c++ 12bit 变量，我该怎么做? [英] c++ 12bit variable, how can I do this?

问题描述

我正在构建一个体素引擎，所以我担心内存使用情况，使用 12 位而不是 16 位块 ID 可以节省大量内存.我有一个 3D 块 id 数组，每个 id 都有一个静态配置.

I'm building a voxel engine so I have concerns about memory usage, using 12bit instead of 16bit block ids could save a lot of memory. I have a 3D array of block ids, each id has a static configuration.

我不确定实现这一目标的好方法是什么.有没有办法只获取一块原始内存并自己管理它，这是一个好主意吗?我可能会遇到什么问题吗?有没有更好的方法来做到这一点?

I'm not sure what a good way to achieve this would be. Is there a way to just get a block of raw memory and manage it myself and would this be a good idea; are there any problems I might run into? Is there a better way to do this?

我对 c++ 有一些经验，但我大部分时间都花在了 Java 和 c# 上.

I have some experience with c++, but most of my time was spent with Java and c#.

感谢阅读！

推荐答案

这是可能的，例如:-

• 保留一个 8 字节的变量(存储 5 个变量，每个 12 位)，或
• 使用char[k]保留k~ceiling{(12*n)/8.0f}，然后使用union等....

• reserve a 8-byte variable (store 5 variables, each 12 bits), or
• reserve using char[k] that k~ceiling{(12*n)/8.0f}, then use union, etc....

这是我学习在块中分配内存的链接(我是提问者).
如何使用 void* 作为单个变量持有人?(例如 void* raw=SomeClass() )

Here is a link (I am the one who ask) that I learn about allocating memory in a chunk.
How to use void* as a single variable holder? (Ex. void* raw=SomeClass() )

不过，我有点不同意你想要做什么.

However, I moderately disagree of what you are trying to do.

据我所知，你的方法的缺点是:-

As far I know, the disadvantage of your approach are :-

• 一些错误:更难实现.
• 对齐问题:性能可能会更差.
  看到这个:内存对齐:如何使用alignof/alignas?

传统推荐:在(过早地)优化之前对其进行分析.

Traditional recommendation : profile it before (prematurely) optimize it.

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