/*
   Copyright (C) 2009-2015 Red Hat, Inc.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   This library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <glib.h>
#include "utils.h"

int rgb32_data_has_alpha(int width, int height, size_t stride,
                         uint8_t *data, int *all_set_out)
{
    uint32_t *line, *end, alpha;
    int has_alpha;

    has_alpha = FALSE;
    while (height-- > 0) {
        line = (uint32_t *)data;
        end = line + width;
        data += stride;
        while (line != end) {
            alpha = *line & 0xff000000U;
            if (alpha != 0) {
                has_alpha = TRUE;
                if (alpha != 0xff000000U) {
                    *all_set_out = FALSE;
                    return TRUE;
                }
            }
            line++;
        }
    }

    *all_set_out = has_alpha;
    return has_alpha;
}