lwgeom_api.c

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/**********************************************************************
 *
 * PostGIS - Spatial Types for PostgreSQL
 * http://postgis.net
 *
 * PostGIS is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * PostGIS is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with PostGIS.  If not, see <http://www.gnu.org/licenses/>.
 *
 **********************************************************************
 *
 * Copyright 2001-2006 Refractions Research Inc.
 *
 **********************************************************************/



#include "liblwgeom_internal.h"
#include "lwgeom_log.h"

#include <stdio.h>
#include <errno.h>
#include <assert.h>
#include "../postgis_svn_revision.h"

const char *
lwgeom_version()
{
  static char *ptr = NULL;
  static char buf[256];
  if ( ! ptr )
  {
    ptr = buf;
    snprintf(ptr, 256, LIBLWGEOM_VERSION" r%d", POSTGIS_SVN_REVISION);
  }

  return ptr;
}


inline float
next_float_down(double d)
{
        float result;
        if (d > (double)FLT_MAX)
                return FLT_MAX;
        if (d <= (double)-FLT_MAX)
                return -FLT_MAX;
        result = d;

        if ( ((double)result) <=d )
                return result;

        return nextafterf(result, -1*FLT_MAX);

}

/*
 * Returns the float thats very close to the input, but >=.
 * handles the funny differences in float4 and float8 reps.
 */
inline float
next_float_up(double d)
{
        float result;
        if (d >= (double)FLT_MAX)
                return FLT_MAX;
        if (d < (double)-FLT_MAX)
                return -FLT_MAX;
        result = d;

        if ( ((double)result) >=d )
                return result;

        return nextafterf(result, FLT_MAX);
}




/************************************************************************
 * POINTARRAY support functions
 *
 * TODO: should be moved to ptarray.c probably
 *
 ************************************************************************/

/*
 * Copies a point from the point array into the parameter point
 * will set point's z=NO_Z_VALUE if pa is 2d
 * will set point's m=NO_M_VALUE if pa is 3d or 2d
 *
 * NOTE: point is a real POINT3D *not* a pointer
 */
POINT4D
getPoint4d(const POINTARRAY *pa, int n)
{
        POINT4D result;
        getPoint4d_p(pa, n, &result);
        return result;
}

/*
 * Copies a point from the point array into the parameter point
 * will set point's z=NO_Z_VALUE  if pa is 2d
 * will set point's m=NO_M_VALUE  if pa is 3d or 2d
 *
 * NOTE: this will modify the point4d pointed to by 'point'.
 *
 * @return 0 on error, 1 on success
 */
int
getPoint4d_p(const POINTARRAY *pa, int n, POINT4D *op)
{
        uint8_t *ptr;
        int zmflag;

        if ( ! pa )
        {
                lwerror("%s [%d] NULL POINTARRAY input", __FILE__, __LINE__);
                return 0;
        }

        if ( (n<0) || (n>=pa->npoints))
        {
                lwnotice("%s [%d] called with n=%d and npoints=%d", __FILE__, __LINE__, n, pa->npoints);
                return 0;
        }

        LWDEBUG(4, "getPoint4d_p called.");

        /* Get a pointer to nth point offset and zmflag */
        ptr=getPoint_internal(pa, n);
        zmflag=FLAGS_GET_ZM(pa->flags);

        LWDEBUGF(4, "ptr %p, zmflag %d", ptr, zmflag);

        switch (zmflag)
        {
        case 0: /* 2d  */
                memcpy(op, ptr, sizeof(POINT2D));
                op->m=NO_M_VALUE;
                op->z=NO_Z_VALUE;
                break;

        case 3: /* ZM */
                memcpy(op, ptr, sizeof(POINT4D));
                break;

        case 2: /* Z */
                memcpy(op, ptr, sizeof(POINT3DZ));
                op->m=NO_M_VALUE;
                break;

        case 1: /* M */
                memcpy(op, ptr, sizeof(POINT3DM));
                op->m=op->z; /* we use Z as temporary storage */
                op->z=NO_Z_VALUE;
                break;

        default:
                lwerror("Unknown ZM flag ??");
                return 0;
        }
        return 1;

}



/*
 * Copy a point from the point array into the parameter point
 * will set point's z=NO_Z_VALUE if pa is 2d
 * NOTE: point is a real POINT3DZ *not* a pointer
 */
POINT3DZ
getPoint3dz(const POINTARRAY *pa, int n)
{
        POINT3DZ result;
        getPoint3dz_p(pa, n, &result);
        return result;
}

/*
 * Copy a point from the point array into the parameter point
 * will set point's z=NO_Z_VALUE if pa is 2d
 *
 * NOTE: point is a real POINT3DZ *not* a pointer
 */
POINT3DM
getPoint3dm(const POINTARRAY *pa, int n)
{
        POINT3DM result;
        getPoint3dm_p(pa, n, &result);
        return result;
}

/*
 * Copy a point from the point array into the parameter point
 * will set point's z=NO_Z_VALUE if pa is 2d
 *
 * NOTE: this will modify the point3dz pointed to by 'point'.
 */
int
getPoint3dz_p(const POINTARRAY *pa, int n, POINT3DZ *op)
{
        uint8_t *ptr;

        if ( ! pa )
        {
                lwerror("%s [%d] NULL POINTARRAY input", __FILE__, __LINE__);
                return 0;
        }

        if ( (n<0) || (n>=pa->npoints))
        {
                lwnotice("%s [%d] called with n=%d and npoints=%d", __FILE__, __LINE__, n, pa->npoints);
                return 0;
        }

        LWDEBUGF(2, "getPoint3dz_p called on array of %d-dimensions / %u pts",
                 FLAGS_NDIMS(pa->flags), pa->npoints);

        /* Get a pointer to nth point offset */
        ptr=getPoint_internal(pa, n);

        /*
         * if input POINTARRAY has the Z, it is always
         * at third position so make a single copy
         */
        if ( FLAGS_GET_Z(pa->flags) )
        {
                memcpy(op, ptr, sizeof(POINT3DZ));
        }

        /*
         * Otherwise copy the 2d part and initialize
         * Z to NO_Z_VALUE
         */
        else
        {
                memcpy(op, ptr, sizeof(POINT2D));
                op->z=NO_Z_VALUE;
        }

        return 1;

}

/*
 * Copy a point from the point array into the parameter point
 * will set point's m=NO_Z_VALUE if pa has no M
 *
 * NOTE: this will modify the point3dm pointed to by 'point'.
 */
int
getPoint3dm_p(const POINTARRAY *pa, int n, POINT3DM *op)
{
        uint8_t *ptr;
        int zmflag;

        if ( ! pa )
        {
                lwerror("%s [%d] NULL POINTARRAY input", __FILE__, __LINE__);
                return 0;
        }

        if ( (n<0) || (n>=pa->npoints))
        {
                lwnotice("%s [%d] called with n=%d and npoints=%d", __FILE__, __LINE__, n, pa->npoints);
                return 0;
        }

        LWDEBUGF(2, "getPoint3dm_p(%d) called on array of %d-dimensions / %u pts",
                 n, FLAGS_NDIMS(pa->flags), pa->npoints);


        /* Get a pointer to nth point offset and zmflag */
        ptr=getPoint_internal(pa, n);
        zmflag=FLAGS_GET_ZM(pa->flags);

        /*
         * if input POINTARRAY has the M and NO Z,
         * we can issue a single memcpy
         */
        if ( zmflag == 1 )
        {
                memcpy(op, ptr, sizeof(POINT3DM));
                return 1;
        }

        /*
         * Otherwise copy the 2d part and
         * initialize M to NO_M_VALUE
         */
        memcpy(op, ptr, sizeof(POINT2D));

        /*
         * Then, if input has Z skip it and
         * copy next double, otherwise initialize
         * M to NO_M_VALUE
         */
        if ( zmflag == 3 )
        {
                ptr+=sizeof(POINT3DZ);
                memcpy(&(op->m), ptr, sizeof(double));
        }
        else
        {
                op->m=NO_M_VALUE;
        }

        return 1;
}


/*
 * Copy a point from the point array into the parameter point
 * z value (if present) is not returned.
 *
 * NOTE: point is a real POINT2D *not* a pointer
 */
POINT2D
getPoint2d(const POINTARRAY *pa, int n)
{
        const POINT2D *result;
        result = getPoint2d_cp(pa, n);
        return *result;
}

/*
 * Copy a point from the point array into the parameter point
 * z value (if present) is not returned.
 *
 * NOTE: this will modify the point2d pointed to by 'point'.
 */
int
getPoint2d_p(const POINTARRAY *pa, int n, POINT2D *point)
{
        if ( ! pa )
        {
                lwerror("%s [%d] NULL POINTARRAY input", __FILE__, __LINE__);
                return 0;
        }

        if ( (n<0) || (n>=pa->npoints))
        {
                lwnotice("%s [%d] called with n=%d and npoints=%d", __FILE__, __LINE__, n, pa->npoints);
                return 0;
        }

        /* this does x,y */
        memcpy(point, getPoint_internal(pa, n), sizeof(POINT2D));
        return 1;
}

const POINT2D*
getPoint2d_cp(const POINTARRAY *pa, int n)
{
        if ( ! pa ) return 0;

        if ( (n<0) || (n>=pa->npoints))
        {
                lwerror("getPoint2D_const_p: point offset out of range");
                return 0; /*error */
        }

        return (const POINT2D*)getPoint_internal(pa, n);
}

const POINT3DZ*
getPoint3dz_cp(const POINTARRAY *pa, int n)
{
        if ( ! pa ) return 0;

        if ( ! FLAGS_GET_Z(pa->flags) )
        {
                lwerror("getPoint3dz_cp: no Z coordinates in point array");
                return 0; /*error */
        }

        if ( (n<0) || (n>=pa->npoints))
        {
                lwerror("getPoint3dz_cp: point offset out of range");
                return 0; /*error */
        }

        return (const POINT3DZ*)getPoint_internal(pa, n);
}


const POINT4D*
getPoint4d_cp(const POINTARRAY *pa, int n)
{
        if ( ! pa ) return 0;

        if ( ! (FLAGS_GET_Z(pa->flags) && FLAGS_GET_Z(pa->flags)) )
        {
                lwerror("getPoint3dz_cp: no Z and M coordinates in point array");
                return 0; /*error */
        }

        if ( (n<0) || (n>=pa->npoints))
        {
                lwerror("getPoint3dz_cp: point offset out of range");
                return 0; /*error */
        }

        return (const POINT4D*)getPoint_internal(pa, n);
}



/*
 * set point N to the given value
 * NOTE that the pointarray can be of any
 * dimension, the appropriate ordinate values
 * will be extracted from it
 *
 */
void
ptarray_set_point4d(POINTARRAY *pa, int n, const POINT4D *p4d)
{
        uint8_t *ptr;
        assert(n >= 0 && n < pa->npoints);
        ptr=getPoint_internal(pa, n);
        switch ( FLAGS_GET_ZM(pa->flags) )
        {
        case 3:
                memcpy(ptr, p4d, sizeof(POINT4D));
                break;
        case 2:
                memcpy(ptr, p4d, sizeof(POINT3DZ));
                break;
        case 1:
                memcpy(ptr, p4d, sizeof(POINT2D));
                ptr+=sizeof(POINT2D);
                memcpy(ptr, &(p4d->m), sizeof(double));
                break;
        case 0:
                memcpy(ptr, p4d, sizeof(POINT2D));
                break;
        }
}


/************************************************
 * debugging routines
 ************************************************/

void printBOX3D(BOX3D *box)
{
        lwnotice("BOX3D: %g %g, %g %g", box->xmin, box->ymin,
                 box->xmax, box->ymax);
}

void printPA(POINTARRAY *pa)
{
        int t;
        POINT4D pt;
        char *mflag;


        if ( FLAGS_GET_M(pa->flags) ) mflag = "M";
        else mflag = "";

        lwnotice("      POINTARRAY%s{", mflag);
        lwnotice("                 ndims=%i,   ptsize=%i",
                 FLAGS_NDIMS(pa->flags), ptarray_point_size(pa));
        lwnotice("                 npoints = %i", pa->npoints);

        for (t =0; t<pa->npoints; t++)
        {
                getPoint4d_p(pa, t, &pt);
                if (FLAGS_NDIMS(pa->flags) == 2)
                {
                        lwnotice("                    %i : %lf,%lf",t,pt.x,pt.y);
                }
                if (FLAGS_NDIMS(pa->flags) == 3)
                {
                        lwnotice("                    %i : %lf,%lf,%lf",t,pt.x,pt.y,pt.z);
                }
                if (FLAGS_NDIMS(pa->flags) == 4)
                {
                        lwnotice("                    %i : %lf,%lf,%lf,%lf",t,pt.x,pt.y,pt.z,pt.m);
                }
        }

        lwnotice("      }");
}


uint8_t
parse_hex(char *str)
{
        /* do this a little brute force to make it faster */

        uint8_t         result_high = 0;
        uint8_t         result_low = 0;

        switch (str[0])
        {
        case '0' :
                result_high = 0;
                break;
        case '1' :
                result_high = 1;
                break;
        case '2' :
                result_high = 2;
                break;
        case '3' :
                result_high = 3;
                break;
        case '4' :
                result_high = 4;
                break;
        case '5' :
                result_high = 5;
                break;
        case '6' :
                result_high = 6;
                break;
        case '7' :
                result_high = 7;
                break;
        case '8' :
                result_high = 8;
                break;
        case '9' :
                result_high = 9;
                break;
        case 'A' :
        case 'a' :
                result_high = 10;
                break;
        case 'B' :
        case 'b' :
                result_high = 11;
                break;
        case 'C' :
        case 'c' :
                result_high = 12;
                break;
        case 'D' :
        case 'd' :
                result_high = 13;
                break;
        case 'E' :
        case 'e' :
                result_high = 14;
                break;
        case 'F' :
        case 'f' :
                result_high = 15;
                break;
        }
        switch (str[1])
        {
        case '0' :
                result_low = 0;
                break;
        case '1' :
                result_low = 1;
                break;
        case '2' :
                result_low = 2;
                break;
        case '3' :
                result_low = 3;
                break;
        case '4' :
                result_low = 4;
                break;
        case '5' :
                result_low = 5;
                break;
        case '6' :
                result_low = 6;
                break;
        case '7' :
                result_low = 7;
                break;
        case '8' :
                result_low = 8;
                break;
        case '9' :
                result_low = 9;
                break;
        case 'A' :
        case 'a' :
                result_low = 10;
                break;
        case 'B' :
        case 'b' :
                result_low = 11;
                break;
        case 'C' :
        case 'c' :
                result_low = 12;
                break;
        case 'D' :
        case 'd' :
                result_low = 13;
                break;
        case 'E' :
        case 'e' :
                result_low = 14;
                break;
        case 'F' :
        case 'f' :
                result_low = 15;
                break;
        }
        return (uint8_t) ((result_high<<4) + result_low);
}


void
deparse_hex(uint8_t str, char *result)
{
        int     input_high;
        int  input_low;
        static char outchr[]=
        {
                "0123456789ABCDEF"
        };

        input_high = (str>>4);
        input_low = (str & 0x0F);

        result[0] = outchr[input_high];
        result[1] = outchr[input_low];

}


void
interpolate_point4d(POINT4D *A, POINT4D *B, POINT4D *I, double F)
{
#if PARANOIA_LEVEL > 0
        double absF=fabs(F);
        if ( absF < 0 || absF > 1 )
        {
                lwerror("interpolate_point4d: invalid F (%g)", F);
        }
#endif
        I->x=A->x+((B->x-A->x)*F);
        I->y=A->y+((B->y-A->y)*F);
        I->z=A->z+((B->z-A->z)*F);
        I->m=A->m+((B->m-A->m)*F);
}


int _lwgeom_interrupt_requested = 0;
void
lwgeom_request_interrupt() {
  _lwgeom_interrupt_requested = 1;
}
void
lwgeom_cancel_interrupt() {
  _lwgeom_interrupt_requested = 0;
}

lwinterrupt_callback *_lwgeom_interrupt_callback = 0;
lwinterrupt_callback *
lwgeom_register_interrupt_callback(lwinterrupt_callback *cb) {
  lwinterrupt_callback *old = _lwgeom_interrupt_callback;
  _lwgeom_interrupt_callback = cb;
  return old;
}