[Piglit] [PATCH] builtin-gl-sample-mask-simple: another test for gl_SampleMask[0] FS output
Ilia Mirkin
imirkin at alum.mit.edu
Wed Jun 4 16:20:17 PDT 2014
Ian: Should gl_SampleMask have any effect when rendering to a non-ms
texture? (There's some top-posted stuff below, but the question
roughly boils down to this.)
Chris confirmed my suspicion on IRC but suggested asking you as well.
Thanks,
-ilia
On Tue, Jun 3, 2014 at 12:57 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
> Well, I'd certainly hope that someone who is more familiar with GL
> than myself would chime in... even the paragraph I quoted leaves a lot
> to interpretation, e.g. what does "this step" encompass? The inserted
> text says "Next, ... the fragment coverage is ANDed with the bits of
> the sample mask". Is that part of "this step" and thus skipped, or is
> that a different step?
>
> And yeah, the whole 1x MSAA thing is extremely confusing, esp to
> people (like myself) who don't have an intimate knowledge of the GL
> spec. I guess the idea was that if one could play with sample
> positions (esp from within the shader), something like 1x MSAA might
> actually make sense?
>
> On Tue, Jun 3, 2014 at 11:52 AM, Marek Olšák <maraeo at gmail.com> wrote:
>> I think you are right. The sample mask should be disabled if MSAA is
>> disabled, so both tests are wrong. However, I don't like this 1x MSAA,
>> which seems to follow some MSAA rules, but isn't MSAA.
>>
>> Marek
>>
>> On Tue, Jun 3, 2014 at 4:43 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>>> From ARB_sample_shading:
>>>
>>> No changes to the fragment alpha or coverage values
>>> are made at this step if MULTISAMPLE is disabled, or if the value of
>>> SAMPLE_BUFFERS is not one.
>>>
>>> Not 100% sure what "MULTISAMPLE" is, but I sort of assumed it'd be
>>> disabled in the num_samples==0 case, no?
>>>
>>> -ilia
>>>
>>>
>>> On Tue, Jun 3, 2014 at 6:36 AM, Marek Olšák <maraeo at gmail.com> wrote:
>>>> ARB_texture_rectangle is already checked by the common FboConfig code.
>>>>
>>>> The 0 case uses a rectangle texture, the 1 case uses a multisample
>>>> texture. Maybe that's the problem?
>>>>
>>>> I'm not sure if it's right, but it's what the other test seems to do.
>>>>
>>>> Marek
>>>>
>>>> On Tue, Jun 3, 2014 at 1:09 AM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>>>>> Well, fails with blob on both GT218 and GK106 (NVIDIA 331.49), as well
>>>>> as with nouveau (which I implemented, so no confidence in that
>>>>> implementation), for argument value of '0' but passes for 1,2,4,6,8.
>>>>> Passes on my intel snb for 0 as well. No idea what the correct thing
>>>>> is though.
>>>>>
>>>>> BTW, you should add a require for ARB_texture_rectangle. You don't
>>>>> _have_ to put it in the shader, although the blob doesn't implement
>>>>> the auto-on behaviour. But probably should do a
>>>>> piglit_require_extension if samples==0 [or maybe always].
>>>>>
>>>>> On Mon, Jun 2, 2014 at 6:52 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>>>>>> Neat, this works on nouveau (both nv50 and nvc0), unlike the other
>>>>>> tests which also fail. Except for the 0 case, it observes a mask of 1
>>>>>> instead of an expected mask of 0. (It passes for samples==1 though.) I
>>>>>> suspect it's because all that machinery gets turned off for non-ms
>>>>>> stuff. Are you sure this is the right behaviour? I guess I should
>>>>>> check on the blob + my snb...
>>>>>>
>>>>>> On Mon, Jun 2, 2014 at 6:48 AM, Marek Olšák <maraeo at gmail.com> wrote:
>>>>>>> From: Marek Olšák <marek.olsak at amd.com>
>>>>>>>
>>>>>>> This one is simpler and easier to debug. It passes on my hardware, while
>>>>>>> the other one fails (due to a shader bug probably).
>>>>>>>
>>>>>>> I don't like tests that return the pass or fail status from the shader,
>>>>>>> because they are impossible to debug. Therefore, this one doesn't do it.
>>>>>>> ---
>>>>>>> tests/all.py | 5 +
>>>>>>> .../arb_sample_shading/execution/CMakeLists.gl.txt | 1 +
>>>>>>> .../execution/builtin-gl-sample-mask-simple.cpp | 221 +++++++++++++++++++++
>>>>>>> 3 files changed, 227 insertions(+)
>>>>>>> create mode 100644 tests/spec/arb_sample_shading/execution/builtin-gl-sample-mask-simple.cpp
>>>>>>>
>>>>>>> diff --git a/tests/all.py b/tests/all.py
>>>>>>> index a13d878..f5c7b39 100644
>>>>>>> --- a/tests/all.py
>>>>>>> +++ b/tests/all.py
>>>>>>> @@ -1725,6 +1725,11 @@ for num_samples in TEST_SAMPLE_COUNTS:
>>>>>>> executable = 'arb_sample_shading-{0} -auto'.format(test_name)
>>>>>>> arb_sample_shading[test_name] = PiglitTest(executable)
>>>>>>>
>>>>>>> +for num_samples in (0,2,4,6,8):
>>>>>>> + test_name = 'builtin-gl-sample-mask-simple {0}'.format(num_samples)
>>>>>>> + executable = 'arb_sample_shading-' + test_name
>>>>>>> + arb_sample_shading[test_name] = concurrent_test(executable)
>>>>>>> +
>>>>>>> for num_samples in TEST_SAMPLE_COUNTS:
>>>>>>> test_name = 'builtin-gl-sample-position {0}'.format(num_samples)
>>>>>>> executable = 'arb_sample_shading-{0} -auto'.format(test_name)
>>>>>>> diff --git a/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt b/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
>>>>>>> index c3690e9..84e2546 100644
>>>>>>> --- a/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
>>>>>>> +++ b/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
>>>>>>> @@ -14,6 +14,7 @@ piglit_add_executable (arb_sample_shading-api api.c)
>>>>>>> piglit_add_executable (arb_sample_shading-builtin-gl-num-samples builtin-gl-num-samples.cpp)
>>>>>>> piglit_add_executable (arb_sample_shading-builtin-gl-sample-id builtin-gl-sample-id.cpp)
>>>>>>> piglit_add_executable (arb_sample_shading-builtin-gl-sample-mask builtin-gl-sample-mask.cpp)
>>>>>>> +piglit_add_executable (arb_sample_shading-builtin-gl-sample-mask-simple builtin-gl-sample-mask-simple.cpp)
>>>>>>> piglit_add_executable (arb_sample_shading-builtin-gl-sample-position builtin-gl-sample-position.cpp)
>>>>>>> piglit_add_executable (arb_sample_shading-interpolate-at-sample-position interpolate-at-sample-position.cpp)
>>>>>>> piglit_add_executable (arb_sample_shading-ignore-centroid-qualifier ignore-centroid-qualifier.cpp)
>>>>>>> diff --git a/tests/spec/arb_sample_shading/execution/builtin-gl-sample-mask-simple.cpp b/tests/spec/arb_sample_shading/execution/builtin-gl-sample-mask-simple.cpp
>>>>>>> new file mode 100644
>>>>>>> index 0000000..42f2f0f
>>>>>>> --- /dev/null
>>>>>>> +++ b/tests/spec/arb_sample_shading/execution/builtin-gl-sample-mask-simple.cpp
>>>>>>> @@ -0,0 +1,221 @@
>>>>>>> +/*
>>>>>>> + * Copyright © 2013 Intel Corporation
>>>>>>> + * Copyright © 2014 Advanced Micro Devices, 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.
>>>>>>> + */
>>>>>>> +
>>>>>>> +/** \file builtin-gl-sample-mask-simple.cpp
>>>>>>> + * This test verifies that supplying a value to gl_SampleMask[]
>>>>>>> + * in fragment shader program works as per ARB_sample_shading
>>>>>>> + * specification.
>>>>>>> + **/
>>>>>>> +
>>>>>>> +#include "piglit-fbo.h"
>>>>>>> +using namespace piglit_util_fbo;
>>>>>>> +
>>>>>>> +PIGLIT_GL_TEST_CONFIG_BEGIN
>>>>>>> +
>>>>>>> + config.supports_gl_compat_version = 21;
>>>>>>> + config.supports_gl_core_version = 31;
>>>>>>> +
>>>>>>> + config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
>>>>>>> +
>>>>>>> +PIGLIT_GL_TEST_CONFIG_END
>>>>>>> +
>>>>>>> +static int num_samples;
>>>>>>> +static unsigned prog_0, prog_1;
>>>>>>> +static Fbo multisampled_tex;
>>>>>>> +
>>>>>>> +static void
>>>>>>> +print_usage_and_exit(char *prog_name)
>>>>>>> +{
>>>>>>> + printf("Usage: %s <num_samples>\n", prog_name);
>>>>>>> + piglit_report_result(PIGLIT_FAIL);
>>>>>>> +}
>>>>>>> +
>>>>>>> +static void
>>>>>>> +compile_shader(void)
>>>>>>> +{
>>>>>>> + static const char *vert =
>>>>>>> + "#version 130\n"
>>>>>>> + "in vec4 piglit_vertex;\n"
>>>>>>> + "void main()\n"
>>>>>>> + "{\n"
>>>>>>> + " gl_Position = piglit_vertex;\n"
>>>>>>> + "}\n";
>>>>>>> + static const char *frag_0 =
>>>>>>> + "#version 130\n"
>>>>>>> + "#extension GL_ARB_sample_shading : enable\n"
>>>>>>> + "out vec4 out_color;\n"
>>>>>>> + "void main()\n"
>>>>>>> + "{\n"
>>>>>>> + " gl_SampleMask[0] = int(gl_FragCoord.x);\n"
>>>>>>> + " out_color = vec4(1.0, 0.0, 0.0, 0.0);\n"
>>>>>>> + "}\n";
>>>>>>> +
>>>>>>> + static const char *frag_template =
>>>>>>> + "#version 130 \n"
>>>>>>> + "%s \n"
>>>>>>> + "uniform %s tex; \n"
>>>>>>> + "#define fetch(i) (texelFetch(tex, ivec2(int(gl_FragCoord.y/8) * 16 + int(gl_FragCoord.x/8) % 16, 0)%s)) \n"
>>>>>>> + "uniform int samples; \n"
>>>>>>> + "out vec4 out_color; \n"
>>>>>>> + "void main() \n"
>>>>>>> + "{ \n"
>>>>>>> + " vec4 outv = vec4(0.0, 0.0, 0.0, 0.0); \n"
>>>>>>> + /* encode the sample mask to RGBA */
>>>>>>> + " outv.x += fetch(0).x * 0.6; \n"
>>>>>>> + " if (1 < samples) outv.y += fetch(1).x * 0.6; \n"
>>>>>>> + " if (2 < samples) outv.z += fetch(2).x * 0.6; \n"
>>>>>>> + " if (3 < samples) outv.w += fetch(3).x * 0.6; \n"
>>>>>>> + " if (4 < samples) outv.x += fetch(4).x * 0.4; \n"
>>>>>>> + " if (5 < samples) outv.y += fetch(5).x * 0.4; \n"
>>>>>>> + " if (6 < samples) outv.z += fetch(6).x * 0.4; \n"
>>>>>>> + " if (7 < samples) outv.w += fetch(7).x * 0.4; \n"
>>>>>>> + " out_color = outv;\n"
>>>>>>> + "} \n";
>>>>>>> +
>>>>>>> + /* Compile program */
>>>>>>> + prog_0 = piglit_build_simple_program(vert, frag_0);
>>>>>>> + if (!piglit_link_check_status(prog_0)) {
>>>>>>> + piglit_report_result(PIGLIT_FAIL);
>>>>>>> + }
>>>>>>> +
>>>>>>> + char *frag_1;
>>>>>>> + if (num_samples)
>>>>>>> + asprintf(&frag_1, frag_template,
>>>>>>> + "#extension GL_ARB_texture_multisample : require",
>>>>>>> + "sampler2DMS", ", i");
>>>>>>> + else
>>>>>>> + asprintf(&frag_1, frag_template, "", "sampler2DRect", "");
>>>>>>> +
>>>>>>> + prog_1 = piglit_build_simple_program(vert, frag_1);
>>>>>>> + if (!piglit_link_check_status(prog_1)) {
>>>>>>> + piglit_report_result(PIGLIT_FAIL);
>>>>>>> + }
>>>>>>> +}
>>>>>>> +
>>>>>>> +void
>>>>>>> +piglit_init(int argc, char **argv)
>>>>>>> +{
>>>>>>> + if (argc != 2)
>>>>>>> + print_usage_and_exit(argv[0]);
>>>>>>> +
>>>>>>> + /* 1st arg: num_samples */
>>>>>>> + char *endptr = NULL;
>>>>>>> + num_samples = strtol(argv[1], &endptr, 0);
>>>>>>> + if (endptr != argv[1] + strlen(argv[1]))
>>>>>>> + print_usage_and_exit(argv[0]);
>>>>>>> +
>>>>>>> + if (num_samples > 8) {
>>>>>>> + puts("This test only supports 8 samples.");
>>>>>>> + piglit_report_result(PIGLIT_SKIP);
>>>>>>> + }
>>>>>>> +
>>>>>>> + piglit_require_extension("GL_ARB_texture_multisample");
>>>>>>> + piglit_require_extension("GL_ARB_sample_shading");
>>>>>>> + piglit_require_GLSL_version(130);
>>>>>>> +
>>>>>>> + /* Skip the test if num_samples > GL_MAX_SAMPLES */
>>>>>>> + GLint max_samples;
>>>>>>> + glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
>>>>>>> + if (num_samples > max_samples)
>>>>>>> + piglit_report_result(PIGLIT_SKIP);
>>>>>>> +
>>>>>>> + FboConfig msConfig(num_samples, 1 << MAX2(num_samples, 1), 1);
>>>>>>> + msConfig.attach_texture = true;
>>>>>>> + multisampled_tex.setup(msConfig);
>>>>>>> +
>>>>>>> + compile_shader();
>>>>>>> + if (!piglit_check_gl_error(GL_NO_ERROR)) {
>>>>>>> + piglit_report_result(PIGLIT_FAIL);
>>>>>>> + }
>>>>>>> +}
>>>>>>> +
>>>>>>> +static bool
>>>>>>> +equal(float a, float b)
>>>>>>> +{
>>>>>>> + return fabs(a - b) < piglit_tolerance[0];
>>>>>>> +}
>>>>>>> +
>>>>>>> +enum piglit_result
>>>>>>> +piglit_display()
>>>>>>> +{
>>>>>>> + bool pass = true;
>>>>>>> + int samples, i, j;
>>>>>>> +
>>>>>>> + glUseProgram(prog_0);
>>>>>>> + glBindFramebuffer(GL_DRAW_FRAMEBUFFER, multisampled_tex.handle);
>>>>>>> + multisampled_tex.set_viewport();
>>>>>>> + glGetIntegerv(GL_SAMPLES, &samples);
>>>>>>> + samples = MAX2(samples, 1);
>>>>>>> +
>>>>>>> + glClear(GL_COLOR_BUFFER_BIT);
>>>>>>> + glUniform1i(glGetUniformLocation(prog_0, "samples"), samples);
>>>>>>> + piglit_draw_rect(-1, -1, 2, 2);
>>>>>>> +
>>>>>>> + glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
>>>>>>> + glViewport(0, 0, piglit_width, piglit_height);
>>>>>>> + glClear(GL_COLOR_BUFFER_BIT);
>>>>>>> +
>>>>>>> + glUseProgram(prog_1);
>>>>>>> + glUniform1i(glGetUniformLocation(prog_1, "tex"), 0);
>>>>>>> + glUniform1i(glGetUniformLocation(prog_1, "samples"), samples);
>>>>>>> + if (samples <= 4)
>>>>>>> + piglit_draw_rect(-1, -1,
>>>>>>> + 8*(1 << samples) * (2.0/piglit_width),
>>>>>>> + 8 * (2.0/piglit_height));
>>>>>>> + else if (samples == 8)
>>>>>>> + piglit_draw_rect(-1, -1,
>>>>>>> + 8*16 * (2.0/piglit_width),
>>>>>>> + 8*16 * (2.0/piglit_height));
>>>>>>> + else
>>>>>>> + assert(0 && "Unimplemented");
>>>>>>> +
>>>>>>> + for (i = 0; i < (1 << multisampled_tex.config.num_samples); i++) {
>>>>>>> + float color[4];
>>>>>>> + unsigned full_mask = (1 << samples) - 1;
>>>>>>> + unsigned expected_mask = i & full_mask;
>>>>>>> + unsigned observed_mask = 0;
>>>>>>> +
>>>>>>> + glReadPixels((i % 16) * 8 + 4,
>>>>>>> + (i / 16) * 8 + 4,
>>>>>>> + 1, 1, GL_RGBA, GL_FLOAT, color);
>>>>>>> +
>>>>>>> + for (j = 0; j < 4; j++) {
>>>>>>> + if (equal(color[j], 1) || equal(color[j], 0.6))
>>>>>>> + observed_mask |= 1 << (j + 0);
>>>>>>> + if (equal(color[j], 1) || equal(color[j], 0.4))
>>>>>>> + observed_mask |= 1 << (j + 4);
>>>>>>> + }
>>>>>>> +
>>>>>>> + if (expected_mask != observed_mask) {
>>>>>>> + printf("Test failed, samples = %u\n"
>>>>>>> + " Expected sample mask: 0x%x\n"
>>>>>>> + " Observed sample mask: 0x%x\n",
>>>>>>> + samples, expected_mask, observed_mask);
>>>>>>> + pass = false;
>>>>>>> + }
>>>>>>> + }
>>>>>>> +
>>>>>>> + piglit_present_results();
>>>>>>> + return pass ? PIGLIT_PASS : PIGLIT_FAIL;
>>>>>>> +}
>>>>>>> --
>>>>>>> 1.9.1
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Piglit mailing list
>>>>>>> Piglit at lists.freedesktop.org
>>>>>>> http://lists.freedesktop.org/mailman/listinfo/piglit
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