[Piglit] [PATCH V2 3/6] ARB_sample_shading: Add test to verify the functionality of gl_SampleID

Anuj Phogat anuj.phogat at gmail.com
Fri Nov 1 15:44:23 PDT 2013


On Tue, Oct 29, 2013 at 8:01 AM, Paul Berry <stereotype441 at gmail.com> wrote:

> On 25 October 2013 16:49, Anuj Phogat <anuj.phogat at gmail.com> wrote:
>
>> V2: Get rid of redundant projection matrix.
>> Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
>> ---
>>  tests/all.tests                                    |   5 +
>>  .../arb_sample_shading/execution/CMakeLists.gl.txt |   1 +
>>  .../execution/builtin-gl-sample-id.cpp             | 230
>> +++++++++++++++++++++
>>  3 files changed, 236 insertions(+)
>>  create mode 100644
>> tests/spec/arb_sample_shading/execution/builtin-gl-sample-id.cpp
>>
>
> I'm not comfortable with this test.  It doesn't verify that gl_SampleID is
> correct for each sample.  It just averages together
> float(gl_SampleID)/float(gl_NumSamples) for all samples and verifies that
> is equals the expected value (which will always be near 0.5).  In
> particular, if there's a bug causing gl_SampleID to identify the samples in
> an incorrect order, that won't be caught by this test.
>
> I'd recommend keeping your vertex and fragment shader, but instead of
> drawing to a renderbuffer, draw to a multisampled texture (using
> ARB_texture_multisample).  Then you can have a second shader which reads
> from the multisampled texture and verifies that every sample is correct at
> every pixel location.
>
> Also, Chris's suggestion from patch 2 (about reinventing piglit_draw_rect)
> applies here as well.
>
I agree. This test may not catch a bug related to incorrect ordering of
samples. I liked your idea of blitting to a multisample texture and then
verify the expected color of each sample.

>
>
>>
>> diff --git a/tests/all.tests b/tests/all.tests
>> index 1fcd08a..d861a91 100644
>> --- a/tests/all.tests
>> +++ b/tests/all.tests
>> @@ -1342,6 +1342,11 @@ for num_samples in TEST_SAMPLE_COUNTS:
>>      executable = 'arb_sample_shading-{0} -auto'.format(test_name)
>>      arb_sample_shading[test_name] = PlainExecTest(executable)
>>
>> +for num_samples in TEST_SAMPLE_COUNTS:
>> +    test_name = 'builtin-gl-sample-id {0}'.format(num_samples)
>> +    executable = 'arb_sample_shading-{0} -auto'.format(test_name)
>> +    arb_sample_shading[test_name] = PlainExecTest(executable)
>> +
>>  # Group ARB_debug_output
>>  arb_debug_output = Group()
>>  spec['ARB_debug_output'] = arb_debug_output
>> diff --git a/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
>> b/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
>> index 56fa0da..35f2905 100644
>> --- a/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
>> +++ b/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
>> @@ -12,4 +12,5 @@ link_libraries (
>>
>>  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)
>>  # vim: ft=cmake:
>> diff --git
>> a/tests/spec/arb_sample_shading/execution/builtin-gl-sample-id.cpp
>> b/tests/spec/arb_sample_shading/execution/builtin-gl-sample-id.cpp
>> new file mode 100644
>> index 0000000..143dc95
>> --- /dev/null
>> +++ b/tests/spec/arb_sample_shading/execution/builtin-gl-sample-id.cpp
>> @@ -0,0 +1,230 @@
>> +/*
>> + * Copyright © 2013 Intel Corporation
>> + *
>> + * 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-id.cpp
>> + *  This test verifies that using gl_SampleID in fragment shader program
>> + *  works as per ARB_sample_shading specification.
>> + *
>> + **/
>> +
>> +#include "piglit-fbo.h"
>> +using namespace piglit_util_fbo;
>> +
>> +const int pattern_width = 128; const int pattern_height = 128;
>> +
>> +PIGLIT_GL_TEST_CONFIG_BEGIN
>> +
>> +       config.supports_gl_compat_version = 10;
>> +
>> +       config.window_width = pattern_width;
>> +       config.window_height = pattern_height;
>> +       config.window_visual = PIGLIT_GL_VISUAL_DOUBLE |
>> PIGLIT_GL_VISUAL_RGBA;
>> +
>> +PIGLIT_GL_TEST_CONFIG_END
>> +
>> +static int  num_samples;
>> +static unsigned prog, vao, vertex_buf;
>> +static Fbo multisampled_fbo, singlesampled_fbo;
>> +
>> +static void
>> +print_usage_and_exit(char *prog_name)
>> +{
>> +       printf("Usage: %s <num_samples>\n", prog_name);
>> +       piglit_report_result(PIGLIT_FAIL);
>> +}
>> +
>> +void
>> +compile_shader(void)
>> +{
>> +       static const char *vert =
>> +               "#version 130\n"
>> +               "in vec2 pos;\n"
>> +               "void main()\n"
>> +               "{\n"
>> +               "  gl_Position = vec4(pos, 0.0, 1.0);\n"
>> +               "}\n";
>> +       static const char *frag =
>> +               "#version 130\n"
>> +               "#extension GL_ARB_sample_shading : enable\n"
>> +               "uniform int samples;\n"
>> +               "out vec4 out_color;\n"
>> +               "void main()\n"
>> +               "{\n"
>> +               "  if(samples == 0)\n"
>> +               "    out_color = vec4(0.0, 1.0, 0.0, 1.0);\n"
>> +               "  else\n"
>> +               "    out_color = vec4(0.0, float(gl_SampleID) / samples,
>> 0.0, 1.0);\n"
>> +               "}\n";
>> +       /* Compile program */
>> +       prog = glCreateProgram();
>> +       GLint vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vert);
>> +       glAttachShader(prog, vs);
>> +       piglit_check_gl_error(GL_NO_ERROR);
>> +       GLint fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, frag);
>> +       glAttachShader(prog, fs);
>> +       glBindAttribLocation(prog, 0, "pos");
>> +       glLinkProgram(prog);
>> +       if (!piglit_link_check_status(prog)) {
>> +               piglit_report_result(PIGLIT_FAIL);
>> +       }
>> +
>> +       /* Set up vertex array object */
>> +       glGenVertexArrays(1, &vao);
>> +       glBindVertexArray(vao);
>> +
>> +       /* Set up vertex input buffer */
>> +       glGenBuffers(1, &vertex_buf);
>> +       glBindBuffer(GL_ARRAY_BUFFER, vertex_buf);
>> +       glEnableVertexAttribArray(0);
>> +       glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4*sizeof(float),
>> +                             (void *) 0);
>> +
>> +       /* Set up element input buffer to tesselate a quad into
>> +        * triangles
>> +        */
>> +       unsigned int indices[6] = { 0, 1, 2, 0, 2, 3 };
>> +       GLuint element_buf;
>> +       glGenBuffers(1, &element_buf);
>> +       glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, element_buf);
>> +       glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices,
>> +                    GL_STATIC_DRAW);
>> +}
>> +
>> +void
>> +draw_pattern(GLint samples)
>> +{
>> +       float vertex_data[4][4] = {
>> +               { -1, -1 },
>> +               { -1,  1 },
>> +               {  1,  1 },
>> +               {  1, -1 }};
>> +
>> +       glUseProgram(prog);
>> +       glBindVertexArray(vao);
>> +
>> +       /* Set up uniforms */
>> +       glUseProgram(prog);
>> +       glUniform1i(glGetUniformLocation(prog, "samples"), samples);
>> +
>> +       glBindBuffer(GL_ARRAY_BUFFER, vertex_buf);
>> +       glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_data), vertex_data,
>> +                    GL_STREAM_DRAW);
>> +       glDrawElements(GL_TRIANGLES, 6 , GL_UNSIGNED_INT, (void *) 0);
>> +}
>> +
>> +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]);
>> +
>> +       piglit_require_gl_version(21);
>> +       piglit_require_extension("GL_ARB_vertex_array_object");
>> +       piglit_require_extension("GL_ARB_sample_shading");
>> +
>> +       /* 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);
>> +
>> +       singlesampled_fbo.setup(FboConfig(0,
>> +                                         pattern_width,
>> +                                         pattern_height));
>> +
>> +       FboConfig msConfig(num_samples, pattern_width, pattern_height);
>> +       multisampled_fbo.setup(msConfig);
>> +
>> +       compile_shader();
>> +       if (!piglit_check_gl_error(GL_NO_ERROR)) {
>> +               piglit_report_result(PIGLIT_FAIL);
>> +       }
>> +}
>> +
>> +bool test_builtin_sample_id(Fbo ms_fbo)
>> +{
>> +       bool pass = true;
>> +       int i, samples;
>> +        float expected[4] = {0.0, 0.0, 0.0, 1.0};
>> +
>> +       glBindFramebuffer(GL_DRAW_FRAMEBUFFER, ms_fbo.handle);
>> +       glGetIntegerv(GL_SAMPLES, &samples);
>> +
>> +       /* Expected color is computed after taking in to account the
>> +        * multisample color resolve:
>> +        * ((sample_id0 + sample_id_1 + sample_id_2 + sample_id_3)
>> +        *  / (samples * samples))
>> +        */
>> +        if (samples == 0)
>> +               expected[1] = 1.0;
>> +       else {
>> +               for (i = 0; i < samples; i++)
>> +                       expected[1] += (((float) i) / samples);
>> +               expected[1] /= samples;
>> +       }
>> +
>> +       glClear(GL_COLOR_BUFFER_BIT);
>> +       draw_pattern(samples);
>> +
>> +       glBindFramebuffer(GL_READ_FRAMEBUFFER, ms_fbo.handle);
>> +       glBindFramebuffer(GL_DRAW_FRAMEBUFFER, singlesampled_fbo.handle);
>> +       glClear(GL_COLOR_BUFFER_BIT);
>> +       glBlitFramebuffer(0, 0,
>> +                         pattern_width, pattern_height,
>> +                         0, 0,
>> +                         pattern_width, pattern_height,
>> +                         GL_COLOR_BUFFER_BIT,
>> +                         GL_NEAREST);
>> +
>> +       glBindFramebuffer(GL_READ_FRAMEBUFFER, singlesampled_fbo.handle);
>> +       glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
>> +
>> +       pass = piglit_probe_rect_rgba(0, 0, pattern_width,
>> +                                      pattern_width, expected)
>> +               && pass;
>> +       glClear(GL_COLOR_BUFFER_BIT);
>> +       glBlitFramebuffer(0, 0,
>> +                         pattern_width, pattern_height,
>> +                         0, 0,
>> +                         pattern_width, pattern_height,
>> +                         GL_COLOR_BUFFER_BIT,
>> +                         GL_NEAREST);
>> +
>> +       piglit_present_results();
>> +       return pass;
>> +}
>> +
>> +enum piglit_result
>> +piglit_display()
>> +{
>> +       bool pass = true;
>> +       pass = test_builtin_sample_id(multisampled_fbo)
>> +               && pass;
>> +       return pass ? PIGLIT_PASS : PIGLIT_FAIL;
>> +}
>> --
>> 1.8.1.4
>>
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>> Piglit at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/piglit
>>
>
>
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