OpenGL ES2.0的IndexBuffer注意事项
void glDrawElements( GLenum mode,GLsizei count,
GLenum type,
const GLvoid * indices);
Parameters
mode Specifies what kind of primitives to render. Symbolic constants GL_POINTS, GL_LINE_STRIP, GL_LINE_LOOP, GL_LINES, GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, and GL_TRIANGLES are accepted.count Specifies the number of elements to be rendered.
type Specifies the type of the values in indices. Must be GL_UNSIGNED_BYTE or GL_UNSIGNED_SHORT.
indices Specifies a pointer to the location where the indices are stored.
可见OpenGL ES2.0明确表示不支持32位索引，所以大家在使用OpenGL ES2.0时要小心，不要使用32位索引。使用32位索引也许在某些机器上能work，但不能在所有机器上work。
http://hi.baidu.com/zwbdb/item/f7c761e9c51019e0fb42badf