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

Processing a single video frame

Now we begin to learn the methods of processing video. Values of pixels in the current video frame can be read in a way similar to the one in ofImage, using access to its pixel array data:

unsigned char *getPixels()

Also, here is the getPixelRef() method, which returns a reference to a pixel array of the current frame, represented by a special class ofPixels.


Note that the ofImage class has getPixelRef() too and can be used in a similar way.

It is easy to get the pixel color using pixels.getColor( x, y ), which returns the ofColor value of pixel ( x,y ). Compared to directly working with pixels data using getPixels(), it is a relatively slow operation, but is more simple and convenient. Note, ofPixels has useful properties such as getWidth() and getHeight() that are used for getting the width and height, and also the channels value, which holds the number of channels in the image (1, 3, or 4).

The vertical lines image example

See the example where we read the...