path: root/base/gsline.c

/* Copyright (C) 2001-2023 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.,  39 Mesa Street, Suite 108A, San Francisco,
   CA 94129, USA, for further information.
*/


/* Line parameter operators for Ghostscript library */
#include "math_.h"
#include "memory_.h"
#include "gx.h"
#include "gserrors.h"
#include "gxfixed.h"		/* ditto */
#include "gxmatrix.h"		/* for gzstate */
#include "gzstate.h"
#include "gscoord.h"		/* for currentmatrix, setmatrix */
#include "gsline.h"		/* for prototypes */
#include "gzline.h"

/* ------ Device-independent parameters ------ */

#define pgs_lp gs_currentlineparams_inline(pgs)

/* setlinewidth */
int
gs_setlinewidth(gs_gstate * pgs, double width)
{
    gx_set_line_width(pgs_lp, width);
    return 0;
}

/* currentlinewidth */
float
gs_currentlinewidth(const gs_gstate * pgs)
{
    return gx_current_line_width(pgs_lp);
}

/* setlinecap (sets all 3 caps) */
int
gs_setlinecap(gs_gstate * pgs, gs_line_cap cap)
{
    if ((uint) cap > gs_line_cap_max)
        return_error(gs_error_rangecheck);
    pgs_lp->start_cap = cap;
    pgs_lp->end_cap   = cap;
    pgs_lp->dash_cap  = cap;
    return 0;
}

/* setlinestartcap */
int
gs_setlinestartcap(gs_gstate * pgs, gs_line_cap cap)
{
    if ((uint) cap > gs_line_cap_max)
        return_error(gs_error_rangecheck);
    pgs_lp->start_cap = cap;
    return 0;
}

/* setlineendcap */
int
gs_setlineendcap(gs_gstate * pgs, gs_line_cap cap)
{
    if ((uint) cap > gs_line_cap_max)
        return_error(gs_error_rangecheck);
    pgs_lp->end_cap = cap;
    return 0;
}

/* setlinedashcap */
int
gs_setlinedashcap(gs_gstate * pgs, gs_line_cap cap)
{
    if ((uint) cap > gs_line_cap_max)
        return_error(gs_error_rangecheck);
    pgs_lp->dash_cap = cap;
    return 0;
}

/* currentlinecap */
gs_line_cap
gs_currentlinecap(const gs_gstate * pgs)
{
    /* This assumes that all caps are the same as start_cap - this will be
     * the case for postscript at least. */
    return pgs_lp->start_cap;
}

/* setlinejoin */
int
gs_setlinejoin(gs_gstate * pgs, gs_line_join join)
{
    if ((uint) join > gs_line_join_max)
        return_error(gs_error_rangecheck);
    pgs_lp->join = join;
    return 0;
}

/* currentlinejoin */
gs_line_join
gs_currentlinejoin(const gs_gstate * pgs)
{
    return pgs_lp->join;
}

/* setmiterlimit */
int
gx_set_miter_limit(gx_line_params * plp, double limit)
{
    if (limit < 1.0)
        return_error(gs_error_rangecheck);
    plp->miter_limit = limit;
    /*
     * Compute the miter check value.  The supplied miter limit is an
     * upper bound on 1/sin(phi/2); we convert this to a lower bound on
     * tan(phi).  Note that if phi > pi/2, this is negative.  We use the
     * half-angle and angle-sum formulas here to avoid the trig functions.
     * We also need a special check for phi/2 close to pi/4.
     * Some C compilers can't handle this as a conditional expression....
     */
    {
        double limit_squared = limit * limit;

        if (limit_squared < 2.0001 && limit_squared > 1.9999)
            plp->miter_check = 1.0e6;
        else
            plp->miter_check =
                sqrt(limit_squared - 1) * 2 / (limit_squared - 2);
    }
    return 0;
}
int
gs_setmiterlimit(gs_gstate * pgs, double limit)
{
    return gx_set_miter_limit(pgs_lp, limit);
}

/* currentmiterlimit */
float
gs_currentmiterlimit(const gs_gstate * pgs)
{
    return pgs_lp->miter_limit;
}

/* setdash */
int
gx_set_dash(gx_dash_params * dash, const float *pattern, uint length,
            double offset, gs_memory_t * mem)
{
    uint n = length;
    const float *dfrom = pattern;
    bool ink = true;
    int index = 0;
    float pattern_length = 0.0;
    float dist_left;
    float *ppat = dash->pattern;

    /* Check the dash pattern. */
    while (n--) {
        float elt = *dfrom++;

        if (elt < 0)
            return_error(gs_error_rangecheck);
        pattern_length += elt;
    }
    if (length == 0) {		/* empty pattern */
        dist_left = 0.0;
        if (mem && ppat) {
            gs_free_object(mem, ppat, "gx_set_dash(old pattern)");
            ppat = NULL;
        }
    } else {
        uint size = length * sizeof(float);

        if (pattern_length == 0)
            return_error(gs_error_rangecheck);
        /* Compute the initial index, ink_on, and distance left */
        /* in the pattern, according to the offset. */
#define f_mod(a, b) ((a) - floor((a) / (b)) * (b))
        if (length & 1) {	/* Odd and even repetitions of the pattern */
            /* have opposite ink values! */
            float length2 = pattern_length * 2;

            dist_left = f_mod(offset, length2);
            /* Rounding errors can leave dist_left > length2 */
            dist_left = f_mod(dist_left, length2);
            if (dist_left >= pattern_length)
                dist_left -= pattern_length, ink = !ink;
        } else {
            dist_left = f_mod(offset, pattern_length);
            /* Rounding errors can leave dist_left > length */
            dist_left = f_mod(dist_left, pattern_length);
        }
        while ((dist_left -= pattern[index]) >= 0 &&
               (dist_left > 0 || pattern[index] != 0)
            )
            ink = !ink, index++;
        if (mem != NULL) {
            if (ppat == NULL)
                ppat = (float *)gs_alloc_bytes(mem, size,
                                               "gx_set_dash(pattern)");
            else if (length != dash->pattern_size)
                ppat = gs_resize_object(mem, ppat, size,
                                        "gx_set_dash(pattern)");
        }
        if (ppat == NULL)
            return_error(gs_error_VMerror);
        if (ppat != pattern)
            memcpy(ppat, pattern, length * sizeof(float));
    }
    dash->pattern = ppat;
    dash->pattern_size = length;
    dash->offset = offset;
    dash->pattern_length = pattern_length;
    dash->init_ink_on = ink;
    dash->init_index = index;
    dash->init_dist_left = -dist_left;
    return 0;
}
int
gs_setdash(gs_gstate * pgs, const float *pattern, uint length, double offset)
{
    return gx_set_dash(&pgs_lp->dash, pattern, length, offset,
                       pgs->memory);
}

/* currentdash */
uint
gs_currentdash_length(const gs_gstate * pgs)
{
    return pgs_lp->dash.pattern_size;
}
const float *
gs_currentdash_pattern(const gs_gstate * pgs)
{
    return pgs_lp->dash.pattern;
}
float
gs_currentdash_offset(const gs_gstate * pgs)
{
    return pgs_lp->dash.offset;
}

/* Internal accessor for line parameters */
const gx_line_params *
gs_currentlineparams(const gs_gstate * pgs)
{
    return gs_currentlineparams_inline(pgs);
}

/* ------ Device-dependent parameters ------ */

/* setflat */
int
gs_gstate_setflat(gs_gstate * pgs, double flat)
{
    if (flat <= 0.2)
        flat = 0.2;
    else if (flat > 100)
        flat = 100;
    pgs->flatness = flat;
    return 0;
}
int
gs_setflat(gs_gstate * pgs, double flat)
{
    return gs_gstate_setflat(pgs, flat);
}

/* currentflat */
float
gs_currentflat(const gs_gstate * pgs)
{
    return pgs->flatness;
}

/* setstrokeadjust */
int
gs_setstrokeadjust(gs_gstate * pgs, bool stroke_adjust)
{
    pgs->stroke_adjust = stroke_adjust;
    return 0;
}

/* currentstrokeadjust */
bool
gs_currentstrokeadjust(const gs_gstate * pgs)
{
    return pgs->stroke_adjust;
}

/* ------ Extensions ------ */

/* Device-independent */

/* setdashadapt */
void
gs_setdashadapt(gs_gstate * pgs, bool adapt)
{
    pgs_lp->dash.adapt = adapt;
}

/* currentdashadapt */
bool
gs_gstate_currentdashadapt(const gs_gstate * pgs)
{
    return gs_currentlineparams_inline(pgs)->dash.adapt;
}
bool
gs_currentdashadapt(const gs_gstate * pgs)
{
    return gs_gstate_currentdashadapt((const gs_gstate *)pgs);
}

/* setcurvejoin */
int
gs_setcurvejoin(gs_gstate * pgs, int join)
{
    if (join < -1 || join > gs_line_join_max)
        return_error(gs_error_rangecheck);
    pgs_lp->curve_join = join;
    return 0;
}

/* currentcurvejoin */
int
gs_currentcurvejoin(const gs_gstate * pgs)
{
    return pgs_lp->curve_join;
}

/* Device-dependent */

/* setaccuratecurves */
void
gs_setaccuratecurves(gs_gstate * pgs, bool accurate)
{
    pgs->accurate_curves = accurate;
}

/* currentaccuratecurves */
bool
gs_gstate_currentaccuratecurves(const gs_gstate * pgs)
{
    return pgs->accurate_curves;
}
bool
gs_currentaccuratecurves(const gs_gstate * pgs)
{
    return gs_gstate_currentaccuratecurves((const gs_gstate *)pgs);
}

/* setdotlength */
int
gx_set_dot_length(gx_line_params * plp, double length, bool absolute)
{
    if (length < 0)
        return_error(gs_error_rangecheck);
    plp->dot_length = length;
    plp->dot_length_absolute = absolute;
    return 0;
}
int
gs_setdotlength(gs_gstate * pgs, double length, bool absolute)
{
    return gx_set_dot_length(pgs_lp, length, absolute);
}

/* currentdotlength */
float
gs_currentdotlength(const gs_gstate * pgs)
{
    return pgs_lp->dot_length;
}
bool
gs_currentdotlength_absolute(const gs_gstate * pgs)
{
    return pgs_lp->dot_length_absolute;
}

/* setdotorientation */
int
gs_setdotorientation(gs_gstate *pgs)
{
    if (is_xxyy(&pgs->ctm) || is_xyyx(&pgs->ctm))
        return gs_currentmatrix(pgs, &pgs_lp->dot_orientation);
    return_error(gs_error_rangecheck);
}

/* dotorientation */
int
gs_dotorientation(gs_gstate *pgs)
{
    return gs_setmatrix(pgs, &pgs_lp->dot_orientation);
}