arb_sample_shading: Test interaction of apha-to-coverage, sample mask and MRT

Test verifies correct work of alpha-to-coverage with every variation of
sample mask, all levels of MSAA and different number of render targets.

Signed-off-by: Andrii Kryvytskyi <andrii.o.kryvytskyi@globallogic.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>

3 files changed, 384 insertions, 0 deletions

diff --git a/tests/opengl.py b/tests/opengl.py
index e252435c8..fb950d85d 100644
--- a/tests/opengl.py
+++ b/tests/opengl.py
@@ -2166,6 +2166,7 @@ with profile.test_list.group_manager(
           'samplemask {} all'.format(num_samples))
 
     g(['arb_sample_shading-builtin-gl-sample-mask-mrt-alpha'])
+    g(['arb_sample_shading-builtin-gl-sample-mask-mrt-alpha-to-coverage-combinations'])
 
 # Group ARB_debug_output
 with profile.test_list.group_manager(
diff --git a/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt b/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
index 124c03022..b219733e7 100644
--- a/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
+++ b/tests/spec/arb_sample_shading/execution/CMakeLists.gl.txt
@@ -15,6 +15,7 @@ piglit_add_executable (arb_sample_shading-builtin-gl-sample-id builtin-gl-sample
 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-mask-mrt-alpha builtin-gl-sample-mask-mrt-alpha.cpp)
+piglit_add_executable (arb_sample_shading-builtin-gl-sample-mask-mrt-alpha-to-coverage-combinations builtin-gl-sample-mask-mrt-alpha-to-coverage-combinations.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-mrt-alpha-to-coverage-combinations.cpp b/tests/spec/arb_sample_shading/execution/builtin-gl-sample-mask-mrt-alpha-to-coverage-combinations.cpp
new file mode 100644
index 000000000..a130b5d2d
--- /dev/null
+++ b/tests/spec/arb_sample_shading/execution/builtin-gl-sample-mask-mrt-alpha-to-coverage-combinations.cpp
@@ -0,0 +1,382 @@
+/*
+ * Copyright © 2019 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-mask-mrt-alpha-to-coverage-combinations.cpp
+ *
+ * Test verifies correct work of alpha-to-coverage with every variation of
+ * sample mask, all levels of MSAA and different number of render targets.
+ *
+ * \author Andrii Kryvytskyi <andrii.o.kryvytskyi@globallogic.com>
+ */
+
+#include "piglit-fbo.h"
+using namespace piglit_util_fbo;
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_core_version = 31;
+
+	config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
+	config.khr_no_error_support = PIGLIT_NO_ERRORS;
+
+	/* 4 possible alphas and 2^16 possible sample masks */
+	config.window_height = 512;
+	config.window_width = 512;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+static Fbo
+make_fbo(int tex_attachments_num, int samples_num)
+{
+	FboConfig config(samples_num, piglit_width, piglit_height);
+	config.num_rb_attachments = 0;
+
+	config.num_tex_attachments = tex_attachments_num;
+
+	for (int i = 0; i < tex_attachments_num; i++)
+		config.tex_attachment[i] = GL_COLOR_ATTACHMENT0 + i;
+
+	Fbo fbo;
+	fbo.setup(config);
+
+	if (!piglit_check_gl_error(GL_NO_ERROR))
+		piglit_report_result(PIGLIT_FAIL);
+
+	return fbo;
+}
+
+static GLuint test_prog;
+static GLuint check_prog;
+static GLint max_samples_num;
+static GLint max_attachments_num;
+
+static bool should_all_be_checked;
+static int num_samples_to_check;
+static int num_render_targets_to_check;
+
+static const char *test_vs =
+	"#version 130\n"
+	"in vec4 piglit_vertex;\n"
+	"\n"
+	"void main()\n"
+	"{\n"
+	"    gl_Position = piglit_vertex;\n"
+	"}\n";
+
+static const char *test_fs =
+	"#version 400\n"
+	"#extension GL_ARB_sample_shading : enable\n"
+	"\n"
+	"layout(pixel_center_integer) in vec4 gl_FragCoord;\n"
+	"uniform int render_targets;\n"
+	"uniform int samples_num;\n"
+	"uniform int screen_width;\n"
+	"out vec4 out_color[gl_MaxDrawBuffers];\n"
+	"\n"
+	"void main()\n"
+	"{\n"
+	"\n"
+	"    float fragment_index = gl_FragCoord.x +"
+	"        gl_FragCoord.y * screen_width;\n"
+	"	int sample_permutations = int(exp2(samples_num));\n"
+	"\n"
+	"    vec4 color = vec4(\n"
+	"                        mod(gl_FragCoord.x, 2),\n"
+	"                        mod(gl_FragCoord.y, 2),\n"
+	"                        mod(fragment_index, 2),\n"
+	"                        mod(gl_FragCoord.x, 4) - 1\n"
+	"                 );\n"
+	"\n"
+	"    gl_SampleMask[0] = int(mod("
+	"                        fragment_index / 4,"
+	"                        sample_permutations)"
+	"                       );\n"
+	"\n"
+	"    out_color[0] = color;\n"
+	"    for (int i = 1; i < render_targets; i++) {\n"
+	"    color = vec4(\n"
+	"                mod(gl_FragCoord.y, 2),\n"
+	"                mod(fragment_index, 2),\n"
+	"                mod(gl_FragCoord.x, 2),\n"
+	"                0.0\n"
+	"            );\n"
+	"\n"
+	"    out_color[i] = color;\n"
+	"    }\n"
+	"}\n";
+
+static const char *check_vs =
+	"#version 130\n"
+	"in vec4 piglit_vertex;\n"
+	"\n"
+	"void main()\n"
+	"{\n"
+	"    gl_Position = piglit_vertex;\n"
+	"}\n";
+
+static const char *check_fs =
+	"#version 400\n"
+	"#extension GL_ARB_texture_multisample : require\n"
+	"\n"
+	"layout(pixel_center_integer) in vec4 gl_FragCoord;\n"
+	"uniform int screen_width;\n"
+	"uniform int screen_height;\n"
+	"uniform int samples_num;\n"
+	"uniform int render_target;\n"
+	"uniform sampler2DMS tex;\n"
+	"\n"
+	"out vec4 out_color;\n"
+	"\n"
+	"vec4 get_expected_color()\n"
+	"{\n"
+	"    float fragment_index = gl_FragCoord.x +"
+	"                            gl_FragCoord.y * screen_width;\n"
+	"    vec4 expected = vec4(0.0);\n"
+	"    float alpha = clamp(mod(gl_FragCoord.x, 4) - 1, 0, 1);\n"
+	"\n"
+	"    if (alpha == 0.0f) {\n"
+	"    expected = vec4(0.0);\n"
+	"    } else if (render_target == 0) {\n"
+	"    expected = vec4(\n"
+	"                    mod(gl_FragCoord.x, 2),\n"
+	"                    mod(gl_FragCoord.y, 2),\n"
+	"                    mod(fragment_index, 2),\n"
+	"                    alpha\n"
+	"               );\n"
+	"    } else {\n"
+	"    expected = vec4(\n"
+	"                    mod(gl_FragCoord.y, 2),\n"
+	"                    mod(fragment_index, 2),\n"
+	"                    mod(gl_FragCoord.x, 2),\n"
+	"                    0.0\n"
+	"               );\n"
+	"    }\n"
+	"\n"
+	"    return expected;\n"
+	"}\n"
+	"\n"
+	"void main()\n"
+	"{\n"
+	"    vec4 expected = get_expected_color();\n"
+	"    bool pass = true;\n"
+	"\n"
+	"    int fragment_index = int(gl_FragCoord.x +"
+	"                            gl_FragCoord.y * screen_width);\n"
+	"    int sample_permutations = int(exp2(samples_num));\n"
+	"    int sample_mask = int(mod("
+	"                        fragment_index / 4,"
+	"                        sample_permutations)"
+	"                      );\n"
+	"\n"
+	"    for (int i = 0; i < samples_num; i++) {\n"
+	"    ivec2 texelToFetch = ivec2(gl_FragCoord.x, gl_FragCoord.y);\n"
+	"    vec4 currentColor = texelFetch(tex, texelToFetch, i);\n"
+	"\n"
+	"    if ((sample_mask & (1 << i)) != 0)\n"
+	"        pass = pass && (expected == currentColor);\n"
+	"    else\n"
+	"        pass = pass && (vec4(0.0) == currentColor);"
+	"    }\n"
+	"\n"
+	"    if (pass)\n"
+	"        out_color = vec4(0.0f, 1.0f, 0.0f, 1.0f);\n"
+	"    else\n"
+	"        out_color = vec4(1.0f, 0.0f, 0.0f, 1.0f);\n"
+	"}\n";
+
+/**
+ * Render to all specified texture attachments of the multisample fbo
+ * enabling alpha-to-coverage to make the implementation pass the additional
+ * alpha component from the first attachment when rendering into the
+ * second. Alpha value is being counted using current fragment coordinates
+ * to cover more possible variations of sample mask and alpha.
+ * The resulting sample mask will still be such as specified in
+ * the fragment shader because an alpha value of 1.0 maps to the
+ * coverage mask ~0.
+ */
+static bool
+run_test(Fbo &fbo, int render_targets, int samples_num)
+{
+	glUseProgram(test_prog);
+	glUniform1i(glGetUniformLocation(test_prog, "render_targets"),
+		render_targets);
+	glUniform1i(glGetUniformLocation(test_prog, "samples_num"),
+		samples_num);
+	glUniform1i(glGetUniformLocation(test_prog, "screen_width"),
+		piglit_width);
+
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo.handle);
+	glDrawBuffers(fbo.config.num_tex_attachments,
+		fbo.config.tex_attachment);
+
+	glEnable(GL_SAMPLE_ALPHA_TO_COVERAGE);
+	fbo.set_viewport();
+
+	glClear(GL_COLOR_BUFFER_BIT);
+	piglit_draw_rect(-1, -1, 2, 2);
+
+	glDisable(GL_SAMPLE_ALPHA_TO_COVERAGE);
+
+	return piglit_check_gl_error(GL_NO_ERROR);
+}
+
+/**
+ * Resolve the green component of each sample in case all checks are
+ * done and equal to expected values.
+ */
+static bool
+check(const Fbo &fbo, unsigned render_target,
+	int render_targets_num, int samples_num)
+{
+	bool pass = true;
+	const float expected[] = { 0.0f, 1.0f, 0.0f, 1.0f };
+
+	glUseProgram(check_prog);
+	glUniform1i(glGetUniformLocation(check_prog, "tex"), 0);
+	glUniform1i(glGetUniformLocation(check_prog, "samples_num"),
+		samples_num);
+	glUniform1i(glGetUniformLocation(check_prog, "screen_width"),
+		piglit_width);
+	glUniform1i(glGetUniformLocation(check_prog, "screen_height"),
+		piglit_height);
+	glUniform1i(glGetUniformLocation(check_prog, "render_target"),
+		render_target);
+
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
+	glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, fbo.color_tex[render_target]);
+	glViewport(0, 0, piglit_width, piglit_height);
+
+	glClear(GL_COLOR_BUFFER_BIT);
+	piglit_draw_rect(-1, -1, 2, 2);
+
+	pass &= piglit_check_gl_error(GL_NO_ERROR);
+	pass &= piglit_probe_rect_rgba(0, 0, piglit_width, piglit_height,
+			expected);
+
+	if (!pass)
+		printf("Test failed with %d samples, %d render targets, "
+			"%d render target.\n",
+			samples_num, render_targets_num, render_target);
+
+	piglit_present_results();
+
+	return pass;
+}
+
+static bool
+run_check(int samples_num, int render_targets_num)
+{
+	bool pass = true;
+
+	Fbo fbo = make_fbo(render_targets_num, samples_num);
+
+	pass &= run_test(fbo, render_targets_num, samples_num);
+
+	for (int render_target_to_check = render_targets_num - 1;
+			render_target_to_check >= 0; render_target_to_check--) {
+		pass &= check(fbo, render_target_to_check, render_targets_num,
+			samples_num);
+	}
+
+	return pass;
+}
+
+static void
+print_usage_and_exit(char *prog_name)
+{
+	printf("%s Should be used without arguments or with: <samples_num>"
+		" <render_targets_num>\n",
+		prog_name);
+
+	piglit_report_result(PIGLIT_FAIL);
+}
+
+void delete_programs()
+{
+	glDeleteProgram(test_prog);
+	glDeleteProgram(check_prog);
+}
+
+void
+piglit_init(int argc, char **argv)
+{
+	piglit_require_extension("GL_ARB_texture_multisample");
+	piglit_require_extension("GL_ARB_sample_shading");
+
+	glGetIntegerv(GL_MAX_SAMPLES, &max_samples_num);
+	glGetIntegerv(GL_MAX_COLOR_ATTACHMENTS, &max_attachments_num);
+
+	/* 32 will have too many permutations */
+	max_samples_num = max_samples_num > 16 ? 16 : max_samples_num;
+
+	if (argc == 1) {
+		should_all_be_checked = true;
+	} else if (argc == 3) {
+		should_all_be_checked = false;
+
+		/* arg1 - samples_num */
+		char *end_ptr = NULL;
+		num_samples_to_check = strtol(argv[1], &end_ptr, 0);
+		if (end_ptr != argv[1] + strlen(argv[1]))
+			print_usage_and_exit(argv[0]);
+
+		/* arg2 - render_targets_num */
+		end_ptr = NULL;
+		num_render_targets_to_check = strtol(argv[2], &end_ptr, 0);
+		if (end_ptr != argv[2] + strlen(argv[2]))
+			print_usage_and_exit(argv[0]);
+
+		if (num_samples_to_check > max_samples_num ||
+			num_render_targets_to_check > max_attachments_num) {
+			printf("Error max supported samples = %d, max supported "
+				"color attachments = %d \n",
+				max_samples_num, max_attachments_num);
+			piglit_report_result(PIGLIT_FAIL);
+		}
+	} else {
+		print_usage_and_exit(argv[0]);
+	}
+
+	test_prog = piglit_build_simple_program(test_vs, test_fs);
+	check_prog = piglit_build_simple_program(check_vs, check_fs);
+
+	atexit(delete_programs);
+}
+
+piglit_result
+piglit_display()
+{
+	bool pass = true;
+
+	if (should_all_be_checked) {
+		for (int samples_num = 1; samples_num <= max_samples_num;
+			samples_num *= 2) {
+			pass &= run_check(samples_num, 1) &&
+					run_check(samples_num, 2) &&
+					run_check(samples_num, max_attachments_num);
+		}
+	} else {
+		pass &= run_check(num_samples_to_check, num_render_targets_to_check);
+	}
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}