#define __SP_CANVAS_UTILS_C__

/*
 * Helper stuff for SPCanvas
 *
 * Authors:
 *   Lauris Kaplinski <lauris@kaplinski.com>
 *
 * Copyright (C) 1999-2002 authors
 * Copyright (C) 2001-2002 Ximian, Inc.
 *
 * Released under GNU GPL, read the file 'COPYING' for more information
 */


#include <2geom/matrix.h>
#include "libnr/nr-pixops.h"
#include "sp-canvas-util.h"
#include <string.h>  /* for memset */


void
sp_canvas_update_bbox (SPCanvasItem *item, int x1, int y1, int x2, int y2)
{
    sp_canvas_request_redraw (item->canvas, (int)item->x1, (int)item->y1, (int)item->x2, (int)item->y2);
    item->x1 = x1;
    item->y1 = y1;
    item->x2 = x2;
    item->y2 = y2;
    sp_canvas_request_redraw (item->canvas, (int)item->x1, (int)item->y1, (int)item->x2, (int)item->y2);
}

void
sp_canvas_item_reset_bounds (SPCanvasItem *item)
{
    item->x1 = 0.0;
    item->y1 = 0.0;
    item->x2 = 0.0;
    item->y2 = 0.0;
}

void
sp_canvas_prepare_buffer (SPCanvasBuf *buf)
{
    if (buf->is_empty) {
        sp_canvas_clear_buffer(buf);
        buf->is_empty = false;
    }
}

void
sp_canvas_clear_buffer (SPCanvasBuf *buf)
{
    unsigned char r, g, b;

    r = (buf->bg_color >> 16) & 0xff;
    g = (buf->bg_color >> 8) & 0xff;
    b = buf->bg_color & 0xff;

    if ((r != g) || (r != b)) {
        int x, y;
        for (y = buf->rect.y0; y < buf->rect.y1; y++) {
            unsigned char *p;
            p = buf->buf + (y - buf->rect.y0) * buf->buf_rowstride;
            for (x = buf->rect.x0; x < buf->rect.x1; x++) {
                *p++ = r;
                *p++ = g;
                *p++ = b;
            }
        }
    } else {
        int y;
        for (y = buf->rect.y0; y < buf->rect.y1; y++) {
            memset (buf->buf + (y - buf->rect.y0) * buf->buf_rowstride, r, 4 * (buf->rect.x1 - buf->rect.x0)); 
        }
    }
}

Geom::Matrix sp_canvas_item_i2p_affine (SPCanvasItem * item)
{
    g_assert (item != NULL); /* this may be overly zealous - it is
                              * plausible that this gets called
                              * with item == 0. */

    return item->xform;
}

Geom::Matrix  sp_canvas_item_i2i_affine (SPCanvasItem * from, SPCanvasItem * to)
{
    g_assert (from != NULL);
    g_assert (to != NULL);

    return sp_canvas_item_i2w_affine(from) * sp_canvas_item_i2w_affine(to).inverse();
}

void sp_canvas_item_set_i2w_affine (SPCanvasItem * item,  Geom::Matrix const &i2w)
{
    g_assert (item != NULL);

    sp_canvas_item_affine_absolute(item, i2w * sp_canvas_item_i2w_affine(item->parent).inverse());
}

void sp_canvas_item_move_to_z (SPCanvasItem * item, gint z)
{
    g_assert (item != NULL);

    gint current_z = sp_canvas_item_order (item);

    if (current_z == -1) // not found in its parent
        return;

    if (z == current_z)
        return;

    if (z > current_z) {
        sp_canvas_item_raise (item, z - current_z);
    } else {
        sp_canvas_item_lower (item, current_z - z);
    }
}

gint
sp_canvas_item_compare_z (SPCanvasItem * a, SPCanvasItem * b)
{
    gint const o_a = sp_canvas_item_order (a);
    gint const o_b = sp_canvas_item_order (b);

    if (o_a > o_b) return -1;
    if (o_a < o_b) return 1;

    return 0;
}

/*
  Local Variables:
  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :