Book Image

Learn OpenGL

By : Frahaan Hussain
Book Image

Learn OpenGL

By: Frahaan Hussain

Overview of this book

Learn OpenGL is your one-stop reference guide to get started with OpenGL and C++ for game development. From setting up the development environment to getting started with basics of drawing and shaders, along with concepts such as lighting, model loading, and cube mapping, this book will get you up to speed with the fundamentals. You begin by setting up your development environment to use OpenGL on Windows and macOS. With GLFW and GLEW set up using absolute and relative linking done, you are ready to setup SDL and SFML for both the operating systems. Now that your development environment is set up, you'll learn to draw using simple shaders as well as make the shader more adaptable and reusable. Then we move on to more advanced topics like texturing your objects with images and transforming your objects using translate, rotate and scale. With these concepts covered, we'll move on to topics like lighting to enable you to incorporate amazing dynamic lights in your game world. By the end of the book, you'll learn about model loading, right from setting up ASSIMP to learning about the model class and loading a model in your game environment. We will conclude by understanding cube mapping to bring advance worlds to your game.
Table of Contents (13 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Spotlight 


Let's discuss and take a look at how we can add spotlights to our game. We've looked at directional lights, we've looked at point lights. Directional lights have a direction but they don't have an original position, so they are infinitely far away. A point light has a position but it shines light in every single direction, whereas a spotlight has a position and a direction.

Take a look at the following diagram of a spotlight:

So, the position of the light is high up somewhere, and you can also see that there is a direction for the light. It essentially creates a cone-like effect, sort of what a lamp or a torch would do. Spotlights are used on stages. But spotlights are used in several scenarios in games throughout your world.

So, without further ado, let's get on with coding our spotlights. 

Making changes to shader files

Follow the below mentioned steps: 

  1. Updating shader files is actually very, very simple. We only need to actually modify the lighting fragment shader in terms of the...