OpenGL ES 2 for Android

Defining an Orthographic Projection

To define an orthographic projection, we’ll use Android’s Matrix class, which resides in the android.opengl package. In that class there’s a method called orthoM, which will generate an orthographic projection for us. We’ll use that projection to adjust the coordinate space, as we just discussed in ​Adjusting to the Aspect Ratio​, and as we’ll soon see, an orthographic projection is very similar to a translation matrix.

Let’s take a look at all of the parameters for orthoM:

orthoM(float[] m, int mOffset, float left, float right, float bottom, float top, float near, float far)

float[] m

The destination array—this array’s length should be at least sixteen elements so it can store the orthographic projection ...