panic on startup on OS X Yosemite when loading BindBuffersBase

[ezpuzz]

thread '<main>' panicked at 'called `Option::unwrap()` on a `None` value', /private/tmp/rust20150626-13301-uiklsd/rustc-1.1.0/src/libcore/option.rs:362
stack backtrace:
   1:        0x102f05e1f - sys::backtrace::write::h4d34c75aaa44ebb3c2r
   2:        0x102f09584 - panicking::on_panic::hacede89293da7355Lgw
   3:        0x102efcc35 - rt::unwind::begin_unwind_inner::h5f5b5041038f2bdbuYv
   4:        0x102efcfdc - rt::unwind::begin_unwind_fmt::hf422928da74ad1a4AXv
   5:        0x102f08e3c - rust_begin_unwind
   6:        0x102f27405 - panicking::panic_fmt::h0ece6850f56551b8f3B
   7:        0x102f26b64 - panicking::panic::h8e0828861061ce45M1B
   8:        0x102ed6278 - option::Option<T>::unwrap::h7340955155689965868
   9:        0x102e56e58 - gpu::opengl::Renderer::new::closure.12112
  10:        0x102e58e9e - load_with::closure.12217
  11:        0x102e58cf4 - metaloadfn::h7713124497418738431
  12:        0x102e58c3d - BindBuffersBase::load_with::h18178951034605948107
  13:        0x102e526a3 - load_with::h2438887132135737744
  14:        0x102e517d0 - gpu::opengl::Renderer::new::h7c8e68b4fea3e7c0pnd
  15:        0x102ee78eb - main::h3e82e9ed9324e15bN2e
  16:        0x102f0a6a8 - rust_try_inner
  17:        0x102f0a695 - rust_try
  18:        0x102f09d90 - rt::lang_start::h204325cf25bd6ae3gbw
  19:        0x102eeb5ee - main

I'm not sure why BindBuffersBase would have an issue?

[ezpuzz]

I'm going to try refactoring to a newer sdl2 and see if that fixes it up

[simias]

I wish I wasn't lazy and put proper error handling in my OpenGL code (but OpenGL error handling is so painful...). I also wish rust's Option wouldn't put the error in libcore instead of the calling code.

From this backtrace it seems that the error is in sdl2::video::gl_get_proc_address(s).unwrap() in src/gpu/opengl/mod.rs

I've just pushed a commit improving the error diagnostics in this part of the code, hopefully it should give us some clues about what goes wrong.

[tatref]

Similar issue here.

thread '<main>' panicked at 'Can't get proc address for glBindTextureUnit', src/gpu/opengl/mod.rs:69
stack backtrace:
   1:     0x7f46479f3bb0 - sys::backtrace::tracing::imp::write::h0f988057ddbbdebbKlt
   2:     0x7f46479f5f45 - panicking::log_panic::_<closure>::closure.39234
   3:     0x7f46479f5991 - panicking::log_panic::h7d832f79be8aa8d4Wlx
   4:     0x7f46479e98e3 - sys_common::unwind::begin_unwind_inner::hb994f7ba157b2162bds
   5:     0x7f46479e9a38 - sys_common::unwind::begin_unwind_fmt::h649a0735a6cdbdf4hcs
   6:     0x7f464797096e - gpu::opengl::_<impl>::new::_<closure>::closure.19026
                        at /home/yann/code/rust/rustation/<std macros>:8
   7:     0x7f4647973323 - gl::load_with::_<closure>::closure.19211
                        at target/debug/build/gl-9653698dd50d604e/out/bindings.rs:22495
   8:     0x7f46479731f2 - metaloadfn::metaloadfn::h9965409650451829332
                        at target/debug/build/gl-9653698dd50d604e/out/bindings.rs:13
   9:     0x7f4647973190 - BindTextureUnit::load_with::load_with::h1925743892630598600
                        at target/debug/build/gl-9653698dd50d604e/out/bindings.rs:9053
  10:     0x7f464796c5e8 - load_with::load_with::h16510004567656881384
                        at target/debug/build/gl-9653698dd50d604e/out/bindings.rs:22495
  11:     0x7f464796b5c1 - gpu::opengl::_<impl>::new::hb7d90dc26a803d4frye
                        at src/gpu/opengl/mod.rs:67
  12:     0x7f46479d7841 - main::h981e8e82b125442aKFi
                        at src/main.rs:82
  13:     0x7f46479f56d4 - sys_common::unwind::try::try_fn::h11739288761102791194
  14:     0x7f46479f30e8 - __rust_try
  15:     0x7f46479f536f - rt::lang_start::hdbc2e8a9fd66e7ff4ix
  16:     0x7f46479db599 - main
  17:     0x7f464707eb44 - __libc_start_main
  18:     0x7f4647945978 - <unknown>
  19:                0x0 - <unknown>

This is strange because glBindTextureUnit is part of OpenGL 4 (https://www.opengl.org/sdk/docs/man/html/glBindTextureUnit.xhtml), but code in gpu/opengl/mod.rs asks for version 3?

sdl2::video::gl_set_attribute(GLAttr::GLContextMajorVersion, 3);

I changed opengl/mod.rs to:

 67                   gl::load_with(|s|
 68                       match sdl2::video::gl_get_proc_address(s) {
 69                           None => {
 70                               //panic!("Can't get proc address for {}", s),
 71                               println!("Can't get proc address for {}", s);
 72                               0 as *const c_void
 73                           }
 74                           Some(a) => a as *const c_void,
 75                       });

Output is then:

Can't get proc address for glBindTextureUnit
Can't get proc address for glBlitNamedFramebuffer
Can't get proc address for glCheckNamedFramebufferStatus
Can't get proc address for glClearNamedBufferData
Can't get proc address for glClearNamedBufferSubData
Can't get proc address for glClearNamedFramebufferfi
Can't get proc address for glClearNamedFramebufferfv
Can't get proc address for glClearNamedFramebufferiv
Can't get proc address for glClearNamedFramebufferuiv
Can't get proc address for glClipControl
Can't get proc address for glCompressedTextureSubImage1D
Can't get proc address for glCompressedTextureSubImage2D
Can't get proc address for glCompressedTextureSubImage3D
Can't get proc address for glCopyNamedBufferSubData
Can't get proc address for glCopyTextureSubImage1D
Can't get proc address for glCopyTextureSubImage2D
Can't get proc address for glCopyTextureSubImage3D
Can't get proc address for glCreateBuffers
Can't get proc address for glCreateFramebuffers
Can't get proc address for glCreateProgramPipelines
Can't get proc address for glCreateQueries
Can't get proc address for glCreateRenderbuffers
...

I searched for some of them, and it seems that these are recent (OpenGL > 4) extensions: https://www.opengl.org/sdk/docs/man/html/glBindTextureUnit.xhtml https://www.opengl.org/sdk/docs/man/html/glCreateBuffers.xhtml https://www.opengl.org/sdk/docs/man/html/glCreateRenderbuffers.xhtml

Also, my driver is supposed to support OpenGL 4:

glxinfo | grep "OpenGL version"
OpenGL version string: 4.4.0 NVIDIA 340.65

Can you tweak opengl/mod.rs and take a look at your output?

[simias]

Thank you for taking the time to test that, does the emulator work (as in, boot the BIOS since it doesn't do a whole lot more at that point) if you replace the panic! with a println! ?

I asked @tomaka for advice and he told me that OS X only supports OpenGL 3.2 and not 3.3 so it gives us a 4.1 context here which explains the errors (I hope I understood that correctly). I don't think I use any of those missing functions so hopefully that shouldn't be an issue.

I guess the right way to do this would be for me to list all the required OpenGL functions and only report an error when one of those can't be loaded.

[simias]

Alternatively I'll try to request OpenGL 3.1 or 3.2 instead of 3.3, maybe it'll solve those issues on hardware/OS that don't support later versions. I thought 3.3 was conservative enough, apparently I was wrong...

[tatref]

I should have precised that, without the panic!, the emulator indeed works (logo is a bit scrambled, but otherwise OK).

[simias]

Okay, I'll make the error non-fatal then. If a required function is missing it'll panic later on. Thank you for the feedback.