/**
 * @file llkdumem.cpp
 * @brief Helper class for kdu memory management
 *
 * $LicenseInfo:firstyear=2010&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, 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;
 * version 2.1 of the License only.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "linden_common.h"
#include "llkdumem.h"
#include "llerror.h"

using namespace kdu_core;
using kd_supp_image_local::image_line_buf;

#if defined(LL_WINDOWS)
# pragma warning(disable: 4702) // unreachable code
#endif

LLKDUMemIn::LLKDUMemIn(const U8 *data,
                       const U32 size,
                       const U16 width,
                       const U16 height,
                       const U8 in_num_components,
                       siz_params *siz)
{
    U8 n;

    first_comp_idx = 0;
    rows = height;
    cols = width;
    num_components = in_num_components;
    alignment_bytes = 0;

    for (n = 0; n < 3; ++n)
    {
        precision[n] = 0;
    }

    for (n = 0; n < num_components; ++n)
    {
        siz->set(Sdims,n,0,rows);
        siz->set(Sdims,n,1,cols);
        siz->set(Ssigned,n,0,false);
        siz->set(Sprecision,n,0,8);
    }
    incomplete_lines = NULL;
    free_lines = NULL;
    num_unread_rows = rows;

    mData = data;
    mDataSize = size;
    mCurPos = 0;
}

LLKDUMemIn::~LLKDUMemIn()
{
    if ((num_unread_rows > 0) || (incomplete_lines != NULL))
    {
        kdu_warning w;
        w << "Not all rows of image components "
            << first_comp_idx << " through "
            << first_comp_idx+num_components-1
            << " were consumed!";
    }
    image_line_buf *tmp;
    while ((tmp=incomplete_lines) != NULL)
    {
        incomplete_lines = tmp->next;
        delete tmp;
    }
    while ((tmp=free_lines) != NULL)
    {
        free_lines = tmp->next;
        delete tmp;
    }
}


bool LLKDUMemIn::get(int comp_idx, kdu_line_buf &line, int x_tnum)
{
    int idx = comp_idx - this->first_comp_idx;
    assert((idx >= 0) && (idx < num_components));
    x_tnum = x_tnum*num_components+idx;
    image_line_buf *scan, *prev=NULL;
    for (scan = incomplete_lines; scan != NULL; prev = scan, scan = scan->next)
    {
        assert(scan->next_x_tnum >= x_tnum);
        if (scan->next_x_tnum == x_tnum)
        {
            break;
        }
    }
    if (scan == NULL)
    { // Need to read a new image line.
        assert(x_tnum == 0); // Must consume in very specific order.
        if (num_unread_rows == 0)
        {
            return false;
        }
        if ((scan = free_lines) == NULL)
        {
            scan = new image_line_buf(cols+3,num_components);
        }
        free_lines = scan->next;
        if (prev == NULL)
        {
            incomplete_lines = scan;
        }
        else
        {
            prev->next = scan;
        }

        // Copy from image buffer into scan.
        memcpy(scan->buf, mData+mCurPos, cols*num_components);
        mCurPos += cols*num_components;

        num_unread_rows--;
        scan->accessed_samples = 0;
        scan->next_x_tnum = 0;
    }

    assert((cols-scan->accessed_samples) >= line.get_width());

    int comp_offset = idx;
    kdu_byte *sp = scan->buf+num_components*scan->accessed_samples + comp_offset;
    int n=line.get_width();

    if (line.get_buf32() != NULL)
    {
        kdu_sample32 *dp = line.get_buf32();
        if (line.is_absolute())
        { // 32-bit absolute integers
            for (; n > 0; n--, sp+=num_components, dp++)
            {
                dp->ival = ((kdu_int32)(*sp)) - 128;
            }
        }
        else
        { // true 32-bit floats
            for (; n > 0; n--, sp+=num_components, dp++)
            {
                dp->fval = (((float)(*sp)) / 256.0F) - 0.5F;
            }
        }
    }
    else
    {
        kdu_sample16 *dp = line.get_buf16();
        if (line.is_absolute())
        { // 16-bit absolute integers
            for (; n > 0; n--, sp+=num_components, dp++)
            {
                dp->ival = ((kdu_int16)(*sp)) - 128;
            }
        }
        else
        { // 16-bit normalized representation.
            for (; n > 0; n--, sp+=num_components, dp++)
            {
                dp->ival = (((kdu_int16)(*sp)) - 128) << (KDU_FIX_POINT-8);
            }
        }
    }

    scan->next_x_tnum++;
    if (idx == (num_components-1))
    {
        scan->accessed_samples += line.get_width();
    }
    if (scan->accessed_samples == cols)
    { // Send empty line to free list.
        assert(scan == incomplete_lines);
        incomplete_lines = scan->next;
        scan->next = free_lines;
        free_lines = scan;
    }

  return true;
}