Merge branch 'installation_centos' into 'master'

Documentation on how to install prerequisites on CentOS

See merge request !6

INSTALL.md

@@ -20,7 +20,7 @@ If you want to build meshalyzer yourself, please check the following sections.
 4. [FLTK 1.3.x](http://www.fltk.org/) or higher.
 5. [glew](http://glew.sourceforge.net) for Linux and Windows only.
 6. [glut](https://www.opengl.org/resources/libraries/glut/) for Linux and Windows only.
-7. [cmake](https://cmake.org) if you want to make compiling easier.
+7. [cmake](https://cmake.org) version 3.12 or higher, if you want to make compiling easier.
 8. <strike>To make the "windowless" rendering version, [OSMesa](https://www.mesa3d.org/osmesa.html)</strike>
 9. To read in VTK/VTU format meshes, install [VTK](https://www.vtk.org/) development files
 
@@ -104,6 +104,8 @@ Follow the steps in the [Compiling](#compiling) to build the code.
 For installing meshalyzer first you need to install the ["Prerequisites"](#prerequisities) using your package manager (e.g. `apt`, `yum`, or `dnf`).
 The [Dockerfile](Dockerfile) provides an installation example based on CentOS7.
 
+### Ubuntu
+
 On Ubuntu (tested with Ubuntu 20.04), you can use:
 ```
 apt-get update && apt-get install -y \
@@ -122,6 +124,39 @@ apt-get update && apt-get install -y \
 
 Follow the steps in [Compiling](#compiling) to build the code.
 
+### CentOS
+
+On CentOS (tested with CentOS 7), you can use:
+```
+yum update && yum install git \
+gcc gcc-c++ \
+libpng-devel \
+libjpeg-devel \
+fltk-devel \
+fltk-fluid \
+glew-devel \
+freeglut-devel
+```
+
+If you want to compile `meshalyzer` with `cmake`, you will also need `cmake` version 3.12 or higher. 
+You can know which version is provided by the package manager with the command:
+```
+yum info cmake
+```
+
+If the version is higher than 3.12, then use:
+```
+yum install cmake
+```
+Otherwise you can get cmake3 from [EPEL](https://docs.fedoraproject.org/en-US/epel/). On CentOS 7, you can use:
+```
+yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
+yum install cmake3
+```
+Please note that you will then have to use the `cmake3` command instead of the `cmake` command to compile `meshalyzer`.
+
+You can now follow the steps in [Compiling](#compiling) to build the code. 
+
 ## Post-compilation
 
 You can execute meshalyzer by typing `./meshalyzer`