Book Image

Mastering Android NDK

Book Image

Mastering Android NDK

Overview of this book

Android NDK is used for multimedia applications that require direct access to system resources. NDK is also the key for portability, which in turn allows a reasonably comfortable development and debugging process using familiar tools such as GCC and Clang toolchains. This is a hands-on guide to extending your game development skills with Android NDK. The book takes you through many clear, step-by-step example applications to help you further explore the features of Android NDK and some popular C++ libraries and boost your productivity by debugging the development process. Through the course of this book, you will learn how to write portable multi-threaded native code, use HTTP networking in C++, play audio files, use OpenGL ES 3, and render high-quality text. Each chapter aims to take you one step closer to building your application. By the end of this book, you will be able to create an engaging, complete gaming application.
Table of Contents (17 chapters)
Mastering Android NDK
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Stringed musical instrument model


Let's implement a simple physical model of a stringed musical instrument using the code from the previous example. Later you can use these routines to create a small interactive synthesizer for Android.

The string is modelled as a sequence of point masses oscillating vertically. Strictly speaking, we solve the linear one-dimensional wave equation with certain initial and boundary conditions. The sound is produced by taking values of the solution at the position of sound pickup.

We need the clGString class to store all the model values and the final result. The method GenerateSound() precalculates string parameters and resizes the data containers accordingly:

class clGString
{
public:
  void GenerateSound()
  {
    // 4 seconds, 1 channel, 16 bit
    FSoundLen  = 44100 * 4 * 2;
    FStringLen = 200;

The Frc value is the normalized fundamental frequency of the sound. Overtones are implicitly created by the physical model:

    float Frc = 0.5f;
    InitString( Frc...