liblept/pixacc.c

/*====================================================================*
 -  Copyright (C) 2001 Leptonica.  All rights reserved.
 -  This software is distributed in the hope that it will be
 -  useful, but with NO WARRANTY OF ANY KIND.
 -  No author or distributor accepts responsibility to anyone for the
 -  consequences of using this software, or for whether it serves any
 -  particular purpose or works at all, unless he or she says so in
 -  writing.  Everyone is granted permission to copy, modify and
 -  redistribute this source code, for commercial or non-commercial
 -  purposes, with the following restrictions: (1) the origin of this
 -  source code must not be misrepresented; (2) modified versions must
 -  be plainly marked as such; and (3) this notice may not be removed
 -  or altered from any source or modified source distribution.
 *====================================================================*/


/*
 *   pixacc.c
 *
 *      Pixacc creation, destruction
 *           PIXACC   *pixaccCreate()
 *           void      pixaccDestroy()
 *
 *      Pixacc finalization
 *           PIX      *pixaccFinal()
 *
 *      Pixacc accessors
 *           PIX      *pixaccGetPix()
 *           l_int32   pixaccGetOffset()
 *
 *      Pixacc accumulators
 *           l_int32   pixaccAdd()
 *           l_int32   pixaccSubtract()
 *           l_int32   pixaccMultConst()
 *
 *  This is a simple interface to some of the pixel arithmetic operations 
 *  in pixarith.c.
 */

#include <stdio.h>
#include <stdlib.h>
#include "allheaders.h"


/*---------------------------------------------------------------------*
 *                     Pixacc creation, destruction                    *
 *---------------------------------------------------------------------*/
/*!
 *  pixaccCreate()
 *
 *      Input:  w, h (of 32 bpp Pix)
 *              subflag (0 if only addition; 1 if subtraction ops as well
 *      Return: pixacc, or null on error
 *
 *  Notes:
 *      (1) Includes the initialization in pixInitAccumulate().
 */
PIXACC *
pixaccCreate(l_int32  w,
             l_int32  h,
             l_int32  subflag)
{
PIXACC  *pixacc;

    PROCNAME("pixaccCreate");

    if ((pixacc = (PIXACC *)CALLOC(1, sizeof(PIXACC))) == NULL)
        return (PIXACC *)ERROR_PTR("pixacc not made", procName, NULL);
    pixacc->w = w;
    pixacc->h = h;
    
    if ((pixacc->pix = pixCreate(w, h, 32)) == NULL)
        return (PIXACC *)ERROR_PTR("pix not made", procName, NULL);

    if (subflag) {
        pixacc->offset = 0x40000000;
        pixSetAllArbitrary(pixacc->pix, pixacc->offset);
    }

    return pixacc;
}


/*!
 *  pixaccDestroy()
 *
 *      Input:  &pixacc (<can be null>)
 *      Return: void
 *
 *  Notes:
 *      (1) Always nulls the input ptr.
 */
void
pixaccDestroy(PIXACC  **ppixacc)
{
PIXACC  *pixacc;

    PROCNAME("pixaccDestroy");

    if (ppixacc == NULL) {
        L_WARNING("ptr address is NULL!", procName);
        return;
    }

    if ((pixacc = *ppixacc) == NULL)
        return;

    pixDestroy(&pixacc->pix);
    FREE(pixacc);
    *ppixacc = NULL;
    return;
}


/*---------------------------------------------------------------------*
 *                            Pixacc finalization                      *
 *---------------------------------------------------------------------*/
/*!
 *  pixaccFinal()
 *
 *      Input:  pixacc
 *              outdepth (8, 16 or 32 bpp)
 *      Return: pixd (8 , 16 or 32 bpp), or null on error
 */
PIX *
pixaccFinal(PIXACC  *pixacc,
            l_int32  outdepth)
{
    PROCNAME("pixaccFinal");

    if (!pixacc)
        return (PIX *)ERROR_PTR("pixacc not defined", procName, NULL);

    return pixFinalAccumulate(pixaccGetPix(pixacc), pixaccGetOffset(pixacc),
                              outdepth);
}


/*---------------------------------------------------------------------*
 *                            Pixacc accessors                         *
 *---------------------------------------------------------------------*/
/*!
 *  pixaccGetPix()
 *
 *      Input:  pixacc
 *      Return: pix, or null on error
 */
PIX *
pixaccGetPix(PIXACC  *pixacc)
{
    PROCNAME("pixaccGetPix");

    if (!pixacc)
        return (PIX *)ERROR_PTR("pixacc not defined", procName, NULL);
    return pixacc->pix;
}


/*!
 *  pixaccGetOffset()
 *
 *      Input:  pixacc
 *      Return: offset, or -1 on error
 */
l_int32
pixaccGetOffset(PIXACC  *pixacc)
{
    PROCNAME("pixaccGetOffset");

    if (!pixacc)
        return ERROR_INT("pixacc not defined", procName, -1);
    return pixacc->offset;
}


/*---------------------------------------------------------------------*
 *                          Pixacc accumulators                        *
 *---------------------------------------------------------------------*/
/*!
 *  pixaccAdd()
 *
 *      Input:  pixacc
 *              pix (to be added)
 *      Return: 0 if OK, 1 on error
 */
l_int32
pixaccAdd(PIXACC  *pixacc,
          PIX     *pix)
{
    PROCNAME("pixaccAdd");

    if (!pixacc)
        return ERROR_INT("pixacc not defined", procName, 1);
    if (!pix)
        return ERROR_INT("pix not defined", procName, 1);
    pixAccumulate(pixaccGetPix(pixacc), pix, L_ARITH_ADD);
    return 0;
}


/*!
 *  pixaccSubtract()
 *
 *      Input:  pixacc
 *              pix (to be subtracted)
 *      Return: 0 if OK, 1 on error
 */
l_int32
pixaccSubtract(PIXACC  *pixacc,
               PIX     *pix)
{
    PROCNAME("pixaccSubtract");

    if (!pixacc)
        return ERROR_INT("pixacc not defined", procName, 1);
    if (!pix)
        return ERROR_INT("pix not defined", procName, 1);
    pixAccumulate(pixaccGetPix(pixacc), pix, L_ARITH_SUBTRACT);
    return 0;
}


/*!
 *  pixaccMultConst()
 *
 *      Input:  pixacc
 *              factor
 *      Return: 0 if OK, 1 on error
 */
l_int32
pixaccMultConst(PIXACC    *pixacc,
                l_float32  factor)
{
    PROCNAME("pixaccMultConst");

    if (!pixacc)
        return ERROR_INT("pixacc not defined", procName, 1);
    pixMultConstAccumulate(pixaccGetPix(pixacc), factor,
                           pixaccGetOffset(pixacc));
    return 0;
}