Texturing and Shading - Learn OpenGL ES: For Mobile Game and Graphics Development - page 182

Note Do not confuse OpenGL ES buffer objects with
java.nio.*Buffer objects, such as
java.nio.ShortBuffer , java.nio.FloatBuffer , and
so on.

Listing 5-1. TANK FENCE 1/src/com/apress/android/tankfence1/GLES20Ren-
derer.java

GLES20.glGenBuffers(2, _tankBuffers, 0);
GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER,
_tankBuffers[0]);
GLES20.glBufferData(GLES20.GL_ARRAY_BUFFER,
tankVFA.length * 4, _tankVFB, GLES20.GL_STATIC_DRAW);
GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER,
_tankBuffers[1]);
GLES20.glBufferData(GLES20.GL_ELEMENT_ARRAY_BUFFER,
tankISA.length * 2, _tankISB, GLES20.GL_STATIC_DRAW);

Finally, after making a buffer object the current buffer object, we need to pass
it the corresponding vertex or index data using the ES 2.0 function glBuffer-
Data . As shown in Listing 5-1 , after the call to
glBindBuffer(GLES20.GL_ARRAY_BUFFER, _tankBuffers[0]) ,
glBufferData is called, with arguments "GLES20.GL_ARRAY_BUFFER" ,
"tankVFA.length

4" , "_tankVFB" ,

and

*

"GLES20.GL_STATIC_DRAW" .
As with glBindBuffer , the first argument passed to glBufferData is either
GL_ARRAY_BUFFER or GL_ELEMENT_ARRAY_BUFFER , denoting the target/
type of the buffer object. The second argument denotes the size of array (of per-
vertex or index data) in bytes. The third argument denotes the Buffer
( java.nio.Buffer ) for the corresponding vertex or index data. Finally, the last
argument can be any one of the following values:

▪ GL_STATIC_DRAW
▪ GL_DYNAMIC_DRAW