/*!
   \file gs_bm.c

   \brief OGSF library - manipulating bitmaps (lower level functions)

   GRASS OpenGL gsurf OGSF Library 

   (C) 1999-2008 by the GRASS Development Team

   This program is free software under the 
   GNU General Public License (>=v2). 
   Read the file COPYING that comes with GRASS
   for details.

   \author Bill Brown USACERL, GMSL/University of Illinois (September 1993)
   \author Doxygenized by Martin Landa <landa.martin gmail.com> (May 2008)
 */

#include <grass/gis.h>
#include <grass/glocale.h>
#include <grass/gstypes.h>

#include "gsget.h"

/*!
   \brief Do combining of bitmaps, make bitmaps from other data w/maskval

   \param frombuff data buffer
   \param maskval mask type
   \param rows number of rows
   \param cols number of cols

   \return pointer to BM struct
 */
struct BM *gsbm_make_mask(typbuff * frombuff, float maskval, int rows,
			  int cols)
{
    int i, j, ioff;
    struct BM *bm;
    float curval;

    bm = BM_create(cols, rows);

    if (frombuff) {
	if (frombuff->bm) {
	    for (i = 0; i < rows; i++) {
		ioff = i * cols;

		for (j = 0; j < cols; j++) {
		    BM_set(bm, j, i, BM_get(frombuff->bm, j, i));
		}
	    }
	}
	else {
	    for (i = 0; i < rows; i++) {
		ioff = i * cols;

		for (j = 0; j < cols; j++) {
		    if (GET_MAPATT(frombuff, (ioff + j), curval)) {
			BM_set(bm, j, i, (curval == maskval));
		    }
		    else {
			BM_set(bm, j, i, 0);	/* doesn't mask nulls */
		    }
		}
	    }
	}
    }

    return (bm);
}

/*!
   \brief Zero mask

   \param map pointer to BM struct
 */
void gsbm_zero_mask(struct BM *map)
{
    int numbytes;
    unsigned char *buf;

    numbytes = map->bytes * map->rows;
    buf = map->data;

    while (numbytes--) {
	*buf++ = 0;
    }

    return;
}

/*!
   \brief mask types
 */
#define MASK_OR		1
#define MASK_ORNOT	2
#define MASK_AND	3
#define MASK_XOR	4

/*!
   \brief Mask bitmap

   Must be same size, ORs bitmaps & stores in bmvar

   \param bmvar bitmap (BM) to changed
   \param bmcom bitmap (BM)
   \param mask_type mask type (see mask types macros)

   \return -1 on failure (bitmap mispatch)
   \return 0 on success
 */
static int gsbm_masks(struct BM *bmvar, struct BM *bmcon, const int mask_type)
{
    int i;
    int varsize, consize, numbytes;

    varsize = bmvar->rows * bmvar->cols;
    consize = bmcon->rows * bmcon->cols;
    numbytes = bmvar->bytes * bmvar->rows;

    if (bmcon && bmvar) {
	if (varsize != consize) {
	    G_warning(_("Bitmap mismatch"));
	    return (-1);
	}

	if (bmvar->sparse || bmcon->sparse)
	    return (-1);

	switch (mask_type) {
	case MASK_OR:
	    for (i = 0; i < numbytes; i++)
		bmvar->data[i] |= bmcon->data[i];
	    break;
	case MASK_ORNOT:
	    for (i = 0; i < numbytes; i++)
		bmvar->data[i] |= ~bmcon->data[i];
	    break;
	case MASK_AND:
	    for (i = 0; i < numbytes; i++)
		bmvar->data[i] &= bmcon->data[i];
	    break;
	case MASK_XOR:
	    for (i = 0; i < numbytes; i++)
		bmvar->data[i] ^= bmcon->data[i];
	    break;
	}

	return (0);
    }

    return (-1);
}

/*!
   \brief Mask bitmap (mask type OR)

   Must be same size, ORs bitmaps & stores in bmvar

   \param bmvar bitmap (BM) to changed
   \param bmcom bitmap (BM)
   \param mask_type mask type (see mask types macros)

   \return -1 on failure (bitmap mispatch)
   \return 0 on success
 */
int gsbm_or_masks(struct BM *bmvar, struct BM *bmcon)
{
    return gsbm_masks(bmvar, bmcon, MASK_OR);
}

/*!
   \brief Mask bitmap (mask type ORNOT)

   Must be same size, ORNOTs bitmaps & stores in bmvar

   \param bmvar bitmap (BM) to changed
   \param bmcom bitmap (BM)
   \param mask_type mask type (see mask types macros)

   \return -1 on failure (bitmap mispatch)
   \return 0 on success
 */
int gsbm_ornot_masks(struct BM *bmvar, struct BM *bmcon)
{
    return gsbm_masks(bmvar, bmcon, MASK_ORNOT);
}

/*!
   \brief Mask bitmap (mask type ADD)

   Must be same size, ADDs bitmaps & stores in bmvar

   \param bmvar bitmap (BM) to changed
   \param bmcom bitmap (BM)
   \param mask_type mask type (see mask types macros)

   \return -1 on failure (bitmap mispatch)
   \return 0 on success
 */
int gsbm_and_masks(struct BM *bmvar, struct BM *bmcon)
{
    return gsbm_masks(bmvar, bmcon, MASK_AND);
}

/*!
   \brief Mask bitmap (mask type XOR)

   Must be same size, XORs bitmaps & stores in bmvar

   \param bmvar bitmap (BM) to changed
   \param bmcom bitmap (BM)
   \param mask_type mask type (see mask types macros)

   \return -1 on failure (bitmap mispatch)
   \return 0 on success
 */
int gsbm_xor_masks(struct BM *bmvar, struct BM *bmcon)
{
    return gsbm_masks(bmvar, bmcon, MASK_XOR);
}

/*!
   \brief Update current maps

   \param surf surface (geosurf)

   \return 0
   \return 1
 */
int gs_update_curmask(geosurf * surf)
{
    struct BM *b_mask, *b_topo, *b_color;
    typbuff *t_topo, *t_mask, *t_color;
    int row, col, offset, destroy_ok = 1;
    gsurf_att *coloratt;

    G_debug(5, "gs_update_curmask(): id=%d", surf->gsurf_id);

    if (surf->mask_needupdate) {
	surf->mask_needupdate = 0;
	surf->norm_needupdate = 1;	/* edges will need to be recalculated */

	t_topo = gs_get_att_typbuff(surf, ATT_TOPO, 0);

	if (!t_topo) {
	    surf->mask_needupdate = 1;

	    return (0);
	}

	if (surf->nz_topo || surf->nz_color ||
	    gs_mask_defined(surf) || t_topo->nm) {
	    b_mask = b_topo = b_color = NULL;

	    if (!surf->curmask) {
		surf->curmask = BM_create(surf->cols, surf->rows);
	    }
	    else {
		gsbm_zero_mask(surf->curmask);
	    }

	    if (surf->nz_topo) {
		/* no_zero elevation */
		b_topo = gsbm_make_mask(t_topo, 0.0, surf->rows, surf->cols);
	    }

	    /* make_mask_from_color */
	    if (surf->nz_color && surf->att[ATT_COLOR].att_src == MAP_ATT) {
		t_color = gs_get_att_typbuff(surf, ATT_COLOR, 0);
		coloratt = &(surf->att[ATT_COLOR]);
		b_color = BM_create(surf->cols, surf->rows);

		for (row = 0; row < surf->rows; row++) {
		    for (col = 0; col < surf->cols; col++) {
			offset = row * surf->cols + col;
			BM_set(b_color, col, row,
			       (NULL_COLOR ==
				gs_mapcolor(t_color, coloratt, offset)));
		    }
		}
	    }

	    if (gs_mask_defined(surf)) {
		t_mask = gs_get_att_typbuff(surf, ATT_MASK, 0);

		if (t_mask->bm) {
		    b_mask = t_mask->bm;
		    destroy_ok = 0;
		}
		else {
		    b_mask = BM_create(surf->cols, surf->rows);
		    gs_set_maskmode((int)surf->att[ATT_MASK].constant);

		    for (row = 0; row < surf->rows; row++) {
			for (col = 0; col < surf->cols; col++) {
			    offset = row * surf->cols + col;
			    BM_set(b_mask, col, row,
				   gs_masked(t_mask, col, row, offset));
			}
		    }
		}
	    }

	    if (b_topo) {
		G_debug(5, "gs_update_curmask(): update topo mask");
		gsbm_or_masks(surf->curmask, b_topo);
		BM_destroy(b_topo);
	    }

	    if (b_color) {
		G_debug(5, "gs_update_curmask(): update color mask");
		gsbm_or_masks(surf->curmask, b_color);
		BM_destroy(b_color);
	    }

	    if (t_topo->nm) {
		G_debug(5, "gs_update_curmask(): update elev null mask");
		gsbm_or_masks(surf->curmask, t_topo->nm);
	    }

	    if (b_mask) {
		G_debug(5, "gs_update_curmask(): update mask mask");

		if (t_mask->bm) {
		    if (surf->att[ATT_MASK].constant) {
			/* invert */
			gsbm_or_masks(surf->curmask, t_mask->bm);
		    }
		    else {
			gsbm_ornot_masks(surf->curmask, t_mask->bm);
		    }
		}
		else {
		    gsbm_or_masks(surf->curmask, b_mask);
		}

		if (destroy_ok) {
		    BM_destroy(b_mask);
		}
	    }

	    /* TODO: update surf->zminmasked */
	    return (1);
	}
	else if (surf->curmask) {
	    BM_destroy(surf->curmask);
	    surf->curmask = NULL;
	    surf->zminmasked = surf->zmin;
	}

    }

    return (0);
}

/*!
   \brief Print bitmap to stderr

   \param bm bitmap (BM)
 */
void print_bm(struct BM *bm)
{
    int i, j;

    for (i = 0; i < bm->rows; i++) {
	for (j = 0; j < bm->cols; j++) {
	    fprintf(stderr, "%d ", BM_get(bm, j, i));
	}

	fprintf(stderr, "\n");
    }

    return;
}