On 2 November 2011 02:07, Zhao, Jian J <<a href="mailto:jian.j.zhao@intel.com">jian.j.zhao@intel.com</a>> wrote: <div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"> <div link="blue" vlink="purple" lang="ZH-CN"><div>Hi Paul, Thanks for your suggestion. My answer is inline. Best regards ZhaoJian <div style="border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt"> <div><div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm">From: Paul Berry [mailto:<a href="mailto:stereotype441@gmail.com" target="_blank">stereotype441@gmail.com</a>] Sent: Wednesday, November 02, 2011 12:20 AM To: Zhao, Jian J Cc: <a href="mailto:piglit@lists.freedesktop.org" target="_blank">piglit@lists.freedesktop.org</a> Subject: Re: [Piglit] [PATCH] Test case on rendering with only fragment shader but no vertex shader. </div></div><div class="im"> Before I get to specific comments, are you familiar with Piglit's "shader runner" framework (look at any of the Piglit files that end in ".shader_test"). It seems like this test could be rewritten as a shader runner test--that would make it shorter and more readable, and save a compilation step. </div>It’s a good idea. But unfortunately I can’t reproduce it with shader_runner, I have a look and find it is because it uses glDrawArraysInstancedARB instead of glDrawArrays or just simple glBegin and glEnd. I don’t know what is glDrawArraysInstancedARB. What’s it difference from glDrawArrays? So I just updated my original patch file. <div class="im"> </div></div></div></div></blockquote><div> You're right that it doesn't make sense to use glDrawArraysInstancedARB--that function is only available if your GL implementation supports the ARB_draw_instanced extension, or GL 3.1, and there's no good reason to make your test dependent on those. (If you're curious, you can find documentation for the extension in <a href="http://www.opengl.org/registry/specs/ARB/draw_instanced.txt">http://www.opengl.org/registry/specs/ARB/draw_instanced.txt</a>. When the extension was folded into GL 3.1, it was renamed to glDrawArraysInstanced). But shader_runner only tries to use glDrawArraysInstancedARB if your shader_test file contains the command "draw instanced rect". You should be able to do the testing you need by just drawing a simple rectangle using the "draw rect" command, which works on GL 2.1. For an example of how this sort of test is typically written using shader_runner, see for instance tests/spec/glsl-1.10/execution/fs-inline-notequal.shader_test. Thanks very much for your patience with this--I really want to avoid having to add more compiled C programs to piglit if at all possible. </div></div>