Book Image

WebGL Beginner's Guide

Book Image

WebGL Beginner's Guide

Overview of this book

WebGL is a new web technology that brings hardware-accelerated 3D graphics to the browser without installing additional software. As WebGL is based on OpenGL and brings in a new concept of 3D graphics programming to web development, it may seem unfamiliar to even experienced Web developers.Packed with many examples, this book shows how WebGL can be easy to learn despite its unfriendly appearance. Each chapter addresses one of the important aspects of 3D graphics programming and presents different alternatives for its implementation. The topics are always associated with exercises that will allow the reader to put the concepts to the test in an immediate manner.WebGL Beginner's Guide presents a clear road map to learning WebGL. Each chapter starts with a summary of the learning goals for the chapter, followed by a detailed description of each topic. The book offers example-rich, up-to-date introductions to a wide range of essential WebGL topics, including drawing, color, texture, transformations, framebuffers, light, surfaces, geometry, and more. With each chapter, you will "level up"ù your 3D graphics programming skills. This book will become your trustworthy companion filled with the information required to develop cool-looking 3D web applications with WebGL and JavaScript.
Table of Contents (18 chapters)
WebGL Beginner's Guide
Credits
About the Authors
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Index

WebGL as a state machine: buffer manipulation


There is some information about the state of the rendering pipeline that we can retrieve when we are dealing with buffers with the functions: getParameter, getBufferParameter, and isBuffer.

Just like we did in the previous chapter, we will use getParameter(parameter) where parameter can have the following values:

  • ARRAY_BUFFER_BINDING: It retrieves a reference to the currently-bound VBO

  • ELEMENT_ARRAY_BUFFER_BINDING: It retrieves a reference to the currently-bound IBO

Also, we can enquire about the size and the usage of the currently-bound VBO and IBO using getBufferParameter(type, parameter) where type can have the following values:

  • ARRAY_BUFFER: To refer to the currently bound VBO

  • ELEMENT_ARRAY_BUFFER: To refer to the currently bound IBO

And parameter can be:

  • BUFFER_SIZE: Returns the size of the requested buffer

  • BUFFER_USAGE: Returns the usage of the requested buffer

Note

Your VBO and/or IBO needs to be bound when you enquire about the state of...