/*
    bmp15.cpp
    Copyright (C) 2007 Acekard, www.acekard.com
    Copyright (C) 2007-2009 somebody
    Copyright (C) 2009 yellow wood goblin

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

//�

#include <list>
#include <string>
#include "bmp15.h"
#include "dbgtool.h"

cBMP15::cBMP15() : _width(0), _height(0), _pitch(0), _buffer(NULL)
{
}

cBMP15::cBMP15( u32 width, u32 height ) : _width(0), _height(0), _pitch(0), _buffer(NULL)
{
    _width = width;
    _height = height;
    _pitch = (width + (width & 1)) << 1;
    //u32 pitch = (((width*16)+31)>>5)<<2;            // 通用算法？
}

cBMP15::~cBMP15()
{
    // dbg_printf( "cBMP15 %08x destructed\n", this );
}

cBMP15 createBMP15( u32 width, u32 height )
{
    cBMP15 bmp( width, height );

    u32 pitch = bmp.pitch();           // 15bit bmp pitch 算法
    //dbg_printf( "pitch: %d bytes\n", pitch );
    //dbg_printf( "buffer %08x\n", bmp.buffer() );

    u32 bufferSize = height * pitch;
    if( bufferSize & 3 ) // 如果 bufferSize 不是按4字节对齐，就把他调整到对齐
        bufferSize += 4 - (bufferSize & 3);
    bmp._buffer = new u32[bufferSize>>2];
    return bmp;
}


typedef std::pair< std::string, cBMP15 >  str_bmp_pair;
typedef std::list< str_bmp_pair > str_bmp_list;
static str_bmp_list _bmpPool;

cBMP15 createBMP15FromMem( void * mem )
{
    return cBMP15();
}

cBMP15 createBMP15FromFile( const std::string & filename )
{
    //dbg_printf( "createBMP15FromFile (%s)\n", filename );

    str_bmp_list::iterator it;
    for( it = _bmpPool.begin(); it != _bmpPool.end(); ++it )
    {
        if( filename == it->first ) {
            return it->second;
        }
    }

    FILE * f = fopen( filename.c_str(), "rb" );
    if( NULL == f ) {
        dbg_printf("(%s) file does not exist\n", filename.c_str() );
        return cBMP15();
    }

    // 读取文件长度
    fseek( f, 0, SEEK_END );
    int fileSize = ftell( f );

    if( -1 == fileSize ) {
        fclose( f );
        return cBMP15();
    }

    u16 bmMark = 0;
    fseek( f, 0, SEEK_SET );
    fread( &bmMark, 1, 2, f );
    if( bmMark != 0x4d42 ) {// 'B' 'M' header
        dbg_printf( "not a bmp file\n" );
        fclose( f );
        return cBMP15();
    }

    // 找出bmp高和宽
    u32 width = 0;
    u32 height = 0;
    fseek( f, 0x12, SEEK_SET );
    fread( &width, 1, 4, f );
    fseek( f, 0x16, SEEK_SET );
    fread( &height, 1, 4, f );
    //dbg_printf( "w:%d h:%d\n", width, height );

    cBMP15 bmp = createBMP15( width, height );

    u32 bmpDataOffset = 0;
    fseek( f, 0x0a, SEEK_SET );
    fread( &bmpDataOffset, 1, 4, f );

    long position = bmpDataOffset;
    fseek( f, position, SEEK_SET );
    u16 * pbuffer = ((u16 *)bmp.buffer()) + (bmp.pitch()>>1) * height - (bmp.pitch()>>1);

    for( u32 i = 0; i < height; ++i ) {
        fread( pbuffer, 1, bmp.pitch(), f );
        position += bmp.pitch();
        pbuffer -= bmp.pitch() >> 1;
        fseek( f, position, SEEK_SET );
    }
    fclose( f );

    pbuffer = (u16 *)bmp.buffer();
    for( u32 i = 0; i < height; ++i )
    {
        for( u32 j = 0; j < (bmp.pitch()>>1); ++j )
        {
            u16 pixelColor = pbuffer[i*(bmp.pitch()>>1)+j];
            pixelColor = ((pixelColor & 0x7C00) >> 10)
                | ((pixelColor & 0x03E0)) | ((pixelColor & 0x1F) << 10);
            pbuffer[i*(bmp.pitch()>>1)+j] = pixelColor | (pixelColor ? BIT(15):0);
            //dbg_printf("%d               %d\n", j, i );
        }
    }

    str_bmp_pair bmpPoolItem( std::string(filename), bmp );
    _bmpPool.push_back( bmpPoolItem );

    //dbg_printf( "load bmp success, %08x\n", bmp.buffer() );
    return bmp;
}