historical/toontown-classic.git/panda/include/fftCompressor.h
2024-01-16 11:20:27 -06:00

100 lines
3 KiB
C++

/**
* PANDA 3D SOFTWARE
* Copyright (c) Carnegie Mellon University. All rights reserved.
*
* All use of this software is subject to the terms of the revised BSD
* license. You should have received a copy of this license along
* with this source code in a file named "LICENSE."
*
* @file fftCompressor.h
* @author drose
* @date 2000-12-11
*/
#ifndef FFTCOMPRESSOR_H
#define FFTCOMPRESSOR_H
#include "pandabase.h"
#include "pvector.h"
#include "pointerToArray.h"
#include "vector_stdfloat.h"
#include "vector_double.h"
#include "luse.h"
class Datagram;
class DatagramIterator;
/**
* This class manages a lossy compression and decompression of a stream of
* floating-point numbers to a datagram, based a fourier transform algorithm
* (similar in principle to JPEG compression).
*
* Actually, it doesn't do any real compression on its own; it just outputs a
* stream of integers that should compress much tighter via gzip than the
* original stream of floats would have.
*
* This class depends on the external FFTW library; without it, it will fall
* back on lossless output of the original data.
*/
class EXPCL_PANDA_MATHUTIL FFTCompressor {
public:
FFTCompressor();
static bool is_compression_available();
void set_quality(int quality);
int get_quality() const;
void set_use_error_threshold(bool use_error_threshold);
bool get_use_error_threshold() const;
void set_transpose_quats(bool flag);
bool get_transpose_quats() const;
void write_header(Datagram &datagram);
void write_reals(Datagram &datagram, const PN_stdfloat *array, int length);
void write_hprs(Datagram &datagram, const LVecBase3 *array, int length);
bool read_header(DatagramIterator &di, int bam_minor_version);
bool read_reals(DatagramIterator &di, vector_stdfloat &array);
bool read_hprs(DatagramIterator &di, pvector<LVecBase3> &array,
bool new_hpr);
bool read_hprs(DatagramIterator &di, pvector<LVecBase3> &array);
static void free_storage();
private:
enum RunWidth {
// We write a byte to the datagram at the beginning of each run to encode
// the width and length of the run. The width is indicated by the top two
// bits, while the length fits in the lower six, except RW_double, which
// is a special case.
RW_width_mask = 0xc0,
RW_length_mask = 0x3f,
RW_0 = 0x00,
RW_8 = 0x40,
RW_16 = 0x80,
RW_32 = 0xc0,
RW_double = 0xff,
RW_invalid = 0x01
};
int write_run(Datagram &datagram, RunWidth run_width,
const vector_double &run);
int read_run(DatagramIterator &di, vector_double &run);
double get_scale_factor(int i, int length) const;
static double interpolate(double t, double a, double b);
PN_stdfloat get_compressability(const PN_stdfloat *data, int length) const;
int _bam_minor_version;
int _quality;
bool _use_error_threshold;
double _fft_offset;
double _fft_factor;
double _fft_exponent;
bool _transpose_quats;
};
#endif