This should check if Qt provides zlib functions, and adds zlib dependency in case of zlibless Qt. Tested with Qt providing zlib functions only.
/********************************************************************
* *
* THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE. *
* *
* USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
* GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
* IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
* *
* THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002 *
* BY THE Xiph.Org FOUNDATION http://www.xiph.org/ *
* *
********************************************************************
function: modified discrete cosine transform prototypes
********************************************************************/
#ifndef _OGG_mdct_H_
#define _OGG_mdct_H_
#include "ivorbiscodec.h"
#include "misc.h"
#define DATA_TYPE ogg_int32_t
#define REG_TYPE register ogg_int32_t
#ifdef _LOW_ACCURACY_
#define cPI3_8 (0x0062)
#define cPI2_8 (0x00b5)
#define cPI1_8 (0x00ed)
#else
#define cPI3_8 (0x30fbc54d)
#define cPI2_8 (0x5a82799a)
#define cPI1_8 (0x7641af3d)
#endif
extern void mdct_forward(int n, DATA_TYPE *in, DATA_TYPE *out);
extern void mdct_backward(int n, DATA_TYPE *in, DATA_TYPE *out);
#endif