[Piglit] Spec justification for test_illegal_begin_mode?
Brian Paul
brianp at vmware.com
Wed Dec 9 18:42:45 UTC 2020
On 12/09/2020 11:19 AM, Ian Romanick wrote:
> On 12/9/20 7:55 AM, Brian Paul wrote:
>> On 12/08/2020 05:47 PM, Ian Romanick wrote:
>>> On 12/1/20 7:43 AM, Brian Paul wrote:
>>>> On 11/26/2020 09:22 AM, Brian Paul wrote:
>>>>> On Wed, Nov 25, 2020 at 8:19 PM Ian Romanick <idr at freedesktop.org
>>>>> <mailto:idr at freedesktop.org>> wrote:
>>>>>
>>>>> I was looking at the dlist-beginend subtest
>>>>> test_illegal_begin_mode.
>>>>> The test compiles a display list with GL_COMPILE_AND_EXECUTE
>>>>> mode. The
>>>>> glBegin in the test uses an invalid mode. This should generate a
>>>>> GL_INVALID_OPERATION error immediately. The test checks this, and
>>>>> that
>>>>>
>>>>>
>>>>> GL_INVALID_ENUM, actually, but anyway..
>>>>>
>>>>>
>>>>> seems correct.
>>>>>
>>>>> The test then tries to execute the display list and checks for
>>>>> GL_INVALID_OPERATION again. I believe this is incorrect. Section
>>>>> 5.4
>>>>> ("Display Lists") of the OpenGL 1.0 spec (this is a gl-1.0 test,
>>>>> after
>>>>> all!) says:
>>>>>
>>>>> If mode is COMPILE_AND_EXECUTE then commands are executed as
>>>>> they
>>>>> are encountered, then placed in the display list.
>>>>>
>>>>> Section 2.5 ("GL Errors") of the OpenGL 1.0 spec says:
>>>>>
>>>>> In other cases, the command generating the error is ignored
>>>>> so that
>>>>> it has no effect on GL state or framebuffer contents.
>>>>>
>>>>>
>>>>> Unfortunately, the spec doesn't clearly define what's meant by
>>>>> "ignored" here. That is, does it mean the command is not compiled
>>>>> into the display list? My intuition is that even if a command has
>>>>> invalid args at compile time, the command should still be compiled
>>>>> into the list. If the spec doesn't spell out the answer, I'd opt to
>>>>> do whatever other vendors do (hoping they're consistent).
>>>>>
>>>>>
>>>>> While the section numbers and titles have changed, every later
>>>>> version
>>>>> of the GL (compatibility profile) spec says the exact same thing.
>>>>>
>>>>> To me, this indicates that the errant glBegin should not be
>>>>> included in
>>>>> the display list. Assuming this test passes on other
>>>>> implementations, I
>>>>> think it does so only by luck. The mis-matched glEnd in the
>>>>> display
>>>>> list will generate the same error. Am I missing some spec
>>>>> language to
>>>>> justify this test?
>>>>>
>>>>>
>>>>> I haven't searched, but I suspect the spec doesn't explicitly describe
>>>>> this situation.
>>>>>
>>>>>
>>>>> I noticed this because I was adding a test that does
>>>>>
>>>>> glNewList(list, GL_COMPILE_AND_EXECUTE);
>>>>> glColor4fv(green);
>>>>> glBegin(GL_QUADS);
>>>>> glBegin(GL_QUADS);
>>>>> glVertex2f(-1, -1);
>>>>> glVertex2f( 1, -1);
>>>>> glVertex2f( 1, 0);
>>>>> glVertex2f(-1, 0);
>>>>> glEnd();
>>>>> glEndList();
>>>>>
>>>>> I expected an error while compiling the list, but I expected
>>>>> glCallList
>>>>> to not generate an error. Errors are generated in both places.
>>>>>
>>>>>
>>>>> I guess my instinct is that errors should be generated both at list
>>>>> compile and execute time. I wonder if there's any API function /
>>>>> argument combinations that would be errant at compile time but not at
>>>>> execute time, depending on some other state. If so, that would
>>>>> indicate that calls should always be compiled into the list, even if
>>>>> they generate an error at compile time.
>>>>>
>>>>>
>>>>> I think it gets worse. There's a second part to this new subtest
>>>>> that
>>>>> replaces the errant glBegin call with glReadPixels. glReadPixels
>>>>> is not
>>>>> allowed between glBegin and glEnd, so it should generate an
>>>>> error in
>>>>> GL_COMPILE_AND_EXECUTE mode. It does not.
>>>>>
>>>>>
>>>>> Sound like a run of the mill bug.
>>>>>
>>>>>
>>>>> These changes are in the top commit of:
>>>>>
>>>>>
>>>>> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.freedesktop.org%2Fidr%2Fpiglit%2F-%2Fcommits%2Fdisplay-list-hell&data=04%7C01%7Cbrianp%40vmware.com%7C89be46b6a92e45dcdaf808d89c6ef860%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C1%7C637431347717810649%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=1tCyEIgpPwDa2VAqxoTRKw93MONcaWEU00qFkL7b40Q%3D&reserved=0
>>>>>
>>>>> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.freedesktop.org%2Fidr%2Fpiglit%2F-%2Fcommits%2Fdisplay-list-hell&data=04%7C01%7Cbrianp%40vmware.com%7C89be46b6a92e45dcdaf808d89c6ef860%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C1%7C637431347717810649%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=1tCyEIgpPwDa2VAqxoTRKw93MONcaWEU00qFkL7b40Q%3D&reserved=0>
>>>>>
>>>>>
>>>>>
>>>>> I don't have any systems currently available with closed-source
>>>>> drivers,
>>>>> but I would be very interested to see the results of
>>>>> gl-1.0-dlist-beginend from that branch on any closed source
>>>>> drivers (on
>>>>> any platform).
>>>>>
>>>>>
>>>>> I can check on Nvidia next week when I'm back. Maybe someone else can
>>>>> test in the mean time.
>>>>
>>>> Here's the results with Nvidia's 455.38 driver:
>>>>
>>>> $ build-debug/bin/gl-1.0-dlist-beginend -auto
>>>> PIGLIT: {"enumerate subtests": ["glCallList inside glBegin-glEnd",
>>>> "nested glCallList inside glBegin-glEnd", "illegal glRect inside
>>>> glBegin-glEnd", "illegal glDrawArrays inside glBegin-glEnd", "illegal
>>>> glDrawArrays inside glBegin-glEnd (2)", "separate glBegin-glVertex-glEnd
>>>> lists", "illegal glBegin mode in display list"]}
>>>> PIGLIT: {"subtest": {"glCallList inside glBegin-glEnd" : "pass"}}
>>>> PIGLIT: {"subtest": {"nested glCallList inside glBegin-glEnd" : "pass"}}
>>>> PIGLIT: {"subtest": {"illegal glRect inside glBegin-glEnd" : "pass"}}
>>>> Probe color at (80,80)
>>>> Expected: 0.000000 1.000000 0.000000 1.000000
>>>> Observed: 1.000000 0.000000 0.000000 1.000000
>>>> PIGLIT: {"subtest": {"illegal glDrawArrays inside glBegin-glEnd" :
>>>> "fail"}}
>>>> PIGLIT: {"subtest": {"illegal glDrawArrays inside glBegin-glEnd (2)" :
>>>> "pass"}}
>>>> PIGLIT: {"subtest": {"separate glBegin-glVertex-glEnd lists" : "pass"}}
>>>> PIGLIT: {"subtest": {"illegal glBegin mode in display list" : "pass"}}
>>>> PIGLIT: {"result": "fail" }
>>>>
>>>> Looks like the subtest in question passes.
>>>
>>>
>>> Uh... I don't think that's the right branch. There should be some new
>>> subtests with GL_COMPILE_AND_EXECUTE in the name. On current Mesa, I
>>> get output more like:
>>>
>>> $ mesa debug bin/gl-1.0-dlist-beginend -auto
>>> PIGLIT: {"enumerate subtests": ["glCallList inside glBegin-glEnd",
>>> "nested glCallList inside glBegin-glEnd", "illegal glRect inside
>>> glBegin-glEnd", "illegal glDrawArrays inside glBegin-glEnd", "illegal
>>> glDrawArrays inside glBegin-glEnd (2)", "separate
>>> glBegin-glVertex-glEnd lists", "illegal glBegin mode in display list",
>>> "glBegin-glEnd inside GL_COMPILE_AND_EXECUTE", "glBegin-glBegin-glEnd
>>> inside GL_COMPILE", "glBegin-glBegin-glEnd inside
>>> GL_COMPILE_AND_EXECUTE"]}
>>> PIGLIT: {"subtest": {"glCallList inside glBegin-glEnd" : "pass"}}
>>> PIGLIT: {"subtest": {"nested glCallList inside glBegin-glEnd" : "pass"}}
>>> PIGLIT: {"subtest": {"illegal glRect inside glBegin-glEnd" : "pass"}}
>>> PIGLIT: {"subtest": {"illegal glDrawArrays inside glBegin-glEnd" :
>>> "pass"}}
>>> PIGLIT: {"subtest": {"illegal glDrawArrays inside glBegin-glEnd (2)" :
>>> "pass"}}
>>> PIGLIT: {"subtest": {"separate glBegin-glVertex-glEnd lists" : "pass"}}
>>> PIGLIT: {"subtest": {"illegal glBegin mode in display list" : "pass"}}
>>> PIGLIT: {"subtest": {"glBegin-glEnd inside GL_COMPILE_AND_EXECUTE" :
>>> "pass"}}
>>> PIGLIT: {"subtest": {"glBegin-glBegin-glEnd inside GL_COMPILE" : "pass"}}
>>> Unexpected GL error: GL_INVALID_OPERATION 0x502
>>> (Error at
>>> /home/idr/devel/graphics/piglit/tests/spec/gl-1.0/dlist-beginend.c:182)
>>> Unexpected GL error: GL_NO_ERROR 0x0
>>> (Error at
>>> /home/idr/devel/graphics/piglit/tests/spec/gl-1.0/dlist-beginend.c:203)
>>> Expected GL error: GL_INVALID_OPERATION 0x502
>>> PIGLIT: {"subtest": {"glBegin-glBegin-glEnd inside
>>> GL_COMPILE_AND_EXECUTE" : "fail"}}
>>> PIGLIT: {"result": "fail" }
>>
>> I'm on master branch and the last change to the test is:
>
> Can you try the branch that I linked before? :)
>
> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.freedesktop.org%2Fidr%2Fpiglit%2F-%2Ftree%2Fdisplay-list-hell&data=04%7C01%7Cbrianp%40vmware.com%7C89be46b6a92e45dcdaf808d89c6ef860%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C1%7C637431347717810649%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=3IzJ999v%2B7Mdwgo0CPzPbsa4L2WcQAmeMH5FQFDRlhQ%3D&reserved=0
>
> The top commits should be:
>
> 937f4bcd0 dlist-beginend: Test for errors in display lists with GL_COMPILE_AND_EXECUTE
> eb2cb99bf dlist-beginend: Test for errors in display lists with GL_COMPILE
> 2a87084b2 nv_primitive_restart: Test for errors in display lists with GL_COMPILE_AND_EXECUTE
> 4d667966e dlist-beginend: Try drawing with GL_COMPILE_AND_EXECUTE
> dea7f61b3 ext_gpu_shader4: Test gl_PrimitiveID when combined with display lists
> 829d5c039 nv_primitive_restart: Add basic state set and get tests
Sorry, I missed the git URL before. Here's the Nvidia results:
PIGLIT: {"enumerate subtests": ["glCallList inside glBegin-glEnd",
"nested glCallList inside glBegin-glEnd", "illegal glRect inside
glBegin-glEnd", "illegal glDrawArrays inside glBegin-glEnd", "illegal
glDrawArrays inside glBegin-glEnd (2)", "separate glBegin-glVertex-glEnd
lists", "illegal glBegin mode in display list", "glBegin-glEnd inside
GL_COMPILE_AND_EXECUTE", "glBegin-glBegin-glEnd inside GL_COMPILE",
"glBegin-glBegin-glEnd inside GL_COMPILE_AND_EXECUTE"]}
PIGLIT: {"subtest": {"glCallList inside glBegin-glEnd" : "pass"}}
PIGLIT: {"subtest": {"nested glCallList inside glBegin-glEnd" : "pass"}}
PIGLIT: {"subtest": {"illegal glRect inside glBegin-glEnd" : "pass"}}
Probe color at (80,80)
Expected: 0.000000 1.000000 0.000000 1.000000
Observed: 1.000000 0.000000 0.000000 1.000000
PIGLIT: {"subtest": {"illegal glDrawArrays inside glBegin-glEnd" : "fail"}}
PIGLIT: {"subtest": {"illegal glDrawArrays inside glBegin-glEnd (2)" :
"pass"}}
PIGLIT: {"subtest": {"separate glBegin-glVertex-glEnd lists" : "pass"}}
PIGLIT: {"subtest": {"illegal glBegin mode in display list" : "pass"}}
PIGLIT: {"subtest": {"glBegin-glEnd inside GL_COMPILE_AND_EXECUTE" :
"pass"}}
PIGLIT: {"subtest": {"glBegin-glBegin-glEnd inside GL_COMPILE" : "pass"}}
Unexpected GL error: GL_INVALID_OPERATION 0x502
(Error at
/home/brianp/projects/piglit-gitlab/piglit/tests/spec/gl-1.0/dlist-beginend.c:191)
Unexpected GL error: GL_NO_ERROR 0x0
(Error at
/home/brianp/projects/piglit-gitlab/piglit/tests/spec/gl-1.0/dlist-beginend.c:212)
Expected GL error: GL_INVALID_OPERATION 0x502
PIGLIT: {"subtest": {"glBegin-glBegin-glEnd inside
GL_COMPILE_AND_EXECUTE" : "fail"}}
PIGLIT: {"result": "fail" }
-Brian
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