Book Image

Mastering openFrameworks: Creative Coding Demystified

By : Denis Perevalov
Book Image

Mastering openFrameworks: Creative Coding Demystified

By: Denis Perevalov

Overview of this book

openFrameworks is a powerful programming toolkit and library designed to assist the creative process through simplicity and intuitiveness. It's a very handy software library written in C++ to reduce the software development process, helping you to kick-start creative coding. With the help of C++ and shaders support, openFrameworks allows for the processing of all kinds of media information with your custom-developed algorithms at the lowest possible level, with the fastest speed. "Mastering openFrameworks: Creative Coding Demystified" will introduce you to a world of creative coding projects, including interactive installations, audio-visual, and sound art projects. You will learn how to make your own projects using openFrameworks. This book focuses on low-level data processing, which allows you to create really unique and cutting-edge installations and projects. "Mastering openFrameworks: Creative Coding Demystified" provides a complete introduction to openFrameworks, including installation, core capabilities, and addons. Advanced topics like shaders, computer vision, and depth cameras are also covered. We start off by discussing the basic topics such as image and video loading, rendering and processing, playing sound samples, and synthesizing new sounds. We then move on to cover 3D graphics, computer vision, and depth cameras. You will also learn a number of advanced topics such as video mapping, interactive floors and walls, video morphing, networking, and using geometry shaders. You will learn everything you need to know in order to create your own projects; create projects of all levels, ranging from simple creative-code experiments, to big interactive systems consisting of a number of computers, depth cameras, and projectors.
Table of Contents (22 chapters)
Mastering openFrameworks: Creative Coding Demystified
About the Author
About the Reviewers

Screen grabbing

Sometimes it is desirable to save the picture drawn by your project in the file. You can do it using tools of your operating system, but it's more comfortable to do it right in your project. So let's see how to save the contents of your project screen to an image file.

For such purposes, we need to use the ofImage class for working with images. Though the class is considered in Chapter 4, Images and Textures, for screen grabbing, it is just enough to understand that the ofImage object holds an image.

The following code saves the current screen to file on the pressing of the Space bar. It should be added to the testApp::keyPressed() function as follows:

//Grab the screen image to file
if ( key == ' ' ) {
  ofImage image;  //Declare image object

  //Grab contents of the screen
  image.grabScreen( 0, 0, ofGetWidth(), ofGetHeight() );  

  image.saveImage( "screen.png" );  //Save image to file

The parameters of the image.grabScreen() function specify the rectangle of the grabbing...