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

Basic utility functions

The last section of the chapter mentions some utility functions, which will be used in examples across the book, or just can be useful in your projects.

  • ofMap( v, v0, v1, out0, out1 ): This function performs linear interpolation of a float value v from the segment [v0, v1] to the segment [out0, out1]. Note, it does not control boundaries of v, and just uses the formula (v-v0)/(v1-v0)*(out1-out0) + out0. For controlling boundaries, call this function with the last optional parameter set to true: ofMap( v, v0, v1, out0, out1, true ). Then the result will be clamped to [out0, out1].

  • ofClamp( v, v0, v1 ): This function clamps the float value v to the segment [v0, v1] that is returns min( max( v, v0 ), v1 ).

  • ofRandom( a, b ): This function generates a pseudo-random number in the segment [a, b]. (Actually, it returns a value always less than that of b).

  • ofNoise ( x ), ofNoise( x, y ), ofNoise( x, y, z ), and ofNoise( x, y, z, w ):These functions return Perlin noise value, see the details in Appendix B, Perlin Noise.

  • ofToString( v ): This function converts the int or float value v into string-returning value

  • ofToInt( s ) and ofToFloat( s ): These functions convert the string s into int or float returning values respectively.

  • ofGetWidth() and ofGetHeight(): These functions return the current width and height of the project's screen, in pixels.

  • ofGetElapsedTimef(): This function returns the value of seconds lapsed from the project's start. This is a float value, measured with millisecond accuracy. For example, returned value 123.4 means 123 seconds and 400 milliseconds.

  • ofShowCursor() and ofHideCursor(): These functions show and hide the mouse cursor.

For printing information into a console window, you can use the standard cout stream. For example, for printing time from the project's start, use the following code:

cout << "Time: " << ofGetElapsedTimef() << endl;

Here, endl is a standard constant, which means starting a new line in the console.