The recipes in this book use some of the latest and greatest features in OpenGL 4.x. Therefore, in order to implement them, you'll need graphics hardware (graphics card or onboard GPU) and drivers that support at least OpenGL 4.6. However, many of the recipes will work with earlier versions. If you're unsure about what version of OpenGL your setup can support, there are a number of utilities available for determining this information. One option is GLview from Realtech VR, available at: http://www.realtech-vr.com/glview/.

If you're running Windows or Linux, drivers are readily available for most modern hardware. However, if you're using macOS, unfortunately, you're stuck with OpenGL 4.1. Apple has officially deprecated OpenGL, so there won't be any official updates coming. However, a large number of these recipes will function under OpenGL 4.1 (sometimes with minor tweaks).

Once you've verified that you have the required OpenGL drivers, you'll also need the following: 

• A C++ compiler. On Linux, the GNU Compiler Collection (gcc, g++, and so on) may already be available, and if not, it should be available through your distribution's package manager. On Windows, Microsoft Visual Studio will work fine, but if you don't have a copy, then the MinGW compiler (available from http://mingw.org/) is a good option.
• The GLFW library Version 3.0 or later, available from http://www.glfw.org/.  This library provides OpenGL context creation, window support, and support for user input events.
• The GLM library Version 0.9.6 or later, available from http://glm.g-truc.net/.  This provides mathematics support with classes for matrices, vectors, common transformations, noise functions, and much more

You can download the example code files for this book from your account at www.packtpub.com. If you purchased this book elsewhere, you can visit www.packtpub.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

1. Log in or register at www.packtpub.com.
2. Select the SUPPORT tab.
3. Click on Code Downloads & Errata.
4. Enter the name of the book in the Search box and follow the onscreen instructions.

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of:

• WinRAR/7-Zip for Windows
• Zipeg/iZip/UnRarX for Mac
• 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/OpenGL-4-Shading-Language-Cookbook-Third-Edition. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

We also provide a PDF file that has color images of the screenshots/diagrams used in this
book. You can download it here: https://www.packtpub.com/sites/default/files/downloads/9781789342253_ColorImages.pdf.

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "The shader would then access these values via built-in variables such as gl_Vertex and gl_Normal."

A block of code is set as follows:

void main() 
{ 
  Color = VertexColor; 
 
  gl_Position = vec4(VertexPosition,1.0); 
}

Any command-line input or output is written as follows:

Active attributes:
    1    VertexColor (vec3)
    0    VertexPosition (vec3)

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Now that we have set up our buffer objects, we tie them together into a Vertex Array Object (VAO)."