12. Raiders: OpenGL ES style
In this book you’ve seen the new GLKit framework’s power and ease of use, along with its limitations, such as being restricted to devices running iOS 5 or greater.
In this chapter, we’ll strip Raiders of the remaining vestiges of GLKit and convert the game to standard OpenGL ES 2.0 (GLES2). You will become familiar with shaders, the shader language, and some of the basic math required for performing transformations.
The parent sprite class in Raiders is the class that does all the rendering. Therefore, this is where our conversion to OpenGL ES 2.0 (GLES2) will begin.
You will copy the classes from the original GLKit-enabled Raiders, as created in Chapter 9, to the empty GLES2-enabled app from