ecvChunk.h

Go to the documentation of this file.

// ----------------------------------------------------------------------------
// -                        CloudViewer: www.cloudViewer.org                  -
// ----------------------------------------------------------------------------
// Copyright (c) 2018-2024 www.cloudViewer.org
// SPDX-License-Identifier: MIT
// ----------------------------------------------------------------------------
 
#pragma once
 
// System
#include <vector>
 
class ccChunk {
public:
    static const size_t SIZE_POWER = 16;
    static const size_t SIZE = (1 << SIZE_POWER);  //~ 64K
 
    inline static size_t Count(size_t elementCount) {
        return (elementCount >> SIZE_POWER) +
               ((elementCount & (SIZE - 1)) ? 1 : 0);
    }
    inline static size_t Size(size_t chunkIndex, size_t elementCount) {
        return (chunkIndex + 1 < Count(elementCount)
                        ? SIZE
                        : elementCount - chunkIndex * SIZE);
    }
    inline static size_t Size(size_t chunkIndex,
                              size_t chunkCount,
                              size_t elementCount) {
        return (chunkIndex + 1 < chunkCount ? SIZE
                                            : elementCount - chunkIndex * SIZE);
    }
    inline static size_t StartPos(size_t chunkIndex) {
        return chunkIndex * SIZE;
    }
    template <typename T>
    inline static T* Start(std::vector<T>& buffer, size_t chunkIndex) {
        return buffer.data() + StartPos(chunkIndex);
    }
    template <typename T>
    inline static const T* Start(const std::vector<T>& buffer,
                                 size_t chunkIndex) {
        return buffer.data() + StartPos(chunkIndex);
    }
    template <typename T>
    inline static size_t Count(const std::vector<T>& buffer) {
        return Count(buffer.size());
    }
    template <typename T>
    inline static size_t Size(size_t chunkIndex, const std::vector<T>& buffer) {
        return Size(chunkIndex, buffer.size());
    }
};