title: iPad missing OpenGL extension string GL_APPLE_texture_2D_limited_npot
body: <p>In my iOS game, I want to use the GL_APPLE_texture_2D_limited_npot extension when available to save memory (the game have NPOT textures, and in my current implementation I add some padding to make those power of two).</p>
  
  <p>I am testing in my iPad (first generation). Every thing I have read so far says that all iOS devices which supports OpenGLES2 (including iPad) also support GL_APPLE_texture_2D_limited_npot (which is very good, since my game use OpenGLES2). I have tested in my iPad, and it does support (I removed the padding and the images work if I set wrap to GL_CLAMP_TO_EDGE), but the extension does not show when I call glGetString(GL_EXTENSIONS). The code:</p>
  
  <pre><code>const char *extensions = (const char *)glGetString(GL_EXTENSIONS);
  std::cout &lt;&lt; extensions &lt;&lt; "\n";
  </code></pre>
  
  <p>Results in:</p>
  
  <pre><code>GL_OES_depth_texture GL_OES_depth24 GL_OES_element_index_uint GL_OES_fbo_render_mipmap GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_texture_float GL_OES_texture_half_float GL_OES_vertex_array_object GL_EXT_blend_minmax GL_EXT_debug_label GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_read_format_bgra GL_EXT_separate_shader_objects GL_EXT_shader_texture_lod GL_EXT_texture_filter_anisotropic GL_APPLE_framebuffer_multisample GL_APPLE_rgb_422 GL_APPLE_texture_format_BGRA8888 GL_APPLE_texture_max_level GL_IMG_read_format GL_IMG_texture_compression_pvrtc
  </code></pre>
  
  <p>Why does this extension does not show with glGetString(GL_EXTENSIONS)? What is the proper way to check for it? Does all OpenGLES2 iOS devices really support it?</p>