[Piglit] [PATCH] gl-1.5-vertex-buffer-offsets: test unusual vertex offsets/strides
Brian Paul
brianp at vmware.com
Mon Jun 22 06:26:50 PDT 2015
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
>>>
>>> _______________________________________________
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