godot/thirdparty/libwebp/src/utils/random_utils.h

// Copyright 2013 Google Inc. All Rights Reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the COPYING file in the root of the source
// tree. An additional intellectual property rights grant can be found
// in the file PATENTS. All contributing project authors may
// be found in the AUTHORS file in the root of the source tree.
// -----------------------------------------------------------------------------
//
// Pseudo-random utilities
//
// Author: Skal ([email protected])

#ifndef WEBP_UTILS_RANDOM_UTILS_H_
#define WEBP_UTILS_RANDOM_UTILS_H_

#include <assert.h>
#include "src/webp/types.h"

#ifdef __cplusplus
extern "C" {
#endif

#define VP8_RANDOM_DITHER_FIX …
#define VP8_RANDOM_TABLE_SIZE …

VP8Random;

// Initializes random generator with an amplitude 'dithering' in range [0..1].
void VP8InitRandom(VP8Random* const rg, float dithering);

// Returns a centered pseudo-random number with 'num_bits' amplitude.
// (uses D.Knuth's Difference-based random generator).
// 'amp' is in VP8_RANDOM_DITHER_FIX fixed-point precision.
static WEBP_INLINE int VP8RandomBits2(VP8Random* const rg, int num_bits,
                                      int amp) { … }

static WEBP_INLINE int VP8RandomBits(VP8Random* const rg, int num_bits) { … }

#ifdef __cplusplus
}    // extern "C"
#endif

#endif  // WEBP_UTILS_RANDOM_UTILS_H_