[Piglit] [PATCH] gl-1.5-vertex-buffer-offsets: test unusual vertex offsets/strides
Brian Paul
brianp at vmware.com
Mon Jun 22 07:26:02 PDT 2015
OK, my piglit test does test what Flockers is doing. At the failure
point there are 8 vertex arrays in use.
Using _mesa_print_arrays():
Vertex: Ptr=00000000, Type=GL_FLOAT, Size=3, ElemSize=12, Stride=87,
Buffer=1041(Size 21489)
Normal: Ptr=0000000C, Type=GL_FLOAT, Size=3, ElemSize=12, Stride=87,
Buffer=1041(Size 21489)
Color: Ptr=00000030, Type=GL_FLOAT, Size=4, ElemSize=16, Stride=87,
Buffer=1041(Size 21489)
TexCoord[0]: Ptr=00000040, Type=GL_FLOAT, Size=2, ElemSize=8,
Stride=87, Buffer=1041(Size 21489)
Attrib[1]: Ptr=0000004B, Type=GL_FLOAT, Size=3, ElemSize=12,
Stride=87, Buffer=1041(Size 21489)
Attrib[4]: Ptr=00000048, Type=GL_UNSIGNED_BYTE, Size=3, ElemSize=3,
Stride=87, Buffer=1041(Size 21489)
Attrib[14]: Ptr=00000024, Type=GL_FLOAT, Size=3, ElemSize=12,
Stride=87, Buffer=1041(Size 21489)
Attrib[15]: Ptr=00000018, Type=GL_FLOAT, Size=3, ElemSize=12,
Stride=87, Buffer=1041(Size 21489)
The Attrib[1] array is float[3] at offset(Ptr) 75 (0x4B) bytes. Also
note that the stride between vertices is 87 bytes so clearly there's no
regard to 4-byte float alignment.
I kind of wish the spec had language saying glVertexPointer, etc.
generated GL_INVALID_OPERATION if the stride or offset didn't meet
alignment restrictions. Too late now.
We could add some debug code in Mesa to warn on unaligned arrays too.
How about this: I could modify the piglit test to generate PIGLIT_WARN
instead of FAIL if there's a rendering failure. I can also mention this
Flockers issue in the comments in the piglit test for future reference.
NVIDIA's driver handles all the cases in the piglit test (and it renders
Flockers correctly).
-Brian
On 06/22/2015 07:26 AM, Brian Paul wrote:
> Thanks for pointing that out, Chris. I had forgotten about that language.
>
> This test came about after fixing a bug in our driver when running the
> game Flockers, from Steam. It has a few vertex arrays with unusual
> layout. I'll have to go back and double-check the data type. Maybe it
> was ubyte instead of float...
>
> -Brian
>
> On 06/21/2015 03:41 AM, Chris Forbes wrote:
>> Jose,
>>
>> I believe that's exactly what it's saying, yes.
>>
>> - Chris
>>
>> On Sun, Jun 21, 2015 at 8:00 PM, Jose Fonseca <jfonseca at vmware.com>
>> wrote:
>>> It depends on the platform. But x86 doesn't require floats to be
>>> 4-byte aligned.
>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__en.wikipedia.org_wiki_Data-5Fstructure-5Falignment-23x86&d=BQIBaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=T0t4QG7chq2ZwJo6wilkFznRSFy-8uDKartPGbomVj8&m=hoZapaHEiAtCP0Hl8wUx6-p35QL0Xat2wQTeFYWssvk&s=udFG-s3z0zheKxzbzEgjB4bmtZ0DLIn3FVJLIpf8L2E&e=
>>>
>>>
>>> I don't know about other platforms though -- it might be indeed
>>> necessary to skip or be less strict on non-x86 platforms.
>>>
>>> I'm having trouble interpreting the "additional base-level
>>> requirement" means. Is it saying that a an offset to a float
>>> (4bytes), must be 4bytes aligned, regardless the platform can deal
>>> with non- 4-byte aligned floats?
>>>
>>> Jose
>>>
>>> ________________________________________
>>> From: Piglit <piglit-bounces at lists.freedesktop.org> on behalf of
>>> Chris Forbes <chrisf at ijw.co.nz>
>>> Sent: 20 June 2015 11:32
>>> To: Brian Paul
>>> Cc: piglit at lists.freedesktop.org
>>> Subject: Re: [Piglit] [PATCH] gl-1.5-vertex-buffer-offsets: test
>>> unusual vertex offsets/strides
>>>
>>> Brian,
>>>
>>> Doesn't this test run afoul of the alignment requirements?
>>>
>>> The OpenGL 1.5 specification, page 33 [first version in which this is
>>> introduced;
>>> equivalent language exists in later spec versions] says:
>>>
>>> "Clients must align data elements consistent with the requirements
>>> of the
>>> client platform, with an additional base-level requirement that an
>>> offset within
>>> a buffer to a datum comprising N basic machine units be a multiple
>>> of N."
>>>
>>> Non-naturally-aligned float attributes sourced from a buffer object
>>> would appear
>>> to violate this rule - or have I misunderstood?
>>>
>>> - Chris
>>>
>>>
>>>
>>>
>>> On Sat, Jun 20, 2015 at 2:39 AM, Brian Paul <brianp at vmware.com> wrote:
>>>> The draw-vertices tests exercises unusual vertex sizes and strides,
>>>> but not with interleaved arrays.
>>>>
>>>> This test creates a VBO with interleaved vertex positions and colors.
>>>> The colors are positioned at offsets like 9, 10 and 11 bytes from the
>>>> start of the vertex. Unusual strides between vertices are tested too.
>>>>
>>>> Exercises a bug in Gallium's u_vbuf code where the driver was passed
>>>> pipe_vertex_element::src_offset values which weren't a multiple of
>>>> four, even when PIPE_CAP_VERTEX_ELEMENT_SRC_OFFSET_4BYTE_ALIGNED_ONLY
>>>> returned 1.
>>>> ---
>>>> tests/all.py | 1 +
>>>> tests/spec/gl-1.5/CMakeLists.gl.txt | 1 +
>>>> tests/spec/gl-1.5/vertex-buffer-offsets.c | 124
>>>> ++++++++++++++++++++++++++++++
>>>> 3 files changed, 126 insertions(+)
>>>> create mode 100644 tests/spec/gl-1.5/vertex-buffer-offsets.c
>>>>
>>>> diff --git a/tests/all.py b/tests/all.py
>>>> index ad4c494..ee11be6 100755
>>>> --- a/tests/all.py
>>>> +++ b/tests/all.py
>>>> @@ -1042,6 +1042,7 @@ with profile.group_manager(
>>>> 'normal3b3s-invariance-byte', run_concurrent=False)
>>>> g(['gl-1.5-normal3b3s-invariance', 'GL_SHORT'],
>>>> 'normal3b3s-invariance-short', run_concurrent=False)
>>>> + g(['gl-1.5-vertex-buffer-offsets'], 'vertex-buffer-offsets')
>>>>
>>>> with profile.group_manager(
>>>> PiglitGLTest,
>>>> diff --git a/tests/spec/gl-1.5/CMakeLists.gl.txt
>>>> b/tests/spec/gl-1.5/CMakeLists.gl.txt
>>>> index 8dcd95d..f10c6cb 100644
>>>> --- a/tests/spec/gl-1.5/CMakeLists.gl.txt
>>>> +++ b/tests/spec/gl-1.5/CMakeLists.gl.txt
>>>> @@ -10,5 +10,6 @@ link_libraries (
>>>> )
>>>>
>>>> piglit_add_executable (gl-1.5-normal3b3s-invariance
>>>> normal3b3s-invariance.c)
>>>> +piglit_add_executable (gl-1.5-vertex-buffer-offsets
>>>> vertex-buffer-offsets.c)
>>>>
>>>> # vim: ft=cmake:
>>>> diff --git a/tests/spec/gl-1.5/vertex-buffer-offsets.c
>>>> b/tests/spec/gl-1.5/vertex-buffer-offsets.c
>>>> new file mode 100644
>>>> index 0000000..6d58331
>>>> --- /dev/null
>>>> +++ b/tests/spec/gl-1.5/vertex-buffer-offsets.c
>>>> @@ -0,0 +1,124 @@
>>>> +/*
>>>> + * Copyright 2015 VMware, Inc.
>>>> + *
>>>> + * Permission is hereby granted, free of charge, to any person
>>>> obtaining a
>>>> + * copy of this software and associated documentation files (the
>>>> "Software"),
>>>> + * to deal in the Software without restriction, including without
>>>> limitation
>>>> + * the rights to use, copy, modify, merge, publish, distribute,
>>>> sublicense,
>>>> + * and/or sell copies of the Software, and to permit persons to
>>>> whom the
>>>> + * Software is furnished to do so, subject to the following
>>>> conditions:
>>>> + *
>>>> + * The above copyright notice and this permission notice (including
>>>> the next
>>>> + * paragraph) shall be included in all copies or substantial
>>>> portions of the
>>>> + * Software.
>>>> + *
>>>> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
>>>> EXPRESS OR
>>>> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>>>> MERCHANTABILITY,
>>>> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
>>>> EVENT SHALL
>>>> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
>>>> DAMAGES OR OTHER
>>>> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
>>>> ARISING
>>>> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
>>>> + * DEALINGS IN THE SOFTWARE.
>>>> + */
>>>> +
>>>> +/*
>>>> + * Test interleaved vertex arrays with unusual element offsets and
>>>> strides.
>>>> + * Brian Paul
>>>> + */
>>>> +
>>>> +#include "piglit-util-gl.h"
>>>> +
>>>> +PIGLIT_GL_TEST_CONFIG_BEGIN
>>>> + config.supports_gl_compat_version = 15;
>>>> + config.window_visual = PIGLIT_GL_VISUAL_RGBA |
>>>> PIGLIT_GL_VISUAL_DOUBLE;
>>>> +PIGLIT_GL_TEST_CONFIG_END
>>>> +
>>>> +
>>>> +void
>>>> +piglit_init(int argc, char **argv)
>>>> +{
>>>> + /* nothing */
>>>> +}
>>>> +
>>>> +
>>>> +static bool
>>>> +test_offset_stride(int color_offset, int stride)
>>>> +{
>>>> + static const GLfloat vertex[4][2] = {
>>>> + { -1, -1 },
>>>> + { 1, -1 },
>>>> + { 1, 1 },
>>>> + { -1, 1 }
>>>> + };
>>>> + static const GLfloat color[4] = { 0.0, 1.0, 0.5, 1.0 };
>>>> + GLubyte buffer[1000];
>>>> + GLuint buf;
>>>> + int i, pos;
>>>> + bool p;
>>>> +
>>>> + assert(color_offset >= sizeof(vertex[0]));
>>>> + assert(stride >= color_offset + sizeof(color));
>>>> +
>>>> + pos = 0;
>>>> + for (i = 0; i < 4; i++) {
>>>> + /* copy vertex position into buffer */
>>>> + memcpy(buffer + pos, vertex[i], sizeof(vertex[i]));
>>>> +
>>>> + /* copy vertex color into buffer at unusual offset */
>>>> + memcpy(buffer + pos + color_offset, color,
>>>> sizeof(color));
>>>> +
>>>> + pos += stride;
>>>> + }
>>>> + assert(pos <= sizeof(buffer));
>>>> +
>>>> + glGenBuffers(1, &buf);
>>>> + glBindBuffer(GL_ARRAY_BUFFER, buf);
>>>> + glBufferData(GL_ARRAY_BUFFER, sizeof(buffer),
>>>> + buffer, GL_STATIC_DRAW);
>>>> +
>>>> + glVertexPointer(2, GL_FLOAT, stride, (void *) 0);
>>>> + glColorPointer(4, GL_FLOAT, stride, (void *) (size_t)
>>>> color_offset);
>>>> + glEnable(GL_VERTEX_ARRAY);
>>>> + glEnable(GL_COLOR_ARRAY);
>>>> +
>>>> + glClear(GL_COLOR_BUFFER_BIT);
>>>> + glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
>>>> +
>>>> + p = piglit_probe_rect_rgba(0, 0, piglit_width,
>>>> piglit_height, color);
>>>> +
>>>> + if (!p) {
>>>> + printf("failure for color_offset %d, stride %d\n",
>>>> + color_offset, stride);
>>>> + }
>>>> +
>>>> + piglit_present_results();
>>>> +
>>>> + glDeleteBuffers(1, &buf);
>>>> +
>>>> + return p;
>>>> +}
>>>> +
>>>> +
>>>> +enum piglit_result
>>>> +piglit_display(void)
>>>> +{
>>>> + bool pass = true;
>>>> +
>>>> + /* test nice values */
>>>> + pass = test_offset_stride(8, 24) && pass;
>>>> + pass = test_offset_stride(12, 28) && pass;
>>>> +
>>>> + /* test unual offset */
>>>> + pass = test_offset_stride(9, 32) && pass;
>>>> +
>>>> + /* test unual stride */
>>>> + pass = test_offset_stride(8, 27) && pass;
>>>> +
>>>> + /* test unusual offset, unusual stride */
>>>> + pass = test_offset_stride(9, 25) && pass;
>>>> + pass = test_offset_stride(10, 26) && pass;
>>>> + pass = test_offset_stride(11, 27) && pass;
>>>> +
>>>> + return pass ? PIGLIT_PASS : PIGLIT_FAIL;
>>>> +}
>>>> +
>>>> --
>>>> 1.9.1
>>>>
>>>> _______________________________________________
>>>> Piglit mailing list
>>>> Piglit at lists.freedesktop.org
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>>>>
>>> _______________________________________________
>>> Piglit mailing list
>>> Piglit at lists.freedesktop.org
>>> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.freedesktop.org_mailman_listinfo_piglit&d=BQIBaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=T0t4QG7chq2ZwJo6wilkFznRSFy-8uDKartPGbomVj8&m=hoZapaHEiAtCP0Hl8wUx6-p35QL0Xat2wQTeFYWssvk&s=uSgoC10Qu989rrrVkIE8_v6OFO5H-_8JffnukAqgkIs&e=
>>>
>
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