p, pcp);
	return code;
    }
    gs_setdevice_no_init(igs, pcp->cdev);
    return 0;
}

/* End a compositing operation. */
static void
end_composite(i_ctx_t *i_ctx_p, alpha_composite_state_t * pcp)
{
    /* Close and free the compositor and the compositing object. */
    if (pcp->cdev != pcp->orig_dev) {
	gs_closedevice(pcp->cdev);	/* also frees the device */
	gs_setdevice_no_init(igs, pcp->orig_dev);
    }
    ifree_object(pcp->pcte, "end_composite(gs_composite_t)");
}

/*
 * Determine whether a device has decomposed pixels with the components
 * in the standard PostScript order, and a 1-for-1 color map
 * (possibly inverted).  Return 0 if not true color, 1 if true color,
 * -1 if inverted true color.
 */
static int
device_is_true_color(gx_device * dev)
{
    int ncomp = dev->color_info.num_components;
    int depth = dev->color_info.depth;
    int i, max_v;

#define CV(i) (gx_color_value)((ulong)gx_max_color_value * i / max_v)
#define CV0 ((gx_color_value)0)

    /****** DOESN'T HANDLE INVERSION YET ******/
    switch (ncomp) {
	case 1:		/* gray-scale */
	    max_v = dev->color_info.max_gray;
	    if (max_v != (1 << depth) - 1)
		return 0;
	    for (i = 0; i <= max_v; ++i) {
		gx_color_value v[3];
                v[0] = v[1] = v[2] = CV(i);
		if ((*dev_proc(dev, map_rgb_color)) (dev, v) != i)
		    return 0;
	    }
	    return true;
	case 3:		/* RGB */
	    max_v = dev->color_info.max_color;
	    if (depth % 3 != 0 || max_v != (1 << (depth / 3)) - 1)
		return false;
	    {
		const int gs = depth / 3, rs = gs * 2;

		for (i = 0; i <= max_v; ++i) {
		    gx_color_value red[3];
                    gx_color_value green[3];
                    gx_color_value blue[3];
                    red[0] = CV(i); red[1] = CV0, red[2] = CV0;
                    green[0] = CV0; green[1] = CV(i); green[2] = CV0;
                    blue[0] = CV0; blue[1] = CV0; blue[2] = CV(i);
		    if ((*dev_proc(dev, map_rgb_color)) (dev, red) !=
			i << rs ||
			(*dev_proc(dev, map_rgb_color)) (dev, green) !=
			i << gs ||
			(*dev_proc(dev, map_rgb_color)) (dev, blue) !=
			i	/*<< bs */
			)
			return 0;
		}
	    }
	    return true;
	case 4:		/* CMYK */
	    max_v = dev->color_info.max_color;
	    if ((depth & 3) != 0 || max_v != (1 << (depth / 4)) - 1)
		return false;
	    {
		const int ys = depth / 4, ms = ys * 2, cs = ys * 3;

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

		    gx_color_value cyan[4];
                    gx_color_value magenta[4];
                    gx_color_value yellow[4];
                    gx_color_value black[4];
                    cyan[0] = CV(i); cyan[1] = cyan[2] = cyan[3] = CV0;
                    magenta[1] = CV(i); magenta[0] = magenta[2] = magenta[3] = CV0;
                    yellow[2] = CV(i); yellow[0] = yellow[1] = yellow[3] = CV0;
                    black[3] = CV(i); black[0] = black[1] = black[2] = CV0;
		    if ((*dev_proc(dev, map_cmyk_color)) (dev, cyan) !=
			i << cs ||
			(*dev_proc(dev, map_cmyk_color)) (dev, magenta) !=
			i << ms ||
			(*dev_proc(dev, map_cmyk_color)) (dev, yellow) !=
			i << ys ||
			(*dev_proc(dev, map_cmyk_color)) (dev, black) !=
			i	/*<< ks */
			)
			return 0;
		}
	    }
	    return 1;
	default:
	    return 0;		/* DeviceN */
    }
#undef CV
#undef CV0
}