/* Copyright (C) 2001-2021 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 the license contained in the file LICENSE in this distribution.

   Refer to licensing information at http://www.artifex.com or contact
   Artifex Software, Inc.,  1305 Grant Avenue - Suite 200, Novato,
   CA 94945, U.S.A., +1(415)492-9861, for further information.
*/


/* Level 2 / Display PostScript graphics extensions */
#include "ghost.h"
#include "oper.h"
#include "gsmatrix.h"
#include "gspath.h"
#include "gspath2.h"
#include "gsstate.h"
#include "gxgstate.h"
#include "ialloc.h"
#include "igstate.h"
#include "ivmspace.h"
#include "store.h"
#include "stream.h"
#include "ibnum.h"

/* Forward references */
static int gstate_unshare(i_ctx_t *);

/* Declare exported procedures (for zupath.c) */
int zsetbbox(i_ctx_t *);

/* Structure descriptors */
public_st_igstate_obj();

/* Extend the `copy' operator to deal with gstates. */
/* This is done with a hack -- we know that gstates are the only */
/* t_astruct subtype that implements copy. */
static int
z1copy(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    int code = zcopy(i_ctx_p);

    if (code >= 0)
        return code;
    if (!r_has_type(op, t_astruct))
        return code;
    return zcopy_gstate(i_ctx_p);
}

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

/* <bool> setstrokeadjust - */
static int
zsetstrokeadjust(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;

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

/* - currentstrokeadjust <bool> */
static int
zcurrentstrokeadjust(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;

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

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

/*
 * Check to make sure that all the elements of a graphics state
 * can be stored in the given allocation space.
 */
/* ****** DOESN'T CHECK THE NON-REFS. ****** */
static int
gstate_check_space(i_ctx_t *i_ctx_p, int_gstate *isp, uint space)
{
    /*
     * ****** WORKAROUND ALERT ******
     * This code doesn't check the space of the non-refs, or copy their
     * contents, so it can create dangling references from global VM to
     * local VM.  Because of this, we simply disallow writing into gstates
     * in global VM (including creating them in the first place) if the
     * save level is greater than 0.
     * ****** WORKAROUND ALERT ******
     */
#if 1				/* ****** WORKAROUND ****** */
    if (space != avm_local && imemory_save_level(iimemory) > 0)
        return_error(gs_error_invalidaccess);
#endif				/* ****** END ****** */
#define gsref_check(p) store_check_space(space, p)
    int_gstate_map_refs(isp, gsref_check);
#undef gsref_check
    return 0;
}

/* - gstate <gstate> */
int
zgstate(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;

    int code = gstate_check_space(i_ctx_p, istate, icurrent_space);
    igstate_obj *pigo;
    gs_gstate *pnew;
    int_gstate *isp;

    if (code < 0)
        return code;
    pigo = ialloc_struct(igstate_obj, &st_igstate_obj, "gstate");
    if (pigo == 0)
        return_error(gs_error_VMerror);
    pnew = gs_gstate_copy(igs, imemory);
    if (pnew == 0) {
        ifree_object(pigo, "gstate");
        return_error(gs_error_VMerror);
    }
    isp = gs_int_gstate(pnew);
    int_gstate_map_refs(isp, ref_mark_new);
    push(1);
    /*
     * Since igstate_obj isn't a ref, but only contains a ref, save won't
     * clear its l_new bit automatically, and restore won't set it
     * automatically; we have to make sure this ref is on the changes chain.
     */
    make_iastruct(op, a_all, pigo);
#if 0 /* Bug 689849 "gstate leaks memory" */
    make_null(&pigo->gstate);
    ref_save(op, &pigo->gstate, "gstate");
    make_istruct_new(&pigo->gstate, 0, pnew);
#else
    make_istruct(&pigo->gstate, 0, pnew);
#endif
    return 0;
}

/* copy for gstates */
int
zcopy_gstate(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    os_ptr op1 = op - 1;
    gs_gstate *pgs;
    gs_gstate *pgs1;
    int_gstate *pistate;
    gs_memory_t *mem;
    int code;

    check_stype(*op, st_igstate_obj);
    check_stype(*op1, st_igstate_obj);
    check_write(*op);
    code = gstate_unshare(i_ctx_p);
    if (code < 0)
        return code;
    pgs = igstate_ptr(op);
    pgs1 = igstate_ptr(op1);
    pistate = gs_int_gstate(pgs);
    code = gstate_check_space(i_ctx_p, gs_int_gstate(pgs1), r_space(op));
    if (code < 0)
        return code;
#define gsref_save(p) ref_save(op, p, "copygstate")
    int_gstate_map_refs(pistate, gsref_save);
#undef gsref_save
    mem = gs_gstate_swap_memory(pgs, imemory);
    code = gs_copygstate(pgs, pgs1);
    gs_gstate_swap_memory(pgs, mem);
    if (code < 0)
        return code;
    int_gstate_map_refs(pistate, ref_mark_new);
    *op1 = *op;
    pop(1);
    return 0;
}

/* <gstate> currentgstate <gstate> */
int
zcurrentgstate(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_gstate *pgs;
    int_gstate *pistate;
    int code;
    gs_memory_t *mem;

    check_stype(*op, st_igstate_obj);
    check_write(*op);
    code = gstate_unshare(i_ctx_p);
    if (code < 0)
        return code;
    pgs = igstate_ptr(op);
    pistate = gs_int_gstate(pgs);
    code = gstate_check_space(i_ctx_p, istate, r_space(op));
    if (code < 0)
        return code;
#define gsref_save(p) ref_save(op, p, "currentgstate")
    int_gstate_map_refs(pistate, gsref_save);
#undef gsref_save
    mem = gs_gstate_swap_memory(pgs, imemory);
    code = gs_currentgstate(pgs, igs);
    gs_gstate_swap_memory(pgs, mem);
    if (code < 0)
        return code;
    int_gstate_map_refs(pistate, ref_mark_new);
    return 0;
}

/* <gstate> setgstate - */
int
zsetgstate(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    int code;

    check_stype(*op, st_igstate_obj);
    check_read(*op);
    code = gs_setgstate(igs, igstate_ptr(op));
    if (code < 0)
        return code;
    pop(1);
    return 0;
}

/* ------ Rectangles ------- */

/*
 * We preallocate a short list for rectangles, because
 * the rectangle operators usually will involve very few rectangles.
 */
#define MAX_LOCAL_RECTS 5
typedef struct local_rects_s {
    gs_rect *pr;
    uint count;
    gs_rect rl[MAX_LOCAL_RECTS];
} local_rects_t;

/* Forward references */
static int rect_get(local_rects_t *, os_ptr, gs_memory_t *);
static void rect_release(local_rects_t *, gs_memory_t *);

/* <x> <y> <width> <height> .rectappend - */
/* <numarray|numstring> .rectappend - */
static int
zrectappend(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    local_rects_t lr;
    int npop = rect_get(&lr, op, imemory);
    int code;

    if (npop < 0)
        return npop;
    code = gs_rectappend(igs, lr.pr, lr.count);
    rect_release(&lr, imemory);
    if (code < 0)
        return code;
    pop(npop);
    return 0;
}

/* <x> <y> <width> <height> rectclip - */
/* <numarray|numstring> rectclip - */
static int
zrectclip(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    local_rects_t lr;
    int npop = rect_get(&lr, op, imemory);
    int code;

    if (npop < 0)
        return npop;
    code = gs_rectclip(igs, lr.pr, lr.count);
    rect_release(&lr, imemory);
    if (code < 0)
        return code;
    pop(npop);
    return 0;
}

/* <x> <y> <width> <height> rectfill - */
/* <numarray|numstring> rectfill - */
static int
zrectfill(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    local_rects_t lr;
    int npop = rect_get(&lr, op, imemory);
    int code;

    if (npop < 0)
        return npop;
    code = gs_rectfill(igs, lr.pr, lr.count);
    rect_release(&lr, imemory);
    if (code < 0)
        return code;
    pop(npop);
    return 0;
}

/* <x> <y> <width> <height> rectstroke - */
/* <numarray|numstring> rectstroke - */
static int
zrectstroke(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    gs_matrix mat;
    local_rects_t lr;
    int npop, code;

    if (read_matrix(imemory, op, &mat) >= 0) {
        /* Concatenate the matrix to the CTM just before stroking the path. */
        npop = rect_get(&lr, op - 1, imemory);
        if (npop < 0)
            return npop;
        code = gs_rectstroke(igs, lr.pr, lr.count, &mat);
        npop++;
    } else {
        /* No matrix. */
        npop = rect_get(&lr, op, imemory);
        if (npop < 0)
            return npop;
        code = gs_rectstroke(igs, lr.pr, lr.count, (gs_matrix *) 0);
    }
    rect_release(&lr, imemory);
    if (code < 0)
        return code;
    pop(npop);
    return 0;
}

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

/* Get rectangles from the stack. */
/* Return the number of elements to pop (>0) if OK, <0 if error. */
static int
rect_get(local_rects_t * plr, os_ptr op, gs_memory_t *mem)
{
    int format, code;
    uint n, count;
    gs_rect *pr;
    double rv[4];

    switch (r_type(op)) {
        case t_array:
        case t_mixedarray:
        case t_shortarray:
        case t_string:
            code = num_array_format(op);
            if (code < 0)
                return code;
            format = code;
            count = num_array_size(op, format);
            if (count % 4)
                return_error(gs_error_typecheck);
            count /= 4;
            break;
        default:		/* better be 4 numbers */
            code = num_params(op, 4, rv);
            if (code < 0)
                return code;
            plr->pr = plr->rl;
            plr->count = 1;
            plr->rl[0].q.x = (plr->rl[0].p.x = rv[0]) + rv[2];
            plr->rl[0].q.y = (plr->rl[0].p.y = rv[1]) + rv[3];
            return 4;
    }
    plr->count = count;
    if (count <= MAX_LOCAL_RECTS)
        pr = plr->rl;
    else {
        pr = (gs_rect *)gs_alloc_byte_array(mem, count, sizeof(gs_rect),
                                            "rect_get");
        if (pr == 0)
            return_error(gs_error_VMerror);
    }
    plr->pr = pr;
    for (n = 0; n < count; n++, pr++) {
        ref rnum;
        int i;

        for (i = 0; i < 4; i++) {
            code = num_array_get(mem, (const ref *)op, format,
                                 (n << 2) + i, &rnum);
            switch (code) {
                case t_integer:
                    rv[i] = (double)rnum.value.intval;
                    break;
                case t_real:
                    rv[i] = rnum.value.realval;
                    break;
                default:	/* code < 0 */
                    return code;
            }
        }
        pr->q.x = (pr->p.x = rv[0]) + rv[2];
        pr->q.y = (pr->p.y = rv[1]) + rv[3];
    }
    return 1;
}

/* Release the rectangle list if needed. */
static void
rect_release(local_rects_t * plr, gs_memory_t *mem)
{
    if (plr->pr != plr->rl)
        gs_free_object(mem, plr->pr, "rect_release");
}

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

/* <llx> <lly> <urx> <ury> setbbox - */
int
zsetbbox(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    double box[4];

    int code = num_params(op, 4, box);

    if (code < 0)
        return code;
    if ((code = gs_setbbox(igs, box[0], box[1], box[2], box[3])) < 0)
        return code;
    pop(4);
    return 0;
}

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

const op_def zdps1_l2_op_defs[] =
{
    op_def_begin_level2(),
                /* Graphics state */
    {"0currentstrokeadjust", zcurrentstrokeadjust},
    {"1setstrokeadjust", zsetstrokeadjust},
                /* Graphics state objects */
    {"1copy", z1copy},
    {"1currentgstate", zcurrentgstate},
    {"0gstate", zgstate},
    {"1setgstate", zsetgstate},
                /* Rectangles */
    {"1.rectappend", zrectappend},
    {"1rectclip", zrectclip},
    {"1rectfill", zrectfill},
    {"1rectstroke", zrectstroke},
                /* Graphics state components */
    {"4setbbox", zsetbbox},
    op_def_end(0)
};

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

/* Ensure that a gstate is not shared with an outer save level. */
/* *op is of type t_astruct(igstate_obj). */
static int
gstate_unshare(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    ref *pgsref = &r_ptr(op, igstate_obj)->gstate;
    gs_gstate *pgs = r_ptr(pgsref, gs_gstate);
    gs_gstate *pnew;
    int_gstate *isp;

    if (!ref_must_save(pgsref))
        return 0;
    /* Copy the gstate. */
    pnew = gs_gstate_copy(pgs, pgs->memory);
    if (pnew == 0)
        return_error(gs_error_VMerror);
    isp = gs_int_gstate(pnew);
    int_gstate_map_refs(isp, ref_mark_new);
    ref_do_save(op, pgsref, "gstate_unshare");
    make_istruct_new(pgsref, 0, pnew);
    return 0;
}
