为什么 GLsizei 没有定义为无符号？

Question

我正在查找 iOS 上 OpenGL ES 1.1 实现的 GLsizei 的 typedef，并惊讶地发现它被定义为 int 。一些快速谷歌搜索表明这是正常的。 （包括在普通 OpenGL 上。）

我期望它将被定义为 unsigned int 或 size_t。为什么它被定义为普通的int？

Answer 1

这似乎不太可能成为问题，除非您有任何 4GB 的数据结构。

这是某人的答案： http://oss.sgi.com/archives /ogl-sample/2005-07/msg00003.html

Quote:

(1) Arithmetic on unsigned values in C doesn't always yield intuitively
correct results (e.g. width1-width2 is positive when width1<width2).
Compilers offer varying degrees of diagnosis when unsigned ints appear
to be misused.  Making sizei a signed type eliminates many sources of
semantic error and some irrelevant diagnostics from the compilers.  (At
the cost of reducing the range of sizei, of course, but for the places
sizei is used that's rarely a problem.)

(2) Some languages that support OpenGL bindings lack (lacked? not sure
about present versions of Fortran) unsigned types, so by sticking to
signed types as much as possible there would be fewer problems using
OpenGL in those languages.

两种解释似乎都有道理 - 我在许多方面遇到了 1)我自己也曾愚蠢地使用 NSUInteger 作为循环计数器（提示：不要这样做，尤其是倒数到零时）。