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OpenGL - GLM和GLSL，它们有何不同？

[英]OpenGL - GLM and GLSL, how are they different?

原文 2013-11-13 05:57:21 3 2 c++/ opengl/ matrix/ glsl/ glm-math

I am starting to learn about OpenGL and GLM and GLSL and I am getting a little confused. 我开始学习OpenGL，GLM和GLSL，我有点困惑。 I will say in here what I have understood so far and my questions, so please feel free to correct me anytime. 我会在这里说到目前为止我所理解的和我的问题，所以请随时随地纠正我。

So far I see that GLM extends the GLSL documentation providing more math functions, but since GLM is C++ based it will run on the CPU, on the other hand, GLSL runs directly in the GPU so I guess matrix math is a lot faster in GLSL since it can use the GPU's power to do all the math in parallel. 到目前为止，我看到GLM扩展了GLSL文档，提供了更多的数学函数，但由于GLM是基于C ++的，它将在CPU上运行，另一方面，GLSL直接在GPU中运行，所以我猜GLSL中的矩阵数学运算要快很多因为它可以使用GPU的功能并行完成所有数学运算。 So why to use GLM? 那么为什么要使用GLM呢？

2 个解决方案

They're completely different things: 他们是完全不同的东西：

GLSL is the language used to write shader programs that run on the GPU. GLSL是用于编写在GPU上运行的着色器程序的语言。 It's a variant of C with some special OpenGL-specific extensions. 它是C的变种，带有一些特殊的OpenGL特定扩展。 But as far as your application is concerned, a GLSL shader is just an opaque data file to be passed to the OpenGL library; 但就您的应用程序而言，GLSL着色器只是一个传递给OpenGL库的不透明数据文件; it's completely independent of the host program. 它完全独立于主机程序。
GLM is a C++ library for working with vector data on the CPU. GLM是一个C ++库，用于处理CPU上的矢量数据。 For convenience, it follows similar naming conventions to GLSL, but it's completely independent of OpenGL. 为方便起见，它遵循与GLSL类似的命名约定，但它完全独立于OpenGL。

GLM isn't meant as a substitute or alternative to GLSL. GLM不是GLSL的替代品或替代品。 It's meant to help with calculations that wouldn't make sense to do on the GPU — things like building a projection matrix to be used by your vertex shaders, or computing distances between points in 3D space. 它旨在帮助进行在GPU上没有意义的计算 - 例如构建顶点着色器使用的投影矩阵，或计算3D空间中点之间的距离。

They're two completely different things: 他们是两个完全不同的东西：

GLSL (OpenGL Shading Language) is a language used by OpenGL (syntax based on C) to run programs on the GPU, called shaders , which you know the purpose of. GLSL（OpenGL着色语言）是OpenGL使用的语言（基于C的语法）在GPU上运行程序，称为着色器 ，你知道它的目的。 They're not even part of your program - instead, they are two files stored in your computer which at runtime are passed to OpenGL and only then they're compiled. 它们甚至不是你程序的一部分 - 相反，它们是存储在你的计算机中的两个文件，它们在运行时传递给OpenGL，然后才编译。 It provides advanced math for two reasons: there's no way to load libraries, and because this is graphics programming , which is very related to math. 它提供高级数学有两个原因：没有办法加载库，因为这是图形编程 ，这与数学非常相关。
GLM (OpenGL Mathematics) is a C++ library used to extend C++'s math capabilities with functions and types that are commonly used in graphics programming - all this will be executed on the CPU, and it's independent from OpenGL. GLM（OpenGL数学）是一个C ++库，用于通过图形编程中常用的函数和类型扩展C ++的数学功能 - 所有这些都将在CPU上执行，并且它独立于OpenGL。

The reason GLM has OpenGL in its name is because it was built with graphics programming in their minds (in other words, made for OpenGL). GLM在其名称中使用OpenGL的原因是因为它是在他们的脑海中使用图形编程构建的（换句话说，是为OpenGL制作的）。

Short version: GLM is for your program, GLSL's math capabilities are for your shader. 简短版本：GLM适用于您的程序，GLSL的数学功能适用于您的着色器。