c pvr转存pvr.ccz格式

pvr.ccz 是把pvr用zlib算法压缩后的图像格式，其优点是可以提升文件读取效率。 

大多数情况下我们可以用一些工具来将pvr压缩到pvr.ccz ,下面提供一个c++方法来完成这个过程

int CompressPvrToCCZFile(unsigned char *buffer,unsigned int fileLength, const char *newFilePath)
{
　　//buffer pvr文件二进制数据，fileLength 文件长度，newFilePath 保存地址
    unsigned long bufferSize = fileLength;
    char* DestBuffer=new char[(uInt)bufferSize];memset(DestBuffer, 0, bufferSize);
    errno_t err; //错误变量的定义
    err = compress((Bytef*)DestBuffer,(uLongf*)&bufferSize,(const Bytef*)buffer,(uLongf)fileLength);

    //
    CCZHeader header;
    header.version = 256;
    header.len = ((fileLength & 0x000000ff) >> 24 | (fileLength & 0x0000ff00) >> 8 | (fileLength & 0x00ff0000) << 8 | (fileLength & 0xff000000) << 24);
    header.compression_type = CCZ_COMPRESSION_ZLIB;
    
    header.sig[0] = 'C';
    header.sig[1] = 'C';
    header.sig[2] = 'Z';
    header.sig[3] = '!';

    //保存文件
    FILE *fp = fopen(newFilePath, "wb+");
    if (!fp)
    {
        delete []DestBuffer;

        return -1;
    }
    fwrite(&header, sizeof(header), 1, fp);
    fwrite(DestBuffer, bufferSize, 1, fp);
    fclose(fp);
    delete []DestBuffer;

    return 1;
}