[Piglit] [PATCH] Add test to verify interpolation at sample position

Anuj Phogat anuj.phogat at gmail.com
Mon Jan 13 10:39:10 PST 2014


On Thu, Jan 9, 2014 at 3:43 PM, Anuj Phogat <anuj.phogat at gmail.com> wrote:
> ARB_sample_shading extension says:
>  "When the sample shading fraction is 1.0, a separate set of colors
>   and other associated data are evaluated for each sample, each set
>   of values are evaluated at the sample location."
>
> Test passes on intel hardware with mesa patch: 'i965: Use sample
> barycentric coordinates with per sample shading'.
>
> Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
> Cc: Chris Forbes <chrisf at ijw.co.nz>
> ---
> Thanks Chris for pointing to a reference test which I used to create
> this test.
>
>  tests/all.tests                                    |   5 +
>  .../arb_sample_shading/execution/CMakeLists.gl.txt |   1 +
>  .../execution/interpolate-at-sample-position.cpp   | 192 +++++++++++++++++++++
>  3 files changed, 198 insertions(+)
>  create mode 100644 tests/spec/arb_sample_shading/execution/interpolate-at-sample-position.cpp
>
> diff --git a/tests/all.tests b/tests/all.tests
> index 29d012b..d7a2393 100644
> --- a/tests/all.tests
> +++ b/tests/all.tests
> @@ -1440,6 +1440,11 @@ 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 MSAA_SAMPLE_COUNTS:
> +    test_name = 'interpolate-at-sample-position {0}'.format(num_samples)
> +    executable = 'arb_sample_shading-{0} -auto'.format(test_name)
> +    arb_sample_shading[test_name] = PlainExecTest(executable)
> +
>  import_glsl_parser_tests(spec['ARB_sample_shading'],
>                           os.path.join(testsDir, 'spec', 'arb_sample_shading'),
>                           ['compiler'])
> diff --git a/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt b/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
> index a832189..9a72439 100644
> --- a/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
> +++ b/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
> @@ -15,4 +15,5 @@ piglit_add_executable (arb_sample_shading-builtin-gl-num-samples builtin-gl-num-
>  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-position builtin-gl-sample-position.cpp)
> +piglit_add_executable (arb_sample_shading-interpolate-at-sample-position interpolate-at-sample-position.cpp)
>  # vim: ft=cmake:
> diff --git a/tests/spec/arb_sample_shading/execution/interpolate-at-sample-position.cpp b/tests/spec/arb_sample_shading/execution/interpolate-at-sample-position.cpp
> new file mode 100644
> index 0000000..253aa08
> --- /dev/null
> +++ b/tests/spec/arb_sample_shading/execution/interpolate-at-sample-position.cpp
> @@ -0,0 +1,192 @@
> +/*
> + * Copyright (c) 2014 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 interpolate-at-sample-position.cpp
> + *
> + * Tests that 'in' variables in fragment shader are interpolated at sample
> + * positions when using per sample shading.
> + *
> + */
> +#include "piglit-util-gl-common.h"
> +#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 = 21;
> +       config.supports_gl_core_version = 31;
> +        config.window_width = 2 * pattern_width;
> +        config.window_height = pattern_height;
> +       config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
> +
> +PIGLIT_GL_TEST_CONFIG_END
> +
> +static piglit_fbo multisampled_fbo;
I noticed my development branch had an unfinished patch to rename few piglit
variables. To make the test compile use:
static Fbo multisampled_fbo;
> +static int sample_pos_loc, sample_id_loc, num_samples;
> +static int draw_prog_left, draw_prog_right, test_prog;
> +
> +enum piglit_result
> +piglit_display(void)
> +{
> +       float pos[2];
> +       bool result = true, pass = true;
> +
> +       glBindFramebuffer(GL_DRAW_FRAMEBUFFER, multisampled_fbo.handle);
> +       glClear(GL_COLOR_BUFFER_BIT);
> +
> +       /* Draw test image in to left half of multisample fbo*/
> +       glUseProgram(draw_prog_left);
> +       glViewport(0, 0, pattern_width, pattern_height);
> +       glEnable(GL_SAMPLE_SHADING);
> +       glMinSampleShading(1.0);
> +       piglit_draw_rect(-1, -1, 2, 2);
> +       glDisable(GL_SAMPLE_SHADING);
> +
> +       for(int i = 0; i < num_samples; i++) {
> +               /* Draw reference image in to right half of multisample fbo */
> +               glUseProgram(draw_prog_right);
> +               glBindFramebuffer(GL_DRAW_FRAMEBUFFER, multisampled_fbo.handle);
> +               glGetMultisamplefv(GL_SAMPLE_POSITION, i, pos);
> +               glUniform2fv(sample_pos_loc, 1, pos);
> +               glEnable(GL_SCISSOR_TEST);
> +               glScissor(pattern_width, 0, pattern_width, pattern_height);
> +               glViewport(pattern_width, 0, pattern_width, pattern_height);
> +               glClear(GL_COLOR_BUFFER_BIT);
> +               piglit_draw_rect(-1, -1, 2, 2);
> +               glDisable(GL_SCISSOR_TEST);
> +
> +               /* Draw sample color from multisample texture in to winsys fbo */
> +               glUseProgram(test_prog);
> +               glUniform1i(sample_id_loc, i);
> +               glViewport(0, 0, 2 * pattern_width, pattern_height);
> +               glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
> +               glClear(GL_COLOR_BUFFER_BIT);
> +               piglit_draw_rect(-1, -1, 2, 2);
> +
> +               result = piglit_probe_rect_halves_equal_rgba(0, 0,
> +                                                            piglit_width,
> +                                                            piglit_height);
> +               pass = pass && result;
> +               printf("sample_id = %d, result = %s\n", i,
> +                      result ? "pass" : "fail");
> +       }
> +       piglit_present_results();
> +       return pass ? PIGLIT_PASS : PIGLIT_FAIL;
> +}
> +
> +static void
> +print_usage_and_exit(char *prog_name)
> +{
> +        printf("Usage: %s <num_samples>\n", prog_name);
> +        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]);
> +
> +       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 == 0 || num_samples > max_samples)
> +               piglit_report_result(PIGLIT_SKIP);
> +
> +       piglit_fbo_config msConfig(num_samples, piglit_width, piglit_height);
Here too use:
FboConfig msConfig(num_samples, piglit_width, piglit_height);

> +        msConfig.attach_texture = true;
> +       multisampled_fbo.setup(msConfig);
> +
> +       /* Reduced tolerence for stricter color matching */
> +       piglit_set_tolerance_for_bits(16, 16, 16, 16);
> +       draw_prog_left = piglit_build_simple_program(
> +               "#version 130\n"
> +               "#extension GL_ARB_sample_shading: require\n"
> +               "in vec4 piglit_vertex;\n"
> +               "out vec2 test;\n"
> +               "void main() {\n"
> +               "       gl_Position = piglit_vertex;\n"
> +               "       test = piglit_vertex.xy;\n"
> +               "}\n",
> +
> +               "#version 130\n"
> +               "#extension GL_ARB_sample_shading: require\n"
> +               "in vec2 test;\n"
> +               "void main() {\n"
> +               "       gl_FragColor = vec4(abs(test), 0, 1);\n"
> +               "}\n");
> +
> +       draw_prog_right = piglit_build_simple_program(
> +               "#version 130\n"
> +               "uniform vec2 sample_pos;\n"
> +               "in vec4 piglit_vertex;\n"
> +               "out vec2 ref;\n"
> +               "void main() {\n"
> +               "       gl_Position = piglit_vertex;\n"
> +               "       ref = piglit_vertex.xy;\n"
> +                       /* Add an offset to account for interplolation
> +                        * at sample position.
> +                        */
> +               "       ref += (sample_pos - 0.5) / 64;\n"
> +               "}\n",
> +
> +               "#version 130\n"
> +               "in vec2 ref;\n"
> +               "void main() {\n"
> +               "       gl_FragColor = vec4(abs(ref), 0, 1);\n"
> +               "}\n");
> +       sample_pos_loc = glGetUniformLocation(draw_prog_right, "sample_pos");
> +
> +       test_prog = piglit_build_simple_program(
> +               "#version 130\n"
> +               "in vec4 piglit_vertex;\n"
> +               "void main() {\n"
> +               "       gl_Position = piglit_vertex;\n"
> +               "}\n",
> +
> +               "#version 130\n"
> +               "#extension GL_ARB_texture_multisample: require\n"
> +               "uniform int sample_id;\n"
> +               "uniform sampler2DMS tex;\n"
> +               "void main() {\n"
> +               "       gl_FragColor =  texelFetch(tex, ivec2(gl_FragCoord.xy),\n"
> +               "                                  sample_id);\n"
> +               "}\n");
> +
> +       glUseProgram(test_prog);
> +       glUniform1i(glGetUniformLocation(test_prog, "tex"), 0);
> +       sample_id_loc = glGetUniformLocation(test_prog, "sample_id");
> +}
> +
> --
> 1.8.3.1
>


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