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// Copyright 2012 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.
// -----------------------------------------------------------------------------
//
// Color Cache for WebP Lossless
//
// Authors: Jyrki Alakuijala (jyrki@google.com)
// Urvang Joshi (urvang@google.com)
#ifndef WEBP_UTILS_COLOR_CACHE_H_
#define WEBP_UTILS_COLOR_CACHE_H_
#include "../webp/types.h"
#if defined(STARBOARD)
#include "starboard/log.h"
#endif
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
// Main color cache struct.
typedef struct {
uint32_t *colors_; // color entries
int hash_shift_; // Hash shift: 32 - hash_bits.
} VP8LColorCache;
static const uint32_t kHashMul = 0x1e35a7bd;
static WEBP_INLINE uint32_t VP8LColorCacheLookup(
const VP8LColorCache* const cc, uint32_t key) {
SB_DCHECK(key <= (~0U >> cc->hash_shift_));
return cc->colors_[key];
}
static WEBP_INLINE void VP8LColorCacheInsert(const VP8LColorCache* const cc,
uint32_t argb) {
const uint32_t key = (kHashMul * argb) >> cc->hash_shift_;
cc->colors_[key] = argb;
}
static WEBP_INLINE int VP8LColorCacheGetIndex(const VP8LColorCache* const cc,
uint32_t argb) {
return (kHashMul * argb) >> cc->hash_shift_;
}
static WEBP_INLINE int VP8LColorCacheContains(const VP8LColorCache* const cc,
uint32_t argb) {
const uint32_t key = (kHashMul * argb) >> cc->hash_shift_;
return cc->colors_[key] == argb;
}
//------------------------------------------------------------------------------
// Initializes the color cache with 'hash_bits' bits for the keys.
// Returns false in case of memory error.
int VP8LColorCacheInit(VP8LColorCache* const color_cache, int hash_bits);
// Delete the memory associated to color cache.
void VP8LColorCacheClear(VP8LColorCache* const color_cache);
//------------------------------------------------------------------------------
#if defined(__cplusplus) || defined(c_plusplus)
}
#endif
#endif // WEBP_UTILS_COLOR_CACHE_H_