/* $Id: plcvt.c,v 1.12 2005/04/27 06:44:23 rlaboiss Exp $

	Coordinate transformation routines.

   Copyright (C) 2004  Alan W. Irwin

   This file is part of PLplot.

   PLplot is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Library Public License as published
   by the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   PLplot 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 Library General Public License for more details.

   You should have received a copy of the GNU Library General Public License
   along with PLplot; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/

#include "plplotP.h"

/*--------------------------------------------------------------------------*\
 * Transformations returning physical coordinates.
\*--------------------------------------------------------------------------*/

/* device coords to physical coords (x) */

PLINT
plP_dcpcx(PLFLT x)
{
    return (ROUND(plsc->phyxmi + plsc->phyxlen * x));
}

/* device coords to physical coords (y) */

PLINT
plP_dcpcy(PLFLT y)
{
    return (ROUND(plsc->phyymi + plsc->phyylen * y));
}

/* millimeters from bottom left-hand corner to physical coords (x) */

PLINT
plP_mmpcx(PLFLT x)
{
    return (ROUND(plsc->phyxmi + plsc->xpmm * x));
}

/* millimeters from bottom left-hand corner to physical coords (y) */

PLINT
plP_mmpcy(PLFLT y)
{
    return (ROUND(plsc->phyymi + plsc->ypmm * y));
}

/* world coords to physical coords (x) */

PLINT
plP_wcpcx(PLFLT x)
{
    return (ROUND(plsc->wpxoff + plsc->wpxscl * x));
}

/* world coords to physical coords (y) */

PLINT
plP_wcpcy(PLFLT y)
{
    return (ROUND(plsc->wpyoff + plsc->wpyscl * y));
}

/*--------------------------------------------------------------------------*\
 * Transformations returning device coordinates.
\*--------------------------------------------------------------------------*/

/* physical coords to device coords (x) */

PLFLT
plP_pcdcx(PLINT x)
{
    return (PLFLT) ((x - plsc->phyxmi) / (double) plsc->phyxlen);
}

/* physical coords to device coords (y) */

PLFLT
plP_pcdcy(PLINT y)
{
    return (PLFLT) ((y - plsc->phyymi) / (double) plsc->phyylen);
}

/* millimeters from bottom left corner to device coords (x) */

PLFLT
plP_mmdcx(PLFLT x)
{
    return ((PLFLT) (x * plsc->xpmm / ABS(plsc->phyxma - plsc->phyxmi)));
}

/* millimeters from bottom left corner to device coords (y) */

PLFLT
plP_mmdcy(PLFLT y)
{
    return ((PLFLT) (y * plsc->ypmm / ABS(plsc->phyyma - plsc->phyymi)));
}

/* world coords into device coords (x) */

PLFLT
plP_wcdcx(PLFLT x)
{
    return ((PLFLT) (plsc->wdxoff + plsc->wdxscl * x));
}

/* world coords into device coords (y) */

PLFLT
plP_wcdcy(PLFLT y)
{
    return ((PLFLT) (plsc->wdyoff + plsc->wdyscl * y));
}

/* subpage coords to device coords (x) */

PLFLT
plP_scdcx(PLFLT x)
{
    return ((PLFLT) (plsc->spdxmi + (plsc->spdxma - plsc->spdxmi) * x));
}

/* subpage coords to device coords (y) */

PLFLT
plP_scdcy(PLFLT y)
{
    return ((PLFLT) (plsc->spdymi + (plsc->spdyma - plsc->spdymi) * y));
}

/*--------------------------------------------------------------------------*\
 * Transformations returning millimeters.
\*--------------------------------------------------------------------------*/

/* device coords to millimeters from bottom left-hand corner (x) */

PLFLT
plP_dcmmx(PLFLT x)
{
    return ((PLFLT) (x * ABS(plsc->phyxma - plsc->phyxmi) / plsc->xpmm));
}

/* device coords to millimeters from bottom left-hand corner (y) */

PLFLT
plP_dcmmy(PLFLT y)
{
    return ((PLFLT) (y * ABS(plsc->phyyma - plsc->phyymi) / plsc->ypmm));
}

/* world coords into millimeters (x) */

PLFLT
plP_wcmmx(PLFLT x)
{
    return ((PLFLT) (plsc->wmxoff + plsc->wmxscl * x));
}

/* world coords into millimeters (y) */

PLFLT
plP_wcmmy(PLFLT y)
{
    return ((PLFLT) (plsc->wmyoff + plsc->wmyscl * y));
}

/*--------------------------------------------------------------------------*\
 * Transformations returning subpage coordinates.
\*--------------------------------------------------------------------------*/

/* device coords to subpage coords (x) */

PLFLT
plP_dcscx(PLFLT x)
{
    return ((PLFLT) ((x - plsc->spdxmi) / (plsc->spdxma - plsc->spdxmi)));
}

/* device coords to subpage coords (y) */

PLFLT
plP_dcscy(PLFLT y)
{
    return ((PLFLT) ((y - plsc->spdymi) / (plsc->spdyma - plsc->spdymi)));
}

/*--------------------------------------------------------------------------*\
 * 3-d plot transformations.
\*--------------------------------------------------------------------------*/

/* 3-d coords to 2-d projection (x) */
/* See c_plw3d for a mathematical explanation of the transformation. */

PLFLT
plP_w3wcx(PLFLT x, PLFLT y, PLFLT z)
{
    return ((PLFLT) ((x - plsc->basecx) * plsc->cxx +
		     (y - plsc->basecy) * plsc->cxy));
}

/* 3-d coords to 2-d projection (y) */
/* See c_plw3d for a mathematical explanation of the transformation. */

PLFLT
plP_w3wcy(PLFLT x, PLFLT y, PLFLT z)
{
    return ((PLFLT) ((x - plsc->basecx) * plsc->cyx +
		     (y - plsc->basecy) * plsc->cyy +
		     (z - plsc->ranmi) * plsc->cyz));
}