15.4 Load ảnh TGA

CImage* CImage::LoadTGA(IReadableStream* stream)

{

    TGA_Header header;

    stream->ReadInt8(header.idlength);

    stream->ReadInt8(header.colourmaptype);

    stream->ReadInt8(header.datatypecode);

    stream->ReadInt16(header.colourmaporigin);

    stream->ReadInt16(header.colourmaplength);

    stream->ReadInt8(header.colourmapdepth);

    stream->ReadInt16(header.x_origin);

    stream->ReadInt16(header.y_origin);

    stream->ReadInt16(header.width);

    stream->ReadInt16(header.height);

    stream->ReadInt8(header.bitsperpixel);

    stream->ReadInt8(header.imagedescriptor);

    CImage *img = 0;

    if (header.datatypecode != 2)

    {

        LogError("[CImage::LoadTGA] Unsupported TGA Format. Use non-compress only");

    }

    else if ((header.bitsperpixel != 24) && (header.bitsperpixel != 32))

    {

        LogError("[CImage::LoadTGA] Unsupported TGA Pixel Format. Use 24-, or 32-bpp only");

    }

    else

    {

        img = new CImage(header.width, header.height, 

                 (header.bitsperpixel == 24)?EIMAGE_FORMAT_R8G8B8:EIMAGE_FORMAT_R8G8B8A8);

        stream->Skip(header.idlength + header.colourmaptype * header.colourmaplength);

        int pixelsize = header.bitsperpixel/8;

        int size = header.width*header.height*pixelsize;

        UINT8 *p = img->m_pData;

        for (int i = 0; i < size; i+=pixelsize, p+=pixelsize)

        {

            stream->Read(p, 0, pixelsize);

            UINT8 tmp = p[0];

            p[0] = p[2];

            p[2] = tmp;

        }

        //stream->Read(img->m_pData, 0, header.width*header.height*header.bitsperpixel/8);

        img->VerticalFlip();

    }

    return img;

}