OpenGL ES: A Gentle Introduction - Beginning Android Games - page 347

Now look at preceding the loop again. Notice something? For each Bob, we enable the same
vertex attributes over and over again via glEnableClientState() . We actually only need to set
those once, as each Bob uses the same model that always uses the same vertex attributes.
The next big problem are the calls to glXXXPointer() for each Bob. Since those pointers are
also OpenGL ES states, we only need to set them once as well, as they will never change once
they're set. So how can we fix that? Let's rewrite the Vertices.draw() method a little:
public void bind() {
GL10 gl = glGraphics.getGL();
gl.glEnableClientState(GL10. GL_VERTEX_ARRAY );
vertices.position(0);
gl.glVertexPointer(2, GL10. GL_FLOAT , vertexSize, vertices);
if if(hasColor) {
gl.glEnableClientState(GL10. GL_COLOR_ARRAY );
vertices.position(2);
gl.glColorPointer(4, GL10. GL_FLOAT , vertexSize, vertices);
}
if (hasTexCoords) {
gl.glEnableClientState(GL10. GL_TEXTURE_COORD_ARRAY );
vertices.position(hasColor?6:2);
gl.glTexCoordPointer(2, GL10. GL_FLOAT , vertexSize, vertices);
}
}
public void draw( int primitiveType, int offset, int numVertices) {
GL10 gl = glGraphics.getGL();
if if(indices != null ) {
indices.position(offset);
gl.glDrawElements(primitiveType, numVertices, GL10. GL_UNSIGNED_SHORT , indices);
} else {
gl.glDrawArrays(primitiveType, offset, numVertices);
}
}
public void unbind() {
GL10 gl = glGraphics.getGL();
if (hasTexCoords)
gl.glDisableClientState(GL10. GL_TEXTURE_COORD_ARRAY );
if if(hasColor)
gl.glDisableClientState(GL10. GL_COLOR_ARRAY );
}