[Piglit] [PATCH] tests/spec/arb_robustness/draw-vbo-bounds.c: add clipping

[Ian Romanick]

On 10/29/2012 05:34 PM, Roland Scheidegger wrote:
> Am 30.10.2012 00:22, schrieb Brian Paul:
>> On 10/29/2012 05:05 PM, sroland at vmware.com wrote:
>>> From: Roland Scheidegger<sroland at vmware.com>
>>>
>>> Make sure clipping is needed sometimes, and more often use small index
>>> counts,
>>> to expose issues and excercise more paths in mesa's draw module.
>>> ---
>>>    tests/spec/arb_robustness/draw-vbo-bounds.c |    4 ++--
>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/tests/spec/arb_robustness/draw-vbo-bounds.c
>>> b/tests/spec/arb_robustness/draw-vbo-bounds.c
>>> index 4351ac9..c780a3a 100644
>>> --- a/tests/spec/arb_robustness/draw-vbo-bounds.c
>>> +++ b/tests/spec/arb_robustness/draw-vbo-bounds.c
>>> @@ -95,7 +95,7 @@ random_vertices(GLsizei offset, GLsizei stride,
>>> GLsizei count)
>>>
>>>        for (i = 0; i<  count; ++i) {
>>>            GLfloat *vertex = (GLfloat *)(vertices + offset + i*stride);
>>> -        vertex[0] = (rand() % 1000) * .001;
>>> +        vertex[0] = (rand() % 1000) * ((rand() % 1000) ? 0.001 : 1.0);
>>>            vertex[1] = (rand() % 1000) * .001;
>>>        }
>>>
>>> @@ -145,7 +145,7 @@ static void test(void)
>>>        vertex_count = 1 + rand() % 0xffff;
>>>
>>>        index_offset = (rand() % 0xff) * sizeof(GLushort);
>>> -    index_count = 1 + rand() % 0xffff;
>>> +    index_count = rand() % 10 ? 1 + rand() % 0xffff : 1 + rand() %
>>> 0x7ff;
>>>        min_index = rand() % vertex_count;
>>>        max_index = min_index + rand() % (vertex_count - min_index);
>>>
>>
>> Randomness in tests can be OK, but in this case wouldn't you want to
>> explicitly test some specific coordinates and indexes to make sure the
>> corner cases are hit?
>>
>> -Brain
>
> Well I'm not sure it's worth the trouble note the test is run 1000 times
> so probability is very very high that these cases are hit anyway.

What happens when one of us gets a bug report that this test fails, but 
we're unable to reproduce it?  If I had been paying attention, I would 
have already objected to the initial use of rand in this test...

> Roland